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Using Remote Sensing Techniques to Improve Hydrological Predictions in a Rapidly Changing World. REMOTE SENSING 2021. [DOI: 10.3390/rs13193865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Remotely sensed geophysical datasets are being produced at increasingly fast rates to monitor various aspects of the Earth system in a rapidly changing world. The efficient and innovative use of these datasets to understand hydrological processes in various climatic and vegetation regimes under anthropogenic impacts has become an important challenge, but with a wide range of research opportunities. The ten contributions in this Special Issue have addressed the following four research topics: (1) Evapotranspiration estimation; (2) rainfall monitoring and prediction; (3) flood simulations and predictions; and (4) monitoring of ecohydrological processes using remote sensing techniques. Moreover, the authors have provided broader discussions, on how to make the most out of the state-of-the-art remote sensing techniques to improve hydrological model simulations and predictions, to enhance their skills in reproducing processes for the fast-changing world.
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Hu S, Ma R, Sun Z, Ge M, Zeng L, Huang F, Bu J, Wang Z. Determination of the optimal ecological water conveyance volume for vegetation restoration in an arid inland river basin, northwestern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 788:147775. [PMID: 34029814 DOI: 10.1016/j.scitotenv.2021.147775] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/12/2021] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
Overexploitation of water resources has led to severe ecological degradation and even desertification in some arid inland river basins, northwestern China. To alleviate or restore the degraded vegetation ecosystem, ecological water conveyance (EWC) has become an important and effective measure. Scientific assessment of the impact of EWC on vegetation restoration and determination of the corresponding optimal EWC volume (EWCV) are important to formulate rational ecological water management. In this study, long time series normalized difference vegetation index (NDVI) was used to extract the restored vegetation area in Qingtu Lake area, a terminal lake in inland Shiyang River basin, northwestern China. The relationship between restored vegetation coverage and EWC was explored to determine the optimal EWCV. The restored vegetation area (RVA) increased dramatically in the first five years and became stable from 2016. The time lag of the response of RVA increase to EWC was about 2 years. A bell-shaped function between RVA and groundwater depth was obtained based on the results from Unmanned Aerial Vehicle (UAV) and micro terrain of the lake area. Based on the fitted function, five groundwater depth thresholds were obtained. The optimal groundwater depth in the hydrometric station was 2.91 ± 0.09 m for the maximal RVA (17.08 ± 3.25 km2). A polynomial function between the yearly EWCV and groundwater depth was developed and the EWCV thresholds corresponding to the groundwater depth thresholds were estimated. The optimal EWCV into Qingtu Lake was 2224.4 × 104 m3 for the maximal RVA. The correspondingly optimal EWCV from Hongyashan Reservoir was 3271.4 × 104 m3. The spatial distribution patterns of remotely sensed water surface and NDVI suggested that expanding the water-receiving area of conveyed water was useful to improve the vegetation growth. This study provides a reference for assessing the impact of EWC on vegetation restoration and determining the correspondingly optimal EWCV in arid inland river basins.
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Affiliation(s)
- Shun Hu
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Rui Ma
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
| | - Ziyong Sun
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Mengyan Ge
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Linglin Zeng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Feng Huang
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Jianwei Bu
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Zheng Wang
- Hubei Key Laboratory of Yangtze River Basin Environmental Aquatic Science, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
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Relationship between Water Surface Area of Qingtu Lake and Ecological Water Delivery: A Case Study in Northwest China. SUSTAINABILITY 2021. [DOI: 10.3390/su13094684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Qingtu Lake is located between Tengger Desert and Badain Jilin Desert, Gansu Province, Northwest China. It is the terminal lake of Shiyang River. In recent years, Qingtu lake has maintained a certain area of water surface and vegetation by artificial water conveyance. It is of great significance in preventing the convergence of the two deserts and restraining the trend of ecological deterioration of Shiyang River Basin. The relationship between the water surface area and the ecological water conveyance have not been thoroughly investigated. This study analyzed the spatial and temporal distribution of water surface area of Qingtu Lake and surrounding reeds by interpreting remote sensing data; the change of water surface area under the influence of meteorological factors and water conveyance by linear regression; the water conveyance to maintain current water surface area by water balance method, as well as the reasonable ecological water delivery in high flow year, normal flow year and low flow year by the means of analyzing the upstream inflow and water consumption in Minqin Basin. The results showed that there is a significant correlation between the water surface area of Qingtu Lake, evaporation and ecological water conveyance, and the minimum and maximum water surface areas generally appear before and after water delivery, indicating that the ecological water delivery and evaporation are the two main factors affecting the water surface area change of Qingtu Lake. The result calculated by linear regression indicated that the ecological water delivery volume to maintain current water surface area of Qingtu Lake is 3.146 × 107 m3/yr, while the value was 3.136 × 107 m3/yr calculated by water balance method. These two results are similar and can be verified with each other. Reasonable ecological water conveyance of Qingtu Lake in high flow year, normal flow year and low flow years were 4 × 107 m3/yr, 3.2 × 107 m3/yr and 2.3 × 107 m3/yr, respectively.
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