Environmental Monitoring And Analysis Based On Remote Sensing And GIS

Due the geographic essence of most environmental problems, introducing the two most informational geographic techniques, remote sensing and geographic information system (GIS), into the environmental research is compatible with its essence and will improve it both in spatial analysis and spectral analysis. After introducing the principles of remote sensing and GIS as well as their basic applications, remote sensing for quantitative monitoring of inland water quality is presented. By a series of pertinence analysis, a multi-temporal, universal remote sensing information model is successfully established for the Changsha Section of the Xiang River. Then, remote sensing and GIS are employed in the research of land use/cover change. Corresponding Landsat imageries are interpreted accurately. By using transformation matrix and change indexes, the characteristic of this change is analyzed, as well as the change of Bary center. Furthermore, spectral enhancement via the Kauth-Thomas transformation is applied to improve the classification of Landsat ETM image. Classification signers are obtained by a combination of supervised method and unsupervised method, and show good separability in the feature space. Sound result of classification is obtained, and the spectroscopic feature and spatial distribution of classification error is analyzed. Based on the previous research of classification, stratified two-stage sampling is introduced into the accuracy assessment of thematic map. The sampling design employs a nested, hierarchical partition constructed of spatial units of different size, which provides a sound spatial distribution of specimen and reduces the sampling cost. Different inclusion probability is assigned to different specimen, and a probabilistic confusion matrix is established based on this. Producer's accuracy, user's accuracy, and overall accuracy are analyzed as well as Kappa coefficient and their improvement is analyzed. At last, some experience in related environmental planning is summarized, which shows the great potential of remote sensing and GIS in the environmental monitoring and analysis, additionally.