Applications of Satellite Remote Sensing

Abstract

Integration of Satellite Remote Sensing (SRS) and Geographic Information Systems (GIS) is a useful tool for monitoring natural resources. This project deals with the monitoring of siltation effects, forest change detection and environmental impact assessments in the precincts of Mangla Darn after increasing the proposed height of darn by using the Satellite Remote Sensing and GIS techniques. A large amount of sediments have deposited in the darn due to which its storage capacity is decreasing gradually, hence an aspect is under consideration that, is it feasible to increase the height of Mangla darn? to enhance the storage capacity of reservoir. Proposed increase in height of dam is 40 feet. Digital image data of SPOT satellite system and Landsat TM with 20m and 30m spatial resolution respectively, has used for this purpose. The data were geo-rectified using Survey of Pakistan (SoP) reference maps. From the rectified and processed satellite image different objects e.g. Reservoir boundary, Forests, Rivers, Drainage (includes small water tributaries, streams and Nallahs), Residential Area and road network have been identified, marked and digitized. Digital Elevation Model (DEM) of Mangla Reservoir area was generated from contour lines, using GIS techniques. From this DEM the Digital Terrain Model (DTM) and 3D grid of Mangla darn's reservoir area was generated for better understanding of the terrain. The interfacing of GIS, DEM and SRS provided a new and exciting capability to analyze the dynamics of land-use change and to assess changes in residential areas and vegetation in the landscape after raising the Dam's height. After analysis it is concluded that some of residential areas, different parts of the forests and reservoir surrounding land will go underwater. This increase in height of dam will affect about 40,000 people. In spite of all these, this will increase the storage capacity of Mangla reservoir up to 3.1 million acres feet and 18% more electricity will be also generated.