\cite{a2000}.
water resource management strategies are supply-oriented and demand-based. Demand management strategies in the region can involve enhancing irrigation efficiency, reducing water consumption, and promoting water conservation among communities \cite{Gohari_2017}. On the other hand, supply-oriented strategies, include expanding water storage capacity, inter-basin water transfers, and adopting water-efficient technologies. Studies have shown that to tackle the water scarcity problem, a combination of demand management and supply-oriented strategies are necessary \cite{Gohari_2014,Madani_2009,Sharifi_2021}. However, it is essential to consider the social, economic, and political aspects of water management to ensure the effectiveness and sustainability of any adopted approach \cite{Madani_2009}. Traditionally, water resource management in this watershed was adapted to local conditions, effectively balancing water consumption with natural inflows. With the population growth and agricultural expansion over time, this balance has been disturbed and intensified water scarcity challenges. In recent decades, the excessive development of modern irrigation systems promoted by the government as a solution to water scarcity. However, the effectiveness of these systems in reducing water consumption remains a subject of debate \cite{fawzi2017}. In contrast to some studies that have shown that modern irrigation systems can increase water use efficiency \cite{Kahlown_2007,Koech_2018}, others have criticized their poor utilization of resources despite their popularity and increasing use \cite{Molle_2011}, This criticism stems from their water losses due to Wind Drift and Evaporation Losses (WDEL) \cite{Play_n_2005}.
Globally, agriculture is responsible for approximately 70 percent of freshwater withdrawals \cite{fao2011}. However, this share varies significantly by country across different countries. Based on the available statistics, agriculture consumes more than 90 percent of water in the Zayandeh-Rud River basin \cite{Abou_Zaki_2020}. As a result, while climate change intensifies the water scarcity in the Eskandari watershed, withdrawals, and water waste in this sector also contribute significantly to the problem. It’s essential to note that the studies mentioned above failed to consider the substantial water loss amount in the agriculture sector.
Therefore, The main objective of this research is to investigate the wastage of the available water resources in the Eskandari watershed due to wind drift and evaporation losses in sprinkler irrigation systems and how they contribute to water consumption in the region. A comprehensive approach was adopted to achieve this objective, all the factors that influence water management in the watershed were analyzed using the classic Mann-Kendall (MK) and Trend-Free pre-whitening Mann-Kendall (TFPW-MK) non-parametric statistical tests. These factors encompass precipitation, discharge, inter-basin water transfer, groundwater extraction, and leaf area index (LAI) over the 16 years from 2004 to 2019. The findings emphasized the need for sustainable irrigation practices to mitigate water scarcity in the region and provide actionable solutions for optimizing water management strategies and irrigation techniques in the Eskandari watershed, aiming to achieve a sustainable balance between agricultural productivity and water conservation.
2 Materials and Methods