VILLAGE INFORMATION SYSTEM (V.I.S) FOR WATERSHED MANAGEMENT IN THE NORTH AHMADNAGAR DISTRICT, MAHARASHTRA Abstract: The drought prone zone in the Western Maharashtra is not in position to achieve the agricultural growth, obviously due to scarcity of water. Even the irrigated areas are facing the problem of retarding the growth of agriculture in the Ahmadnagar district. Majority of the villages in the north Ahmadnagar (study area) are facing problem of drinking water. There is a main environmental issue due to depleted quality of surface water resources in the river that has been polluted to a large extent. Therefore it is the need of the hour that the system of agriculture should be revitalized, to make an environmentally stronger. For this, first and foremost step is to conserve the surface and ground water. This can be achieved by implementing watershed management program. Thus, the study may have following hypothesis: Integrated Watershed Management Programmes (IWMP) will be useful for improving groundwater resource in the study area. If groundwater resource is improved, it would increase productivity of the agricultural area falling under different villages deprived of canal and lift irrigation facilities. The watershed wise village level planning using modern techniques like GIS and remote sensing for building Village Information System (V.I.S.) can result in planned utilization of water resources, wasteland development, and prioritization of villages for action plans. In the light of the above it is necessary to consider the above mentioned issues pertaining to the area for carrying out the study that has main aim to develop village information system through integrated watershed management programme and in turn to develop strategies for micro level planning. This need to divide the region into watershed for appraisal of soil and water resources at one hand and agriculture and other agro based activities on the other.
1. To carry out water balance evaluation through integrated watershed analysis for location of conservation measures. 2. To analyze watershed based landscape analysis and applying quantitative remote sensing technique. This kind of analysis would be carried out for different crop groups in both kharif and rabi seasons to enable approximate estimation of crop water requirement for each village. 3. To generate agricultural land productivity analysis, wasteland prioritization for development and composite ground water quality analysis outputs useful for suggestion of village development action plans. 4. To create village level database in GIS domain for demographic, social, and economic parameters like population, amenities in villages for carrying out heuristic analysis by assigning subjective weights to each parameters and evolving index necessary for village prioritization. 5. To design strategic plan for village level development on the basis of improvement of water resource potentials, village resources, facilities, landscape characteristics and agronomic activities. The entire Ahmadnagar district is covered by basaltic lava flows of the Deccan traps belonging to the Upper Cretaceous to Eocene age. The Deccan Trap basaltic formations in the area is lying above the alluvial deposits along the river Godavari and are occupying the northern part of the district. The drainage of study area (Rahata, Shrirampur, and Newasa Tahsils) belongs to Godavari river system of Maharashtra. The Godavari flows on the northern boundaries of the study area and the tributaries of river Godavari such as river Pravara and river Mula has its origin in Akola tahsil. The confluence point with river Godavari for Pravara river occurs at Pravara sangam. The Mula River joins the Pravara River before the confluence point at Pravara sangam near village Pachegaon of Newasa Tahsil. The average annual rainfall in the district is 566 mm 1995. The average annual rainfall in the Rahata tahsil 441.0. Shrirampur tahsil 448.6 and Newasa tahsil is 531.3.
The district mostly is in rain shadow to the east of Western Ghats. Near the western border of the district the rainfall decreases rapidly as one proceeds towards east. Importance of irrigation as an essential input hardly needs emphasis. Moreover, it is a pre-requisite for the adoption of new technology in agriculture and for the rapid growth of agricultural sector. The conversion of dry land into wetland provides a security against the vagaries of rainfall, preventing crop failure and enabling higher yield per hectare. It also helps to the farmers to take two or more crops from the same field within a year and it increases the productivity of the land by transforming the agriculture. The methodology adopted in the present study is the integration of remote sensing and GIS. The data in digital form is voluminous and the volume increases with the improvement of spatial resolution. So with the improvement of spatial resolution, the ground coverage area will have to be reduced to keep the volume within the manageable limits as required for computer processing. Optimally the spatial resolution varying from 10 m to 40 m would be adequate for watershed development application. The digital images are available in different formats. This process of reallocating the input remote sensing images or other spatial data to suitable output images image which has a close agreement with the standard map is called as Geo-referencing. The geo-referencing of remote sensing data in watershed development can help in updating useful information apart from obtaining the current land use/land cover maps. A Spatial Village Information System can be developed using Geographical Information System (GIS) software. The commercial Arc GIS-9.3 can be effectively used for integrated watershed management and development of spatial village information system. This is necessary for solving complex problems involving planning encompassing the watershed development and heuristic analysis for village prioritization for preparation of action plans. The GIS software s should perform Cartographic displays, Map digitization, Database Management System, Geographic data analysis, Statistical analysis and decision support system. The Remote sensing images can be a part of spatial data in GIS environment.
The integrated raster GIS analysis can utilize number of water and soil conservation parameters into the analysis for generating holistic watershed management plans. The technique of raster interpolation has its precision based upon the number of sample points and the statistical interpolation used in arriving at a continuous raster layer pertaining to different parameters involved in the raster analysis. The automated watershed delineation tool is less precise for plain areas and its reliability in comparison to manual method of watershed delineation is less. The resolution of the raster layer is also a factor on which the accuracy of the analysis is dependent. There are number of runoff and soil erosion models which can be tested in the raster GIS approach to enable compatibility of analysis. The LISS-III data at 23.5 meter resolution gives level-i land use details derived using image classification techniques and therefore the analysis cannot be visualized at micro level. In view of which, the integrated watershed based raster analysis has been carried out for site suitability analysis for conservation measures and then the raster layer indicating the location of conservation sites has been overlaid with village boundaries to have an assessment regarding the details of conservation measures existing in every village of the tahsil as a part of village information system. The socio economic factors associated with every village have been taken as attribute information into the data base of the village information system. The SCS runoff potential model is more reliable for meteorologically homogeneous watersheds and is based upon the details of the landscape at the instant of satellite data acquisition. The soil properties and its infiltration capacity have a bearing on the runoff estimation. The raster slope layer derived using raster grid DEM has its accuracy dependent upon its resolution and in raster domain it is observed that the terrain controlling features such as ridge lines, valley lines, break lines etc do not get adequately represented in raster DEM. There are number of soil erosion models used in GIS and the Stehlik s equation has been observed to give reliable outputs in semiarid tropics in which there is limited terrain undulation.
The integrated raster approach followed using spatial data representing level I generalization gives locations of sites suitable for various conservation measures validated through local site visits. The village boundaries overlaid on spatial terrain variation indicating suggested sites of conservation can give synergistic value added output product needed for building village information system. Accordingly this can help in crop area assessment for crop season of kharif and rabi period to a reasonable accuracy at LISS-III resolution. The collection of different crop parameters like field capacity, root zone depth, soil density and Evapotranspiration of crops can help assess the crop water requirement along with approximate scheduling of irrigation water. However the spatial and temporal variation of field parameters plays an important part in assessment of quantity of irrigation water for each application and number of water applications during the entire base period of crop groups. The exercise on village information system should examine the water resources potential of the watersheds in which the villages in the tahsils are going to exist. The water balance evaluation should consider the supply and demand issues arising out of availability of precipitation water and demand for water after catering to the various water requirements. This will ensure the watershed based surplus or deficiency in the water resources required to be stored through various conservation measures in each watershed consisting of different villages. Eventually this can lead to channelizing the water requirement for the villages contained in the watershed. The well water in the region has to be assessed for its quality so that its suitability for different needs could be ascertained. The spatial and temporal variation of water quality parameters in this context may be useful to suggest the line of treatment to the ground water for its suitability in various usages apart from making it potable. The development of villages in the area involves analysing the productivity of the land on a watershed basis, which also incorporate the land area of villages. The integrated raster based utilization can facilitate creation of land productivity outputs that gives the quantified productivity assessment for the lands in the village area.
The properly designed and developed village information system as per the various objectives of analysis requires building up of database comprising of multifarious data derived from different sources. This calls for maintaining interoperability for the data formats along with use of common coordinate system to achieve compatible analysis. The data base for village information system should necessarily have both spatial and attribute components to perform attribute query outputs and spatial query outputs on geo-relational vector data. A properly formulated village information system should be giving outputs after considering number of attributes that characterize the socio-economical, resources potential and terrain aspects of the villages. The heuristic analysis in village information system incorporates multiple weighted criteria as per their importance to formulate village prioritization plans required for according priority to the villages to implement phase wise development. The village information system need to integrate the different spatial layers using appropriate process models to obtain decision support output layers. In this context it may also be required to carry out spatial interpolation tools to generate outputs that can be useful for data integration. The generation of resources potential spatial outputs and other landscape spatial representation could be of value addition. The wasteland identification and formulation of strategies for its categorization and suggestion of implementation plans for its development is considered to be an important facet in village information system.