Ingénierie des systèmes d’irrigation et de drainage

Spatiotemporal Variability of Reference Evapotranspiration Estimation and Mapping for Arjo-Dedessa Sugar Factory and Its Surrounding

Abstract

Etefa Tilahun

Evapotranspiration, which represents a significant amount of moisture lost from a catchment, is an important parameter in the hydrologic cycle. However, it was challenging to determine the quantity due to the non-uniform distribution of meteorological stations and data in adequacy, which can be solved by an interpolation technique. Accordingly, the objective of this study was to estimate the spatiotemporal variability of reference evapotranspiration for the Arjo Dedessa sugar factory and its surroundings. ArcGIS, CROPWAT, and XLSTAT were the materials used. GIS was utilized to map the ETo variability, the XLSTAT2019 software was used to fill in the missing data, and the ETo was calculated using the CROPWAT. The data came from the Ministry of Water, Irrigation, Electricity, and Energy, as well as the National Meteorological Service Agency. Fourteen meteorological stations were identified, and data from 10 of them was selected for study after their quality was verified. The ETo map was created using the elevation and position of each station. Over the whole study area, the ETo values were interpolated using Kriging. The results show that the yearly spatial average daily ETo ranges from 3.67 millimetres to 4.65 millimetres of water depth. Because of the cold climate and heavy precipitation, the ETo value was lower at higher elevations. However, because of the warm temperature, it was higher in low-altitude places. Throughout the year, the monthly ETo temporal distribution has varied. During the summer, daily ETo values ranged from 3.10 to 3.39 millimetres, with a mean of 3.24 millimetres.