Document Type : Research Paper
Department of Water Engineering and Management, Tarbiat Modares University, Tehran, Iran.
School of Engineering, University of Northern British Columbia, British Columbia, Canada.
Alborz Regional Water Authority, Karaj, Iran.
Water budget evaluations are important research topics in various regions of the world, as they aim to determine one or more components of the water balance. To estimate these components accurately, it is necessary to have adequate knowledge and methods. Therefore, reviewing the common methods used in international models can help to improve the estimation of water resources budget. The present study seeks to identify the challenges of groundwater budget estimation and to propose solutions for enhancing the accuracy of calculations, based on a critical analysis of previous studies conducted in Hashtgerd from 1987 to 2022. A three-level analysis was performed at the technical, institutional-structural, and infrastructural levels. The technical analysis of water budget components indicates that in the recent periods, the total output and input of groundwater were 257 and 245 MCM, respectively. Moreover, the average storage deficit was estimated at 18 MCM, which showed an increasing trend. This research suggests several measures to address the challenges, such as: equipping the study area with hardware facilities (lysimeters and data loggers); revising and updating the monitoring network of observation wells in the region; using remote sensing techniques to estimate evapotranspiration and other water budget components; updating the hydrodynamic information of the aquifer; measuring the withdrawal amount from exploitation wells and Qanats at a frequency of less than five years with more accurate methods; and establishing facilities for recording and displaying online components of the water budget in Hashtgerd at different scales. In this regard, the need for conducting water resources budget studies is emphasized, considering the uncertainties associated with the estimation of inputs and outputs.