[Prediction of Soil Conservation and Water Conservation in the Yellow River Water Conservation Area Under Climate and...

Soil conservation and water conservation are important service functions of the surface ecosystem. It is of great significance to explore the spatial and temporal evolution characteristics of soil conservation and water conservation in the water conservation area of the Yellow River and the future multi-scenario prediction for regional ecological protection and sustainable development. Based on CA-Markov and InVEST models， this study analyzes the spatial and temporal evolution and influencing factors of water conservation and soil conservation from 2000 to 2020 and predicts the change trend under three scenarios [SSP1-1.9-ecological protection （scenario A）， SSP2-4.5-natural development （scenario B）， and SSP5-8.5-economic priority （scenario C）] combined with climate change and land use development in 2030. The results showed that： ① From 2000 to 2020， the soil conservation and water conservation in the Yellow River water conservation area showed an upward trend. The spatial distribution of water conservation showed a decreasing trend from west to east and from south to north. The spatial distribution of soil conservation was high in the south and low in the north. Precipitation had a significant spatial positive correlation with water conservation and soil conservation and played a major role. Evapotranspiration had a significant spatial negative correlation with water conservation and had a weak spatial correlation with soil conservation. ② The land use type in the water conservation area of the Yellow River was dominated by grassland. From 2000 to 2020， the cultivated land decreased， and the construction land increased. Under the three scenarios of 2020-2030， the area of cultivated land in the ecological protection scenario decreased by 4 668 km2 （9.97%）， and the area of grassland increased by 3 633 km2（1.65%）. The area of each category in the natural development scenario remained stable； in the economic priority scenario， the area of forest land and grassland accounted for the least， and the cultivated land increased by 1 981 km2（4.23%）. Under the three scenarios， the construction land maintained a high growth trend. ③ The change rates of water conservation under scenario A， scenario B， and scenario C in 2030 compared with 2020 were -25.06%， 31.16%， and 15.36%， respectively. The change rates of soil retention were -29.95%， 43.97%， and 20.42%， respectively. The soil conservation and water conservation of scenario A showed a downward trend， and the significant reduction area was mainly located in the source area of the Yellow River and the south of the Tangnaihai-Lanzhou Region. The soil conservation and water conservation of scenario B and scenario C showed an upward trend， and the increase of scenario B was the largest. Scenario C was affected by human activities， and the water conservation and soil conservation in the Yiluo River Basin and the area south of Maqu Station were slightly reduced. The research results can provide scientific reference for water resource management and sustainable development of the ecological environment under future climate and land use changes in the Yellow River water conservation area.