一种提取北部湾沿海地区水体信息的动态阈值方法

准确地获取水体分布信息与水体变化规律在流域综合治理等方面具有重要意义。本文基于高分六号(GF-6)影像与Landsat 8影像,选取北部湾海域作为测试研究区,在海洋水体指数(OWI)基础上,针对水体光谱特性,分析了水体像元OWI与归一化植被指数之间的相关性,基于两种指数动态平衡,提出了一个稳定性较高的动态阈值的水体提取方法,并进行了试验验证。试验结果表明,动态阈值方法能够稳定、准确地提取水体信息,避免了人为设定阈值存在的误差,并且本文提出的指数无论是针对国产高分影像还是其他光学影像,都具有较好的普适性,可应用于沿海海岸线的监测等方面。

A method for extracting dynamic threshold value of water body information in Beibu Gulf coastal area

Accurate acquisition of water body distribution information and water body variation patterns is of great importance in the comprehensive management of watersheds. Based on the ocean water index (OWI), the correlation between OWI and the normalized difference vegetation index (NDVI) was analyzed based on the spectral characteristics of the water body. The method is based on the dynamic equilibrium of the two indices, and a dynamic threshold method with high stability is proposed and experimentally validated. The experimental results show that the dynamic threshold method can extract water body information stably and accurately, avoiding the error of artificially set thresholds, and the proposed index has good universality for both domestic high resolution images and the rest of optical images, which can be applied to the monitoring of coastal coastline.