Impact of watershed habitat quality based on land use: a case study of taking Ciyao River Basin

Land use pattern is one of the most important factors affecting the quality of habitats, which is taken as the research objective in this study. Based on the land use data of Ciyao river basin from 1985 to 2020, transfer matrix analysis, superposition analysis, and zoning statistics were carried out by ArcGIS. The impact of main threat sources (cultivated land, urban land, and rural residential land) on water quality was calculated using the investment model. The habitat changes and the impact of the habitat quality of the basin on the hydrological and water quality were analyzed. The findings demonstrated that the land-type conversion in Ciyao River Basin from 1985 to 2020 is mainly manifested in the conversion from cultivated land to construction land (94.49 km2), and from grassland to cultivated land (21.59 km2) and forest land (27.15 km2). The habitat quality of the Ciyao River Basin decreased gradually from North to South. The medium and high habitat quality areas are mainly concentrated in the headwater area of the river. Due to the change in land type, the habitat quality in the headwater area of the river significantly improved from 2005 to 2020, while the habitat quality in the confluence area of the Wuliang section significantly declined from 1995 to 2015. Due to the improvements of habitat quality in the source area of the river and water conservation capacity, the total amount of water resources and annual runoff depth of Ciyao River significantly increased from 2005 to 2019 without significant changes in precipitation. The water quality of the Ciyao River has improved due to development of environmental pollution control and the improvement of watershed habitat in 2016–2020.