典型岩溶县生态承载力演变分析——以云南泸西为例

Evolution of ecological carrying capacity in typical karst counties:A case study of Luxi county,Yunnan Province

以云南省泸西县为研究对象,从生态弹性力、生态支撑力、生态压力3个维度将生态承载力目标分层,结合研究区石漠化严重、水资源匮乏、经济结构以农业为主的特点构建了岩溶石漠化县的生态承载力综合评价指标体系,并采用主客观有机结合的赋权方式,评价了泸西县2008-2017年生态承载力演变规律。结果显示:在研究时段内,生态弹性力指数波动剧烈,生态支撑力指数稳定上升,生态压力指数略有下降,生态承载力指数由0.2692增加至0.7590,由低承载力上升到较高承载力,虽然在2012年受严重自然灾害影响有所下降,但是承载力整体上升明显,泸西县生态系统的承载能力有所提高,可持续发展状况有所提升;受岩溶断陷盆地坡度陡、水土流失及石漠化严重等问题的制约,叠加原始粗放的耕作方式,泸西县第二、三产业发展缓慢,这仍制约着泸西县经济的可持续发展。

Luxi county is located in the southeast of Yunnan Province,where karst accounts for 79%of the total area.The vulnerable ecosystem overlapping with unreasonable human activities in the county has caused serious water and soil erosion and rocky desertification,thus the contradiction between human and land is prominent.Besides,there are many poor people in the county,and the deterioration of the ecological environment and poverty seriously limit the sustainable development of Luxi county.The purpose of this work is to understand ecological carrying capacity,analyze sustainable development capacity and the bottleneck factors restricting the development of Luxi county from the structure of ecological carrying capacity,thus to provide a scientific theoretical basis for promoting the coordinated sustainable development of ecology,economy and society as well as poverty alleviation in this area.We use the multi-index comprehensive evaluation method from three dimensions of ecological resilience,ecological support and ecological pressure to stratify the ecological carrying capacity,combining with the characteristics of the study area to construct an evaluation index system suitable for the karst rocky desertification area.In terms of the entropy method and the Analytic Hierarchy Process(AHP)method,combining subjective and objective weighting methods,we analyze the evolution of ecological carrying capacity of Luxi county from 2008 to 2017.Results show that the ecological resilience index has an upward trend,while the intermediate process fluctuates sharply,indicating that the karst ecosystem is less stable and has obvious fragile characteristics.As the rapid economic growth has given supports to the management and utilization of environmental resources,residents’income and other aspects,the ecological support index has increased year by year,from 0.133,2 to 0.896,3.With the improvement of the ecological environment and the promotion of ecological civilization in recent years,the ecological pressure index is in a stable state and has been decreasing slowly in recent years,and the pressure on the ecosystem is also decreasing gradually.Except for the severe natural disasters in 2012,the index of ecological carrying capacity has been steadily increasing year by year,from 0.269,2 to 0.759,0.The carrying capacity has changed from low to high state.The structure of the ecosystem turns gradually stable and reasonable,and the capacity for sustainable development has been improved.The overall development trend in the past ten years is fairly good.Although the ecological carrying situation exhibits a good development trend,due to the steep karst slope in the fault basin,the restriction of natural environment,such as serious soil erosion and rocky desertification,superposition of original extensive farming,the development of the secondary and tertiary industries in Luxi country remains slow,limiting its economic development.So there is still a long way to the national well-off society.