Executive Sumary

Viewing a watershed as a system of different structures involving hierarchically organized landscape, it is possible to delineate these watershed where the soil / water erosion are most manifested. Barak watershed encompasses an area of approximately 145000 sq km is located in Manipur and adjoining Assam and Mozoram. The Tipaimukh Dam project (15000MW) is planned at the junction of Mizoram, Manipur and Assam. An area of about 390 sq. km. Is proposed for the construction of reservoir with a dam height of 162 m. Therefore, it is necessary to assess the soil / water erosion characteristics in the watershed. In order to identify the watersheds producing high silt and generating high runoff for soil conservation measures on priority basis, the priority delineation using remote sensing technique is cost and time affective. The identification and codification of subwatersheds is based on National watershed Atlas of India. Assessing the large geographical area of watershed, the remote sensing techniques are used to generate the resource information in the watershed. The computation of composite Runoff Potential units in subwatershed of Barak Basin is based on the application of GIS.

There are 20 sub watersheds in the Barak Basin. Based on resource information, all the watershed are delineated on priority for soil / water conservation measures. The three subwatersheds are identified as high to very high priority, eleven subwatershed are medium erosion rates and remaining five subwatersheds falls in low priority rating for soil conservation.

Further investigations and analysis will be carried out on GIS formats to provide the site specific locations for conservation measures in subwatersheds. The run off potential index is based on secondary data from Brahamputra Board, Guwahati. The data on runoff is collected for a period of 20-25 years in the watersheds. Priority delineation analysis will be continued for all the wubwatersheds for soil/water conservation measures.

Title of the Project : Evaluation of Natural Resources and Environment of the Kolli Hills, Tamil Nadu using Remote Sensing and GIS

Executive Summary

An R&D project entitled "Evaluation of Natural Resources and Environment of the Kolli Hiss, Tamil Nadu using Remote sensing and GIS" was proposed with the aims of taking stock of the resources, analyzing their status, potential and preparing an area specific treatment package for sustainable utilization, conservation and development.

Kolli Hills, the study area is a hilly terrain covering an area of about 503 sq km situated above river Cauvery having diverse vegetation and land use. The annual mean rainfall is 1318 mm. Kolli hills receives maximum rainfall in Southwest monsoon (719 mm). The mean maximum and mean minimum temperature is 37^o and 18^o C respectively.

Forest in kolli hills occupies comparatively more area (271 sq km) than the non-forest area (232 sq km). Evergreen, Semi-evergreen, Deciduous, Thorn and Scrub are the major forest types present. Major portion of the forest area is occupied by the Thorn and Scrub forests (203 km). In the non-forest area most of the area comes under wasteland (50%). Single crop and double crop cultivation is practiced. Tapiaco is the major cash crop. There is no industry in Kolli hills.

Total population of Kolli hills according to 1991 census is 33,888. Among them 95% belong to tribals. The literacy rate is very poor (27%). The economic status of the population is also not satisfactory. They have very poor awareness on environment and family planning. The economy of the people mainly depends on agriculture and livestock rearing.

Primary and secondary data collected on various resources from field and various Government agencies and departments are utilized to generate spatial and non-spatial data.

Resource status, potential and changes through time is analyzed with database prepared. Changes occurred in land use / land cover and in forest is also analyzed. The results are certainly alarming and warrant serious efforts to conserve the existing resources and recover the lost.

Finally, conservation and developmental packages for sustainable utilization and management on various resources have been given for the entire area. The developmental packages are pepared with data derived from 50,000 scale. Therefore, for micro level implementation, it is suggested to go for further detailed mapping on large scale data.

done.