[Optimization Analysis of Vegetation Pattern in the Xiliao River Basin from the Perspective of Hydrological and...

The optimization of vegetation pattern is of great significance for ensuring ecosystem function and sustainable water resource utilization. This study focused on the Xiliao River Basin, wherein an optimization analysis of vegetation pattern was conducted from the perspective of coordinating and stabilizing hydrological and ecological function stability, aiming to determine the appropriate scale and distribution of vegetation. Firstly, methods such as the InVEST model, morphological spatial pattern analysis, and circuit theory were employed to identify the key ecological restoration areas that support stable ecosystem services. Then, based on groundwater table zoning and terrestrial water storage recovery targets, the scale of cultivated land and grassland required to maintain terrestrial water balance was determined. Finally, considering both ecological and hydrological functions, the spatial distribution and scale of converting cultivated land to grassland in each district and county were determined, obtaining the optimized vegetation pattern for the entire basin. The results indicate that: ① From 1980 to 2020, the average value of habitat quality in the Xiliao River Basin decreased from 0.46 to 0.41, with 95.4% of the area experiencing varying degrees of degradation. To maintain the stability of basin ecosystem services, the key area for ecological restoration was 1 031.78 km², with cultivated land accounting for nearly 50%. ② Among the 24 districts and counties involved in the basin, 21 of them showed a deficit in terrestrial water storage during 1980-2020. To maintain hydrological function stability, the annual water consumption of the whole basin should be reduced by 427.829 million m³, and 4 278.29 km² of cultivated land should to be converted to grassland. ③ For Horqin Right Middle Banner, Tongyu County, Zhalot Banner, and Horqin Left Middle Banner, converting cultivated land within the key ecological restoration areas into grassland could ensure hydrological and ecological function stability. For the other districts and counties, converting cultivated land within the key ecological restoration areas into grassland could only achieve the stability of ecological service, but it still cannot meet the demand for hydrological function stability. Therefore, an additional 3 790.60 km² of cultivated land would still need to be reduced. This study addresses the limitations of a single perspective focused on hydrological or ecological functions. The findings can provide valuable references for formulating vegetation pattern optimization strategies and ensuring the stability of ecosystems and water resources.