MODELING BLUE AND GREEN WATER FOR SUSTAINABLE WATER RESOURCES MANAGEMENT IN WATERSHED
KrishiKosh
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Title |
MODELING BLUE AND GREEN WATER FOR SUSTAINABLE WATER RESOURCES MANAGEMENT IN WATERSHED
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Creator |
B.K.VARA PRASAD, ANNEPU ANNEPU
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Contributor |
MANI, A
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Subject |
irrigation, land resources, crops, runoff, area, surface water, land management, clay, water balance, yields
BLUE AND GREEN WATER, SUSTAINABLE, WATER RESOURCES MANAGEMENT, WATERSHED |
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Description |
Ground water is an important source for irrigation and drinking water in many parts of Andhra Pradesh. Over exploitation through indiscriminate pumping of water has led to aquifer depletion and ground water contamination causing agriculture vulnerable in rainfed areas. Kothakunta sub watershed having an area of 550 ha in Medak district is also dependent on ground water for agricultural production and it is the only source for irrigation. About 98% of ground water resources of the mandal already have been exploited. Hence, for sustainable water resources in watershed, rational planning including water management practices integrated with suitable cropping system is required. That can be achieved by reliable estimates of water balance by incorporating spatial variability of watershed characteristics employing suitable hydrological model, SWAT. Soil and water assessment tool (SWAT) is one such model which can be used to quantify the impact of land management practices on the water yield of the watershed with varying soils, land use and management conditions over long period of time. The model quantifies different components of water balance which include surface runoff, lateral flow, ground water contribution to stream flow (GWQ), actual evapotranspiration and soil moisture storage respectively. Surface runoff, lateral flow and ground water contribution to stream flow account for blue water resources whereas Actual ET and soil moisture storage indicate groundwater resources of the watershed. The precipitation and irrigation that was applied was apportioned into different water balance components in which percolation has amounted to 554.98mm followed by actual evapotranspiration as 540.1mm, total aquifer recharge as 536.23mm, surface runoff as 90.32mm and lateral flow as 32.87mm. However, surface runoff and lateral flow were less compared with other components. The watershed has considerable area of 13.45% under paddy cultivation. The cultivation of paddy has shown significant impact on water balance components by simulating more runoff (153.15mm), ground water contribution towards stream flow (250.68mm) and actual ET of 1225.2mm respectively. Hence, for sustainability of ground water resources, it was tried to simulate water yield of watershed by reducing area under paddy cultivation and allocating that area for irrigated dry crops namely maize, cotton and potato. Three different cropping scenarios were proposed by reducing area under rice with 25%, 50% and 60% respectively. The cropping scenario-2 with 25% reduction in paddy area and assigning that area to beans, maize and cotton was proved to be suitable for watershed. In this particular scenario, the ground water recharge i.e. deep percolation and total aquifer recharge were more leading to high ground water table (blue water). The stream flow was however less compared to existing cropping scenario. The stream flow reaches to Kothakunta tank and evaporation losses over a period of time will decrease the availability of water. On the other hand the crops distributed in this scenario shows predisposal conditions like less evapotranspiration and capillary rise leading to lower green water loss. Under above said grounds, it is concluded that the proposed alternative land scenario-2 is suitable to the kothakunta watershed for sustainability of ground water resources. |
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Date |
2016-06-06T12:16:51Z
2016-06-06T12:16:51Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/66839
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Language |
en
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Relation |
;D9220
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Format |
application/pdf
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Publisher |
ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY
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