论文部分内容阅读
依据ENVISAT ASAR数据中后向散射系数的差异对湖北四湖地区的城镇、水域、植被覆盖区进行划分;根据区域种植制度及物候特点,以4月下旬至5月上旬MODIS-NDVI值区别植被覆盖区中的作物植被与非作物植被;并采用基于高分辨率ETM数据的土地分类结果对基于上述规则分类的结果进行验证.结果表明:借助DEM高程数据,可将研究区非作物植被划分为林地与滩地;利用月份NDVI平均值的差异,可将作物划分为中稻、棉花和晚稻,并获得水田和旱地的区分;采用低空间分辨率的MODIS数据获得的土地覆盖分类结果,与采用高分辨率ETM数据分类的结果具有一定程度的相似性,以ETM数据分类结果为标准的总误差率为13.15%;利用上述判别流程进行大尺度土地覆盖分类与制图可以实现对区域土地覆盖变化的快速跟踪.
According to the difference of backscattering coefficient in ENVISAT ASAR data, the area of town, water area and vegetation coverage in the four lakes of Hubei Province is divided. According to the regional planting system and phenological characteristics, the MODIS-NDVI value is used to distinguish vegetation cover from the late April to early May And the crop classification based on the high resolution ETM data was used to verify the results of the classification based on the above rules.The results show that the DEM data can be used to divide the non-crop vegetation in the study area into forest land And paddy fields. Crops can be divided into middle-grade rice, cotton and late rice by using the difference of average monthly NDVI values, and the distinction between paddy fields and dry land can be obtained. The land cover classification results obtained by using MODIS data with low spatial resolution are similar to those by high resolution ETM data classification results have a certain degree of similarity, and the total error rate based on ETM data classification results is 13.15%. Using large-scale land cover classification and cartography based on the discriminant flow can achieve rapid tracking of land cover change in the region.