开都河上游高寒湿地退化风险评估

随着自然环境变化和人类活动干扰强度加剧,高寒湿地正在退化甚至消失。以新疆维吾尔自治区开都河上游高寒湿地分布区为研究区,利用遥感影像、地形数据和气象数据等,从生态系统胁迫度和退化度角度出发,采用专家打分、层次分析、综合指数和马尔柯夫模型等方法,选取11个指标,构建了研究区高寒湿地退化风险评价体系,对2000年和2018年研究区高寒湿地退化风险进行了评价。研究结果表明,开都河上游地区平均胁迫度指数由2000年的0.35增大到2018年的0.37,增幅为0.06%;平均退化度指数由2000年的0.21增大到2018年的0.32,增幅为52.4%;研究区平均湿地退化风险指数由2000年的0.28增大到2018年的0.34,增幅为21.43%;湿地退化风险指数略增大区和增大区面积合计2 378.14 km^2,占研究区总面积的64.70%,其主要分布在小尤路都斯盆地和大尤路都斯盆地的东、西部;与2000年相比,2018年,低风险区转变为中风险区和高风险区的面积分别为569.97 km^2和465.99 km^2;中风险区转变为高风险区的面积为878.98 km^2;研究区湿地退化高风险区的面积明显增加;人口数量增加、水源涵养量减少、景观破碎程度增大、栖息地适宜性变差、净初级生产力和平均弹性度减小都反映了研究区高寒湿地的生态环境在向负面方向发展。

Degradation Risk Assessment of Alpine Wetlands in the Upper Reaches of Kaidu River

With the evolution of the natural environment and the disturbance of human activities, the alpine wetlands has been degenerating and even disappeared, which has caused a serious of problems for the ecological environment and socical development. The distribution area of the alpine wetlands in the upper reaches of Kaidu River, Xinjiang was selected as the research area. Using remote sensing images, terrain data and meteorological data, 11 indicators were selected from the perspective of ecosystem stress degree and degradation degree to construct the risk assessment system for degradation of the alpine wetlands in the research area, we evaluated the degradation risk of the alpine wetlands in 2000 and 2018. The results showed that the average stress degree index of the upper reaches of Kaidu River region increased from 0.35 in 2000 to0.37 in 2018, with an increase of 0.06%. The average degradation degree index increased from 0.21 in 2000 to0.32 in 2018, with an increase of 52.4%. The average wetland degradation risk index in the study area increased from 0.28 in 2000 to 0.34 in 2018, with an increase of 21.43%. The area that wetland degradation risk index increased was 2 378.14 km^2, accounting for 64.70% of the total area of the study area, which was mostly located in the east and west parts of the Xiaoyouludusi Basin and the Dayouludusi Basin. Compared with those in 2000, the areas of low-risk area transformed into medium-risk area and high-risk area in 2008 were 569.97 km^2 and 465.99 km^2, respectively. And the area of medium-risk area transformed into high-risk area was 878.98 km^2. Beside, the area of the high-risk wetland degradation increased significantly in 2008. In addition, it was indicated that increased population, decreased water conservation, increased degree of landscape fragmentation, poor habitat suitability, reduced net primary productivity and average elasticity all reflected the ecological environment of the alpine wetlands in the study area on the way to the negative.