近岸水域悬浮物的遥感分析

利用多时相的卫星遥感影像Landsat TM／ETM＋为数据源，对厦门近岸水域悬浮物浓度分布及其变化趋势进行了研究分析。研究发现修正后的归一化水体提取指数（MNDWI）能很好地剔除非水体信息，研究应用该指数法并结合矢量层数据对研究区进行了准确提取。由于红光波段与悬浮物浓度呈现较好的线性相关性，研究将利用该波段数据来反映悬浮物浓度状况。利用建立的浓度等级划分标准对不同时相影像进行浓度等级划分，并采用分级后比较和影像差值法等变化检测技术清晰地反映了不同年份间悬浮物浓度的时空变化。研究结果显示，厦门近岸水域悬浮物污染状况总体较好，但是研究年份间悬浮物浓度均值仍呈升高趋势，升高的区域主要位于九龙江入海口和同安湾。

Remote Sensing of Suspended Sediment in the Coastal Water Surrounding Xiamen Island

Two deffierent Landsat TM/ETM scenes were used in this paper to estimate the condition of the suspended sediment concentration(SSC) in the coastal water surrounding Xiamen island.The images were rectified and corrected to eliminate geometric and atmospheric affects.The water area of the study area was extracted by utilizing the MNDWI(Modified Normalized Difference Water Index),(simultaneity,an island boundary vector layer was created to mask out the part of inland water) and extract interest areas from the images.The TM/ETM band 3 was chosen for study SSC in the water.After using image enhancing and change detect techniques(including post grade comparison and image difference,etc),the changes of SSC from 1996 to 2000 was revealed.The result indicated that the SSC level are well on the whole.But SSC in the water from 1996 to 2000 still increased annually.The rising areas were mainly located in the estuary of Jiulong river and the tong' an gulf.