Correlational relationship between land use and landscape ecological risks in Inner Mongolia section of middle Nenjiang River

Inner Mongolia section in the middle reaches of Nenjiang River was an important part of the ecological security barrier in the north of China and played an important role in maintaining the ecological security in the middle and lower reaches of the river basin. This paper analyzed the spatial and temporal succession characteristics of land use pattern in watershed from 2000 to 2020, as well as the landscape ecological risk assessment model had been built. Based on the spatial and temporal succession of landscape ecological risk in the river basin over the past 20 years, the relationship between land use pattern and landscape ecological risk had been revealed. The results showed that in the past 20 years, the land use type in Inner Mongolia in the middle reaches of Nenjiang River was mainly forest land, and the overall pattern of land use had not changed much. However, the area of natural forests, wetlands and dryland had decreased significantly, and the area of paddy fields and artificial reservoirs had increased markedly. The landscape ecological risk area of the basin was mainly concentrated in the lower reaches of the Choer River and the Handahan River. In the last 20 years, the artificial reservoirs were the most obvious type of ecological transition to high risk, which increased from 8.90% in 2000 to 53.99% in 2020. The highest proportion of landscape ecological high risk area was paddy field, followed by dry land, urban land, rural residential area and other building land. Although with little change in global aggregation trends, there was a trend of increasing high-risk agglomerations and decreasing low-risk clusters in local aggregation trends. The land use type with the highest proportion of landscape ecological risk high-high agglomeration area was paddy field, accounting for 33.26% of the whole agglomeration area. Artificial land use types such as paddy fields and artificial reservoir were not only higher than other land use types in landscape ecological risk level, but also higher in agglomeration. This study provided strong support for the structural adjustment of subsequent industries in the river basin and the deepening of ecological protection. © 2023 Chinese Society for Environmental Sciences. All rights reserved.