喀斯特地区石漠化综合治理生态效益指标体系构建及评价——以杠寨小流域为例

Construction of eco-efficiency index system for preventing and controlling rocky desertification in Gangzhai karst small watershed,Kaiyang,Guizhou and system evaluation

以杠寨小流域为例,采用标准差系数法,从水源涵养、水土保持、改良土壤、固碳释氧、生物多样性和生物效应等6个方面,对初选指标进行了权重的确定及优选,最终确定了17项评价指标,构建了该流域石漠化综合治理生态效益评价指标体系。根据选定的评价指标,采用灰色关联度法对该流域综合治理的生态效益进行了评价.结果表明:经过3年的石漠化综合治理,该流域的水源涵养、水土保持、固碳释氧和生物效益评价值均有所提高,其中以水土保持效益增幅最大,其效益评价值由治理初期的0.083 0上升到了0.092 1,效益增幅将近11%;综合生态效益评价值由治理初期的0.437 7上升到了0.450 7,效益增幅将近3%。不同植被类型的综合生态效益评价值,除了少数几个样地以外,其余各样地均有所提高。总体而言,该流域的石漠化综合治理在生态效益方面取得了一些成效,但还有很大提升空间,这也说明了石漠化治理的长期性和艰巨性。

By taking the Gangzhai small watershed as an example, and using standard deviation coefficient method, from six aspects of water conservation, water and soil conservation, soil improvement, carbon fixation and oxygen release, biological diversity and biological effects, the primary selected indexes’ weights were determined and then the weighted indexes were screened, there were 17 evaluating indexes to be reserved for constructing a evaluating system, finally, the eco-efficiency index system for preventing and controlling rocky desertification in Gangzhai karst small watershed, Kaiyang, Guizhou were set up. Moreover, According the 17 evaluating indexes, and by using gray relevancy method, the ecological benefits of the watershed’s comprehensive control were evaluated. The results show that after the rocky desertification comprehensive treatment for 3 years, the basin’s evaluating values of water conservation, soil and water conservation, carbon sequestration and release oxygen, and the biological efficiency evaluation were all enhanced, of them the soil and water conservation benefit had the largest increase, the benefit evaluation values rose from 0.0830 to 0.0921 at the early stage of the governance, and efficiency increase amplitude was nearly 11%;the integrated evaluation of ecological benefit values rose from 0.4377 to 0.4507 at the early stage of the governance and the efficiency increase amplitude was nearly 3%. The comprehensive ecological benefit evaluation values of different vegetation types, except a few of samples, the rest all increased. In general, the basin’s rocky desertification comprehensive treatment had achieved some successes in aspect of ecological benefits, but also had the very big promotion space, it also illustrated that there were long-term and arduous nature for desertification control.