Identification of Surface Water Harvesting Sites for Water Stressed Area Using GIS: A Case Study of Ausgram Block, Burdwan District, West Bengal, India - Management of Natural Resources in a Changing Environment - page 76

Methodology
Ausgram blocks I and II are affected by water stress condition due to serenity of
surface water; cultivation is done only once in a year in majority of the areas. Present
study tried to identify and map the surface water harvesting potential zones using
the geomorphic resources. Geomorphic resource layers (Ruggedness Index (RI),
Relative Relief (RR), Drainage Density (DD), Slope and Frequency of Surface
Water Bodies (FSWB)) were superimposed over each other and the suitable zones
identified for surface water harvesting based on methodology described as follows.
Existing geomorphic resource have been evaluated from Survey of India (SOI)
topographical maps (73 M/06, 10, 11, 14 and 15; published in 1972) as a base data
at 1:50,000 scale. Physical information is extracted from every 1 km 2 grid. Features
like contours, spot heights, bench marks, drainage lines and surface water bodies
(pond, tank, lake) are taken into consideration for characterisation of the physical
resources of the region. These phenomena were measured and analysed to generate
information on Ruggedness Index (RI), Relative Relief (RR), Drainage Density
(DD), Slope and Frequency of Surface Water Bodies (FSWB). These resources are
directly or indirectly controlling and influencing the availability of surface water
resources which in turn dictate the land use land cover, water stressed situation and
agriculture resources in Ausgram blocks I and II.
The basic methodologies to identify the surface water harvesting potential zones
are as follow:
1. Minimum Ruggedness Index+Minimum Relative Relief+Maximum Drainage
Density + Maximum Frequency of Surface Water bodies + Minimum Slope = Maximum
Surface Water Harvesting Potential Zone .
2. Moderate Ruggedness Index+Moderate Relative Relief+Moderate Drainage
Density + Moderate Frequency of Surface Water bodies + Moderate Slope = Moderate
Surface Water Harvesting Potential Zone .
3. Maximum Ruggedness Index+Maximum Relative Relief+Minimum Drainage
Density + Minimum Frequency of Surface Water bodies + Maximum Slope = Minimum
Surface Water Harvesting Potential Zone .
With the help of the above mentioned methodology and Table 1 , surface water
harvesting potential zones have been identified and classified in three categories.
GIS tool has been used to prepare the different thematic layers and surface water
harvesting potential zone map through overlay analysis method.
Result and Discussion
Evaluation of the existing geomorphic resources is the fundamental key to
understand the surface forms and process. Geomorphic resources are the natural
phenomena on the earth's surface, which have originated due to the active geo-
morphic processes. The resources directly or indirectly control various