Map India 2000 - Poster :Integration Of GPS And GIS Data For Preparing Action Plan For The KG4 Sillahalla Water Shed In The Nilgiris District

Abstract
The Eco-system of Nilgiris has been greatly impaired due to denudation of forest, indiscriminate grazing and unscientific landuse practices. The Government of Tamil Nadu is taking action of Water Shed basis for maintaining the ecological balance through eco-restoration, eco-development and eco-preservation. The entire Nilgiris district has been divided into seventy five water sheds and based on the intensity of degradation ten priority water sheds have been identified. Action plans for Land resources development for KG4 Sillahalla micro water shed which is one of the ten priority water sheds has been prepared in a GIS environment.Aerial Photos taken during 1996 on 1:8000 scale were used for preparing large scale maps. The GPS was used for establishing Ground Control and Orthophotos on 1:5000 scale and Contour maps with 5m contour interval were generated.The Orthophotos were used for generating thematic maps such as landuse, soil, drainage etc., and these maps were digitized and stored in different layers. GIS package has been used for the preparation of action plan for the land resources development and management in the KG4 Sillahalla waer shed.Thus GPS and GIS have been found to be very effective and economical in the preparation of action plans for the water sheds in Nilgiris district.

Introduction
Nilgiris is one of the important Hilly areas in south India and lying in the junction of Eastern Westernghats of India. It includes many hill stations those are all rich of various flora and fauna, which are manifested at all levels. Nilgiris is one of smallest district in Tamil Nadu, with the geographical area of 2549 km2. Nature manifests itself in the forms of Forests, Grass Lands and Tea Estates over here. Over a period of twenty years there is a lot of change in the agricultural practice resulting in the soil erosion in many parts of the district. This study has been taken to evaluate the role of Remote Sensing, GIS and ground control surveys using GPS for delineating such zones and to suggest suitable changes in the existing agriculture practices.

Objective of the Study
The main objective of the study is to address the remedial/developmental measures using Remote Sensing, GPS and GIS to arrive at site-specific action plans for tackling the following problems:

Improper Landuse Practice (Landuse in conflict with slope)
Deforestation/forest conditions

The broad objectives of the integrated study are:

To develop a reliable database of all natural resources in the Kattteri Watershed using Remote sensing, GPS and GIS technology
To evolve and arrive at local-specific developmental action plans considering Land and forest resources for their optimal utilisation and to address the remedial/developmental measures for the said problems.

About The Area

Geology
Based on the detailed geological structural and geomorphological studies and a number of evidences have led to the conclusion that block faulting resulted in the upliftment of the Nilgiris plateau. Structurally the Katteri watershed comprise Archaean metamorphic rocks made up of charnockite, biotite gneiss, and magnetic quartzite hornblende granite - along with some intrusive bodies like pegmatite dolerite and quartz veins. Apart from these small enclaves of schistose rocks like talc chlorite schist chlorite schist are also found. The laterite found over the charnockites is hard. Structurally the area is highly disturbed and is subjected to faulting. Block faulting resulted in the upliftment of the plateau. Due to these tectonic activities the deep-seated matemorphic rocks have undergone considerable deformation during Precambrian times, which resulted in different structural features such as folds, faults and joints. The major rivers in the district flow along the prominent fractures. The prominent fractures in the district are trending northeast, northwest. (GSI, 1982).