Abstract

Extremely erratic rainfall, unevenly distributed and very heavy precipitation in short time resulting in flash floods and inundation in India became a usual phenomena in recent years. At every event, a huge quantity of water is being wasted into the sea as run-off quite frequently due to inadequate harvesting structures. This huge run-off / surplus water can be harvested through the proposed linking of river basins envisaged by National Water Development Agency (NWDA). Out of the total mega projects, the NWDA suggested three link canals from Godvari to Krishna basin, to harvest the surplus water as well as to transfer flood water from Godavari. The Godavari (Inchampalli) - Krishna (Nagarjunasagar) link canal and its possible impact on the socio-economic and infrastructural forms the present study. The link canal of length 299 km (including a tunnel of 9.150 km) is proposed in the upper reaches connecting Godavari and Krishna basins succeeded by two other links towards their downstream. It takes off from the foreshore of the Inchampalli reservoir and joins the existing Nagarjunasagar via Musi reservoir. IRS-1D, LISS-III data is analysed for morphological, geological and land use/land cover information. Geology, geomorphology and soil base maps were obtained and updated with remote sensing data and their aerial distribution in the study area was discussed. The study includes 10 km buffer area on either side of the alignment and the proposed canal command area (5157.48 Sq km) spread in Warangal and Nalgonda districts. The canal command area is occupied by dry land and wasteland classes. Pediplain weathered is the main landform that occupied major part of the study area. The study area in Warangal district is mostly occupied by unclassified crystalline rocks of Archean age. Fine to medium grained, granite gneisses and migmatities of older metamorphics from chainage 102 km to the end point of the canal. Deep loamy soil, deep clayey soil, deep clayey calcareous soil and gravelly clay soils are dominant in the canal study area. Clayey and loamy soils are suitable for wet / dry crops and gravely calcareous for plantations and dry crops. The study revealed that 23 villages are to be rehabilitated while executing the canal and about 816 villages would benefit from it by way of drinking water / groundwater in addition to crop requirements.

Key words: Link canal, donor basin, command area, geomorphology.