Few researches about prioritization of sub-WATERSHEDs of WATERSHEDs were conducted to WATERSHED management operations in the world. Cause of existing of professional intervention in traditional method of WATERSHED management office, this research was carried out to prioritization of sub-WATERSHEDs via multi-criteria decision making techniques (TOPSIS and VIKOR method in 12 different weighting conditions) in Asyabjofeth WATERSHED. Problems was divided to 5 criteria as soil erosion and deposition, drought, flood, aridity, socio-economic problem. According to results, first scenario (equal weight of sub criteria) of TOPSIS and VIKOR methods and traditional method conducted same in recognition of two most and least critical sub CATCHMENTS and differed together in recognition of sub WATERSHEDs with moderate critical.

The purpose of this descriptive-correlation study was to investigate personal and social factors influencing rural participation of Hone Jan's Zar Cheshmeh CATCHMENTS in WATERSHED management projects. A close-ended questionnaire was used to gather respondents' opinions and its face validity was established by using a panel of experts consisting of senior faculty members in agriculture extension and education, irrigation and natural resources. Cronbach's alpha, an internal consistency measure, was used to estimate the reliability, and was found to be in acceptable range from 0.81 to 0.87. The target population of this study consisted of all rural people who lived in Hone Jan's Zar Cheshmeh CATCHMENTS (N=4989) out of which, according to Cochran's table, a number of 131 people were selected using statistical sampling in a simple randomization method. Finally, 127 questionnaires were gathered and analyzed (n=127). The results of Spearman test showed that there was a statistically significant positive relationship between age, social participation, social statues, the tendency for collective works, attitude toward participation, innovativeness, and social trust with their participation in WATERSHED management projects. The results of the multivariate regression revealed that 75.7 percent of variability in rural participation in WATERSHED management projects stems from age, social participation, attitude toward participation, innovativeness, and social trust.

Valuable studies have been conducted in recent years to collect water from impermeable urban levels in some parts of the country. Nevertheless, the background of the studies in this field has been poor in south Khorasan province, Iran. This study aims to help urban planners and managers to recognize the potential of water harvesting. The purpose of this study is to identify and prioritize the sub-catchment covered by the rock outcrops playing an important role in runoff production. This work was carried out via the modeling of runoff by empirical methods and the SWMM model in Qaen urban WATERSHED. Accordingly, it is possible to determine the amount of water available for supplemental irrigation of the urban green space and thereby provide a suitable extension pattern for similar areas. The irrigation in the urban park is done by well, which is a major problem for Qaen, as an arid area. About 54% (248. 4 ha) of the basin surface has been populated by the 90% rock outcrops that has high runoff potential and can be useful in planning in terms of high potential of runoff production. Considering the existing facilities and the number of park trees, an approach is needed. The water shortage for supplemental irrigation of this park will compensate, if only 10% of the annual runoff equivalent to 11800 m3 can be harvested and stored during the months with no precipitation.

Studying the various issues related to dam- building projects is of high importance, and the results derived from these increase the success rate in performing such projects. Studies concerning erosion and sedimentation in the WATERSHED CATCHMENTS are among those issues. Ilam Dam is located on the konjancham area and the Amir- Ababd diversion Dam is under construction on the konjancham River, this research then has evaluated the erosion and the sedimentation in the given area from the qualitative and quantitative points of view by using the MPSIAC method in the GIS environment. To do so, after entering the data layers into the GIS environment and combining these layers, area was divided into 336 sedimentation units, of which 216 units are situated above the Ilam Dam. The minimum and maximum amounts of sedimentations in this units 2.3 and 26.7 ton/h/year and the average of produced sediment of the region is estimated by MPSIAC model as 14.98 ton/h/year. The amount of sedimentations in the basin has been estimated at 32994.9 tons per year and The amount of sedimentations of the basin at the dam has been calculated to be 2340309.13 tons per year which is tantamount to 181716.12 cubic Meters per year. Furthermore the amount of sedimentations of the basin at the Amir- Abad diversion dam, without calculating its six above sub- basins, has been estimated to be 265016.77 cubic meters per year. Considering erosion classes and sedimentation intensity, the basin has been divided into classed called low, medium and high classes.

Soil erosion is one of the main problems of WATERSHEDs in Iran. It can also be considered as one of the most important obstacles in achieving sustainable development in agriculture and natural resources. The sediments from the erosion of WATERSHED CATCHMENTS usually reach the river after each rainfall, and are combined with the sediments from the river walls and beds, and, as a result, endanger the effective life of dam storage. As such, quantitative and qualitative study of the soil erosion is vitally important in long term water structure plans. Since the initial study of constructing a dam across the Chikhab river (Moosian Plain in the Province of Ham) is currently underway, the present article makes attempts to present a model and investigate the erosion and sediment of the WATERSHEDs in the study area quantitatively, as well as, qualitatively. Methods for determining soil erosion and the river sediments were evaluated, and the optimum procedures were adopted. Using PSIAC method in a GIS environment, the information layers are produced, adequately weighted, and combined. The given CATCHMENTS were divided into 576 sediment yield units from which 504 units are located in upper part of the likely dam. The minimum and maximum amounts of produced sediment were estimated 1.6 and 27.3 tons per hectare annually. The total amount of produced sediment calculated was 505737.3 tons per year, and the amount of the CATCHMENTS deposit in the dam area reached 397298/3 tons per year equal to 264865/5 cubic meters. In terms of erosional classes and the sediment yield, the given CATCHMENTS were divided into four classes of low, average, high and very high. In this category the given catchment falls in the high erosion class.

Prediction equations for runoff depth from rainfall in small mountainous CATCHMENTS located in the north and south face of the Alborz chain have been derived in this research. For this purpose two CATCHMENTS were selected so as having full and reliable rainfall runoff data and suitable regionally representative distribution over the studying area. The prediction equations have been obtained based on the rainfall depth, antecedent precipitation index and base flow. Statistical methods were used to obtain the multiple linear regression equations, correlation coefficients and the standard error for each of the techniques used for the WATERSHEDs. All peak events greater than 0.7 cms for Amameh representative catchment and also all peak events greater than 1.0 cms for Kasilian representative catchment were considered for analysis and deriving final equations. The standard error of the optimum prediction equations for runoff was 0.248 and 0.205 mm for Amameh and Kasilian representative CATCHMENTS, respectively. Also, the multiple correlation coefficient (R) was 0.842 and 0.857, respectively. Finally, the results of the developed regression equations were extended to the neighboring CATCHMENTS of similar hydrological characteristics.

To day, the progressive of technology and access able various software and also to recognize in significant parameters of soil erosion and sediment yield is provided in possibility of using different mathematical models. The models, demonstrate to create of hydrologicalevents through mathematical relationships between catchment's parameters. Whereas, the results of using some of models has been satisfied for this purpose. Therefore, using of these models is increased in the most WATERSHEDs through more than 40 models. Other side, as the mountainous CATCHMENTS is very complicated, so simulation models are suitable for estimation of erosion and sediment yield. One of the reliable models for above purpose, is known SWAT model. Where is applied in Amameh CATCHMENTS. SWAT model has been modified. At present study, the SWAT model has calibrated by monthly and annually observed data, which is recorded in Amameh stations with monthly and daily estimated data, which are obtained by model. In this study catchment's parameters are used as physical parameters for SWAT model. After calibration process, the model has been evaluated by some of sensitivity testing models such as, Nash - Sutcliff model and P-bias model. This process is shown which some of physical parameters are sensitive among the another parameters of the SWAT model such as, K (Soil erodibility parameters) and n (Roughness coefficient parameters). In final, the determine coefficient of observed value and estimated value is obtained, R2=0.74. This result can be obtained for unpaged CATCHMENTS at same hydrological condition.

The main aim of the current paper is to discuss the important effective variables, particularly synoptic patterns, in creating flood in Masoule basin using flood discharge data in Komadoul station during 20 year period (1984-2003). To achieve the aim, daily average and instantaneous maximum of discharge in mentioned station were used. Data accuracy was done using the data for Chomesghal station and technical report from the unexpected events section in the area. In the study period, among the 181 identified flash flood events, 61 events were chosen between years 1996-2003. Then, based on the most effective creator parameters, they were classified into two main groups; events which were due to atmospheric instability and synoptic patterns and those occurred as a result of combination rainfall and short length of main channel. About 51% and 49% of destructive floods in the study area belong to the first and second groups, respectively. Using the synoptic maps of surface level, 700 and 500 HP, and based on the position of cyclone and anticyclone on basin and their movement over the moisture resources, three specified patterns was distinguished. The cyclonic systems come from Mediterranean Sea and Black Sea, while the anti-cyclonic models mainly come from Caspian Sea and rarely from Black Sea. The result of the research also showed that mentioned systems, based on their characteristics or establishment period on the basin, have been made flood with different magnitude. Among the sampled events, 34, 13, and 14 events were adjusted with one, two and three consecutive day rainfall, respectively. From the temporal point of view, distribution of flood shown that most of them were occurred between Sept. and Oct., late winter and early spring.

Large hydraulic structures and the consequent dangers originated from the break of such structures make the designers apply extreme conditions in their designs. Probable maximum flood (PMF) is one of the design criterions that are widely used in this regard. To calculate PMF, huge data and information such as probable maximum precipitation (PMP), storm duration, rainfall temporal pattern and antecedent soil moisture condition are required. This study aims at calculating PMF, considering the conditions governing ungauged CATCHMENTS. For this purpose a combination of effective factors affecting PMF, especifically rainfall temporal pattern accompanied with different rainfall systems direction and antecedent soil conditions have been evaluated for the rivers located in the east of Hormozgan Province. The results show that combining the observed average of temporal patterns and random block procedure is a relevant approach for the study area.Also the results show sensitivity of PMF to antecedent soil moisture and not significant response of PMF to the rainfall systems direction.

This papare is resaults of analysing the data which reported from a harvesting project. The site for collecting data is buildings' roofs of Azad Islamic University of Mashhad. A rain gauge and a small reservoir (capacity is 4 cubic meters) were set at this site. Then the amount of precipitation and its runoff were measured during two years (from 1386, Dey, 23 to 1388, Tir, 3).The sample size is 35 observations. The relationship between runoff and rainfall was estimated by regression methods. The best model was chosen by analyzing residuals and testing the Models. Then the runoff were estimated through this model. The 55-year annual rainfalls of Mashhad synoptic station (1951-2005) were selected and frequency analysis was done on them. Then the roofs' runoff was estimated by this frequency analysis for both wet and dry years. The total area of roofs and their mean annual runoff in ordered are 18680 square meters and 8428 cubic meters.