基于TM影像的典型内陆淡水湿地水体提取研究

水是维系湿地生态系统稳定和健康的决定性因子,利用卫星遥感影像快速、准确地提取湿地水体信息已经成为湿地调查、研究与保护的重要手段。鉴于TM遥感影像具有较高的空间分辨率、波谱分辨率、极为丰富的信息量、较高的定位精度和相对较低的价格，其必然成为近一段时期湿地调查、研究与保护的重要数据源之一。研究基于TM遥感影像，运用多种方法针对典型内陆淡水湿地的水体信息进行了提取实验，通过对实验结果的分析得出：在面积的准确性、提取的准确度以及视觉效果3种指标下，光谱分类法较其它方法效果要好，其次为单波段阈值分析法与植被指数法，较差的是多波段谱间关系法与水体指数法；影响提取效果的主要原因是湿地水体提取不够完全，这是由影像的分辨率及湿地特殊的水文条件所造成的，采用像元分解及多源遥感数据融合技术将成为提高水体提取精度的重要手段。

Inland Limnetic Wetlands Water Body Extraction Using TM Imagery

Water was the crucial factor that kept wetlands stable and health,to fast and accurately extract wetlands water body using remote sensing imagery became an important wetlands investigation,research and protection method.Considering the middle spatial resolution and high spectrum resolution,high positioning accuracy and low price,TM remote sensing imagery would be one of the main data for wetlands investigation,research and protection.The research carried out an experiment of extracting water from inland limnetic wetlands using TM remote sensing imagery based on many arithmetic,and concluded that spectrum classification was the best among the area accuracy index,extraction accuracy index and visual effect index,the following was single band threshold and vegetation index method,however,multi-band relationship and water index method was the worst.The main negative factor that affect extraction result was that wetlands water couldn't be extracted absolutely,which was caused by the resolution of imagery and complex hydrology condition of wetlands.Therefore,pixel unmixing and multi-source remote sensing data fusion would be the important techniques of promoting water extraction accuracy.