基于Landsat TM影像的圩田结构信息提取与分析--以皖东南圩田区为例

皖东南圩田是中国主要圩田区之一，圩田结构特征主要反映在圩田水网以及圩田堤坝的组合上，对狭窄沟渠及水体与堤坝形成的混合像元的结构信息提取是圩田结构信息提取成功的关键。基于陆地卫星Landsat TM数据，采用了谱间关系法与阈值法两种方法进行圩田结构信息提取实验，实验表明：谱间关系法可以精确的提取水体信息，由于水体的混合像元不易与其它地物区分，所以无法合理的处理混合像元；阈值法中发现在第5波段，水体阈值的一定离散范围内的混合像元主要表现为圩田水网与圩田堤坝的组合，但易多提取居民地信息。通过对闲值法提取信息的二值图像与居民地信息二值图像进行布尔运算来剔除冗余信息，成功提取了圩田结构信息，探讨了圩田结构的4种类型并分析了它们的功能与形成背景。

Extracting and Analyzing of Weitian(Artificial Field) Structure's Information Based on Landsat TM Data--Weitian of Southeast of AnHui Province for Example

The characters and structures of Weitian(artificial field) has be reflected by its water nets and dyke,extracting the information of tiny canals and pixel mixture composed by water and dyke is a key.Based on Landsat TM remote sensing data,two methods,relationship between bands and threshold values,were used in experimentation of extracting structure of those artificial field.The result was compared on the interpreting by eyes and experience.Relationship between bands,which had been widely used in early single band image for identifying water,but this method didn't extract the pixel mixture which composed by water and dyke.Threshold values,we find within the discrete range of water digital number value the pixel mixture is mostly composed by water,right threshold value is a key to extracting the structures of those artificial field,this method would extracting unwanted residential area information,extracting residential area information binary image.Used Boolean operation between mainly information binary image and unwanted information(residential area information) binary image.Finally,successfully gain the characters and structures information of Weitian(artificial field).The field(Weitian) is divided into four categories: tessellation pattern,polygon pattern,feather water net pattern and rectangular pattern.On the angle of comprehensive influences of natural humanity factors,the paper analyzes the functions of each pattern,and acquires the following four conclusions: a tessellation pattern has a comprehensive function of defending,irrigating and transporting;a polygon pattern has a function of combining and expanding;a feather water net pattern has a good function of buffer protection for the flood,and a rectangular pattern has a function of convenience for the intensive mechanization of modern time.