Studying the Structural and Non-structural Solutions for Sustainable Water resources Management of Hamedan-Bahar Plainn

Ekbatan Dam and groundwater resources in Hamedan-Bahar plain are the main suppliers of drinking water in Hamedan city. The aim of this study is to evaluate drinking water supply in the medium-term time horizons (1410) and long term (1430). Therefore, resource system, consumption area of Ekbatan dam and underground provider  are modeled by WEAP using 40-year-old statistics. calibrating the findings, the actual conditions of use and watershed resources in the current situation (in 1391) and both unauthorized and authorized the withdrawal of underground water source were modeled. The results showed that water shortage of Hamedan is around 2.8% annually. Having per capita expenditure per person as well as the urban population estimated in the aforesaid period, at first, the demand for drinking water is calculated. Then, considering water demand to be constant in other sectors, water demand was modeled. The results showed that about 19.6% and 34. 4% in 1410 and 1430 respectively face water shortage. The situation was almost the same in other sectors. Due to constant water resources and significant deficiencies in the research horizons, respectively, structural and non-structural solutions and their effects were tested. However, it was observed that structural measures alone are not helpful. That is why non-structural solutions on side structural solutions were proposed and examined.
Extended Abstract
1-Introduction 
As Iran is located in the arid and semi-arid region, it has an increasing population rate and developing irrigation and industry sectors, it has faced water scarcity. (Mohie and Moussa, 2016) and (Xue et. al., 2015) have applied the WEAP model including some scenarios to analyze water resources scarcity in long term periods. These scenarios are considered as new irrigation methods, modifying crop pattern and water distribution networks and changing water allocation policy. (Samboum et. al., 2015), (Hollerman et. al., 2010) and (Mehta et. al., 2015) added the effects of climate changes on water resources scenarios to previous ones. Hafezparast and Fatemi, (2016) investigated water and water basin sustainability indexes to evaluate the water scarcity in the Gamasiab water sub basin using WEAP model. They stated the best scenario is calculated by multi criteria decision making approach. Ekbatan Dam and groundwater resources in Hamedan-Bahar plain are the main suppliers of drinking water. The aim of this study is to evaluate the drinking water supply in medium-term time horizons (1410) and long term (1430) using WEAP model.
2- Materials and Methods
In order to simulate water resources and consumption in the Ekbatan water basin, the data during the period from 1973 to 2012 were used and modeled by WEAP model. In this study five water management scenarios were used as following:
Increasing of population rate, increasing of irrigation efficiency, using water transfer out of water sub-basin, reducing the loss of water supply network and adjusting of per capita consumption. Moreover, three operating rules are considered in Ekbatan reservoir system including allocating the available water to any water users, minimizing the water deficit and flood risk and finally managing the environmental resources.
The amount of environmental flow requirement in downstream of reservoirs are considered by Montana method (1976). Data calibration in WEAP model has been done by trial and error. As, Ekbatan dam has operated in 1963 and there were none hydrometric stations in the downstream, observed and calculated storage capacity in each periods were used to model for calibration.
3- Results and Discussion
After applying the structural scenarios 2031, there was no significant water deficit on water user sectors, but due to increasing of water consumptions in 2051, it overpassed the limitation. So that other scenarios would be considered able enough to overcome this difficulty. By adding the non-structural scenarios to structural scenarios, all water users would be supplied in 2031 and 2051.
4- Conclusion
The present study aims to present sustainable management of water resources in Ekbatan water basin. Therefore, current situation of the water basin and short-term and long-term water resources and consumption have been modeled. The structural and non-structural scenarios are defined to supply any water demands.  Due to constant water resources and significant deficiencies in the research horizons, respectively structural solutions were initially provided. However, it was observed that structural measures alone are not helpful. That's why non-structural solutions and their effects on side structural solutions were proposed and examined