• Energy Research

The Southern Shaanxi Province, an important ecological security barrier area in central China, is the primary water source of the south-to-north water transfer project in China. However, severe soil erosion seriously affects the safety of regional ecological security and water quality of the water diversion project. To reveal the characteristics and variation of soil erosion in the southern Shaanxi Province after the implementation of a series of eco-environmental construction measures, in this study, the spatio-temporal characteristics of soil erosion from 2000 to 2014 were evaluated based on the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information Systems (GIS). The average soil erosion of southern Shaanxi Province in China was characterized as slight (less than 500 t·km–2·a–1) and mild erosion (500–2500 t·km–2·a–1) with an average soil erosion modulus of 1443.49 t·km–2·a–1, 1710.49 t·km–2·a–1, 1771.99 t·km–2·a–1 and 1647.74 t·km–2·a–1 in 2000, 2005, 2010 and 2014, respectively. The results revealed an increase in soil erosion until 2000 and a mitigation during the period of 2000 to 2014. After 2010, the soil erosion was controlled effectively. The spatial distribution of soil erosion displayed obvious spatial heterogeneity, and the high soil erosion (greater than 2500 t·km–2·a–1) was primarily distributed in the north-central and south counties of the study area. The soil erosion remained high and aggravated in six counties (i.e., Zhen’an, Zhashui, Ningshan, Ningqiang, Lueyang and Shanyang), and high erosion (greater than 5000 t·km–2·a–1) was found in the regions with slope gradients greater than 35 degrees and the middle mountainous (800–2000 m) regions. Therefore, the eco-environmental construction measures could effectively control soil erosion. However, unreasonable human activities remain the primary cause of soil erosion in the southern Shaanxi Province. In the future, more comprehensive and thorough ecological construction measures will be necessary to ensure regional ecological security and the eco-environmental quality of water sources.

The Southern Shaanxi Province, an important ecological security barrier area in central China, is the primary water source of the south-to-north water transfer project in China. However, severe soil erosion seriously affects the safety of regional ecological security and water quality of the water diversion project. To reveal the characteristics and variation of soil erosion in the southern Shaanxi Province after the implementation of a series of eco-environmental construction measures, in this study, the spatio-temporal characteristics of soil erosion from 2000 to 2014 were evaluated based on the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information Systems (GIS). The average soil erosion of southern Shaanxi Province in China was characterized as slight (less than 500 t·km–2·a–1) and mild erosion (500–2500 t·km–2·a–1) with an average soil erosion modulus of 1443.49 t·km–2·a–1, 1710.49 t·km–2·a–1, 1771.99 t·km–2·a–1 and 1647.74 t·km–2·a–1 in 2000, 2005, 2010 and 2014, respectively. The results revealed an increase in soil erosion until 2000 and a mitigation during the period of 2000 to 2014. After 2010, the soil erosion was controlled effectively. The spatial distribution of soil erosion displayed obvious spatial heterogeneity, and the high soil erosion (greater than 2500 t·km–2·a–1) was primarily distributed in the north-central and south counties of the study area. The soil erosion remained high and aggravated in six counties (i.e., Zhen’an, Zhashui, Ningshan, Ningqiang, Lueyang and Shanyang), and high erosion (greater than 5000 t·km–2·a–1) was found in the regions with slope gradients greater than 35 degrees and the middle mountainous (800–2000 m) regions. Therefore, the eco-environmental construction measures could effectively control soil erosion. However, unreasonable human activities remain the primary cause of soil erosion in the southern Shaanxi Province. In the future, more comprehensive and thorough ecological construction measures will be necessary to ensure regional ecological security and the eco-environmental quality of water sources.

Rapid urban expansion has significantly altered the regional landscape pattern, posing a serious threat to the sustainable development of natural and social ecosystems. By using landscape patterns indices and an area transfer matrix, this study analyzed the spatial-temporal changes of landscape patterns in the karst mountainous cities of southwest China from 2000 to 2020, by taking the central urban area of Guiyang City (CUAG) as the study area. This study explored the spatial and temporal driving factors of landscape pattern changes by using stepwise multiple linear regression and geographic detector methods. The results show: (1) CUAG’s landscape types altered changed drastically, with the area of forestland and construction land rapid increment and cultivated land decrement significantly. (2) The patches of construction land and forestland tended to be aggregated, the degree of fragmentation was reduced, and the shape was complex; cultivated land fragmentation was intensified. The connectivity of the landscape was improved, while the level of landscape diversity declined, the trend of landscape homogenization was obvious. (3) Socioeconomic and geographical endowment drivers have determined landscape pattern changes. The findings of this study may be used to interpret other similar landscapes worldwide and may imply the protection of urban ecosystem and sustainable development.

Rapid urban expansion has significantly altered the regional landscape pattern, posing a serious threat to the sustainable development of natural and social ecosystems. By using landscape patterns indices and an area transfer matrix, this study analyzed the spatial-temporal changes of landscape patterns in the karst mountainous cities of southwest China from 2000 to 2020, by taking the central urban area of Guiyang City (CUAG) as the study area. This study explored the spatial and temporal driving factors of landscape pattern changes by using stepwise multiple linear regression and geographic detector methods. The results show: (1) CUAG’s landscape types altered changed drastically, with the area of forestland and construction land rapid increment and cultivated land decrement significantly. (2) The patches of construction land and forestland tended to be aggregated, the degree of fragmentation was reduced, and the shape was complex; cultivated land fragmentation was intensified. The connectivity of the landscape was improved, while the level of landscape diversity declined, the trend of landscape homogenization was obvious. (3) Socioeconomic and geographical endowment drivers have determined landscape pattern changes. The findings of this study may be used to interpret other similar landscapes worldwide and may imply the protection of urban ecosystem and sustainable development.

Quantifying and spatial mapping the ecosystem services driven by land use change will help better manage land and formulate relevant ecological protection policies. However, most studies to date just focused on water supply services, and ignore water demand services and their supply–demand coupling mechanisms. Ecosystem service flow could be used to evaluate the imbalance between water supply and demand. Therefore, this study takes the Yellow River Basin as the research object to quantify the supply, demand, and spatial flow of water provision services. The results showed that land use and land cover (LULC) played a critical role in the spatial distributions of water supply and demand in the Yellow River Basin. The total water supply was 3.03 × 1011 m3, with a range of 3.29 × 108 m3 to 7.35 × 1010 m3 for different sub-watersheds. The spatial patterns of water supply were strongly different from those in water demand, resulting in obvious spatial mismatches. There was a higher water demand for constructional areas and agricultural lands, which had relatively lower water supply. Most water areas and natural lands provide much more water supply than demand. We used a water flow process to assess the water provision service between water supply side and demand side. The water flow process suggested that the Yellow River Basin had an obvious imbalance between water supply and demand depending on land use and populations, which would help policy makers to manage water resources through optimizing land management in different cities and finally achieving a balance between water supply side and demand site.

Quantifying and spatial mapping the ecosystem services driven by land use change will help better manage land and formulate relevant ecological protection policies. However, most studies to date just focused on water supply services, and ignore water demand services and their supply–demand coupling mechanisms. Ecosystem service flow could be used to evaluate the imbalance between water supply and demand. Therefore, this study takes the Yellow River Basin as the research object to quantify the supply, demand, and spatial flow of water provision services. The results showed that land use and land cover (LULC) played a critical role in the spatial distributions of water supply and demand in the Yellow River Basin. The total water supply was 3.03 × 1011 m3, with a range of 3.29 × 108 m3 to 7.35 × 1010 m3 for different sub-watersheds. The spatial patterns of water supply were strongly different from those in water demand, resulting in obvious spatial mismatches. There was a higher water demand for constructional areas and agricultural lands, which had relatively lower water supply. Most water areas and natural lands provide much more water supply than demand. We used a water flow process to assess the water provision service between water supply side and demand side. The water flow process suggested that the Yellow River Basin had an obvious imbalance between water supply and demand depending on land use and populations, which would help policy makers to manage water resources through optimizing land management in different cities and finally achieving a balance between water supply side and demand site.