中文摘要：

基于DPSIR概念模型，以延安市水土保持与生态环境建设试验示范区为实证研究对象，从驱动力、压力、状态、影响、响应5个环节综合对研究区域1999--2009年退耕还林（草）实施的生态环境效应进行评估。结果表明：退耕还林（草）工程实施阶段驱动力值、影响值和生态环境效应值呈现增加趋势，工程结束后均有所降低，而后随时间逐步增加并趋于稳定，压力值随年限总体波动较大，状态值则持续平稳增加。总体而言，工程的实施有效地改善了研究区生态环境状况，水土流失问题也得以缓解。研究还发现，输沙模数、降雨量、耕地压力、自然偏离度和人均纯收入等指标是研究区退耕还林（草）工程实施过程中的敏感指标，其对生态环境综合值影响较明显。退耕还林（草）工程通过改变传统的广种薄收耕作观念，发展集水灌溉及大棚等高效设施农业，在促进生态环境恢复的同时提高了当地农民收入，减轻了人类活动对生态环境的压力，调整其朝着与自然环境和谐的方向发展。

英文摘要：

Based on DPSIR conceptual model and taking Yan＇ an demonstration area of soil conservation and coo-environment construction as a study object, coo-environmental effect of ＂grain for green＂ project from 1999 to 2009 in study area was evaluated on the basis of five links including driving force, pres- sure, state, impact and response. The results show that values of driving force, impact and eco-environmen- tal effect increased in practice stage of the project, while decreased after the end of the project, and then they increased gradually with time and tended to be stable. Pressure value gave larger fluctuations, while state value increased continuously and reposefully. Overall, ＂grain for green＂ project effectively improved eeo-environmental status and soil erosion. In addition, sediment transport modulus, precipitation, farmland pressure, natural deviation degree, and net income per capita, which had significant effects on integrated value of eco-environment, were sensitive indices for implementation process of ＂grain for green＂ project in study area. ＂Grain for green＂ project has changed traditional farming mode characterized by high rate of rec- lamation and lower productivity, and developed high benefit installation agriculture such as water catchment irrigation and greenhouse. Such new mode not only promoted eeo-environment restoration but also increased the income of farmer, meanwhile, the pressure of human activities on the ecological environment were re- lieved and were effectively adjusted to be harmony with nature environment.