Geographical Setup

Namakkal district forms part of the upland plateau region of Tamil Nadu with many hill ranges, hillocks and undulating terrain with a gentle slope towards east. The prominent geomorphic units identified in the district through interpretation of Satellite imagery are 1) Structural hills, 2) Bazada zone, 3) Valley fill, 4) Pediments, 5) Shallow Pediments and (6) Deep Pediments.

A number of hill ranges are located in the eastern and north-eastern parts of the district, whereas the southern, western and northern parts of the districtare plain to undulating, dotted with a few isolated hillocks. The important hill ranges in the district are Kollimalai hills, Bodamalai hills, Naraikinaru hills and Pachamalai hills. The highest peak in the district is the Kollimalai hill peak with an elevation of 1293 m. above MSL. Other important peaks are Kedda Malai (1284 m) and Melur hill in the Bodamalai hill range

SI.NO	Geomorphic Feature	Area in sq km
1	Structural Hill	513.35
2	Plateau	237.519
3	Flood Plain	179.936
4	Composite Slope	275.336
5	Bazada Zone	82.79
6	Shallow Pediment	2115.339

Drainage:

Cauvery river, which is perennial in nature, flows along the western and southern boundaries of the district. Tirumanimuttar river, which is the most important tributary of Cauvery in the district, has its origin in Manjavadi area of Shevroy hills in Salem district and traverses the district before its confluence with Cauvery at Nanjai Edayar village of Paramathi taluk. A small area in the northeastern part, which is drained mainly by Vasista Nadi and Sweta Nadi rivers, which are tributaries of Vellar River

Slope:

Slope of an area is an indicator of the infiltration rate. The contact period of water with the surface is less where the slope is more and thereby the infiltration rate will be less. In places where the slope is relatively less, the terrain is almost plain and the contact of the run off water with surface is high and it results in good groundwater recharge. The contour map is prepared in 1:50000 scale from SOI topo sheets. TIN map is created from contour map. Based on the TIN map, slope map is prepared for the study area. The slope map of the study area reveals that the slope is high in hilly terrains which are present in north and east parts. The most part of the study area contains a gentle slope of 0- 1 degree

Climatic Charcteristic:

The District receives the rain under the influence of both southwest and northeast monsoons. The northeast monsoon chiefly contributes to the rainfall in the District. Most of the precipitation occurs in the form of cyclonic storms caused due to the depressions in Bay of Bengal. The southwest monsoon rainfall is highly erratic and summer rains are negligible.