Spatial differentiation and scenario simulation of cultivated land in mountainous areas of Western Hubei, China: a PLUS model

A useful spatial pattern of cultivated land utilization in mountainous areas is a basic prerequisite for promoting efficient utilization of cultivated land and has a practical use for ensuring regional food security and rural revitalization. In this paper, we use Enshi and Lichuan cities as case studies and the PLUS model to analyze the spatial differentiation characteristics of cultivated land from 2000 to 2020. In addition, we simulated the spatial pattern of cultivated land in 2030 concerning the ecological priority scenario (scenario I) and the ecological and economic coordination scenario (scenario II). The results show that (1) the degree of cultivated land fragmentation from 2000 to 2020 is characterized as "high in the east and low in the west," and the spatial aggregation of cultivated land decreases slightly over time and that there is a risk of increasing fragmentation of cultivated land in the future. (2) The complexity of cultivated land shape shows a fluctuating decrease between 2000 and 2030, and an overall trend of landscape homogenization. (3) The spatial distribution of cultivated land is concentrated in the peak cluster depressions and river valleys. The imbalance in the distribution of cultivated land has increased in the past two decades which should be curbed in the future. (4) In 2030, concerning the ecological priority development scenario, cultivated land use tends to evolve in the direction of balanced distribution and a relatively complex shape. (5) Concerning the coordinated ecological and economic development scenario, the spatial aggregation of cultivated land is higher and the patches of cultivated land are more regular, but the distribution imbalance is more serious. The results can provide scientific references for sustainable and effective use of cultivated land in mountainous areas.

Effects of land use transition on ecological vulnerability in poverty-stricken mountainous areas of China: A complex network approach

Poverty-stricken mountainous areas are often subject to ecological vulnerability, and land use transition is a major factor affecting that vulnerability. Land use transition forms a complex network comprised of different land use types which interact with each other and respond to external environment processes, resulting in dynamics. This study develops complex network approach with cascade failure model to quantitatively explore the effects of land use transition on ecological vulnerability from the holistic and dynamic perspective. The study analyzes the characteristics of land use transition, identifying key transition types and simulating their impact on ecological vulnerability in 16 poverty-stricken mountainous counties in western Hubei Province, China, with the following findings. (1) The heterogeneity of change in agricultural land and construction land is significant; from 1990 to 2015, a short-term increase in the amount of agricultural land is followed by a gradual reduction, while the amount of construction land increased continuously. (2) Agricultural land is the dominant output land type, exported mainly to construction land and water area, and construction land is the dominant input land type, imported mainly from agricultural land. Sparse woods, woods, and dryland are the key land use types in the study area. (3) the critical points for maintaining resilience of ecosystem are 80% or higher for cultivated land and 80% or higher for woodland. (4) For the tolerance parameter α, 20% increase in cultivated land and a 10% increase in woodland would enhance ecosystem resilience and reduce its damage degree to corresponding land use transition. These findings are important points of reference for the sustainable management of poverty-stricken mountainous counties in western Hubei Province and in China more generally. They also have policy implications for land resources, especially in terms of the alleviation of poverty and the coordination between ecological protection and economic development.

Watershed-scale assessment of surface water-related risks from shale gas development in mountainous areas, China

Water risks are one of the key issues dominating environmental debates on shale gas development. Water withdrawals and wastewater discharges in shale gas fields of mountainous areas are more complicated than in plain areas due to different climatic, topographical and hydrological conditions, which would impact water resources. This research identifies the surface water-related risks from shale gas development in mountainous areas as water shortage and water pollution. Conceptions of accessibility for both water supply and water pollution are proposed to describe the vulnerability of water resources and the exposure to water pollution. Based on a risk probability model, a water risk assessment method for mountainous areas is constructed from the perspectives of dangers, exposures and vulnerabilities. Finally, the assessment method is applied in Chongqing, China. The results show that, from 2010 to 2020, the water consumption of shale gas development has a little impact on regional water resources in total, but more significant impacts are seen in a few areas, including the seasonal water-deficient areas in Western Chongqing, the urban and suburban areas with high pollutant loadings in Midwest Chongqing, and other areas with high pollutant accessibility and vulnerable water environments. The surface water-related risks of the shale gas development in Chongqing are principally composed of low and relatively low levels of risks, which cover 60% of the total area of Chongqing and display a spatial difference of west > northeast > southeast areas. Based on Monte Carlo method, the results of uncertainty analyses show the model is reliable. This research provides a reference for water comprehensive risk assessment of shale gas development in mountainous areas.

Evaluating medical convenience in ethnic minority areas of Southwest China via road network vulnerability: a case study for Dehong autonomous prefecture

BACKGROUND

Southwest China is home to more than 30 ethnic minority groups. Since most of these populations reside in mountainous areas, convenient access to medical services is an important metric of how well their livelihoods are being protected.

METHODS

This paper proposes a medical convenience index (MCI) and computation model for mountain residents, taking into account various conditions including topography, geology, and climate. Data on road networks were used for comprehensive evaluation from three perspectives: vulnerability, complexity, and accessibility. The model is innovative for considering road network vulnerability in mountainous areas, and proposing a method of evaluating road network vulnerability by measuring the impacts of debris flows based on only links. The model was used to compute and rank the respective MCIs for settlements of each ethnic population in the Dehong Dai and Jingpo Autonomous Prefecture of Yunnan Province, in 2009 and 2015. Data on the settlements over the two periods were also used to analyze the spatial differentiation of medical convenience levels within the study area.

RESULTS

The medical convenience levels of many settlements improved significantly. 80 settlements were greatly improved, while another 103 showed slight improvement.Areas with obvious improvement were distributed in clusters, and mainly located in the southwestern part of Yingjiang County, northern Longchuan County, eastern Lianghe County, and the region where Lianghe and Longchuan counties and Mang City intersect.

CONCLUSIONS

Development of the road network was found to be a major contributor to improvements in MCI for mountain residents over the six-year period.

Seasonal changes in hemograms and Theileria orientalis infection rates among Holstein cattle pastured in the mountains in the Republic of Korea

In the current study, we compared seasonal changes in complete blood counts (CBCs) and rates of infection with a tick-borne pathogen between Holstein cattle housed indoors and those maintained outside on pasture. There were differences in white blood cell (WBC) parameters, but the changes were not associated with seasons or the housing type. Analysis of red blood cell (RBC) parameters showed lower values in August and November versus March, and in the cattle maintained on pasture versus the housed cattle. In comparison with the RBC count of the housed cattle in March (10.1M/μL), the RBC counts of the pastured cattle were significantly lower in August (7.8M/μL; p<0.01) and November (7.5M/μL; p<0.01). The hematocrit (HCT) also showed a decrease in March (33.5%), August (30.0%, p<0.01) and November (28.5%, p<0.01). According to PCR analysis, the Theileria infection rate among the pastured cattle in March was only 11%, but this rate increased to 22% and 60% in August and November, respectively. The RBC count (7.4M/μL) and HCT (27.7%) values in Theileria-positive pastured cattle in November showed a dramatic decrease compared to those of cattle examined in March. Phylogenetic analysis revealed that these Theileria isolates correspond to T. orientalis. These results suggest that a remarkable increase in tick infestation in mountainous areas in the summer may cause increased rates of infection with T. orientalis, leading to significant changes in the RBC profile after grazing. Therefore, these hematological changes may be associated with T. orientalis infection caused by tick-biting; thus, additional studies on the pathogenicity of T. orientalis are needed.

Diurnal variation of surface ozone in mountainous areas: Case study of Mt. Huang, East China

To explore the variations in atmospheric environment over mountainous areas, measurements were made from an intensive field observation at the summit of Mt. Huang (30.13°N, 118.15°E, 1841m above sea level), a rural site located in East China, from June to August 2011. The measurements revealed a diurnal change of surface O3 with low concentrations during the daytime and high concentrations during the nighttime. The causes of diurnal O3 variations over the mountain peak in East China were investigated by using a fairly comprehensive WRF-Chem and HYSPLIT4 modeling approach with observational analysis. By varying model inputs and comparing the results to a baseline modeling and actual air quality observations, it is found that nearby ozone urban/anthropogenic emission sources were contributing to a nighttime increase in mountaintop ozone levels due to a regional transport lag and residual layer effects. Positive correlation of measured O3 and CO concentrations suggested that O3 was associated with anthropogenic emissions. Sensitivity modeling experiments indicated that local anthropogenic emissions had little impact on the diurnal pattern of O3. The diurnal pattern of O3 was mainly influenced by regional O3 transport from the surrounding urban areas located 100-150km away from the summit, with a lag time of 10h for transport.