Zhang Jin Xi, Li Hong Ying, Cao Er Jia, Gong Jie
Ministry of Education Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
Ying Yong Sheng Tai Xue Bao. 2018 Sep;29(9):2897-2906. doi: 10.13287/j.1001-9332.201809.008.
The study of ecological vulnerability is of great significance to regional ecological environment protection and sustainable development. Bailongjiang Watershed (BLJW) of Gansu Pro-vince is a vital area for water conservation and environmental fragile in the upper Yangtze River. Therefore, it is necessary to understand the ecological vulnerability of BLJW for local sustainable development. Based on the sensitivity-recovery-pressure (SRP) model, landscape pattern index and the typical ecosystem type, we constructed the assessment system of ecological vulnerability by taking township as the spatial unit to analyze the spatiotemporal pattern of ecological vulnerability from the township, county, watershed scales in BLJW of Gansu Province in 2002 and 2014 via the auxi-liary regression, entropy weight, synthetic index, and spatial autocorrelation methods. The results showed that from the view of the township scale, the townships of severe or extreme vulnerability were concentrated in the northwestern Tanchang and most of Wudu in 2002 and 2014. The ecological vulnerability in the watershed had changed from moderate vulnerability to light vulnerability at township scale. At the county scale, the change of ecological vulnerability in Zhouqu was relatively stable, while that of Wudu, Wenxian, Tanchang and Diebu were relatively violent from 2002 to 2014. The ecological vulnerability of Wudu, Wenxian and Diebu improved to a certain extent, while that of Tanchang was deteriorating gradually. On watershed scale, the average value of ecological vulnerability index in the watershed were 0.2976 and 0.2904 in 2002 and 2014, respectively, showing a small downward trend, indicating that the ecological vulnerability in the watershed decreased in the past 12 years. The coefficients of variation were 0.3905 and 0.4358, respectively, with an increasing trend, suggesting that the spatial pattern of ecological vulnerability in the watershed developed in an unbalanced way. In 2002, the Moran I of ecological vulnerability index in the watershed was 0.5460, implying that the ecological vulnerability in the watershed was spatially agglomerated. Specifically, the areas of high-high were mainly distributed in the northern and central Wudu, and northwestern Tanchang. In 2014, the Moran I of ecological vulnerability index in the watershed increased to 0.5635, which indicated that the spatial agglomeration was more significant, and the areas of high-high were concentrated in central Wudu and northwestern Tanchang.
生态脆弱性研究对于区域生态环境保护和可持续发展具有重要意义。甘肃省白龙江流域是长江上游重要的水源涵养区和生态环境脆弱区。因此，了解白龙江流域的生态脆弱性对于当地可持续发展很有必要。基于敏感性 - 恢复力 - 压力（SRP）模型、景观格局指数和典型生态系统类型，我们构建了以乡镇为空间单元的生态脆弱性评估体系，通过辅助回归、熵权法、综合指数法和空间自相关方法，从乡镇、县、流域尺度分析了2002年和2014年甘肃省白龙江流域生态脆弱性的时空格局。结果表明，从乡镇尺度来看，2002年和2014年，重度或极重度脆弱性的乡镇集中在宕昌西北部和武都大部分地区。流域内乡镇尺度的生态脆弱性已从中度脆弱转变为轻度脆弱。在县级尺度上，2002 - 2014年舟曲生态脆弱性变化相对稳定，而武都、文县、宕昌和迭部变化较为剧烈。武都、文县和迭部的生态脆弱性有一定程度改善，而宕昌则逐渐恶化。在流域尺度上，2002年和2014年流域生态脆弱性指数平均值分别为0.2976和0.2904，呈小幅下降趋势，表明过去12年流域生态脆弱性降低。变异系数分别为0.3905和0.4358，呈上升趋势，说明流域生态脆弱性空间格局发展不均衡。2002年流域生态脆弱性指数的Moran I为0.5460，表明流域生态脆弱性在空间上呈集聚分布。具体而言，高高集聚区主要分布在武都北部和中部以及宕昌西北部。2014年，流域生态脆弱性指数的Moran I升至0.5635，表明空间集聚更为显著，高高集聚区集中在武都中部和宕昌西北部。
