Ingle, V.K.Jawale, Balaji Vivekanand2022-09-092022-09-092022-01-0722003https://krishikosh.egranth.ac.in/handle/1/5810187499The present project entitled, “Estimation and generation of spatial reference evapotranspiration maps using GIS techniques for Marathwada region” was carried out during year 2020-2021 at the Department of Irrigation and Drainage Engineering, CAET, VNMKV, Parbhani. The project aimed with specific objectives of estimation of reference evapotranspiration for Marathwada region and generation of spatial maps using GIS. To find out reference evapotranspiration for Marathwada region, daily weather data such as maximum and minimum temperature, average relative humidity, wind speed and solar radiation was collected from https://power.larc.nasa.gov website. Daily weather data of 31 years (1990-2020) was used to estimate reference evapotranspiration. The DSS_ET software was used to estimate daily reference evapotranspiration for Marathwada region. The results or outputs obtained from the software were further analyzed according to Standard Meteorological weeks. Daily reference evapotranspiration converts into weekly basis by using weather cock software. The average weekly reference evapotranspiration for Aurangabad, Beed, Hingoli, Jalna, Latur, Nanded, Osmanabad and Parbhani was obtained as 5.13, 5.41, 5.06, 5.13, 5.06, 5.13, 5.12 and 5.47 mm/day and 5.26, 5.42, 5.21, 5.26, 5.21, 5.22, 5.31 and 5.45 mm/day for HS and PM method respectively for 31 years. The regression analysis values of coefficient of regression (R2) between Penman-Monteith and Hargreaves-Samani method for Aurangabad, Beed, Hingoli, Jalna, Latur, Nanded, Osmanabad and Parbhani district were 0.914, 0.720, 0.878, 0.897, 0.885, 0.872, 0.885 and 0.707 respectively. The values of R2 shows that Hargreaves-Samani is closely related to Penman-Monteith method. The spreading of ET0 values near the regression line implies that these two HS and PM methods are closely correlated with each other. The linear regression equation developed for different districts were presented and these equations will assist in future to select better methods in accordance to the availability of meteorological data, and to understand the extend of variations between estimated ET0 results by HS and PM method. In this study, the annual average values of ET0 obtained from HS and PM methods were nearly identical. A remarkable comparison was found between the performance of HS and PM methods in terms of weekly ET0 calculations. The minimum data requirements of HS method are a major advantage for areas such as the current study region, where data is scarce. Also Hargreaves-Samani method overestimated over the Penman-Monteith method. The extraction of weekly spatial reference evapotranspiration map for taluka level was also performed. The spatial maps produced are useful for hydrologic design, climate change prediction and water management studies in Marathwada region.EnglishThesis