Journal of Rangeland Science (JRS) Annual Water Yield Estimation for Different Land Uses by GIS-Based InVEST Model (Case Study: Mish-khas Catchment, Ilam Province, Iran) Volume 9 (2019) Issue 1, January 2019 2024 01 30 Annual Water Yield Estimation for Different Land Uses by GIS-Based InVEST Model (Case Study: Mish-khas Catchment, Ilam Province, Iran) EN Ali Akbar Jafarzadeh Faculty of natural resources, Ilam University, IRAN Ali Mahdavi Dept. Forest Sciences, University of Ilam Rashid FallahShamsi Department of Natural Resources and Environmental Engineering, Shiraz University, Shiraz, Iran Rasoul Yousefpour Department of Forest Economics and Forest Management Planning, ALU Freiburg, Germany Journal Article 2024 01 30 Fresh water supply and its security encounter a high level of fluctuating variability under global climate changes. To address these concerns in catchment water management, a good understanding of land use/cover impacts on the hydrological cycle affecting water supply is crucial. The objective of this study is to define a model to investigate the impact of existing land use/cover on water yielding in Mish-khas catchment of Zagros region, Ilam province, Iran. In this research, a water yield model of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) was employed to estimate annual water yield in the catchments as a basic foundation for policy and decision making. The input data set included land use/cover layers of the region produced in 2016, average annual precipitation and potential evapotranspiration from 1986-2016, soil depth, plant available water content and land use/cover bio-physical database. Based on the results, total annual water yield was estimated 30.2 million m3 for the whole Mish-khas catchment. The annual water yield percent for rangeland, forest, farmland and orchards land uses was 57%, 31%, 8.6% and 3.4% of the total water yield of the catchment, respectively. In addition, the results showed that the farmland had the highest water yield (2449 m3/ha) followed by forests (2269 m3/ha), orchards (2254 m3/ha) and rangeland (2196 m3/ha) land uses. In terms of water distribution, the northern regions with a volume of 2315 m3/ha had higher water yield than the southern regions (2210 m3/ha). The results also indicate that a GIS-based InVEST model is a useful instrument to identify more suitable areas for water-table recharge.