Assessment of the status of surface waterlogging in Sarda Sahayak Command area of Uttar Pradesh, India using IRS-1A, LISS-1 Data
P.N. Shah and A.C. Mathew
Remote Sensing applications centre, U.P.
Sector-G, Jankipuram, Kursi road,
Lucknow-226007, India
Abstract
The Sarda Sahayak Command area lies between the Ghaghra and the Ganga rivers in Uttar Pradesh extending upto their confluence. Since the commissioning of canal system in 1976, the groundwater regiment in the canal command has led to a general rise in groundwater
table. At some places it has resulted in surface waterlogging and increase of areas of salinity. An attempt has, therefore, been made to understand the impact of seepage from the Sarda Sahayak canal system with special reference tot eh land degradation using IRS-1A, Liss-1 satellite data of February 1989. About 200 ground observation points were selected in the field for measurement of standing water above round. These points were accurately located on the 1:50,000 image analysis. Maximum likelihood supervised classification algorithms was used for classifying various categories of aquatic vegetation in the categorized waterlogged areas and in assessing the surrounding landuse features. The surface water depth classification has shown that it is possible to discriminate the different levels of standing water within waterlogged areas viz., (i) water less than 15cm., (ii) water more than 15cm and less than 75cm, and (iii) water more than 75 cm. the computer classified IRS-1A, Liss-1 satellite data after integration of groundtruth has shown that 15.19% of the area has become surface waterlogged and rendered infertile for the winter crops (Rabi).
Introduction
The Sarda Sahayak feeder channel is a major canal system in the state of Uttar Pradesh commissioned in 1976 to supplement water supplies in the lower reaches. The command of the canal system covers 14 districts of central and eastern part of Uttar Pradesh. A feeder channel taking off on the right bank of Sarda barrage has a designed capacity discharge of 650 cumecs at the head and supplies water to Dariyabad, Barabanki, Haidergarh, Sultanpur, Jaunpur, Azamgarh, Pratapgarh, Raebareli, Allahabad, Shahganj and Marihau branches and their distributaries. The seepage along the feeder channel and in their distributaries. The seepage along the feeder channel and in the command has brought in its wake the attendant problems of water logging and increase in soil salinity. These land degradation processes have further adversely affected the efficient utilization of the land resources in the command. The groundwater regimen has also undergone changes and a general rise in the ground water
table has been observed and in certain areas it has risen to the surface during the years of operation of the canal system. The resultant damage to the ecosystem is severe.
IRS-1A, Liss-I data of February, 1989 covering the entire Sarda Sahayak command have been digitally analysed after integrating the real time groundtruth to generate real time information on the status of waterlogging. The maximum likelihood supervised classification algorithms was used for accurate and the quick assessment of surface waterlogging in the canal command area and can be operationally utilized for dynamic assessment of environmental of impact of the large scale canal system.
Objectives
The main objectives of the study were :
- to study land degradation as a result of surface waterlogging and salinity
- to assess the extent of surface waterlogging and discriminate the aquatic vegetation in waterlogged areas of command.
- to develop methodology to identify different levels of standing water above the surface in the water logged lands.
- to delineate level-I landuse pattern in the command.
- to detect changes I the status of waterlogging in space and time.
