Watershed Characteristics

Watershed is a geo-hydrogeological unit draining at a common point by a system of streams. The depth of a watershed may extend from the top of the vegetation to the confining geological strata beneath (Fig 15.1). In areal extend, it may vary up to few thousand hectares. Watershed management must consider the social, economic and institutional factors operating within and outside the watershed. It is an integrated and inter-disciplinary approach aiming at increased agriculture production, generation of rural employment and balance growth of the national economic.
Watershed Characteristics
Physiography
Size The size of watershed is an important parameter in determining the peak rate of runoff. The rate and volume of runoff increases with increases in size of watershed
Shape
Long and narrow watershed will have longer rainwater infiltration and low runoff rate.
Land Slope
Slope is an important factor to find out the speed and extend of runoff and also to know the land use pattern
Drainage and Density
Drainage density and pattern is main Characteristic of a watershed. High drainage density is a Characteristic of shale, clay and schistose formation. The coarser drainage texture, the higher the conductivity.
Soil and Geology
Soil and geology of the watershed determines the infiltration and percolation rates of water, runoff and soil erosion, drainage pattern, drainage density etc.,
Land Use
The land in a watershed has to be used for numerous purposes like cultivation, housing, water harvesting etc, the land use affects rate of runoff, infiltration rates.
Vegetation Cover
Vegetation cover in watershed influences rainfall, runoff, erosion, rate of evaporation and rate of infiltration. A good cover of vegetation, treat the watershed from land and water scarcity and hazards.
Rainfall
Rainfall in a watershed is an important key to determine its behavior, that why the amount, frequency and intensity of rainfall are important in a water shed.
Socio-Economic factor
In every watershed, three socio-economic factors namely demographic profile, sociological factors and economic factors are important. These there are interrelated to each other.
Causes of Watershed Deterioration
Land, water, flora and fauna and community constitute the four components of a watershed, which are complementary to each other. Any distortion in any one has been carried over to all the components thereby creating a vicious circle, which is capable of deteriorating the watershed.
Watershed Management
Watershed management defined as the process of formulating and carrying out a course of action involving in the manipulation of natural, agricultural and human resources of a watershed to provide resources that are desired by and suitable to the watershed community, but are not adversely affected.
Selection of Watershed Villages
The selection of watershed villages are based on the following category
At least 5% of the cost of investment shall be contribution by the community
At least 10% of the investment on individual work on private property must come from the beneficiary/ user
A resolution from Gram panchayat expressing its willingness to take over and maintain.
A resolution from Gram Panchayat and watershed community willing to share the benefit from those created assets.

Selection of Watershed
The selection of water shed based on following criteria
Watershed which has acute shortage of drinking water
Watershed having large SC/ST population
Watershed which has preponderance of common and waste land
Watershed having special problems like drought, soil erosion ground water stress and quality problems
Land and Water Management
The basic idea of land and water management is to use the resources to its utmost capability and its treatment according to its needs. Thus the knowledge of land capacity classification is a pre-requisite in integrated water shed development programme. The land capability classification is defined as a systematic arrangement of different. Kinds of land according to these properties that determine the ability of the land to reproduce on a virtually permanent basis. Land is arrangement in various capacity classes after considering factor like soil texture, soil depth, permeability, soil chemistry, slope, and frequency of overflow, climate and rainfall.
Ground Water Management
The groundwater management objectives are based on geological, hydrological, economic, ecological and legal consideration. Proper ground water basin management involves the development and maximum utilization of sub-surface water at a least cost for economic or community purposes. Hence, the optimal use of groundwater can made by conjunctive use of both surface and groundwater.