MULTIPURPOSE UTILIZATION OF RAINWATER HARVESTING UNDER THE COMMAND OF JEWARGI BRANCH CANAL (KBJNL) AND BHIMA BASIN IN KARNATAKA

Abstract

Utilization for multiple purposes Rainwater harvesting (RWH) is used to assist small-scale agriculture and manage seasonal water supply, particularly in areas where people are dispersed and developing surface or groundwater resources is expensive. However, doubts may arise as to whether this methodology can support larger-scale irrigation projects and, in addition, aid in the fight against the JBC Command's D18's tail end farmers. The issue is important since rainfall collected in catchments is frequently stored in small-capacity reservoirs known locally as MI Tanks, which are built by small-height dams. The dam wall height was introduced as an assessment criteria in this study, which enhanced a prior RWH site allocation approach. The researched Command (Bhima River basin) is largely found in Kalaburagi District's south-west corner and Karnataka's north-east corner. This is a rural Command where agriculture is the main source of income [R1]. Climate data, crop data, and soil data were the most important input data in the CropWat-8 model. Because climate variability and water shortage are present in every part of the D18 command area, knowing crop water needs (CWR) is critical for better irrigation methods, scheduling, and effective use of canal water. So, the secondary focus of this research was to estimate crop water requirements and irrigation scheduling for a variety of common crops that have been sown in recent decades, primarily Cotton and Redgram, which account for approximately 37% and 49% of total ICA harvested in this study area, respectively. Sorghum, Bhara, Millets, Pulses, Wheat, Ground Nuts, Maize, Sunflower, Sugercane, and other less Horticultural Crops are among the other crops. Water delivery via most channels is insufficient and varies greatly, making it difficult to satisfy the supply requirements of their command. Assessing the different components of the water discharged from the canal is critical to ensuring optimum water usage in the canal command. This project report presents a case study to determine whether the water supply provided by the various Lateral 4 | P a ge WRDM, IIT Roorkee Outlets is sufficient to meet the actual supply requirement, as well as to recommend a suitable Multipurpose Rainwater Harvesting Reallocation Plan for water resources for potential crop production. The research was done out for Jewargi Branch Canal Distributory 18, an analysis by KBJNL finds that there is a conflict between water deficiency and canal supply. Water customers reported that the tail end consumers were never given irrigation water, despite officials claiming that they had provided enough water to satisfy the demand. After collecting data in the command area using FAO-recommended models, potential evapotranpiration was calculated using a modified Penman equation (FAO - 1997). Crop water needs, project supply needs, and irrigation schedules were all calculated. During the agricultural growing season, there was a lack of and an abundance of water supplies. The water provided by each was found to be insufficient to satisfy the supply requirements for their respective command regions[I7]. The study's goal was to convert 7583 ha of the D18 command's suffering atchcut area into cultivable irrigated land in order to fill the demand supply gap by collecting rainwater in two locations and installing RWH sites to supply water as an alternative source for irrigation to the suffering atchcut area, in order to fill the demand supply gap. Both RWH sites in the Janiwar and Kolkur areas now have storage capacities of 0.85 mcm and 1.16 mcm, respectively. These RWH cover catchment areas of 7.76 and 23.27 Sqkm, respectively, and these catchments provide a volumetric quantity in the year 2020 as runoff of 2.80 mcm and 8.466 mcm[R1]. In India's rural areas, another form of irrigation, groundwater, has emerged as the major democratic water supply and poverty-reduction instrument. Ground water has aided the growth of a variety of grains, millets, and vegetables in the command area, which accounts for more than 85 percent of India's rural domestic water needs. The current study aimed to calculate the crop water requirement (CWR) of main crops such as wheat, maize, pearl millet, chickpea, green gramme, peanuts, mustard, and cotton cultivated in the JBC region's D18 over various seasons. The FAO Penman-Monteith technique was used to estimate the daily reference evapotranspiration (ETo) using 30 years of mean meteorological data from Gulbarga [C5]. As a consequence, cotton's total water need is expected to be 538.7mm in 2018, 435.10mm in 2019, and 247.7mm in 2020. Then there's Sorghum Hyv in 2018-1953 5 | P a ge WRDM, IIT Roorkee 4.80mm, wheat 516.4mm in 2018-19, 477.00 in 2020-21, Red Gram (Arhar Dal) 224.1mm in 2018, 74.20mm in 2019, 82.2mm in 2020, and so on. Respectfully, the net amount of irrigation required in volumetric quantity for 2018, 2019, and 2020, using the CropWAT model with Sugarcane crop in mind, is 109.92mcm, 98.27mcm, and 82.84mcm, respectively. The IWR computed using the same model if the sugarcane crop is ignored is 78.96mcm, 62.42mcm, and 64.67 mcm [C7]. It is critical to make efficient use of water for agricultural production in both irrigated and rain fed settings. For scheduling irrigation to fulfil the crop's water demands and for maximum crop output, using the exact or precise amount of water and applying it at the precise time is critical [C5].