Application of InVEST Ecosystem Services Model to Prioritize Sub-watersheds of Talar in term of Soil Erosion, Sediment Retention and Yield

Ecosystem services refer to the benefits and advantages provided directly and indirectly by ecosystem to the people. The concept of ecosystem services has been recognized as a tool for comprehensive decision-making in natural resource management, land use policy design and land use planning in recent years. In this regard, the present study was planned to implement the InVEST sediment delivery ratio (SDR) model and prioritize sub-watersheds of the Talar in Mazandaran province in terms of soil loss, sediment retention and sediment yield. For this purpose, the input factors of the model prepared were including rainfall erosivity, soil erodibility, land use, digital elevation model, crop management, land management, sediment connectivity index, K parameter (Determinant of the relationship shape between hydrological connection and SDR) and maximum SDR in the study watershed and then were employed to the mentioned model. Based on the results, the amount of annual soil loss, sediment retention and, sediment yield (ton) obtained were 652683, 757588 and 57426, respectively. Moreover, the spatial changes of the studied variables indicated an increasing trend from the south to the north of the research watershed. In addition, Aseran sub-watershed (2.23 ton/ha) in terms of sediment retention hydrological service and Ghadmagah sub-watershed in terms of soil loss (4.43 ton/ha) and sediment yield (0.39 ton/ha) as critical sub-watersheds were identified. The results of sub-watersheds prioritization based on sediment retention can be used in environmental policy-making in order to carry out executive operations of rehabilitation and achieving sustainable development in the study area.