一种结合坡度信息调节的水体指数  

Extraction of Open Water in Rugged Area with A Novel Slope Adjusted Water Index

作　　者：张强[1,2,3] 吴波 杨艳魁[1,2] ZHANG Qiang;WU Bo;YANG Yankui(National Engineering Research Center of Geo-spatial Information Technology,Fuzhou University,Fuzhou 350116,China;Key Laboratory of Spatial Data Mining&Information Sharing of MOE,Fuzhou University,Fuzhou 350116,China;Jinan Urban Construction Archives,Jinan 250000,China;College of Geography and Environment,Jiangxi Normal University,Nanchang 330022,China)

机构地区：[1]福州大学地理空间信息技术国家地方联合工程研究中心,福州350116 [2]福州大学空间数据挖掘与信息共享教育部重点实验室,福州350116 [3]济南市城建档案馆,济南250000 [4]江西师范大学地理与环境学院,南昌330022

出　　处：《遥感信息》2018年第4期98-107,共10页Remote Sensing Information

基　　金：国家自然科学基金(41571330);福建省自然科学基金(2015J01136)

摘　　要：在分析水体和山区背景地物反射与地形坡度特性的基础上,提出了一种坡度调节水体指数(slope adjusted water index,SAWI)。针对水体与阴影在短波红外的反射率都很低的问题,通过坡度信息对位于不同地形条件下地物的短波红外波段进行不同程度的拉伸,使得水体与山区阴影得到区分。试验利用SAWI提取了OLI(operational land imager)影像位于不同地形条件下的水体信息。结果表明,在山区起伏区域,SAWI比改进的归一化差异水体指数(modified NDWI,MNDWI)能够更有效地抑制阴影效应;在平坦区域,SAWI比归一化差异水体指数(normalized difference water index,NDWI),具有更高的水体信息敏感性,从而有利于细小水体的提取。这表明在山区的复杂地形条件下,SAWI是一种可选的水体指数提取方法。According to the analysis of the reflectance difference between water body and other materials,we proposed a novel slope adjusted water index(SAWI)to refine modified normalized difference water index(MNDWI)in the case of rugged areas,where water body and terrain shadow are possibly confused.Due to the low reflectance of water and shadow in short and medium wave infrared bands,a varying degree of strength of the band for each pixel was imposed to enlarge the difference between shadow and water in order to discriminate the water body from shadows.The OLI(operational land imager)image was used to validate the effectiveness of the proposed method with four different typical terrain regions,and the results show that our method can not only preserves the advantages of MNDWI,but also gain the ability to relief the effect of terrain in water body extraction.Comparisons with normalized difference water index(NDWI)and MNDWI were also implemented,and experimental result demonstrated that SAWI generally outperforms others for all the cases in terms of our measurements.The SAWI is thus an alternative option for water body extraction from remote sensing image in practice.

关 键 词：水体信息 阴影 光谱 坡度 水体指数 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]