2000—2018年贵州喀斯特山区小流域综合生态风险变化及其驱动因素

Spatio-temporal Change and Driving Factors of Integrated Ecological Risk of Catchments in Karst Mountainous Area of Guizhou Province From 2000 to 2018.

喀斯特山区存在生态本底脆弱、水土流失、石漠化等环境问题,造成流域内人地矛盾突出,经济发展受到严重制约。在综合考虑喀斯特山区景观演替过程、土壤侵蚀过程和石漠化过程生态风险的基础上,构建流域综合生态风险评价模型,以贵州乌江流域内324个小流域为评价单元,评估与分析2000—2018年流域综合生态风险时空变化特征,并利用地理探测器方法探测其变化的空间驱动因素。结果表明:(1)2000—2018年流域景观格局变化显著,其中林地、草地、人工表面和湿地面积占比分别提高2.87、1.10、0.49和0.21个百分点,耕地面积占比减少4.7个百分点。(2)2000、2005、2010、2015和2018年流域综合生态风险平均值分别为0.58、0.61、0.66、0.31和0.34,流域生态风险整体呈下降趋势。高生态风险区主要集中分布在流域上、下游地区,低生态风险区分布在中游地区。(3)流域内表征人类活动因素的干扰度、人口密度空间分布和GDP空间分布的解释力比自然因素解释力大,其中干扰度因子解释力(38.00%~83.00%)最大,人为活动因素是综合生态风险动态变化的主要驱动因素。研究结果对乌江流域社会-经济-生态环境系统治理和可持续发展具有参考价值。

Due to the fragile ecological background,soil erosion,rocky desertification and other environmental problems in Karst mountainous areas,the contradiction between people and land in the basin is prominent,and the economic development is seriously restricted.On the basis of comprehensively considering the ecological risk for the process of the landscape succession,soil erosion and rocky desertification of Karst mountain areas,the evaluation model of integrated ecological risk of the basin was constructed to evaluate and analyze the spatio-temporal evolution characteristics of integrated ecological risk of watershed from 2000 to 2018,with 324 small catchments in the Wujiang Basin of Guizhou province as evaluation unit,and used the geographical probe to detect the spatial drivers.The results show that:(1)The landscape pattern of the Basin changed significantly from 2000 to 2018,in which the area proportion of forest land,grassland,artificial surface and wetland increased by 2.87,1.10,0.49 and 0.21 percent,respectively,and the one of cultivated land continued to decrease by 4.7 percent.(2)The average value of integrated ecological risk was 0.58,0.61,0.66,0.31 and 0.34 in 2000,2005,2010,2015 and 2018,respectively,and the overall ecological risk of the basin was on the decline.The ecological areas of higher risk were mainly distributed in the upper and lower reaches of basin,while the ones of lower risk were distributed in the middle reaches.(3)The explanatory power of human activity factors such as the interference degree and the spatial distribution of population density and GDP were greater than that of natural factors,among which the explanatory power of human interference factors was the highest(38.00%-83.00%).Human activity factors are the main driving factors for the dynamic change of integrated ecological risk.The results of the study are referenciale value for the sustainable management and development of the social-economic-ecological environment system in Wujiang Basin.