陕西省黄土高原地表水体遥感监测与时空演变特征分析

Remote Sensing Monitoring and Analysis of Spatiotemporal Evolution Characteristics of Surface Water Bodies in the Loess Plateau of Shaanxi Province

受气候变化与人类活动共同影响,黄土高原地表水文过程和水循环演变规律发生显著改变。为探究21世纪以来陕西省黄土高原地表水体的变化特征及主要驱动因子,在GEE(Google Earth Engine)遥感云计算平台上,通过水体提取模型实现了从Landsat系列遥感影像中提取2000—2018年陕西省黄土高原地表水体分布信息,分析了地表水体的时空分布特征,利用累积量斜率变化分析法识别了自然和人类活动因素对研究区地表水体面积变化的影响。结果表明:(1)构建的水体提取模型能够有效实现对研究区地表水体信息的提取,提取精度达95.30%。(2)2000—2018年,研究区多年平均地表水体总面积为684.07 km^(2),且呈逐年增加的趋势;空间上,地表水体主要分布在榆林市(271.06 km^(2))和渭南市(203.42 km^(2)),该两市的水体面积占研究区总水体面积的69.3%。(3)人类活动是陕西省黄土高原地表水体面积的主要影响因素。自然因素对地表水体面积增加的贡献率为26.8%,人类活动因素的贡献率为73.2%。该研究结果可为黄河流域生态保护和区域水资源可持续利用提供科学依据。

Affected by climate change and human activities, the surface hydrological process and water cycle evolution law of the Loess Plateau have changed significantly. In order to explore the change characteristics and main driving factors of surface water bodies on the Loess Plateau in Shaanxi Province since the 21st century, this study used the GEE(Google Earth Engine) remote sensing cloud computing platform. Using the water body extraction model, the distribution information of surface water bodies on the Loess Plateau of Shaanxi Province from 2000 to 2018 was extracted from the Landsat series of remote sensing images. The spatial and temporal distribution characteristics of surface water bodies were analyzed, and the influence of natural and human activities on the changes of surface water bodies in the study area was identified with the cumulative slope change analysis method. The results are as follows. Firstly, the constructed water body extraction model can effectively extract the surface water body information in the study area, with an extraction accuracy of 95.30%. Secondly, from 2000 to 2018, the total area of surface water in the study area was 684.07 km^(2), and it showed an increasing trend year by year. Spatially, surface water bodies are mainly distributed in Yulin City(271.06 km^(2)) and Weinan City(203.42 km^(2)). The water area of the two cities accounts for 69.3% of the total water area of the study area. Thirdly, human activities are the main factor affecting the surface water area of the Loess Plateau in Shaanxi Province. The contribution rate of natural factors to the increase of surface water area was 26.8%, and the contribution rate of human activities was 73.2%. The results of this study can provide a scientific basis for the ecological protection of the Yellow River Basin and the sustainable utilization of regional water resources.