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Ayugi BO, Ullah I, Chung ES. Observed flash drought to persist in future over southern Africa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175744. [PMID: 39182766 DOI: 10.1016/j.scitotenv.2024.175744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 08/21/2024] [Accepted: 08/22/2024] [Indexed: 08/27/2024]
Abstract
Southern Africa has experienced multiple occurrences of drought episodes, which is projected to persist in the future, considering all climate scenarios. Despite the documented change in a meteorological, agricultural, and hydrological drought situation in the region, few studies are yet to explore the changes in flash drought (hereafter; FD), which is characterized by a rapid reduction in root-zone soil moisture and more substantial intensification in few days to weeks. Here, we analyze the observed FD and related underlying drivers during the past 34 years. Also, we estimate the future changes in FD using the severity-duration magnitude matrix under the middle of the road (SSP2-4.5) and business as usual (SSP5-8.5), scenario. Lastly, the study investigates the role of anthropogenic warming using the fraction of attributable risk (FAR) approach and possible bivariate return periods of FD events. Our results demonstrate that the region has experienced multiple occurrences up to 72 pentads from 1980 to 2014. Underlying mechanisms revealed the compounding influence of Vapor Pressure Deficit (VPD), Potential Evapotranspiration (PET), and precipitation deficit that have a significant impact on the abrupt onset and rapid intensification of FD events and other hot extremes over the SAF region. Under a high emission scenario, the region will experience FD duration lasting for 30 days with >40 % severity projected to impact the region. Anthropogenic climate change and land use and land cover changes remain the most dominant drivers altering the FD events over the SAF region. The return period of FD events under the SSP5-8.5 scenario shows that the SAF region will witness multiple FD events of up to 80 pentads in the far future. These findings reinforce the need to limit the emission of greenhouse gases. Sustained warming of the climate will exacerbate the extreme events and other compounding factors, thus affecting the livelihoods of humans and life-supporting strata.
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Affiliation(s)
- Brian Odhiambo Ayugi
- Faculty of Civil Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, South Korea
| | - Irfan Ullah
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China; China Meteorological Administration Hydro-Meteorology Key Laboratory, Hohai University, Nanjing 210098, China
| | - Eun-Sung Chung
- Faculty of Civil Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, South Korea.
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2
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Elkouk A, Pokhrel Y, Satoh Y, Bouchaou L. Implications of changes in climate and human development on 21st-century global drought risk. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 317:115378. [PMID: 35636116 DOI: 10.1016/j.jenvman.2022.115378] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 05/19/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Climate change is expected to exacerbate drought conditions over many global regions. However, the future risk posed by droughts depends not only on the climate-induced changes but also on the changes in societal exposure and vulnerability to droughts. Here we illustrate how the consideration of human vulnerability alters global drought risk associated with runoff (hydrological) and soil moisture (agriculture) droughts during the 21st-century. We combine the changes in drought frequency, population growth, and human development as a proxy of vulnerability to project global drought risk under plausible climate and socioeconomic development pathways. Results indicate that the shift toward a pathway of high greenhouse gas emissions and socioeconomic inequality leads to i) increased population exposure to runoff and soil moisture droughts by 81% and seven folds, respectively, and ii) a stagnation of human development. These consequences are more pronounced for populations living in low than in very high human development countries. In particular, Sub-Saharan Africa and South Asia, where the majority of the world's less developed countries are located, fare the worst in terms of future drought risk. The disparity in risk between low and very high human development countries can be substantially reduced in the presence of a shift toward a world of rapid and sustainable development that actively reduces social inequality and emissions. Our results underscore the importance of rapid human development in hotspots of drought risk where effective adaptation is most needed to reduce future drought impacts.
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Affiliation(s)
- Ahmed Elkouk
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA; Applied Geology and GeoEnvironment Laboratory, Faculty of Sciences, University Ibn Zohr of Agadir, Agadir, Morocco.
| | - Yadu Pokhrel
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Yusuke Satoh
- National Institute for Environmental Studies, Tsukuba, Japan; International Institute for Applied Systems Analysis, Laxenburg, Austria
| | - Lhoussaine Bouchaou
- Applied Geology and GeoEnvironment Laboratory, Faculty of Sciences, University Ibn Zohr of Agadir, Agadir, Morocco; International Water Research Institute (IWRI), Mohammed VI Polytechnic University, Ben Guerir, Morocco
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3
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Development and Evaluation of a Real-Time Hourly One-Kilometre Gridded Multisource Fusion Air Temperature Dataset in China Based on Remote Sensing DEM. REMOTE SENSING 2022. [DOI: 10.3390/rs14102480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
High-resolution gridded 2 m air temperature datasets are important input data for global and regional climate change studies, agrohydrologic model simulations and numerical weather predictions, etc. In this study, the digital elevation model (DEM) is used to correct temperature forecasts produced by ECMWF. The multi-grid variation formulation method is then used to fuse the data from corrected temperature forecasts and ground automatic station observations. The fused dataset covers the area over (0–60°N, 70–140°S), where different underlying surfaces exist, such as plains, basins, plateaus, and mountains. The spatial and temporal resolutions are 1 km and 1 h, respectively. The comparison of the fusion data with the verification observations, including 2400 weather stations, indicates that the accuracy of the gridded temperature is superior to European Centre for Medium-Range Weather Forecasts (ECMWF) data. This is because a more significant number of stations and high-resolution terrain data are used to generate the fusion data than are utilized in the ECMWF. The obtained dataset can describe the temperature feature of peaks and valleys more precisely. Due to its continuous temporal coverage and consistent quality, the fusion dataset is one of China’s most widely used temperature datasets. However, data uncertainty will increase for areas with sparse observations and high mountains, and we must be cautious when using data from these areas.
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Manzur ME, Garello FA, Omacini M, Schnyder H, Sutka MR, García-Parisi PA. Endophytic fungi and drought tolerance: ecophysiological adjustment in shoot and root of an annual mesophytic host grass. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:272-282. [PMID: 35130476 DOI: 10.1071/fp21238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Epichloid endophytic fungi, vertically transmitted symbionts of grasses, can increase plant tolerance to biotic and abiotic stress. Our aim was to identify ecophysiological mechanisms by which the endophyte Epichloë occultans confers drought tolerance to the annual grass Lolium multiflorum Lam. Endophyte-associated or endophyte-free plants were either well-watered or subjected to water deficit. We evaluated plant biomass, root length and nitrogen concentration, and we assessed intrinsic water use efficiency (iWUE) and its components net photosynthesis and stomatal conductance, by carbon and oxygen isotope analysis of shoot tissues. Endophyte-free plants produced more biomass than endophyte-associated ones at field capacity, while water deficit strongly reduced endophyte-free plants biomass. As a result, both types of plants produced similar biomass under water restriction. Based on oxygen isotope composition of plant cellulose, stomatal conductance decreased with water deficit in both endophyte-associated and endophyte-free plants. Meanwhile, carbon isotope composition indicated that iWUE increased with water deficit only in endophyte-associated plants. Thus, the isotope data indicated that net photosynthesis decreased more strongly in endophyte-free plants under water deficit. Additionally, endophyte presence reduced root length but increased its hydraulic conductivity. In conclusion, endophytic fungi confer drought tolerance to the host grass by adjusting shoot and root physiology.
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Affiliation(s)
- Milena E Manzur
- IIBIO-CONICET-UNSAM, Avenida 25 de Mayo y Francia, San Martín, CPA B1650HMP Buenos Aires, Argentina; and Departamento de Biología Aplicada y Alimentos, Cátedra de Fisiología Vegetal, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina
| | - Fabián A Garello
- Departamento de Biología Aplicada y Alimentos, Cátedra de Fisiología Vegetal, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina; and IFEVA-CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina
| | - Marina Omacini
- IFEVA-CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina; and Departamento de Recursos Naturales y Ambiente, Cátedra de Ecología, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina
| | - Hans Schnyder
- Lehrstuhl für Grünlandlehre, Technische Universität München, D-85354 Freising-Weihenstephan, Germany
| | - Moira R Sutka
- DBBE-IBBEA, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Buenos Aires, Argentina
| | - Pablo A García-Parisi
- IFEVA-CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina; and Departamento de Producción Animal, Cátedra de Forrajicultura, Facultad de Agronomía, Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE Buenos Aires, Argentina
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5
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Evaluating the Potential of Different Evapotranspiration Datasets for Distributed Hydrological Model Calibration. REMOTE SENSING 2022. [DOI: 10.3390/rs14030629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Evapotranspiration (ET), a key component of the hydrological cycle, has a direct impact on runoff and water balance. Various global satellite-based and numerical datasets provide continuous and high spatiotemporal resolution data, which makes it possible to calibrate hydrological parameters against ET. However, the accuracy of ET datasets varies with region and algorithm, introducing uncertainties in hydrological parameter calibration. This study focused on evaluating the potential of different ET datasets in the calibration of distributed hydrological model parameters. Five different ET datasets (PML, SEBAL, EB-ET, GLASS, REA-ET) were evaluated using the water balance method to explore the effect of intrinsic dataset accuracy on applications. The benchmark calibration scheme calibrated parameters by using observed streamflow data from the outlet. Two calibration schemes were proposed to take advantage of the temporal dynamics and spatial patterns of the raw ET datasets. The results show that the model parameters calibrated by all selected ET datasets produced satisfactory results in streamflow simulations. These results were dependent on the calibration schemes and accuracy of ET datasets. Overall, the scheme calibrated by using temporal dynamics of ET at the grid scale provided better streamflow simulations at the basin outlet than the scheme calibrated by using spatial patterns of ET at the basin scale. Three metrics (bias, root mean square error [RMSE], and correlation coefficient [R]) showed that there is a high potential for selected ET datasets to improve soil moisture simulations, as compared to the benchmark scheme. Parameters calibrated by EB-ET and PML datasets provided the best performance in the simulation of streamflow at the outlet and the sub-basin scale. The calibration case with the SEBAL dataset showed the highest potential to improve soil moisture simulation. The annual average ET estimates of these three datasets were closest to the water balance-based ET values.
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Chikabvumbwa SR, Salehnia N, Manzanas R, Abdelbaki C, Zerga A. Assessing the effect of spatial-temporal droughts on dominant crop yield changes in Central Malawi. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:63. [PMID: 34993655 DOI: 10.1007/s10661-021-09709-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Central Malawi has intensely been subjected to different climate-related shocks such as floods, dry spells, and droughts, resulting in decreases in crop yields. Due to their recurrence arising from the effects of climate change, drought characterization, monitoring, and prediction are crucial in guiding agriculture-water users and planners to prepare drought risk management plans and early warning systems. This research analyzed droughts, using multiple drought indices and their impacts on dominant crops over Central Malawi. Forty years of hydro-meteorological data (1977-2017) from nine rain-gauging stations and crop yield data from 1983 to 2017 from four districts were analyzed. The study discovered that drought events in the Agricultural Development Division (ADD) are highly a function of rainfall deficit and high temperatures. The results highlighted that the rainfall patterns in the area are not dependable, calling for the utilization of climate-smart irrigation systems such as drip irrigation and rainwater harvesting technologies. Furthermore, we achieved that crops such as cassava and groundnuts must be promoted to withstand the long water stress duration. These crops also have a multiplier effect; hence, they can enhance food security in the region. This study recommends that using more robust variables in drought analysis studies is necessary for effective drought monitoring and early warning systems. In corroboration with disaster management NGOs, it is recommended that the government should be proactive in developing integrated drought management policies and planning strategies for drought adaptation and mitigation.
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Affiliation(s)
- Sylvester Richard Chikabvumbwa
- Institute of Water and Energy Sciences Including Climate Change, Pan African University, University of Tlemcen, B.P. 119, 13000, Tlemcen, Algeria
| | - Nasrin Salehnia
- School of Earth and Environmental Science, Seoul National University, Seoul, South Korea.
- Center for Cryospheric Sciences, Seoul National University, Siheung, South Korea.
| | - Rodrigo Manzanas
- Santander Meteorology Group, Dpt. of Applied Mathematics and Computer Science, University of Cantabria, Santander, Spain
| | - Cherifa Abdelbaki
- Institute of Water and Energy Sciences Including Climate Change, Pan African University, University of Tlemcen, B.P. 119, 13000, Tlemcen, Algeria
| | - Abdellatif Zerga
- Institute of Water and Energy Sciences Including Climate Change, Pan African University, University of Tlemcen, B.P. 119, 13000, Tlemcen, Algeria
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7
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Huang Y, Xiao W, Hou B, Zhou Y, Hou G, Yi L, Cui H. Hydrological projections in the upper reaches of the Yangtze River Basin from 2020 to 2050. Sci Rep 2021; 11:9720. [PMID: 33958608 PMCID: PMC8102517 DOI: 10.1038/s41598-021-88135-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 04/08/2021] [Indexed: 02/03/2023] Open
Abstract
Understanding the impact of climate change on runoff is essential for effective water resource management and planning. In this study, the regional climate model (RCM) RegCM4.5 was used to dynamically downscale near-future climate projections from two global climate models to a 50-km horizontal resolution over the upper reaches of the Yangtze River (UYRB). Based on the bias-corrected climate projection results, the impacts of climate change on mid-twenty-first century precipitation and temperature in the UYRB were assessed. Then, through the coupling of a large-scale hydrological model with RegCM4.5, the impacts of climate change on river flows at the outlets of the UYRB were assessed. According to the projections, the eastern UYRB will tend to be warm-dry in the near-future relative to the reference period, whereas the western UYRB will tend to be warm-humid. Precipitation will decreases at a rate of 19.05-19.25 mm/10 a, and the multiyear average annual precipitation will vary between - 0.5 and 0.5 mm/day. Temperature is projected to increases significantly at a rate of 0.38-0.52 °C/10 a, and the projected multiyear average air temperature increase is approximately 1.3-1.5 ℃. The contribution of snowmelt runoff to the annual runoff in the UYBR is only approximately 4%, whereas that to the spring runoff is approximately 9.2%. Affected by climate warming, the annual average snowmelt runoff in the basin will be reduced by 36-39%, whereas the total annual runoff will be reduced by 4.1-5%, and the extreme runoff will be slightly reduced. Areas of projected decreased runoff depth are mainly concentrated in the southeast region of the basin. The decrease in precipitation is driving this decrease in the southeast, whereas the decreased runoff depth in the northwest is mainly driven by the increase in evaporation.
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Affiliation(s)
- Ya Huang
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Catchment, China Institute of Water Resources and Hydropower Research, Beijing, 100038 China ,College of Oceanography, Hohai University, Nanjing, 210098 China ,China Water Resources Pearl River Planning, Surveying & Designing Co., Ltd., Zhanyi Road 19#, Guangzhou, 510610 China ,Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK Canada
| | - Weihua Xiao
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Catchment, China Institute of Water Resources and Hydropower Research, Beijing, 100038 China
| | - Baodeng Hou
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Catchment, China Institute of Water Resources and Hydropower Research, Beijing, 100038 China
| | - Yuyan Zhou
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Catchment, China Institute of Water Resources and Hydropower Research, Beijing, 100038 China
| | - Guibing Hou
- China Water Resources Pearl River Planning, Surveying & Designing Co., Ltd., Zhanyi Road 19#, Guangzhou, 510610 China
| | - Ling Yi
- China Water Resources Pearl River Planning, Surveying & Designing Co., Ltd., Zhanyi Road 19#, Guangzhou, 510610 China
| | - Hao Cui
- State Key Laboratory of Simulation and Regulation of Water Cycle in River Catchment, China Institute of Water Resources and Hydropower Research, Beijing, 100038 China
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8
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Characteristics of hydrological extremes in Kulfo River of Southern Ethiopian Rift Valley Basin. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-3097-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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9
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Estravis-Barcala M, Mattera MG, Soliani C, Bellora N, Opgenoorth L, Heer K, Arana MV. Molecular bases of responses to abiotic stress in trees. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3765-3779. [PMID: 31768543 PMCID: PMC7316969 DOI: 10.1093/jxb/erz532] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/25/2019] [Indexed: 05/05/2023]
Abstract
Trees are constantly exposed to climate fluctuations, which vary with both time and geographic location. Environmental changes that are outside of the physiological favorable range usually negatively affect plant performance and trigger responses to abiotic stress. Long-living trees in particular have evolved a wide spectrum of molecular mechanisms to coordinate growth and development under stressful conditions, thus minimizing fitness costs. The ongoing development of techniques directed at quantifying abiotic stress has significantly increased our knowledge of physiological responses in woody plants. However, it is only within recent years that advances in next-generation sequencing and biochemical approaches have enabled us to begin to understand the complexity of the molecular systems that underlie these responses. Here, we review recent progress in our understanding of the molecular bases of drought and temperature stresses in trees, with a focus on functional, transcriptomic, epigenetic, and population genomic studies. In addition, we highlight topics that will contribute to progress in our understanding of the plastic and adaptive responses of woody plants to drought and temperature in a context of global climate change.
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Affiliation(s)
- Maximiliano Estravis-Barcala
- Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales, (Consejo Nacional de Investigaciones Científicas y Técnicas- Universidad Nacional del Comahue), San Carlos de Bariloche, Rio Negro, Argentina
| | - María Gabriela Mattera
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas), San Carlos de Bariloche, Rio Negro, Argentina
| | - Carolina Soliani
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas), San Carlos de Bariloche, Rio Negro, Argentina
| | - Nicolás Bellora
- Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales, (Consejo Nacional de Investigaciones Científicas y Técnicas- Universidad Nacional del Comahue), San Carlos de Bariloche, Rio Negro, Argentina
| | - Lars Opgenoorth
- Department of Ecology, Philipps University Marburg, Marburg, Germany
- Swiss Federal Research Institute WSL, BirmensdorfSwitzerland
| | - Katrin Heer
- Department of Conservation Biology, Philipps University Marburg, Marburg Germany
| | - María Verónica Arana
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (Instituto Nacional de Tecnología Agropecuaria - Consejo Nacional de Investigaciones Científicas y Técnicas), San Carlos de Bariloche, Rio Negro, Argentina
- Correspondence:
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10
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Satellite-Based Operational Real-Time Drought Monitoring in the Transboundary Lancang–Mekong River Basin. REMOTE SENSING 2020. [DOI: 10.3390/rs12030376] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Existing gauging networks are sparse and not readily available in real-time over the transboundary Lancang–Mekong River (LMR) basin, making it difficult to accurately identify drought. In this study, we aimed to build an operational real-time Lancang–Mekong drought monitor (LMDM), through combining satellite real-time data and the Variable Infiltration Capacity (VIC) hydrological model at a 0.25° spatial resolution. Toward this, three VIC runs were conducted: (1) a 60-year (1951–2010) historical simulation driven by Princeton’s global meteorological forcing (PGF) for yielding ‘normal’ conditions (PGF-VIC), wherein the VIC was calibrated with 20-year observed streamflow at six hydrological stations; (2) a short-period (2011–2014) simulation to bridge the gap between the historical and the real-time modeling; (3) the real-time (2015–present) simulation driven by bias-corrected satellite data, wherein the real-time soil moisture (SM) estimate was expressed as percentile (relative to the ‘normal’) for drought monitoring. Results show that VIC can successfully reproduce the observed hydrographs, with the Nash–Sutcliffe efficiency exceeding 0.70 and the relative bias mostly within 15%. Assessment on the performance of LMDM shows that the real-time SM estimates bear good spatial similarity to the reference, with the correlation coefficient beyond 0.80 across >70% of the domain. In terms of drought monitoring, the LMDM can reasonably reproduce the two recorded droughts, implying extreme droughts covering the Lower LMR during 2004/05 and widespread severe 2009/10 drought across the upper domain. The percentage drought area implied by the LMDM and the reference is close, corresponding to 66% and 60%, 43% and 40%, and 44% and 36% for each typical drought month. Since January 2015, the LMDM was running in an operational mode, from which the 2016 unprecedented drought was successfully identified in Mekong Delta. This study highlights the LMDM’s capability for reliable real-time drought monitoring, which can serve as a valuable drought early warning prototype for other data-poor regions.
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11
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He J, Yang K, Tang W, Lu H, Qin J, Chen Y, Li X. The first high-resolution meteorological forcing dataset for land process studies over China. Sci Data 2020; 7:25. [PMID: 31964891 PMCID: PMC6972748 DOI: 10.1038/s41597-020-0369-y] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 12/20/2019] [Indexed: 12/03/2022] Open
Abstract
The China Meteorological Forcing Dataset (CMFD) is the first high spatial-temporal resolution gridded near-surface meteorological dataset developed specifically for studies of land surface processes in China. The dataset was made through fusion of remote sensing products, reanalysis datasets and in-situ station data. Its record begins in January 1979 and is ongoing (currently up to December 2018) with a temporal resolution of three hours and a spatial resolution of 0.1°. Seven near-surface meteorological elements are provided in the CMFD, including 2-meter air temperature, surface pressure, and specific humidity, 10-meter wind speed, downward shortwave radiation, downward longwave radiation and precipitation rate. Validations against observations measured at independent stations show that the CMFD is of superior quality than the GLDAS (Global Land Data Assimilation System); this is because a larger number of stations are used to generate the CMFD than are utilised in the GLDAS. Due to its continuous temporal coverage and consistent quality, the CMFD is one of the most widely-used climate datasets for China.
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Affiliation(s)
- Jie He
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Kun Yang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China.
- Center for Excellence in Tibetan Plateau Earth Sciences, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Wenjun Tang
- Center for Excellence in Tibetan Plateau Earth Sciences, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
- Center of Earth Observation and Big Data Analysis for Three Poles, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hui Lu
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Jun Qin
- Center of Earth Observation and Big Data Analysis for Three Poles, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yingying Chen
- Center for Excellence in Tibetan Plateau Earth Sciences, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
- Center of Earth Observation and Big Data Analysis for Three Poles, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xin Li
- Center for Excellence in Tibetan Plateau Earth Sciences, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
- Center of Earth Observation and Big Data Analysis for Three Poles, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
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12
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Zhang B, Xia Y, Huning LS, Wei J, Wang G, AghaKouchak A. A Framework for Global Multicategory and Multiscalar Drought Characterization Accounting for Snow Processes. WATER RESOURCES RESEARCH 2019; 55:9258-9278. [PMID: 32025062 PMCID: PMC6988450 DOI: 10.1029/2019wr025529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/23/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
Drought indices do not always provide the most relevant information for water resources management as most of them neglect the role of snow in the land surface water balance. In this study, a physically based drought index, the Standardized Moisture Anomaly Index (SZI), was modified and improved by incorporating the effects of snow dynamics for drought characterization at multiple time scales. The new version of the SZI, called SZIsnow, includes snow in both the water supply and demand in drought characterization by using the water-energy budgets from the Global Land Data Assimilation Systems product. We compared and evaluated the performance of SZIsnow and SZI in drought identification globally across various time scales using observed multicategory drought evidences from several sources. Results show that the SZIsnow agrees better with the observed changes in hydrological and agricultural droughts than the SZI, particularly over basins with high snow accumulation. Furthermore, the SZIsnow is more consistent with the residual water-energy ratio than the SZI over snow-influenced regions. Overall, the SZIsnow can be either a complement or an improvement over the SZI for identifying, monitoring, and characterizing hydrological and agricultural droughts at various scales (e.g., 1-48 months) over high-latitude and high-elevation regions that receive snow.
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Affiliation(s)
- Baoqing Zhang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education)College of Earth and Environmental SciencesLanzhou UniversityLanzhouChina
- State Key Laboratory of Hydroscience and EngineeringDepartment of Hydraulic EngineeringTsinghua UniversityBeijingChina
| | - Youlong Xia
- I. M. Systems Group at Environmental Modeling CenterNational Centers for Environmental PredictionCollege ParkMDUSA
| | - Laurie S. Huning
- Department of Civil and Environmental EngineeringUniversity of CaliforniaIrvineCAUSA
| | - Jiahua Wei
- State Key Laboratory of Hydroscience and EngineeringDepartment of Hydraulic EngineeringTsinghua UniversityBeijingChina
| | - Guangqian Wang
- State Key Laboratory of Hydroscience and EngineeringDepartment of Hydraulic EngineeringTsinghua UniversityBeijingChina
| | - Amir AghaKouchak
- Department of Civil and Environmental EngineeringUniversity of CaliforniaIrvineCAUSA
- Department of Earth System ScienceUniversity of CaliforniaIrvineCAUSA
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13
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Spatiotemporal Evolution of Droughts and Their Teleconnections with Large-Scale Climate Indices over Guizhou Province in Southwest China. WATER 2019. [DOI: 10.3390/w11102104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The spatiotemporal evolution of meteorological droughts in Guizhou Province, Southwest China is analyzed based on a new set of the Standardized Precipitation Index series that mainly includes drought events that occurred from 1961 to 2004 at 81 meteorological stations. The cluster analysis shows that the study region can be classified into six homogeneous sub-regions where the drought characteristics and their temporal evolutions are quite different. The trend test and periodicity analysis indicate that Guizhou Province experienced a drier trend, which was most significant in the western parts of the region. It was found that the intensified drought severity was not always coincident with the drier trend but relied on the occurrence of extreme drought events. The trends of drier climate and drought severity were highly coincident with the temporal evolution of the drought periodicities, which were shortened from 1–4 years to less than one year. The shortened drought periodicity was found to be associated principally with a shift of the large-scale dominant climate indices from the North Atlantic Oscillation to the Indian Ocean Dipole after the late 1970s, and variations of the extreme drought events were mostly related to NINO34 in the study region.
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14
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Zhu L, Wang H, Tong C, Liu W, Du B. Evaluation of ESA Active, Passive and Combined Soil Moisture Products Using Upscaled Ground Measurements. SENSORS 2019; 19:s19122718. [PMID: 31212964 PMCID: PMC6632010 DOI: 10.3390/s19122718] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/12/2019] [Accepted: 06/15/2019] [Indexed: 11/16/2022]
Abstract
The European Space Agency (ESA) Climate Change Initiative (CCI) project combines multi-sensors at different microwave frequencies to derive three harmonized soil moisture products using active, passive and combined approaches. These long-term soil moisture products assist in understanding the global water and carbon cycles. However, extensive validations are a prerequisite before applying the retrieved soil moisture into climatic or hydrological models. To fulfill this objective, we assess the performances of three CCI soil moisture products (active, passive and combined) with respect to in-situ soil moisture networks located in China, Spain and Canada. In order to compensate the scale differences between ground stations and the CCI product's coarse resolution, we adopted two upscaling approaches of Inverse Distance Weighting (IDW) interpolation and simple Arithmetic Mean (AM). The temporal agreements between the satellite retrieved and ground-measured soil moisture were quantified using the unbiased root mean square error (ubRMSE), RMSE, correlation coefficients (R) and bias. Furthermore, the temporal variability of the CCI soil moisture is interpreted and verified with respect to the Tropical Rainfall Measuring Mission (TRMM) precipitation observations. The results show that the temporal variations of CCI soil moisture agreed with the in-situ ground measurements and the precipitation observations over the China and Spain test sites. In contrast, a significant overestimation was observed over the Canada test sites, which may be due to the strong heterogeneity in soil and vegetation characteristics in accordance with the reported poor performance of soil moisture retrieval there. However, despite a retrieval bias, the relatively temporal variation of the CCI soil moisture also followed the ground measurements. For all the three test sites, the soil moisture retrieved from the combined approach outperformed the active-only and passive-only methods, with ubRMSE of 0.034, 0.050, and 0.050-0.054 m3/m3 over the test sites in China, Spain and Canada, respectively. Thus, the CCI combined soil moisture product is suggested to drive the climatic and hydrological studies.
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Affiliation(s)
- Luyao Zhu
- Institute of Agricultural Remote Sensing and Information Technology Application, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Hongquan Wang
- Institute of Agricultural Remote Sensing and Information Technology Application, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Cheng Tong
- Institute of Agricultural Remote Sensing and Information Technology Application, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Wenbin Liu
- Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Benxu Du
- Natural Resources Service Center, Dalian 116021, China.
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15
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Spatial Pattern of the Unidirectional Trends in Thermal Bioclimatic Indicators in Iran. SUSTAINABILITY 2019. [DOI: 10.3390/su11082287] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Changes in bioclimatic indicators can provide valuable information on how global warming induced climate change can affect humans, ecology and the environment. Trends in thermal bioclimatic indicators over the diverse climate of Iran were assessed in this study to comprehend their spatio-temporal changes in different climates. The gridded temperature data of Princeton Global Meteorological Forcing with a spatial resolution of 0.25° and temporal extent of 1948–2010 was used for this purpose. Autocorrelation and wavelets analyses were conducted to assess the presence of self-similarity and cycles in the data series. The modified version of the Mann–Kendall (MMK) test was employed to estimate unidirectional trends in 11 thermal bioclimatic indicators through removing the influence of natural cycles on trend significance. A large decrease in the number of grid points showing significant trends was noticed for the MMK in respect to the classical Mann–Kendall (MK) test which indicates that the natural variability of the climate should be taken into consideration in bioclimatic trend analyses in Iran. The unidirectional trends obtained using the MMK test revealed changes in almost all of the bioclimatic indicators in different parts of Iran, which indicates rising temperature have significantly affected the bioclimate of the country. The semi-dry region along the Persian Gulf in the south and mountainous region in the northeast were found to be more affected in terms of the changes in a number of bioclimatic indicators.
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16
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Spinoni J, Barbosa P, De Jager A, McCormick N, Naumann G, Vogt JV, Magni D, Masante D, Mazzeschi M. A new global database of meteorological drought events from 1951 to 2016. JOURNAL OF HYDROLOGY. REGIONAL STUDIES 2019; 22:100593. [PMID: 32257820 PMCID: PMC7099764 DOI: 10.1016/j.ejrh.2019.100593] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/25/2019] [Accepted: 01/25/2019] [Indexed: 04/29/2023]
Abstract
STUDY REGION This study has three spatial scales: global (0.5°), macro-regional, and country scale. The database of drought events has specific entries for each macro-region and country. STUDY FOCUS We constructed a database of meteorological drought events from 1951 to 2016, now hosted by the Global Drought Observatory of the European Commission's Joint Research Centre. Events were detected at macro-regional and country scale based on the separate analysis of the Standardized Precipitation-Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI) at different accumulation scales (from 3 to 72 months), using as input the Global Precipitation Climatology Centre (GPCC) and Climatic Research Unit (CRU) Time Series datasets. The database includes approximately 4800 events based on SPEI-3 and 4500 based on SPI-3. Each event is described by its start and end date, duration, intensity, severity, peak, average and maximum area in drought, and a special score to classify 52 mega-droughts. NEW HYDROLOGICAL INSIGHTS FOR THE REGION UNDER STUDY We derived trends in drought frequency and severity, separately for SPI and SPEI at a 12-month accumulation scale, which is usually related to hydrological droughts. Results show several drought hotspots in the last decades: Amazonia, southern South America, the Mediterranean region, most of Africa, north-eastern China and, to a lesser extent, central Asia and southern Australia. Over North America, central Europe, central Asia, and Australia, the recent progressive temperature increase outbalanced the increase in precipitation causing more frequent and severe droughts.
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Affiliation(s)
| | - Paulo Barbosa
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Alfred De Jager
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Niall McCormick
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Gustavo Naumann
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Jürgen V. Vogt
- European Commission, Joint Research Centre (JRC), Ispra, Italy
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17
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Nashwan MS, Shahid S, Abd Rahim N. Unidirectional trends in annual and seasonal climate and extremes in Egypt. THEORETICAL AND APPLIED CLIMATOLOGY 2019; 136:457-473. [DOI: 10.1007/s00704-018-2498-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/30/2018] [Indexed: 09/02/2023]
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18
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Gimeno TE, Saavedra N, Ogée J, Medlyn BE, Wingate L. A novel optimization approach incorporating non-stomatal limitations predicts stomatal behaviour in species from six plant functional types. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1639-1651. [PMID: 30715494 PMCID: PMC6411372 DOI: 10.1093/jxb/erz020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 01/14/2019] [Indexed: 05/23/2023]
Abstract
The primary function of stomata is to minimize plant water loss while maintaining CO2 assimilation. Stomatal water loss incurs an indirect cost to photosynthesis in the form of non-stomatal limitations (NSL) via reduced carboxylation capacity (CAP) and/or mesophyll conductance (MES). Two optimal formulations for stomatal conductance (gs) arise from the assumption of each type of NSL. In reality, both NSL could coexist, but one may prevail for a given leaf ontogenetic stage or plant functional type, depending on leaf morphology. We tested the suitability of two gs formulations (CAP versus MES) on species from six plant functional types (C4 crop, C3 grass, fern, conifer, evergreen, and deciduous angiosperm trees). MES and CAP parameters (the latter proportional to the marginal water cost to carbon gain) decreased with water availability only in deciduous angiosperm trees, while there were no clear differences between leaf ontogenetic stages. Both CAP and MES formulations fit our data in most cases, particularly under low water availability. For ferns, stomata appeared to operate optimally only when subjected to water stress. Overall, the CAP formulation provided a better fit across all species, suggesting that sub-daily stomatal responses minimize NSL by reducing carboxylation capacity predominantly, regardless of leaf morphology and ontogenetic stage.
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Affiliation(s)
- Teresa E Gimeno
- INRA, UMR ISPA, Villenave d’Ornon, France
- Basque Centre for Climate Change (BC3), Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Noelia Saavedra
- INRA, UMR ISPA, Villenave d’Ornon, France
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | | | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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19
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Liu Y, Zhu Y, Ren L, Yong B, Singh VP, Yuan F, Jiang S, Yang X. On the mechanisms of two composite methods for construction of multivariate drought indices. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 647:981-991. [PMID: 30180373 DOI: 10.1016/j.scitotenv.2018.07.273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/11/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Droughts are comprehensive and complex issues that need to be characterized from a multivariate perspective. In recent years, a number of composite indices have been proposed for drought characterization. However, rare studies have systematically compared similarities and dissimilarities of these indices, and they have provided little insights into the combination mechanisms. To address this issue, two widely used combination approaches, namely the principal component analysis (PCA) and copula based joint probability distribution were employed, with the corresponding integrated product denoted as the Aggregate Drought Index (ADI) and Joint Drought Deficit Index (JDI). Five constituents for constructing ADI and JDI were derived from the variable infiltration capacity model (VIC) monthly simulations over the Yellow River basin (YRB), China, including precipitation (P), actual evapotranspiration (ET), soil moisture of top two layers, and runoff (during 1961-2012). Results showed that the behavioral patterns of ADI and JDI may not be easily influenced by the variation of one single element, and they represented comprehensive moisture status well. A further comparison between these two composite indices suggested that ADI and JDI behaved similarly in most areas of YRB, with some dissimilarities in the source region. The particular behavior of ET was responsible for the inconsistency. Comparing to other regions, an enhanced role of potential evapotranspiration (PET) was imposed on ET in the source region, leading to a poor relationship of ET with P and other hydrological variables. Accordingly, when constructing composite drought indices, the drought information indicated by ET was more easily abandoned by ADI but reserved in JDI. This study clearly demonstrates the mechanisms of two common integrated approaches in blending different drought information, which has significant implications for composite drought indices construction and application, and potentially provides some valuable references for the improvement of monitoring techniques in future drought related researches.
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Affiliation(s)
- Yi Liu
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China; School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China
| | - Ye Zhu
- College of Hydrometeorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Liliang Ren
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China.
| | - Bin Yong
- School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China
| | - Vijay P Singh
- Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77843-2117, USA
| | - Fei Yuan
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
| | - Shanhu Jiang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
| | - Xiaoli Yang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
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20
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Dastogeer KMG. Influence of fungal endophytes on plant physiology is more pronounced under stress than well-watered conditions: a meta-analysis. PLANTA 2018; 248:1403-1416. [PMID: 30121874 DOI: 10.1007/s00425-018-2982-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 08/09/2018] [Indexed: 05/24/2023]
Abstract
A meta-analysis of published articles shows that the influence of fungal endophytes on plant performance is dependent on plant water status. The magnitude of endophytic effects is higher in plants grown in water-limiting environments than those in adequate watering environments. The outcome of plant-endophyte interactions depends on the identity of the plant host and fungal symbionts. Water limitation often hinders plant productivity in both natural and agricultural settings. Endophytic fungal symbionts can mediate plant water stress responses by enhancing drought tolerance and avoidance, but these effects have not been quantified across plant-endophyte studies. A meta-analysis of published studies was performed to determine how endophytic fungal symbionts influence plant response under non-stressed versus water-stressed conditions. A significantly positive or neutral overall effect of fungal endophyte was noted under water-stressed conditions. In contrast, under non-stressed conditions, the overall effect of fungi on plants was mostly neutral. In general, the presence of fungal endophytes increased plant's total biomass, chlorophyll content, and stomatal conductance irrespective of water availability. In addition, plant shoot biomass, tiller density, plant height, maximum quantum yield (Fv/Fm), net photosynthesis, relative water content (RWC), amounts of ascorbate peroxidase (APX), glutathione (GSH), polyphenol oxidase (PPO), superoxide dismutase (SOD), and phenolics were significantly increased by endophyte colonisation under stressed conditions. Malondialdehyde (MDA) and hydrogen peroxide (H2O2) were reduced in endophytic plants under stress as compared with non-endophytic counterparts. Categorical analysis revealed that accumulation in plant biomass is influenced by factors such as host and fungi identity, the magnitude of which is greater under stressed than non-stressed conditions.
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Affiliation(s)
- Khondoker M G Dastogeer
- Plant Biotechnology Group-Plant Virology and Plant-Microbe Interaction, Western Australian State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth, WA, 6150, Australia.
- Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh.
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21
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Creek D, Blackman CJ, Brodribb TJ, Choat B, Tissue DT. Coordination between leaf, stem, and root hydraulics and gas exchange in three arid-zone angiosperms during severe drought and recovery. PLANT, CELL & ENVIRONMENT 2018; 41:2869-2881. [PMID: 30106477 DOI: 10.1111/pce.13418] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/30/2018] [Indexed: 05/13/2023]
Abstract
The ability to resist hydraulic dysfunction in leaves, stems, and roots strongly influences whether plants survive and recover from drought. However, the coordination of hydraulic function among different organs within species and their links to gas exchange during drought and recovery remains understudied. Here, we examine the interaction between gas exchange and hydraulic function in the leaves, stems, and roots of three semiarid evergreen species exposed to a cycle of severe water stress (associated with substantial cavitation) and recovery. In all species, stomatal closure occurred at water potentials well before 50% loss of stem hydraulic conductance, while in two species, leaves and/or roots were more vulnerable than stems. Following soil rewetting, leaf-level photosynthesis (Anet ) returned to prestress levels within 2-4 weeks, whereas stomatal conductance and canopy transpiration were slower to recover. The recovery of Anet was decoupled from the recovery of leaf, stem, and root hydraulics, which remained impaired throughout the recovery period. Our results suggest that in addition to high embolism resistance, early stomatal closure and hydraulic vulnerability segmentation confers drought tolerance in these arid zone species. The lack of substantial embolism refilling within all major organs suggests that vulnerability of the vascular system to drought-induced dysfunction is a defining trait for predicting postdrought recovery.
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Affiliation(s)
- Danielle Creek
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
| | - Chris J Blackman
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
| | - Timothy J Brodribb
- School of Biological Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, Australia
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22
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Hiep NH, Luong ND, Viet Nga TT, Hieu BT, Thuy Ha UT, Du Duong B, Long VD, Hossain F, Lee H. Hydrological model using ground- and satellite-based data for river flow simulation towards supporting water resource management in the Red River Basin, Vietnam. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 217:346-355. [PMID: 29621701 DOI: 10.1016/j.jenvman.2018.03.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
The Red River basin (RRB) exhibits substantial variation of water resource seasonally and annually. Sustainable water resource management in the RRB has been challenging due to the lack of in situ hydrological measurement data over the basin-wide scale. To address this issue, this study aimed to perform the setting up, calibration, and validation of the variable infiltration capacity (VIC) hydrological model forced with ground- and satellite-based datasets at a high spatial resolution of 0.1° for simulating the daily river flow of the Red River system in the RRB during the period of 2005-2014. By using the finely resolved land cover characterization with 15 types of land cover and leaf area index - the most important feature of vegetation that significantly influences the simulation of hydrological variables provided by the spatially distributed satellite remote sensing data, this study would not only address the poor data availability over the RRB but also enhance the accuracy of model simulation. The simulation results generally indicated that the calibrated VIC model could satisfactorily capture the river flow dynamics of the Red River system in the RRB. The VIC model's underestimated river flow compared to the observed data during the dry season for the downstream stations was likely due to the operation of the large man-made reservoirs and dams in the upstream catchments of the RRB that not represented by the VIC model. The findings also suggested that for further improving the VIC model performance, the use of more spatially representative meteorological data provided by satellite remote sensing should be considered in future studies.
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Affiliation(s)
- Nguyen Hoang Hiep
- Faculty of Environmental Engineering, National University of Civil Engineering (NUCE), 55 Giai Phong Road, Ha Noi, Viet Nam
| | - Nguyen Duc Luong
- Faculty of Environmental Engineering, National University of Civil Engineering (NUCE), 55 Giai Phong Road, Ha Noi, Viet Nam.
| | - Tran Thi Viet Nga
- Faculty of Environmental Engineering, National University of Civil Engineering (NUCE), 55 Giai Phong Road, Ha Noi, Viet Nam
| | - Bui Thi Hieu
- Faculty of Environmental Engineering, National University of Civil Engineering (NUCE), 55 Giai Phong Road, Ha Noi, Viet Nam
| | - Ung Thi Thuy Ha
- Faculty of Environmental Engineering, National University of Civil Engineering (NUCE), 55 Giai Phong Road, Ha Noi, Viet Nam
| | - Bui Du Duong
- National Center for Water Resources Planning and Investigation (NAWAPI), Ministry of Natural Resource and Environment (MONRE), 93/95 Vu Xuan Thieu Street, Ha Noi, Viet Nam
| | - Vu Duc Long
- National Center for Hydro-Meteorological Forecasting (NCHMF), MONRE, 8 Phao Dai Lang Street, Ha Noi, Viet Nam
| | - Faisal Hossain
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, USA
| | - Hyongki Lee
- Department of Civil and Environmental Engineering, University of Houston, 4800 Calhoun Rd, Houston, TX 77004, USA
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23
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On the Dominant Factor Controlling Seasonal Hydrological Forecast Skill in China. WATER 2017. [DOI: 10.3390/w9110902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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High-resolution near real-time drought monitoring in South Asia. Sci Data 2017; 4:170145. [PMID: 28972569 PMCID: PMC5625554 DOI: 10.1038/sdata.2017.145] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 08/03/2017] [Indexed: 11/09/2022] Open
Abstract
Drought in South Asia affect food and water security and pose challenges for millions of people. For policy-making, planning, and management of water resources at sub-basin or administrative levels, high-resolution datasets of precipitation and air temperature are required in near-real time. We develop a high-resolution (0.05°) bias-corrected precipitation and temperature data that can be used to monitor near real-time drought conditions over South Asia. Moreover, the dataset can be used to monitor climatic extremes (heat and cold waves, dry and wet anomalies) in South Asia. A distribution mapping method was applied to correct bias in precipitation and air temperature, which performed well compared to the other bias correction method based on linear scaling. Bias-corrected precipitation and temperature data were used to estimate Standardized precipitation index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) to assess the historical and current drought conditions in South Asia. We evaluated drought severity and extent against the satellite-based Normalized Difference Vegetation Index (NDVI) anomalies and satellite-driven Drought Severity Index (DSI) at 0.05°. The bias-corrected high-resolution data can effectively capture observed drought conditions as shown by the satellite-based drought estimates. High resolution near real-time dataset can provide valuable information for decision-making at district and sub-basin levels.
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25
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26
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Bartlett MK, Klein T, Jansen S, Choat B, Sack L. The correlations and sequence of plant stomatal, hydraulic, and wilting responses to drought. Proc Natl Acad Sci U S A 2016; 113:13098-13103. [PMID: 27807136 PMCID: PMC5135344 DOI: 10.1073/pnas.1604088113] [Citation(s) in RCA: 246] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Climate change is expected to exacerbate drought for many plants, making drought tolerance a key driver of species and ecosystem responses. Plant drought tolerance is determined by multiple traits, but the relationships among traits, either within individual plants or across species, have not been evaluated for general patterns across plant diversity. We synthesized the published data for stomatal closure, wilting, declines in hydraulic conductivity in the leaves, stems, and roots, and plant mortality for 262 woody angiosperm and 48 gymnosperm species. We evaluated the correlations among the drought tolerance traits across species, and the general sequence of water potential thresholds for these traits within individual plants. The trait correlations across species provide a framework for predicting plant responses to a wide range of water stress from one or two sampled traits, increasing the ability to rapidly characterize drought tolerance across diverse species. Analyzing these correlations also identified correlations among the leaf and stem hydraulic traits and the wilting point, or turgor loss point, beyond those expected from shared ancestry or independent associations with water stress alone. Further, on average, the angiosperm species generally exhibited a sequence of drought tolerance traits that is expected to limit severe tissue damage during drought, such as wilting and substantial stem embolism. This synthesis of the relationships among the drought tolerance traits provides crucial, empirically supported insight into representing variation in multiple traits in models of plant and ecosystem responses to drought.
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Affiliation(s)
- Megan K Bartlett
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095;
| | - Tamir Klein
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Steven Jansen
- Ulm University, Institute of Systematic Botany and Ecology, 89081 Ulm, Germany
| | - Brendan Choat
- Western Sydney University, Hawkesbury Institute for the Environment, Richmond, NSW 2753, Australia
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095
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27
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Feng H. Individual contributions of climate and vegetation change to soil moisture trends across multiple spatial scales. Sci Rep 2016; 6:32782. [PMID: 27600157 PMCID: PMC5013547 DOI: 10.1038/srep32782] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/15/2016] [Indexed: 11/10/2022] Open
Abstract
Climate and vegetation change are two dominating factors for soil moisture trend. However, their individual contributions remain unknown due to their complex interaction. Here, I separated their contributions through a trajectory-based method across the global, regional and local scales. Our results demonstrated that climate change accounted for 98.78% and 114.64% of the global drying and wetting trend. Vegetation change exhibited a relatively weak influence (contributing 1.22% and −14.64% of the global drying and wetting) because it occurred in a limited area on land. Regionally, the impact of vegetation change cannot be neglected, which contributed −40.21% of the soil moisture change in the wetting zone. Locally, the contributions strongly correlated to the local environmental characteristics. Vegetation negatively affected soil moisture trends in the dry and sparsely vegetated regions and positively in the wet and densely vegetated regions. I conclude that individual contributions of climate and vegetation change vary at the global, regional and local scales. Climate change dominates the soil moisture trends, while vegetation change acts as a regulator to drying or wetting the soil under the changing climate.
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Affiliation(s)
- Huihui Feng
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 21008, China
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Yan W, Zhong Y, Shangguan Z. A meta-analysis of leaf gas exchange and water status responses to drought. Sci Rep 2016; 6:20917. [PMID: 26868055 PMCID: PMC4751433 DOI: 10.1038/srep20917] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 01/14/2016] [Indexed: 11/28/2022] Open
Abstract
Drought is considered to be one of the most devastating natural hazards, and it is predicted to become increasingly frequent and severe in the future. Understanding the plant gas exchange and water status response to drought is very important with regard to future climate change. We conducted a meta-analysis based on studies of plants worldwide and aimed to determine the changes in gas exchange and water status under different drought intensities (mild, moderate and severe), different photosynthetic pathways (C3 and C4) and growth forms (herbs, shrubs, trees and lianas). Our results were as follows: 1) drought negatively impacted gas exchange and water status, and stomatal conductance (gs) decreased more than other physiological traits and declined to the greatest extent in shrubs and C3 plants. Furthermore, C4 plants had an advantage compared to C3 plants under the same drought conditions. 2) The decrease in gs mainly reduced the transpiration rate (Tr), and gs could explain 55% of the decrease in the photosynthesis (A) and 74% of the decline in Tr. 3). Finally, gas exchange showed a close relationship with the leaf water status. Our study provides comprehensive information about the changes in plant gas exchange and water status under drought.
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Affiliation(s)
- Weiming Yan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
| | - Yangquanwei Zhong
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
| | - Zhouping Shangguan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
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Zhang B, He C, Burnham M, Zhang L. Evaluating the coupling effects of climate aridity and vegetation restoration on soil erosion over the Loess Plateau in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 539:436-449. [PMID: 26379259 DOI: 10.1016/j.scitotenv.2015.08.132] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 08/26/2015] [Accepted: 08/26/2015] [Indexed: 06/05/2023]
Abstract
In this study, the coupling effects of climate aridity and vegetation restoration on runoff and sediment yield over the Loess Plateau were examined and characterized. To take into consideration the complexity of drought, as well as the varied strengths and weaknesses of different drought measures, two drought indices are selected to identify and evaluate drought variability. The Normalized Difference Vegetation Index (NDVI) data were obtained to monitor and express spatiotemporal variations in vegetation cover. The results show that most regions of the Loess Plateau experienced increasingly severe droughts over the past 40years, and these regions comprise the major source of the Yellow River sediment. Climatic drying initially occurred in the 1990s, and became statistically significant in 2000s. The increasingly severe droughts could negatively impact surface and groundwater supplies as well as soil water storage, but may also minimize surface runoff yield, which is one of the major causes of soil erosion on the Loess Plateau. Vegetation cover on the Loess Plateau was significantly improved after the implementation of "Grain for Green" project, which were helpful for controlling severe soil erosion. With the impacts of the construction of check dams, terraces and large reservoirs, runoff and sediment yield over the Loess Plateau initially exhibited downward trends between 1970 and 1990. After 1990, with the effects of the climate warming and drying, a second sharp reduction in runoff and sediment yield occurred. The coupling effects of climate aridity and vegetation restoration have led to a third significant decrease in runoff and sediment yield over the Loess Plateau after 2000.
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Affiliation(s)
- Baoqing Zhang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.
| | - Chansheng He
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China; Department of Geography, Western Michigan University, Kalamazoo, MI 49008, USA.
| | - Morey Burnham
- Department of Environmental Studies, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Lanhui Zhang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China
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Global land moisture trends: drier in dry and wetter in wet over land. Sci Rep 2015; 5:18018. [PMID: 26658146 PMCID: PMC4676011 DOI: 10.1038/srep18018] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/10/2015] [Indexed: 12/04/2022] Open
Abstract
The “dry gets drier, wet gets wetter” (DGDWGW) paradigm is widely accepted in global moisture change. However, Greve et al.1 have declared that this paradigm has been overestimated. This controversy leaves a large gap in the understanding of the evolution of water-related processes. Here, we examine the global moisture trends using satellite soil moisture for the past 35 years (1979–2013). Our results support those of Greve et al., although there are quantitative differences. Generally, approximately 30% of global land has experienced robust moisture trends (22.16% have become drier, and 7.14% have become wetter). Only 15.12% of the land areas have followed the DGDWGW paradigm, whereas 7.77% have experienced the opposite trend. A new finding is that there is a significant “drier in dry, wetter in wet” (DIDWIW) trend paradigm; 52.69% of the drying trend occurred in arid regions, and 48.34% of the wetter trend occurred in the humid regions. Overall, 51.63% of the trends followed the DIDWIW paradigm, and 26.93% followed the opposite trend. We also identified the DGDWGW and DIDWIW paradigms in low precipitation-induced arid regions in which the dry soil led to an increasing sensible heat flux and temperature and subsequently potential evapotranspiration.
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On the Role of Land Surface Temperature as Proxy of Soil Moisture Status for Drought Monitoring in Europe. REMOTE SENSING 2015. [DOI: 10.3390/rs71215857] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Bartlett MK, Zhang Y, Kreidler N, Sun S, Ardy R, Cao K, Sack L. Global analysis of plasticity in turgor loss point, a key drought tolerance trait. Ecol Lett 2014; 17:1580-90. [DOI: 10.1111/ele.12374] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/07/2014] [Accepted: 08/25/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Megan K. Bartlett
- Department of Ecology and Evolutionary Biology; University of California Los Angeles; 621 Charles E. Young Drive South Los Angeles California 90095 USA
| | - Ya Zhang
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Mengla Yunnan 66303 China
| | - Nissa Kreidler
- Department of Ecology and Evolutionary Biology; University of California Los Angeles; 621 Charles E. Young Drive South Los Angeles California 90095 USA
| | - Shanwen Sun
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Mengla Yunnan 66303 China
| | - Rico Ardy
- Department of Ecology and Evolutionary Biology; University of California Los Angeles; 621 Charles E. Young Drive South Los Angeles California 90095 USA
| | - Kunfang Cao
- Key Laboratory of Tropical Forest Ecology; Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences; Mengla Yunnan 66303 China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, and College of Forestry; Guangxi University; Nanning Guangxi 530005 China
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology; University of California Los Angeles; 621 Charles E. Young Drive South Los Angeles California 90095 USA
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Temperature and Snow-Mediated Moisture Controls of Summer Photosynthetic Activity in Northern Terrestrial Ecosystems between 1982 and 2011. REMOTE SENSING 2014. [DOI: 10.3390/rs6021390] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Little change in global drought over the past 60 years. Nature 2012; 491:435-8. [PMID: 23151587 DOI: 10.1038/nature11575] [Citation(s) in RCA: 307] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/11/2012] [Indexed: 11/08/2022]
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Troy TJ, Sheffield J, Wood EF. The role of winter precipitation and temperature on northern Eurasian streamflow trends. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016208] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Qin J, Liang S, Yang K, Kaihotsu I, Liu R, Koike T. Simultaneous estimation of both soil moisture and model parameters using particle filtering method through the assimilation of microwave signal. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011358] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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