مجله ترویج و توسعه آبخیزداری
پیاپی 7 (زمستان 1393)

According to dry conditions, low rainfall and high evaporation in Yazd province, surface water storage is not technically and financially feasible. Therefore, the use of underground dams in areas where there is appropriate underground water storage is a reliable and economic way. In this study, underground dam (rock and concrete) constructed in Ardakan (Millsefid watershed), with the aim of developing a new water supply for agricultural needs of the region and Khranaq village (located in the downstream of the area) was evaluated in terms of economic. 887765630 rials was calculated as the total cost of the dam. Benefits of the plan (for 42 m3 per day in base year( was calculated 214.62 million rials. According to 50-years design life, the Benefit/Cost index, for the first 5 years of operation, was calculated. This represents that in the fifth year of the project, the cost is depreciated and the project has economic feasibility. The per m3 water price, produced during the life of the dam is 1158 rials, comparing to today's water price (14,000 rials) is very economic. Impact factor of the dam wall was achieved 12.67 that is justified, with geological and geomorphological constraints and water requirement of the area.

Review of economic and social outcomes of management practices in the watershed scale, is essential to achieve integrated management of watersheds and ensure the participation of the watershed stakeholders. In this context, the conceptual model for integrated watershed management was provided for Shastkalate Watershed and socio-economic framework from conceptual model was undertaken to assess interested outcomes and impacts. The results of the economic analyses showed that scenarios 6, 14 are much more preferred due to less variable cost, whereas results of social analysis along with field survey and binomial distribution denote that scenarios 2, 4 are prioritized for implementation given the highest social acceptance.

With attention to high potential in sediment delivery of semi-arid and semi-humid regions, in this study was prepared sediment-discharge equation for Poldoab Shazand station (Markazi province) with semi-arid climate and Tireh Dorud station (Lorestan province) with semi-humid climate. Then with applying the MVUE, Smearing, QMLE, FAO and β compared the correction amounts of equations for two regions. According to results, the most number of Nash-Sutcliffe criteria was related to FAO with 0.558 in the Poldoab Shazand station and 0.715 in the Tireh Dorud station. Also correction coefficients in the Tireh Dorud station was around 1.7 equal then to Poldoab Shazand station. Due to the high variation of coefficients a and b of equations two stations, as well as an inverse relationship between the two coefficients, it is needed in preparation of sediment rating equation that moreover river flows variable, other parameters related to precipitation specifications and physical properties of watershed can be applied.

During the last years land and water resources in Iran have suffered severe degradation. In this regard government of Iran has established several policies to Sustainable Management of Land and Water Resources during the last years. Most of these efforts have taken top down strategy. Watershed management program is one of the current approaches to sustainable management of land and water resources in Iran. It was started at the time of third Iranian 5th socio economic and cultural development plan; as a strategy to land and water resources development. In recent year’s government has developed participatory approach in watershed management in several areas. Hable-Rud program is one of these programs to sustainable management of land and water resources in Iran which is initiated as a joint program of UNDP and Islamic Republic of Iran in 1997. The degree of popular participation in such programs is a major determinant of success or failure, but the factors which make participation efforts successful still remained a mystery. This study was designed to discover this mystery and determine the factors that influence local people’s participation in such programs. The data for this study were gathered from 200 respondents through personal interview. Descriptive analysis, Parsons Product moment correlation and regression analysis was used to analyze the data. The findings of study showed that level of participation in program was moderate; however people preferred more involvement in social rather than economical and environmental activities. Correlation analysis showed that factors: satisfaction of prior programs, attitude toward program, knowledge of program, alternative income, marital status, sex and expectations of program have positive relationship with level of participation. Regression analysis discovered that these factors provided the best prediction for the level of people’s participation and explained 52.5% of the variation.

In recent years not only the total amount of precipitation decreased but also the proportion of the annual precipitation toward to snowfall has decreased. Instead, the precipitation with low amounts has been increasing than the precipitation with more amounts. These conditions increase the rate of evaporation from the soil surface and reduce the amount of water penetration into the soil. Snow due to white color and reflection of sunlight adsorbed lot of sun heat and therefore it can be protected amongst surface evaporation. Snow also as cover layering on the ground surface and gradually melting and consequently infiltrating in to the soil, is more effective than rain. Due to the possibility of harvesting and utilization of water from snow, be fit for investigating, identifying and using a variety of useful and effective methods of harvesting the snow melt water. Precipitation of snow on the ground sits almost uniform in each region. But if snow mass do not have enough adhesions that particles detach and transport by wind flow and finally accumulate at rest places. Fresh snow usually lacks adequate adhesion is therefore easily to transported by windfows. Places of deposition and accumulation the snow particles have more affected on possibility and water harvesting methods. If the position of deposition snow particles select well, can harvest more water. Toward to implementation of the project aimed to investigate the rate of accumulation and snowmelt in the cervix, Chari located in Chahar-Mahal and Bakhtiari Province which studied for 6 years. Valuable results and experiences has been obtained from mentioned project. In this paper method of trapping, snow deposition and accumulation and structures of using the water obtained from snow melt is presented.

Land degradation development is one of the existing issues in human communities. Degraded lands cover approximately 23% of the global terrestrial area and increasing at an annual rate of 5- 10 million ha. Apart that, economical development, unscientific and illogical utilization of resources are inevitable due to growing population and needs. On the other hand, the unsustainable management strategies due to incorrect identification of the natural resources, increases the land degradation. Appling appropriate management plans is therefore necessary to mitigate damage and protect water resources, soils and vegetation, proper utilization and economic development needs. In this regard, adaptive management is a systematic approach, provides an optimal management of natural resources and reduces land degradation through minimizing uncertainty and greater convergence among stakeholders. In addition, Zero Net Land Degradation (ZNLD) strategy as a new approach can also be achieved when non-degraded land remains healthy and already degraded land is restored, thus reducing to zero the net rate of loss in productive land.

Nowadays, studying intractions between hydrological components and different ecosystems named as ecohydrology has been considered by specilaists and experts. Towards this, ecohydrological studies in rangeland ecosystems are very important due to spatial extension in global and national scales. However, it has not been consered yet. The present study has therefore attempted to present a state of art of the rangeland ecohydrology by revieweing avaialbe literatures and accssible documents. Accordingly, the importantant hydrological components viz. precipitation, evapotranspiration, runoff, sediment, soil erosion and groundwater recharge were considered in comparison with other ecosystems and corresponding conlusion was ultimately drawn.