Litang Yao

Human activities have caused different degrees of land-use change on different topographic gradients, with impacts on the landscape and ecosystem. Effectively preventing and addressing ecological risk (ER) and achieving harmonious coexistence between humans and nature are important aspects of sustainable development. In this study, we used Gansu Province as an example, adopted five periods of land-use data in 1980, 1990, 2000, 2010 and 2020, and used the geoinformatic Tupu method and the terrain distribution index to study land-use changes under different topographic gradients, and then constructed the landscape ecological risk assessment (LERA) model based on the landscape pattern index to analyze landscape ecological risk (LER) spatiotemporal changes under different topographic gradients, and finally explored the LER driving factors using the geodetector model. The results showed that (1) the dominant land-use types were unused land and grassland, accounting for approximately 74% of the land. The situation of transferring and changing each type was more drastic. The distribution and changes in cropland and built-up land were easily found in low topographic gradient areas with low elevations and small slopes; the distribution and changes in woodland, grassland and water areas were easily found in high topographic gradient areas with high elevations and large slopes. (2) The landscape ecological risk index (LERI) was 0.018, 0.019, 0.019, 0.019 and 0.020, respectively, with spatial expressions of high in the northwest and low in the southeast. Low LER was concentrated in high topographic gradient ecological reserves; high LER was concentrated in low topographic gradient human interference areas and high topographic gradient natural environmental complex areas. (3) Natural factors mainly acted on the LER on moderate and high topographic position gradients; socioeconomic factors mainly acted on the LER on low topographic position gradients. Human interference interacted with natural factors more than human interference alone on LER. This study can provide a scientific basis for ensuring ecological security and sustainable development in areas with complex topography and geomorphology.

Ecological management zoning plays a significant role in optimizing resource utilization, improving ecosystem service function, and promoting coordinated regional development. Taking Hexi Corridor as a representative region of the Mountain–Oasis–Desert composite system in arid regions of Asia, this study analyzed the spatial and temporal evolution of ecosystem service values and explored the influencing mechanism based on the optimal parameters-based geographical detector model. We have comprehensively divided ecological management zones and proposed corresponding control strategies. The results show that (1) the Hexi Corridor is characterized by regional differentiation, which is composed of three systems: The southern mountain system, central oasis system, and northern desert system. The mountain system is mainly composed of forestland and grassland, the oasis system is mainly composed of cropland, and the desert system is mainly composed of unused land. The conversion of land use mainly involves the conversion of unused land to cropland and grassland, while grassland is mainly converted to cropland. (2) The ecosystem service value of the Hexi Corridor increased significantly and demonstrated agglomeration characteristics in space. The highest value areas are mainly distributed in the southern mountain, with higher value and medium areas mainly distributed in the central oasis, and the lowest value areas are mainly located in the northern desert. (3) Socio-economic factors greatly influence the spatial differentiation of ecosystem service values in the Hexi Corridor, with natural environmental factors having less impact. Additionally, the internal interaction of natural environmental factors is the most significant. (4) The Hexi Corridor is divided into three ecological management zones: Ecological function protection zone, ecological and agricultural coordinated development zone, and ecological and urbanization coordinated development zone. This research has important reference value for global ecological management in arid regions.

Strengthening ecosystem monitoring and improving the efficiency of ecological risk assessment are of great significance for the sustainable development of ecosystems in an arid area. Using remote sensing monitoring data of land use, the ecological risk status of typical arid areas is assessed, its spatial heterogeneity is analyzed from the perspective of space-time, and the key areas of ecological risk management are finally identified. The results show that (1) the transformation mode of landscape ecological risk was dominated by medium–low risk to medium risk, and low risk to medium–low risk as a secondary level; in addition, the ecological risk level of the region increased. From 2000 to 2020, the transformation mode of landscape ecological risk was dominated by medium risk to medium–low risk, and medium–low risk to low risk as a secondary level; in addition, the regional ecological risk level shows a moderating trend. (2) The spatial difference in the ecological risk level in the Hexi region is obvious, showing a gradual decline from east to west, and the spatial difference in the ecological risk level in the west is significant. (3) A total of 1194 grid units are identified as key areas for ecological risk management in the Hexi region, accounting for 43% of the study area. This study provides important theoretical basis for ecosystem monitoring and risk assessment management in similar areas of arid regions.

At the intersection of the Qinghai–Tibet Plateau and Loess Plateau, topographic factors often profoundly affect the evolution of the regional land use pattern and ecological risk. This paper takes the Lanzhou–Xining urban agglomeration as the research area, divides the topographic gradient based on the topographic index, analyzes the characteristics of the land use pattern using the land use transfer matrix model, dynamic attitude and state degree model, and analyzes the influence of topographic factors on the land use pattern using the distribution model. At the same time, an ecological risk evaluation index system is constructed, the spatial principal component method is used to evaluate the ecological risk, and the influence of topography on the regional ecological risk is discussed. The results show that from 1990 to 2020, the area of construction land in the study area increased by 1045.807 km² and the area of ecological land increased by 587.41 km², with the most significant changes occurring in the attitude and state of construction land and unused land. It is found that cultivated land, water area and construction land are dominant in low terrain, while woodland, grassland and unused land are mainly distributed in middle and high terrain. During the study period, the ecological risk in the midwest and southeast of the Lanzhou–Xining urban agglomeration decreased, while the ecological risk in the northeast increased first and then decreased, although generally there was an increasing trend. Moran’s I varied from 0.942 to 0.955 from 1990 to 2020, indicating that the ecological risk index in the study area was highly positively correlated in space, while the spatial aggregation effect of the ecological risk was obvious. Low and moderately low risk areas are mainly distributed in high terrain, while high and moderately high risk areas are dominant in low terrain. The research results of this paper can make a lot of sense for ecological protection, land resource utilization and sustainable development of the Lanzhou–Xining urban agglomeration.

The Belt and Road Initiative (BRI) has revealed that it is necessary to strengthen research on land use and land cover change (LUCC) and ecological risk in key regions of countries around the world. In this study, the spatiotemporal characteristics of LUCC in the five capitals of Central Asian countries within the BRI were analyzed. Based on the grid scale, a landscape pattern index was introduced to quantitatively evaluate the landscape ecological risk levels of the five capitals. The results showed the following: first, the components of land use types in the five capitals have different structural characteristics, which are mainly grassland, unused land, and cultivated land. The landscape types that changed significantly were water and unused land, while the construction land area showed a trend of continuous increase. Second, different capitals have different land-use transfer patterns. Akmola State is mainly converted from cultivated land to grassland; Chuy State is mainly converted from forest land to grassland; Dushanbe and Tashkent City are mainly converted from grassland to forestland; and Ahal State is mainly converted from grassland to unused land. Third, the overall landscape ecological risks of the five capitals were low. Akmola State had the largest proportion of lowest ecological risk areas, whereas Chuy State and Dushanbe City had an increasing trend of highest ecological risk areas. The level of ecological risk in Tashkent remained stable during the study period, and the highest ecological risk areas in Ahal State decreased to 49,227.86 km². This study has enriched the research results of land use change and landscape ecological risk assessment of countries within the BRI and can provide a research reference for these countries and regions to achieve ecological sustainable development and strengthen ecosystem management.