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.

In regional flood frequency analysis, instead of using the data from a single station, it considers the data AND characteristics of a group of similar stations. This study was carried out in Qazvin PROVINCE AND is based on linear momentum that Hosking AND Wallis are provided this method as a new approach to flood frequency analysis. The results of factor analysis showed that perimeter, equivalent diameter, time of concentration, length of main waterway AND area were the main variables affected flood magnitude. Based on cluster analysis AND using the factors affected flood peak, the remaining 15 stations, were divided into two homogenous regions. Homogeneity of these two regions was confirmed using homogeneity test of L-moments. Based on the best-fit criteria of Zdist, GNO distribution is the best fit for the entire region but for one AND two homogeneous regions, GLO AND GPA distributions were the best fit, respectively. Parameter values for each of the selected distributions were calculated using linear moments AND discharges with different return periods were estimated using the best regional distribution for all stations. Finally, after drawing of growth curves, the regression relation between average discharges AND watershed areas were obtained at each region. Based on these relationships, at un-gauged locations, peak discharges can be estimated using index flood method for different recurrence interval.

Prediction of runoff is very important in UNGAUGED CATCHMENTS to design hydraulic structures. Estimation of the parameters of the rainfall-runoff in many cases is not simple. Therefore, hydrologists usually attempt to develop AND apply simple AND even accurate enough methods to model runoff in such catchment. In this study, the Nash storage coefficient (k) was defined as a function of time of concentration by combining the Nash AND Clark models AND assuming the number of reservoir be 5. A non-dimensional equation to obtain synthetic unit hydrograph of CATCHMENTS was presented based on the Nash instantaneous unit hydrograph. In the new equation flow discharge is a function of time AND time of concentration. The model was used to simulate runoff in Kasilain catchment, North of Iran, AND Ajay, India. The results showed that the efficiency coefficient for three of four events is higher than 0. 82 for Kasilian AND for four events varied from 0. 78 to 0. 89 for Ajay catchment. The error value for peak flow prediction was from 5. 3 to 9. 7 for the Kasilian catchment. The mean of error value for four events was 7. 8 for Ajay. Generally, the accuracy of the prediction of the new model was shown to be satisfactory in the two CATCHMENTS.

Grouping of CATCHMENTS based on their climatic factors AND physiographic characteristics is a prerequisite for regional analysis of runoff AND its use for estimating discharge of CATCHMENTS without discharge measurement station. In this study, CATCHMENTS located in Ardabil PROVINCE were separated into homogeneous hydrological zones using discharge, mean annual precipitation AND physiographic characteristics of CATCHMENTS AND hierarchical clustering method. Due to the large number of parameters, by using principal component analysis, the first four components with 83. 6% of total variance were selected as inputs for cluster analysis. Then, the optimal number of clusters was determined by using hierarchical method AND drawing the tree diagram, AND finally the final clustering was done by K-means method. Subsequently, the sub-CATCHMENTS that followed a hydrological process were identified using the Dalrymple uniformity test. The results of the uniformity test showed that by excluding stations outside the confidence limits of each cluster, CATCHMENTS that were similar in terms of annual discharge AND other physiographic AND meteorological parameters were clustered. Therefore, the number of sub CATCHMENTS located in clusters 1, 2, 3 AND 4 were 8, 4, 9 AND 9 CATCHMENTS, respectively, which can be used in regional analysis to estimate runoff AND floods in CATCHMENTS without discharge measurement data.

Study of the snowpack in the mountainous CATCHMENTS is important from different aspects including the assessment of river yield or the avalanche control. Lack of data AND low accuracy models for distributed simulation, especially on issues related to snow depth AND cover, are however serious obstacles in such analysis. This research aimed to develop an appropriate algorithm for snowmelt AND snow pack distributed simulation, in UNGAUGED snow capped CATCHMENTS. In this regard the snowpack of the region was spatially simulated, using snow balance equation AND SRM (Snow Runoff Model) snowmelt algorithm. Additionally, the SWIFT algorithm was embedded in the model incorporating slope AND aspect for calculation of radiation. Finally, the model is linked to the SWAT model to use its data generation capabilities AND also calculate runoff. Comparison of the model with observation data in Imamzadeh Davoud catchment, Iran, showed acceptable performance of developed algorithm in mountainous basins relying only on readily available data.

Hydrological models are one of the currently used techniques for simulating runoff produced from rainfall. These models by simulation of rainfall-runoff process, are able to estimate runoff values in UNGAUGED cachments without spending high cost AND long time. AWBM rainfall-runoff model developed by Boughton in 1993, can calculate runoff based on hourly AND daily rainfall. Daily AND hourly results obtained from the modelling are used in flood management AND planning, respectively. This model includes set of surface storage parameters (C1, C2, C3), partial area parameters (A1, A2, A3), AND using daily rainfalls AND discharges, monthly runoffs AND evaporations. In this study, in order to evaluate the model performance, six sub-CATCHMENTS located in the south of Sistan AND Balochestan PROVINCE were chosen under a case study. The analysis was carried out by the available data from these sub-catchment including Bah in Sistan AND Balochstan PROVINCE. Daily rainfall data by using TPSS method were converted to regional data AND daily diacharge to specific discharge in mm. Finally, accurancy AND efficiency of the AWBM model in simulating runoff evaluated by efficiency was AND determination cofficients. The results show the model can simulate runoff reasonably in all sub-CATCHMENTS under study AND other UNGAUGED CATCHMENTS, AND also can be used as a useful tool for research AND modelling hydrological process of rainfall-runoff in CATCHMENTS located in arid AND semi-arid regions.

In this study, to simulate streamflow time series in UNGAUGED CATCHMENTS, the parameters of two HBV AND IHACRES hydrological models were transfer from gauged (donor) to UNGAUGED CATCHMENTS using three main regionalization methods including Physical Similarity (PS), Multiple Regression (MR), Spatial Proximity (SP) AND an integrated method (IDW-PS). This study was carried out using daily data including precipitation, temperature AND evaporation related to at 21 sub-CATCHMENTS in Hamoun-Jazmourian River Basin in southeast Iran over a 14-year period (2004-2016). Regionalization methods were studied under three modes: temporal (transferring across different periods), spatial (transferring between same calibration periods but different sites) AND spatiotemporal (transferring across both different periods AND sites). The results indicated that: (1) the more complex HBV model showed better results than the simple model, so that the average NSE coefficients in two different periods in the HBV model were 0. 625, 0. 57 AND 0. 5 for calibration, validation AND the most appropriate regionalization method (physical similarity) respectively, while these values for IHACRES model were 0. 57, 0. 51 AND 0. 46, (2) multiple regression method with mean NSE coefficients equal to 0. 2 AND 0. 24 for HBV AND IHACRES models showed the worst regionalization results AND (3) the HBV parameters related to snow AND runoff components, were associated with the highest AND the lowest uncertainties respectively, while for the IHACRES, the most AND least robustness parameters were plant stress threshold factor, f AND the proportion of slow flow to total flow, vs, respectively.

The central issue of the present paper is the study of the causes of the mother tongue decline in the Sahne city in Kermanshah PROVINCE. The issue of language is beyond the dialect of people AND is refer to the form of life AND the matter of macroeconomic AND political relations. From this perspective, the form of life AND the language associated with it explain the praxis of the members of the society. The appropriate method of examining the problem should be able to analyze the justification of agents to their situation, that is why Grounded Theory is chosen as the method of this research AND data analysis is taken from abduction reasoning. The results of the analysis introduced the categories of globalizing, modernizing, de-use of language, economic necessity AND the government as the most important factors of local language fading. In this essay the meaning of globalization is the globalizing of special type of economic relation that explain other categories role in the process of fading of languages.