基于TM图像的潮滩表层沉积物含水量推算模型研究——以江苏辐射沙洲区为例

Study on Model of Surface Sediment Humidity on Tidal Flat Based on Remote Sensing Image of TM——A Case Study of Radial Sands Banks in Jiangsu Province,China

潮滩表层沉积物含水量是反映潮滩与潮水周期性作用并指示潮滩高程的重要指标,了解潮滩表层沉积物含水量是开发利用潮滩资源的重要工作之一。以江苏辐射沙洲为例,在对应于2000年4月的TM遥感图像成像时潮位特征的潮汐周期时,测量了两条断面的表层沉积物含水量,然后通过对辐射沙洲TM遥感图像的多种处理及其比较,找出了TM图像与潮滩表层沉积物含水量的相关系数绝对值最高的数字图像处理方法,然后再进行傅立叶变换等处理,并推算出可决系数较高的表层沉积物含水量推算模型。

Surface sediment humidity of the tidal flat reflects the periodicity action of the tide, and it is connected closely with the elevation of the tidal flat. The remote sensing image of TM can show the surface sediment humidity fairly, so the elevation of the tidal fiat can be deduced by the remote sensing image of TM, and it is very important to know the elevation of the tidal fiat in studying the sands movement and using the tidal fiat resources which can not be measured easily by traditional method because of the poor topographical environment. In this study, the main purpose is to find the relationship between the surface sediment humidity of the tidal flat and the data of the remote sensing image of TM with the case of the Radial Sands Banks in Jiangsu Province, China. The two sections were selected, which can represent the Radial Sands Banks nearly, one is near Xiaoyangkou, the other is on Tiaozini sands, and the surface sediment samplings of the two sections were collected when the tidal period were equivalent to the moment of the TM remote sensing image taken, and the sediment humidity were measured. Then the data in the remote sensing image of TM corresponding to the surface sediment sampling point were collected, and the transforming method to the remote sensing image were carried out, and the relativity coefficients were calculated between the humidity of the surface sediment samplings and the the light value of the remote sensing image of TM after the transforming. The results of correlation coefficients were compared with each other, and the highest correlation coefficient was selected, which was the first component after the principal component analysis of the 2, 3 and 4 wave band. After that, Fourier transform, filter the waves and the contrary Fourier transform was taken to the first component after the principal component analysis, the result show that the correlation coefficients between the surface sediment humidity and the image data is high. At last, surface sediment humidity by the remote sensing image of TM was calculated, which has high coefficient of determination, and the result can be used easily for calculating surface sediment humidity of the radial sands banks.