Water Management through Remote Sensing
Authors: DEBARATI DATTA1* and SOURAV GHOSH2
1 PhD Research Scholar, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
2 PhD Research Scholar, Indian Agricultural Research Institute, Pusa, New Delhi, Indi
The term Remote Sensing is applied to the study of earth’s features from images taken from space using satellites, or from nearer the earth using aircrafts. The technique of remote sensing has picked up in the past half a decade, largely due to the availability of digital computers, improved communication systems, digital imaging techniques and space technology.
Electro-Magnetic energy obtained from sun is used as a source in it. Transmission of this energy into the atmosphere is caused on the ground as a source through absorption or expansion. Reflection and abandonment of electro-magnetic energy from the ground is important for getting information from the earth. They cause interaction, which transmits energy from the earth to remote sensors.The remote sensors located in satellites, collect different types of information and send it to receiving stations on the earth, which is used after digital image processing.
The following aspects of water resources management can be studied with the help of Geographical Information System and Remote Sensing:
1. Surface Water Inventory and Surveying:
Satellite capacity is important for surface water management because information regarding hydrological regions of large geographical states can be obtained very quickly. Occasional rays of infra-red electromagnetic wavelength are absorbed by water, whereas they are reflected by the earth and vegetation. Hence, this view appears as black in the imagery.
The Above study is helpful in planning the following things:
1. Supply of water for agriculture
2. Supply of drinking water
3. Development of probable sources for recharging of groundwater
Study of different aspects of hydrology can be done easily with the help of Geographical Information System and Remote Sensing technique. Modeling of rain water, study of water balance, flow forecast and estimate etc. are important among them. In modeling of rain water flow first of all, contour map is prepared. After that an elevation map is prepared.This is superimposed on the land utilization map and a soil map is then prepared. Knowledge of rainfall, evaporation, evapotranspiration, infiltration etc. is essential for study of water balance. Hydrological balance is important in certain conditions when hydrological cycle is affected. Hydrological cycle affects climatic changes. Forecast regarding flow of water and its estimate can also be easily done with the help of Geographical Information System and Remote Sensing technique.
3.Watershed Conservation, Planning and Management:
Work plan of watershed management can be prepared with the help of Geographical Information System and Remote Sensing technique. After scanning the toposheet, drainage system maps and contour maps can be prepared through digitization. A digital elevation model can then be prepared after counting from the contour bund map.Water management has become the necessity of the day. Optimum utilization of land and water resources is possible only through this technique.
Watershed management is resorted to with the following objectives:
1. Control over degradation of flow water.
2. Management and use of flowing water for useful purposes.
3. Control on soil erosion and reduction in quantity of silting.
4. Diversion of water towards suitable direction in flood affected areas.
5. Making provision for groundwater recharging wherever possible.
6. Suitable use of land resource.
For meeting the above objectives, Geographical Information System and Remote Sensing technique is used and prioritization of methods is done for watershed development. Land utilization maps are prepared from statistics of remote sensing. Micro watershed area maps are drawn from contour maps and drainage basin maps are prepared from toposheets.
About Author / Additional Info:
PhD Research scholar in Agronomy, Agriculture at GBPUAT, Pantnagar