Estimation and evaluation of trend analysis of the Penman-Monteith reference evapotranspiration of Raipur region, Chhattisgarh central India

Understanding evapotranspiration and its long-term trends is essential for water cycle studies, modeling and for water uses. Temporal analysis of evapotranspiration is therefore important for the management of water resources, particularly in the context of climate change. The objective of this study is to evaluate reference evapotranspiration using the AquaCrop model developed by FAO and analyze the trend of reference evapotranspiration (ET0) in the Raipur Region. Mann-Kendall test and Sen’s slope were used to detect trends and amplitude changes in ET0. The average monthly ET0 was found maximum in May (8.91 mm/day), whereas the average minimum ET0 was estimated in December (1.91 mm/day). The mean daily reference evapotranspiration ranges from 2.49 mm per day to 7.61 mm per day in the study area. Results show on the monthly time scale, decreasing trends were identified in ET0 data in most of the months. A significant negative trend magnitude was found for March, April and May. This study provides the necessary information on atmospheric demand on water requirements for growing different crops in different seasons. This information will be very important for researchers and farmers in planning irrigation scheduling, irrigation water management studies in different seasons.