中文摘要：

植被的土壤保持功能评估是生态安全研究中的重要内容之一。现有研究中缺乏较大尺度、较高精度的土壤保持估算。基于通用水土流失方程与年尺度风蚀预报方程,估算西北地区土壤现实侵蚀量与潜在侵蚀量,得出植被土壤保持物质量与价值量,并进行土壤保持效益分区。结果表明：植被土壤水蚀保持量高值集中在秦巴山区一带,其值超过5000t/（hm^2·a）;青海东南部三江源地区植被土壤水蚀保持量在（500～2000）t/（hm^2·a）;而1万t/（hm^2·a）以上的植被土壤风蚀保持量样本很少,集中在天山、西祁连山、三江源三大区域;沙漠内部几乎不发生植被土壤保持作用。单位面积价值量大于2亿元/km^2的像元几乎全部位于陕南和陇东南的秦巴山区中。黄土高原土壤保持价值量也多在1000万元/km^2以上。最后统计土壤保持价值总量,进行县域单元的土壤保持生态效益分级,并阐述了4种县域生态建设定位。

英文摘要：

The assessment of soil conservation by vegetation is one of the important aspects of ecological security research. Based on the USLE model and Wind Erosion Prediction Equations,this study aimed to estimate the potential and actual quantity of soil erosion. We found that the high value grids for soil conservation by vegetation in hydraulic erosion （number is larger than 5000t/（hm^2·a）） are almost all concentrated in the Qin-Ba Mountain area. Grids with more than 1 0000t/ （hm^2·a） soil conservation value are few, and concentrated in three regions： Tianshan Mountains,west of the Qilian Mountains and the Three River Source. The statistical results show that grids with a soil conservation value of more than 0.1 billion CNY/ km^2 are located in the Qin-Ba Mountain area and eastern Gansu. The vegetation coverage rate is not low in southeastern Qinghai, but the total quantity of soil conservation is low, indicating that the soil conservation function of vegetation is also a function of regional climate, topography and soil conditions. These data are important parameters in the evaluation of ecological safety, and the precision of the grid is also applicable to internal sub-zones. The goal of research in this field should be one of moving from data precision to model precision.