一种遥感影像快速计算水面率的方法

为了有效去除阴影噪声对遥感影像水体提取的干扰，快速准确计算大区域范围内的水面率，本文提出基于GF6（高分六号卫星）影像，利用UWI（Urban Water Index，城市水体指数）并结合FROM-GLC10（Finer Resolution Observa-tion and Monitoring of Global Land Cover 10，全球陆地覆盖精细化观测与监测10）数据，通过求交计算和小碎斑删除实现水体提取结果的精细化，有效消除了阴影等噪声对水体提取的干扰，实现水面率的快速计算。本文选择中山市作为试验区，试验区域范围广、地物背景复杂，综合对比本文算法、NDWI（Normalized Water Index，归一化水体指数）算法和TSUWI（Two-Sted Urban Water Index，城市二类水体指数）算法，从定性与定量角度分析，结果表明：本文算法提取的水体连续完整、漏提和误提较少，可有效去除阴影、建筑、道路等噪声干扰，在总体精度、Kappa系数、错分误差、漏分误差等指标均取得了较好结果。利用UWI与FROM-GLC10数据相结合计算水面率具有可行性，为工程化、大面积、快速计算水面率提供了一种新的思路。

A fast method for calculating water surface ratio in remote sensing images

In order to remove the influence of shadow noise on water extraction from remote sensing images effectively, and calculate the water surface rate in a large area quickly and accurately, this paper proposes a method which uses the UWI(Urban Water Index) index and FROM-GLC10(Finer Resolution Observation and Monitoring of Global Land Cover 10) data based on GF6 image to achieve the refinement of water body extraction results through intersection calculation and small speckle deletion, eliminate the interference of shadow noise on water body extraction effectively, and achieve the rapid calculation of water surface ratio. Zhongshan City is selected as the test area in this paper which is large and the ground features are complex. By comparing the algorithm in this paper, NDWI(Normalized Water Index) algorithm and TSUWI(Two-Sted Urban Water Index) algorithm, the qualitative and quantitative analysis shows that the water body extracted by the algorithm in this paper is continuous and complete, with fewer omissions and errors, which can remove noise interference such as shadows effectively, buildings and roads, and the bestter results have been achieved in the overall accuracy, Kappa coefficient, wrong score error, missing error and other indicators. It is concluded that the combination of UWI index and FROM-GLC10 data is feasible to calculate water surface ratio, which provides a new idea for engineering and large-area calculation of water surface ratio quickly.