Water Resources Studies by Remote Sensing Techniques in Bangladesh
1. Introduction
Water is life. But in Bangladesh it is both life and death The country has a large network of rivers, dominated by the Ganges-Brahmaputra-Meghna (GBM), channels and depressions such as beels, haors, boars and ponds. The GBM originates in the number of rivers, channels and stream in Bangladesh is about 230 with a total length of about 24,000 km which occupy a riverine area of about 9000 sq km. The country comprises the eastern portion of the Ganges delta which is characterized by flat terrain interlaced with an intricate system of rivers and tidal channels which carry downstreem an enormus amount of sediment laden water to the Bay of Bengal which is to the south of the country. The Bay acts as both the source and sink of water. During the southwest monsoon period, the country has excess water leading to catastrophic ravages like flood. The floods of 1984, 1987 and 1988 are the living examples. On the other hand, during the winter the country faces the acute shortage of water leading to drought like situations. Such opposing situations call for proper management of water resources of the country minimizing the effects of both the extremes (flood and drought) and maximizing the uses of the water resources in the country and regular Monitoring of water conditions both inside and outside the country. Towards this, the application of remote sensing has great potential.
SPARRSO operates an Advanced Meteorological satellites (NOAA, GSM) and from a few Data Collection Platforms (DCPs) located in different parts of the country. The installation of SPOT/Landsat Ground Station with the complete facility for real time reception, archiving, preprocessing and analysing of data from U.S. Landsat and French SPOT resource satellites is yet to be complete. Digital image analysis systems and visual photo interpretation equipment are available to support the application-oriented resource management
and environmental studies, SPARRSO has highly trained resource scientists, computer engineers and other technical personnel. The research activities of SPARRSO are carried out in different fields for solving the practical resource inventory and environmental problems confronting Bangladesh. SPARRSO provides its research: results and remote sensing data/information to the user agencies in the country. The future programmes of SPARRSO include the strengthening of its technical facilities, creating a resource data bank including Geographic Information System at national level, training of manower and development of aerial photographic capability. SPARRSO also envisages to cooperate with the countries in the region and supports international collaboration in space research and remote sensing activities.
Regarding water resource studies, continued use of satellite imagery and aerial photographs is being made for studying surface water distribution, river course monitoring, seasonal variations of water levels, dry season conditions of water pools, upstream conditions of water including those outside the country, discharge conditions in the estuaries, turbnidity levels in waters, water temperature both within the rivers and in the Bay of Bangal. The future studies are likely to include snow melting in the Himalayas, quantitative assessment of perceptible water in clouds, flood area mapping development of GIS-etc. The remote sensing technique has been found quite useful in water resources studies.
