Spatial gradient modeling of water yield service using InVEST in northern sub-basins of ‎Kerman province

The ecosystem service of water yield is affected by damaging human activities, and the estimation of its quantity ‎through modeling is the first step to sustainable management of this service. This research applied the InVEST ‎hydrological model to quantify the ecosystem service of water yield and its valuation in the northern arid and semi-arid ‎sub-basins of Kerman province. First, for modelling the water yield were entered the maps such as annual average ‎precipitation, depth of root limiting layers, plant accessible water capacity, land use/land cover (LULC), and the ‎boundaries of the basin and sub-basins, and the approximate amount of actual evapotranspiration (AET) in each pixel. ‎Then maps of estimated water yield in each pixel was obtained. The model calculated 5112.43 million cubic meters of ‎water with a value of more than 418500 billion Rails are produced annually, the highest amount of water yield is in sub-‎basin one (Abargho-Sirjan) with 2103 million cubic meters per year and the lowest amount of water yield in sub-region ‎three (north Kavir-e lut) with the amount of 741.84 MCM. The results showed that the value of supply the ‎water yield service is strongly influenced by the spatial changes of LULC. Dense range lands produce 27630.7 MCM of ‎water per hectare, and each hectare of dense forest can produce 1104.6 MCM of water. Therefore the role of vegetation ‎shows the influence of water infiltration and feeding of aquifers in high areas. The results of this study can be used in ‎spatial planning to reduce the destructive effects of floods and droughts, prevent land degradation and develop vegetation, ‎feed aquifers, and also estimate damages in green accounting.‎