黄土高原丘陵区水土流失综合治理生态环境效应评价

生态环境的层次性、复杂性和多变性,决定了对其质量进行评价的难度。确立构建一套合理、科学,在解决同一类问题中具有代表性的指标体系和评价方法,是众多学者长久以来关注的关键问题。该文以延安水土保持与生态环境建设试验示范区为实证对象,选取灰色关联度法、综合评价法和驱动力-压力-状态-影响-响应多方案综合决策支持系统(driving force pressure state impact response framework-multiple decision support system,DPSIR-mDSS)对研究区域1999-2009年水土流失综合治理生态恢复环境效应进行了评家,结果表明:DPSIR-mDSS模型在构建水土流失综合治理生态恢复环境效应评价指标体系时将人类社会行为和经济行为与环境系统间复杂的相互关系简化为一对一因果链,评价过程得以分解、简化,且评价结果与研究区域生态恢复环境效应实际变化情况一致,能较好的解释研究区域水土流失综合治理生态恢复环境效应随时间的变化情况,为生态恢复环境效应评价提供了一种新的评价思路和方法。总体而言,退耕还林(草)工程的实施极大的促进了研究区生态环境状况,但一些新的问题诸如耕地压力、生态需水亏缺等接踵而至,应在今后予以重视。

Ecological and environmental evaluation for water and soil loss comprehensive harness in Loess hilly region

Hierarchy, complexity and polytropy of eco-environment determine the difficulty in accessing its quality. It is a key issue that many scholars concern for a long time in establishing a set of index system and evaluation method, which is reasonable, scientific and representative in solving the same kind of problem. Methods of Grey relation degree, comprehensive evaluation and DPSIR-mDSS model (driving force, pressure, state, impact, response framework-multiple decision support system) were adopted to compare their difference in accessing eco-environmental effects. Meanwhile, demonstration area of soil conservation and eco-environment construction in Yan'an was taken as a study object to access environmental effects of ecological restoration of water and soil loss comprehensive harness from 1999 to 2009. The results showed that complicated relationship between human social and economic behavior and environmental system could be simplified to "one to one" causal chain by DPSIR model in constructing index system for accessing environmental effect of ecological restoration of water and soil loss comprehensive harness, accessing process could be decomposed and simplified. Also, the evaluation results of DPSIR-mDSS model was consistent with the actual situation of ecological restoration effects of study area, and would be better explained the variation of ecological restoration effects of water and soil loss comprehensive harness with time, which also provide a new method for ecological restoration effects assessment. In general, the eco-environmental status improved greatly due to the implement of "grain for green" project. However, more attention should be paid to problems in the future, such as pressure on cropland and ecological water storage deficit.