基于长时序稠密遥感数据分析黄河流域大中型湖库水域面积动态变化特征

Analysis of Dynamic Changes in Water Area of Large and Medium-sized Lakes and Reservoirs in the Yellow River Basin Based on Long-Term Dense Remote Sensing Data

黄河流域在我国经济社会发展和生态安全中具有重要地位。但从全流域的角度,基于长时序稠密遥感数据对黄河流域大中型湖库开展的研究却较少。本文基于MODIS 8天合成数据,提取了2000—2020年黄河流域大中型湖库长时序的水域信息,分析其时空变化特征,结果表明:从月际变化看,3—5月为水域面积第一个快速增长时期,6—10月为第二个增长时期,在10月达到最大值,10月之后逐渐下降,至次年2月达到最小值;从年际变化看,近20年上、中、下游湖库水域面积均呈现增长趋势,其中上游地区对全流域面积增长的贡献度最大,中游次之;湖库水域空间分布不均衡,上、中、下游近20年湖库水域面积平均占比分别为69.27%、25.02%、5.72%。

The Yellow River Basin holds a significant position in China’s economic and social development as well as ecological security.However,there has been limited research conducted on the large and medium-sized lakes and reservoirs in the Yellow River Basin using long-term dense remote sensing data from a holistic perspective.This paper utilizes MODIS 8-day composite data to extract water area information for the large and medium-sized lakes and reservoirs in the Yellow River Basin from 2000 to 2020.It analyzes the temporal and spatial characteristics of their changes.The results reveal the following trends:concerning monthly variations,the water area experiences its first rapid increase from March to May,followed by a second growth period from June to October,reaching its peak in October and gradually declining thereafter until it reaches its minimum in February of the following year.In terms of yearly variations,over the past two decades,the water areas of lakes and reservoirs in the upper,middle,and lower reaches of the Yellow River Basin have all shown an increasing trend.The upper reaches contribute the most to the overall increase in water area,followed by the middle reaches.The spatial distribution of water areas in lakes and reservoirs is uneven,with the average proportions over the past two decades being 69.27%for the upper reaches,25.02%for the middle reaches,and 5.72%for the lower reaches.