针对华北地区地下水河湖生态补水成效的卫星遥感动态监测

Satellite remote sensing dynamic monitoring of ecological water replenishment effect for groundwater in North China

摘要:

为评估华北地区地下水超采治理河湖生态补水成效，基于现有国产卫星遥感影像覆盖能力，收集 2020 年华北地区 22 条(个)河湖流域卫星遥感动态监测影像数据，以相关水利基础数据为依据，构建一套完整的针对华北地区地下水河湖生态补水成效的水体遥感监测方案，将影像进行正射、融合、裁剪等预处理后，运用水体指数和深度学习 2 种方法对预处理后的遥感影像进行解译分析，提取河湖流域水面面积和有水河段长度，并结合河湖生态补水量进行验证，分析年内变化规律。监测结果表明：2020 年 7—12 月期间华北地区补水河湖水面面积和有水河段长度减少趋势减缓，并出现增加趋势。通过生态补水有利于缓解超采区水面面积减少趋势，验证通过统筹多种水源、调节时空布局，开展河湖回补地下水的方案是确有成效的。

Abstract:

In order to evaluate the effect of river and lake ecological water replenishment for groundwater overexploitation in North China, the satellite remote sensing image data of 22 river and lake basins in North China during 2020 are collected based on the coverage capability of existing domestic satellite remote sensing imagery. A complete framework of remote sensing monitoring on the effect is set up based on relevant water resources data. After preprocessing steps of orthophoto, fusion, and clipping, water body index and deep learning methods are applied to interpret and analyze the pre-processed images. Water surface area and river length are extracted. Verification is then carried out by comparing with the amount of ecological water replenishment of rivers and lakes, and annual variation is analyzed. The monitoring results show that from July to December 2020, the decreasing trend of water surface area and channel length of rivers and lakes in North China slows down Instead, the results show an increasing trend. Ecological water replenishment can help alleviate the decreasing trend of water surface area in groundwater overexploited areas, and it is verified that the scheme of groundwater recharge by rivers and lakes is indeed effective by multiple use of water resources and optimizing the spatial and temporal distributions.