Evaluation of Sediment Management Techniques of Dokan Dam Accomplished with Climate Change Scenarios Using ResCon 2.2 Beta Model

Abstract

The storage capacity of dams is affected directly by sediment build-up. Drought, heavy rainfall, and catastrophic events on watershed increase soil washout up to unusual and unbeaten records. Dokan Dam as a strategic dam in Iraq plays a vital role in water management with strongly firm with the even worse scenario of actual predicted sediment rate of 3.8 M m³/y. Sediment management is an essential process that enhances dam functions. Reservoir conservation model ResCon 2.2 Beta was used to predict and analyze sediment management techniques taking into consideration the climate change scenarios. the model gives a good and acceptable interpretation of the sediment management in both watershed and reservoir. Dokan reservoir is a sustainable reservoir within long-term capacity. 4 different techniques and 37 different methods are evaluated to reduce the sediment entering the reservoir up to 300 years. Economic approaches are applied to calculate the basic parameters of sustainable projects. Satellite images, dam operations policy, inflow, and sediment data are used as input to calculate the aggregate net present value NPV and gross storage capacity. In terms of climate change, results show the watershed management technique is the best option to decrease the soil washout and sediment deposition in the reservoir with NPV of 24.5 B$ assuming the unit price of water yield is 10 cents, long term gross storage capacity is 6.4 BM3. Dokan Dam can sustain for the applied period in terms of water storage depletion provided there is no structural defect in the dam body. Check dams, reforestation, and vegetation of specific areas in watersheds are necessary to maintain the storage capacity of the dam as much as possible up to 6 BM3.