黄土高原沟壑区小流域生态与经济要素演变及相互作用——以陕西省长武县王东沟小流域为例

以黄土高原沟壑区长武县王东沟流域为例，分析了流域治理过程中（1985—2000年）生态与经济要素的变化及其相互作用，揭示了治理条件下流域生态经济系统演变趋势。通过调整流域农、林、草、果用地比例，土地利用结构趋于合理，单位面积生产力和流域粮食产量得到显著提高。与此同时，流域纯收入大幅度增加。表明这一治理模式是成功的。在生态脆弱区，国家投入是当地脱贫致富、实现生态与经济良性发展的前提；农民脱贫增收是生态与经济协调、持续发展的保障；利用当地资源，发展优势产业，是实现经济效益与生态效益良性发展的动力。同时发现，人均收入低于500元，粮食产量低于400公斤是国家进行投入治理的参考线，在保障口粮的基础上，人均收入提高到1000元时，可实现当地群众的自主投入发展。

Analysis on Small Watershed Ecological and Economic System in Gully Regions of the Loess Plateau——A Case Study in Wangdonggou Watershed of Changwu County, Shaanxi

Integrated small watershed management, as one of the main measures of ecological restoration, was widely used in the Loess Plateau and many achievements were made. In this study, Wangdonggou small watershed in Changwu County, Shaanxi Province was used as a case study area, the ecological and economic elements and its dynamic during the restoration process were analyzed, and the interaction approach and manner between economic and ecological in the system was explored. The results showed that the ratio for cropland, woodland, grassland, and orchard was adjusted from 1985 to 2004, and the landuse structure became rational. Soil fertility in cropland was improved,and the soil productivity and food production increased significantly compared to that in 1985. The income per person also increased significantly during the same period. Harmony between economy and ecology in the study area was improved and the Wangdonggou watershed management model was successful. In the ecotone, the state support is the premise to eliminate poverty and harmonize ecology and economy; the income increase could enhance the harmony of ecology and economy and sustain development. State support to control environment was necessary under the condition of less than 500 RMB of the income and less than 400 kg of food production per person. When income per person reached over 1000 RMB, sustainable development was gained based on local farmers＇ input and management.