黄河下游植被覆盖度动态变化及其与水沙过程关系

Vegetation Dynamic Variation and Its Relations with Water⁃Sediment Processes in Lower Yellow River

黄河下游滨河植被覆盖度是滩区生态环境重要表征指标之一。基于MODIS-NDVI数据,采用M-K法分析研究了黄河下游植被覆盖度动态变化情况,结合Pearson相关分析、逐步多元回归分析法研究了气温、降水量及河道水沙因素对滨河植被覆盖度的影响情况。结果表明:时间上,2001—2019年黄河下游植被覆盖度无显著变化趋势,各河段年内变化幅度不一;空间上,滨河植被覆盖度沿横向离河距离的变化而变化,其中游荡河段影响范围最宽,过渡河段次之,弯曲河段最窄;相关性及多元回归分析结果表明,相较于降水量,气温及河道水沙过程对黄河下游滨河植被覆盖度的影响较大。

The coverage of riparian vegetation is one of the important environmental indicators in the floodplain of theLower Yellow River.Based on MODIS⁃NDVI,this paper researched on the riparian vegetation dynamics in the Lower Yellow River and its relations with some nat⁃ural factors(temperature,precipitation,hydraulic factors and sediment processes)using the M⁃K analysis,Pearson correlation analysis and stepwise multiple regression analysis.The results show that in terms of time,there is no significant change trend of vegetation coverage in the Lower reaches of the Yellow River in the period of 2001-2019 and the annual variation range of each river section is different.In terms of space,the riparian vegetation coverage changes along the transverse distance from the river,among which the wandering reach have the wi⁃dest influence range,followed by transition reach,and the meandering reach’s influence range is the narrowest.The results of correlation and multiple regression analysis show that compared with rainfall,the influence of temperature and river flow process on riparian vegetation cover⁃age in the Lower Yellow River is greater.