黄河流域生态安全屏障防风固沙时空变化及驱动因素

黄河流域是我国重要的生态屏障和经济区，防风固沙服务及其驱动机制的研究对于筑牢黄河流域生态安全屏障具有重要意义。基于修正土壤风蚀模型(RWEQ)定量评估黄河流域2000—2018年防风固沙服务时空变化，采用相关分析和地理加权回归模型(GWR)从社会、气候、土壤、植被、地形等角度探究各驱动因素对黄河流域防风固沙服务影响的空间异质性。结果表明：(1)2000—2018年黄河流域土壤风蚀模数与单位面积防风固沙量分别以0.04 t hm^-2 a^-1和0.14 t hm^-2 a^-1的速率下降，而防风固沙保有率和植被覆盖度则分别以0.05%·a^-1和0.26%·a^-1的速率上升。(2)黄河流域土壤风蚀以微度(<2 t hm^-2 a^-1)和轻度(2—25 t hm^-2 a^-1)为主，共占研究区面积的96.28%。土壤风蚀在空间分布呈现西北高东南低的特点，而防风固沙服务高值则主要分...

Spatio-temporal changes and driving factors of windbreak and sand-fixing services in the ecological security barrier of the Yellow River Basin

The Yellow River Basin is an important ecological barrier and economic zone in China. Study of windbreak and sand-fixing services and their driving mechanisms is of great significance for building a firm ecological security barrier in the Yellow River Basin. This paper quantitatively assessed the spatial and temporal variation of windbreak and sand-fixing service in the Yellow River Basin from 2000 to 2018 based on the revised wind erosion equation (RWEQ). The correlation analysis and geographically weighted regression models (GWR) were used to explore the spatial heterogeneity of the influence of various drivers on windbreak and sand-fixing service in the Yellow River Basin from the perspectives of society, climate, soil, vegetation and topography. The results show that (1) the soil wind erosion modulus and the amount of windbreak and sand-fixing service per unit area in the Yellow River Basin decreased at the rates of 0.04 t hm^-2 a^-1 and 0.14 t hm^-2 a^-1, respectively, from 2000 to 2018, while the windbreak and sand-fixing service retention rate and vegetation cover increased at the rates of 0.05%·a^-1 and 0.26%·a^-1, respectively. (2) Soil wind erosion in the Yellow River basin was predominantly slight (<2 t hm^-2 a^-1) and mild (2-25 t hm^-2 a^-1), accounting for a total of 96.28% of the study area. Soil wind erosion showed a spatial distribution of high in the northwest and low in the southeast, while high values of windbreak and sand-fixing service were mainly distributed in the northwest and downstream watersheds. (3) There is significant spatial heterogeneity in the effects of the drivers on the windbreak and sand-fixing service in the Yellow River Basin, with precipitation, temperature, actual evapotranspiration, soil clay content, soil organic matter content and slope gradient mainly showing negative inhibition, while wind speed, air pressure, Normalizd Difference Vegetation Index and soil coarse sand content mainly show positive promotion. The results of this study can provide some references and basis for desertification control and ecological protection and restoration in the Yellow River basin.