河道流量对疏勒河中下游河岸带植被变化的影响评价

Impact of river flow on vegetation change in the riparian zone of the middle and lower reaches of Shule River

应用多源遥感数据与遥感水文站技术,结合野外大范围水文和植被调查,分析了2015年和2020年疏勒河因生态输水而导致河道流量变化的河岸带植被响应,定量评价了疏勒河流量变化对中下游植被恢复和生长的影响。结果表明:1)主成分分析(PCA)显示,在植物指数、径流要素、地形和人为干扰度等10个指标中,流量是疏勒河河岸带植被生态变化的主要影响因素。2)河岸带植被按流量大小与离岸边距离呈现出2个维度的梯度特征。随着流量减小,河岸带植物种类稳步减少了64.00%,植物数量与多样性分别下降了85.69%与69.29%;随着离岸边距离不断增加,植物数量与多样性则分别下降了68.06%与60.06%。3)建立基于NDVI与VFC的二元线性回归模型,对比2015年与2020年的植被生态恢复效应,该区域植物种类、数量和多样性分别增大了33.42%、95.51%与52.71%。

Using multi-source remote sensing and remote sensing hydrological station technology, combined with large-scale hydrological and vegetation field investigation, this study analyzed the riparian vegetation changes after river flow change of Shule River in 2015 and 2020, and quantitatively evaluated the impact of river flow change on the vegetation restoration and growth in middle and lower reaches. The results of PCA shows that for the 10 indexes, such as plant index, runoff elements, topography and human disturbance, the river flow is the main factor that influences the vegetation ecological change in the riparian zone of Shule River. The vegetation along the riparian presents 2 dimensions gradient characteristics according to flow and offshore distance. With the decrease of river flow, the vegetation species in riparian zone decreases steadily by 64.00%, and the number and diversity of plants decrease by 85.69% and 69.29%, respectively. The number and diversity of plants decrease by 68.06% and 60.06%, respectively, with the increasing of offshore distance. A binary linear regression model based on NDVI and VFC was established to compare the vegetation ecological restoration effects between 2015 and 2020. Result shows the vegetation types, quantities and diversity in this area increase by 33.42%, 95.51% and 52.71%, respectively.