Spatial and Temporal Analyses :

Sustainable management of natural resources depends on optimal planning based on spatial and temporal data. In this regard, GIS aids as a dynamic and versatile technology capable of providing information for efficient planning and implementation. The unique feature of GIS is its ability as decision support system and provides answers to the queries through rational and systematic analysis of the situation. This aids planners to take quick decision. 

For example, in order to understand the topographic undulation a DEM is generated with the help of GIS. It consists of terrain elevations for ground positions at regularly spaced horizontal intervals. DEM data are arrays of regularly spaced elevation values referenced horizontally to a geographic coordinate system. The grid cells are spaced at regular intervals along south to north profiles that are ordered from west to east. A DEM is a set of points defined in a three–dimensional Cartesian space (x, y, and z) that approximates a real surface. X and Y-axis may be expressed as geographic co-ordinates (i.e. longitude and latitude), whereas Z-axis usually represents the altitude above sea level. The low elevation areas are identified by creating the DEM with the contour data, which helps the decision makers in selecting the sites for setting the rain water harvesting structure.

The repetitive synoptic coverage provided by the space borne sensors (which operates on various bands of electro magnetic spectrum) has been widely used for mapping and monitoring areal extent of natural resources including surface water bodies / reservoirs. This is useful for reliable estimation of storage capacity of the reservoirs and its changes over the years. Ground water surveys through satellite remote sensing have been found to narrow down considerably the areas for detailed ground water exploration.