Using the water accounting plus framework for evapotranspiration and water productivity assessment (Study area: Plasjan catchment)

New approaches in analyzing the status of basic water resources data in the WA+ framework have been able to be introduced as a standard method in water resources accounting. In this study, with WA+ water accounting approach, evaluation of basin evapotranspiration was performed to determine water productivity. According to the amount of rainfall in the region, the transfer flow from Karoon basin, the shortage of water resources, outflow from the basin and evapotranpiration in each land use class, resource base sheet was calculated. Then, by calculating the evapotranspiration sheet, benefical and non-benefical consumption are separated from each other. In the sheet of agricultural services, the water demand of the products in each landuse is calculated and finally the water and land productivity for the priod 1396-97 is obtained. The results showed that of the volume of 651 million cubic meters of water entering the system, 465.5 million cubic meters are for evapotranspiration and 185 million cubic meters are surface flows. In the second sheet, for representive crops in land use, the amount of evaporation, transpiration and interception was extracted with Wapor product. Accordingly, the volume of 264.3 million cubic meters was determined as a benefical volume in agricultural and environmental activities and 201.1 million cubic meters as non-benefical evapotranspiration. Also, the amount of water efficiency in each land use class was determined based on the biomass of the products of each land use. The results of this worksheet showed that managed water lands had the highest water productivity of 1.28. The results of water accounting system (WA+) in Plasjan basin indicate a high volume of non-benefical evapotranspiration and water loss, and suggestions for management measures to reduce this issue should be considered.