HYDROLOGICAL AND ECOLOGICAL EFFECTS OF CLIMATE CHANGE IN CAOHAI WATERSHED BASED ON SWAT MODEL

To understand the impact of meteorological changes on hydrological and water quality in Caohai watershed, Guizhou Province, China, based on the ArcGIS software, the land use map of Caohai watershed in 2017 was used to construct the land use database in the SWAT model, and then the soil database and the default meteorological database were used to establish the SWAT model of the Caohai Dongshan river watershed, the Zhonghe river watershed, the Baima river watershed and the Haizi river watershed. Sixteen climatic scenarios were set to simulate the hydrological response process of Caohai watershed. The results of the model analysis show that the variation of surface runoff and total nitrogen and phosphorus in each watershed is different when the temperature of the watershed rises by 1 degrees C and the precipitation remains unchanged. Under the same rainfall gradient, the surface runoff decreases with the increase of temperature; under the same temperature gradient, the surface runoff increases with the increase of rainfall, and the change of total nitrogen and phosphorus is more complex, which is related to the soil type and land cover.