长江上游典型石漠化地区生态环境质量评价

  目的  长江上游石漠化地区影响着整个长江流域的生态安全，在国家大力推行石漠化综合防治下，石漠化形势有明显缓解，但目前缺乏石漠化地区的生态环境质量评价方法，无法实时、定量地进行生态评价。  方法  以长江上游典型石漠化地区云南省会泽县2002、2010、2018年Landsat 5、Landsat 7、Landsat 8卫星影像数据为基础，划分研究区石漠化等级，利用遥感生态指数(RSEI)法对研究区生态环境质量进行定量评价与分析。  结果  ① 2002—2018年，会泽县石漠化状况整体明显改善，石漠化面积减少583.33 km2。②石漠化与生态环境质量呈显著正相关(r2 为0.688~0.873)，表明RSEI法评价石漠化地区生态环境质量效果较好。③ 2002、2010、2018年研究区遥感生态指数均值分别为0.458、0.490、0.488，生态环境质量整体表现为中等水平，16 a间生态环境质量优化面积占全县面积的27.42%，生态变差的地区面积占15.09%。④干度指标对遥感生态指数的贡献度不断增加，第一主成分载荷值由?0.029变为?0.622，是制约会泽县生态环境质量优化的重要因素。  结论  2002—2018年，会泽县石漠化状况得到明显改善，生态环境质量呈中等水平，干度是制约生态环境质量优化的重要因素。今后应着重石漠化严重地区的保护。表8参28

Evaluation of eco-environmental quality in typical rocky desertification areas in the upper reaches of the Yangtze River

  Objective  The rocky desertification area in the upper reaches of the Yangtze River affects the ecological security of the whole basin. Under the comprehensive control of rocky desertification vigorously implemented by the state, the situation of rocky desertification has been significantly alleviated. But at present, there’s no evaluation method for eco-environmental quality in rocky desertification areas. The objective of this study is to carry out the real-time and quantitative evaluation of eco-environmental quality in rocky desertification areas.   Method  Based on Landsat 5, Landsat 7, and Landsat 8 satellite image data of Huize County, Yunnan Province in 2002, 2010, and 2018, the rocky desertification grades of the study area were divided, and the remote sensing ecological index (RSEI) was used to quantitatively evaluate and analyze the eco-environmental quality of the study area.   Result  (1) From 2002 to 2018, the overall rocky desertification situation in Huize County was significantly improved, and the rocky desertification area decreased by 583.33 km2. (2) There was a significant positive correlation between rocky desertification and eco-environmental quality (r2＝0.688?0.873), indicating that RSEI was effective in evaluating eco-environmental quality in rocky desertification areas. (3) In 2002, 2010, and 2018, the average RSEI value in the study area was 0.458, 0.490, and 0.488 respectively, and the overall eco-environmental quality was at a medium level. The area of eco-environmental quality optimization in 16 years accounted for 27.42% of the total county area, and the area of ecological deterioration accounted for 15.09%. (4) The contribution of dryness index to RSEI was increasing, and the first principal component load value changed from ?0.029 to ?0.622, which was an important factor restricting the optimization of eco-environmental quality of Huize County.   Conclusion  From 2002 to 2018, the rocky desertification situation in Huize County was significantly improved, and the eco-environmental quality was at a medium level. The dryness index was an important factor restricting the optimization of eco-environmental quality. The protection of rocky desertification areas should be emphasized in the future. Ch, 8 tab. 28 ref.]