Satellite Surveillance for Disaster Mitigation
V.S. Arya, B.S. Chaudhary, A.Beniwal, T.P. Babu and R.S. Hooda
Haryana State Remote Sensing Application Centre,
Hisar - 125 004, Haryana, India
Abstract
In India floods have become an unfailing annual national event causing rate havoc and extensive losses to agricultural statistics at an early stage is one of the essential requirement for effective management of flood problem and also to make the base-line information for taking preventive measures in future. Haryana witnessed severe floods during September 1995. The present study deals with mapping management of floods in Rohtak district, Haryana (India). Fifty five percent of the total geographical area of the district was inundated by floods covering three hundred villages. Heavy down pour in shorter duration, non maintenance and breaching of drain no8 and presence of localized depressions were the main causes of floods in the district. Desilting and deweeding of drain no.8, proper maintenance of embankments and construction of ring bunds around major settlements were suggested as the management practices for mitigating floods.
Introduction
In India, floods have an unfailing annual national even causing great havoc and extensive losses to agricultural crops, human life and property. The total flood affected area in 1987 was about 11.4 million hectare as compared to only 6 million hectare in 1981 (Rao, 89). Flood mapping through satellite remote sensing has been successfully carried out in India (Rammoorthy 1989, Hooda et. Al. 1995 Chaudhary et. Al. 1996) and abroad (Florezano, 1989 and Brouwer, 1996). Haryana which is one of the most agrarian State in India, has suffered from floods during the year 1995. However, during the last 40 years, efforts are being made by Central and State Governments to reduce the floods damages by taking appropriate measures. For planning the flood control and related works, reliable and timely information about flooded areas, river behavior and configuration prior to floods, during and after the floods is required. Such information is very difficult to acquire through conventional surveys. Advent of satellite remote sensing technology has helped in
solving the problem of mapping, monitoring and management of flood prone areas. Keeping this in view, the present study was carried out to map the extent of floods in Rohtak district, Haryana using remote sensing technology and to suggest management practices for mitigating flood.
Study Area
The study area that included entire Rotak district lies between 28o21' to 29o06'N latitudes and 76o13' to 76o58' E longitudes. It covers a total geographical area of 3580 sq. kms. Rohtak district forms the outer of the bowel shaped topography of the Haryana state and therefore prone to floods despite low rainfalls.
Hot summer, cool winter and merge rainfall are the main climatic characteristics of Rohtak district. The average annual rainfall in the district is 457.6 mm. It generally increases towards north east
About 74% of the annual rainfall is received during the rainfall is received during the monsoon season. On an average there is 24 rainy days in a year in the district.
Data Base and Methodology
The data used are given as under :
-
IRS IB LISS II Diapositive of September 16 and 18, 1995 and LANDSAT TM diapostive bulk scene of September 24, 1995 of the area.
- Survey of Inda topgraphical maps on 1:50,000 scale.
- Other ancillary data.
Base maps were prepared on 1:50,000 scale with the help of survey of India toposheets. Visual Interpretation techniques were employed by taking into consideration various image interpretation elements such as color, tone, texture, size, shape, shadow, pattern and association. The information regarding flood affected areas from film positive had been transferred on to the base maps using PROCOM-2. Doubtful areas were verified during field visits. The area were verified during field visits. The area under each category was calculated using dot-grid method.
Results and Discussion
The flood affected areas were delineated based up on the sharp contrast between water spread and adjacent areas. Following two categories of flood affected areas were identified (Fig. 1).
Figure 1
- Standing water
- Receded Water/Wet Areas
The standing water areas appeared as dark blue to light blue depending upon the depth of water, wheras, the receded water/wet areas appeared as dark grary to light gray in tone. The vusual interpretation of the satellite imageries showed that about 196957.47 hactare area was inundated, which covers 55.01% of the total geographical area of the total geographical area of the district. The area of the district. The area under standing water comes to 60924.85 hectare i.e. 17.02% and receded water/wet area comes to 136032.62 hectare i.e. 37.99 percent of the total geographical area as on
Date of satellite pass.
