Abstract: Under the support of GIS technique, the authors evaluated the capital stocks of the ecosystem's soil conservation with a case study in Beijing, Tianjin and Hebei Province. On the basis of the data of daily rainfall, NDVI, DEM, LUCC, and soil types of the study area, according to the Revised Universal Soil Loss Equation, the maximum amount of potential soil erosion and its actual quantities were calculated. The deviation between them was the conserved amount, which was converted into capital stocks with the methods of Shadow Price and Market Price. The result show that the value of the soil conservation in the study area was about 176.832 billion RMB yuan, which approximately equaled to the 21.41 percent of the total GDP in 2000, of which the preserved nutrient was about 167.797 billion RMB yuan and the alluvial bedload was 9.035 billion RMB yuan respectively. The contributing percent of individual ecosystems was as follows: the forest occupies 44.34%, cropland 44.91%, grassland and water 10.75%.

Key words: universal soil loss equation, soil conservation, ecological value assessment, Beijing, Tianjin and Hebei Province

摘要： 基于GIS技术和通用土壤侵蚀方程，以京津冀地区为案例区，对农业生态系统保持土壤的资本价值进行了评估。测算结果表明，京津冀地区农业生态系统具有巨大的土壤保持价值，整个区域农业生态系统保持土壤价值总量约为1768.32亿元，相当于该区2000年GDP（8261.02亿元）的21.41％。其中保持养分价值为1677.97亿元，减少泥沙淤积的价值为90.35亿元。各类农业生态系统价值量所占比例为：林地44.34％，农田44.91％，草地与水域10.75％。研究结果可以为区域生态补偿及生态系统管理提供科学依据。

关键词: 通用土壤侵蚀方程（RUSLE）, 土壤保持, 生态价值评估, 京津冀地区