فصلنامه جغرافیا و پایداری محیط
پیاپی 10 (بهار 1393)

Simulation of rainfall - runoff in the watersheds can provide a way to estimate the peak flow and analyze the relationship between rainfall and runoff appropriately. Therefore, the current study aims to investigate the relationship of rainfall - runoff in catchment Kashkan of Lorestan province in which American Soil Conservation Organization method (SCS) was applied stimulating HEC-HMS hydrological model. Kashkan Basin with an area equal to 39/9287 square kilometers and an average slope of 5/19 percent, was divided into seven sub- basins. Daily rainfall and discharge data rate for seven rain gauge and hydrometric stations, Kaka Reza, Chulhul, Afryneh, Poldokhtar, Madyanrud, Syed Ali and Cham Mirage during a 40-year period, from 1995 to 2008, were collected. They were analyzed regarding vegetation, soil, land use, etc. applying SCS. Moreover, the analysis of calculated rainfall-runoff relations and observed rainfall-runoff relations were carried out by HEC-HMS model, using SCS method, and regression method respectively. The findings show that HEC-HMS model has an accuracy of about 94% for the calculation of calculated rainfall - runoff relations and observed rainfall - runoff relationships proving high ability of the model to simulate the rainfall-runoff in catchment Kashkan. In the calibration phase of the model, maximum flow was estimated as 6795 cubic feet per second, while runoff height as 57/6 inches showing more than 80% similarity compared with the observed values (maximum flow of 5777 cubic feet per second runoff height 91/6 inch). Fault simulation parameters are not identical, but they are estimated up to 35 percent. The model performance has more similarity for two sub- basins of Khorramabad and lower Kashkan.

The importance of precipitation forecasting as the most important climatologic element and the basis of all planning, especially in areas where there are significant changes in precipitation regimes, is considerable. The use of artificial neural networks is one of the forecasting methods that have been widely developed in recent years. In this research the data set of some climatologic elements, related to the cold seasons of previous year, were used to forecast the next year precipitations in Kermanshah and Nouje Hamedan synoptic stations. Therefore, time series of seven climatologic elements including mean temperature, precipitation, relative humidity, mixing ratio, vapor pressure, dew point temperature and sea level pressure were entered to the artificial neural networks as input, while next year precipitation was considered as the output of network. Due to nonlinear nature of selected climatologic elements of this research, the multi-layer perceptron (MLP) networks were applied. In fact, they are among the progressive networks with supervising training algorithms and suitable for nonlinear data. Other two categories of training algorithms including BP training algorithms and number normalization algorithm were used for training of networks. Eventually, the combination of these algorithms led to the production of 720 training networks at two stations, and finally the artificial neural network succeeded to proper forecasting of annual precipitation amounts. The best forecast for Kermanshah station is related to the traingd training function with mean and standard deviation normalization algorithm and testerror amount equal to 0.0195 in cold period of the year (overall autumn and winter), and in Nouje station is related to the traingdx training function with pca 0.06 normalization algorithm with testerror amount equal to 0.0047 in the winter.

The aim of the present study is to recognize and analyze the strengths and weaknesses, opportunities and threatens encountered by urban management of Songhor in order to achieve the excellent strategies of urban management. The present study is an applied one with descriptive method. For the data collection and the required information, survey, library and documentary studies were used. Besides, SWOT model was used for data analysis. The population of the study includes all municipality staff and city council of Songhor. The findings indicated that the urban management of Songhor, having 12 factors as weaknesses, 12 factors as strengths, 13 factors as threats and 9 opportunity factors, has been in a desirable situation. Moreover, since the sum of the final score of evaluation of the urban management internal factors of Songhor was (2.90) and the sum of final score of evaluation of the urban management external factors was (3.039), the strategies should be performed so that they cause "growth and recognition" of the system while the strategy of focus including penetration to the market, development of the market and production could be performed. In next priority, the strategies based on vertical integration to the top, vertical integration to the bottom and also horizontal integration that cause the excellence of urban management in Songhor could be implemented. They include the strategies such as edition and performance of urban developments like urban plan CDS, creation of places as representative of the central municipality in different areas of Songhor, providing new sources of income for urban management and participating the citizens in urban management decisions.

Radical increase of soil and water resource losses of watersheds has been increasingly intensified in recent decades which is mostly due to irregular utilization of the resources, exacerbating floods, increasing sedimentation rates and reducing the useful life of reservoirs. The current study, conducted in Hajiabad watershed- Kermanshah province, aims to assess the impact of watershed management practices on runoff storage, reducing flood and flood potential. At first, field surveys were carried out, then mechanical and physical properties of constructed structures were recorded and the data were analyzed. In the next step, the impact of structures on flood and runoff control has been studied using HEC-HMS model and watershed flood simulation. According to the evaluations and frequent field visits, Hajiabad watershed has a low flood potential and most of created runoff penetrate before they reach the watershed outlet. In addition, there was no sediment accumulation indicative of the surface runoff behind constructed flood control structures in the Hajiabad watershed (soil dam, dry stone and gabion). It shows that the amount of constructed structures is much more than the area needs.

Earthquake is considered as one of the issues encountered by many cities worldwide. It is originated to both natural factors such as limiting among Alborz Mountain range, existence of several active faults, and human factors such as the existence of old and inefficiency textures in the center of city and plenty of the unregulated construction ignoring the standard distance from fault. The present study aims to evaluate the earthquake risk-made environmental potential, framework physical, economic and social factors of Tehran. Therefore, distributing some questionnaires among 88 related experts, the data from the indicators of environmental factors, framework physical, economic and social factors related to the quality of buildings, and the seismic vulnerability of the study area were gathered. They were codified and analyzed using SPSS statistical software. Due to qualitative nature of the variables, having rate scale and small samples, T test was applied to the findings. It turns out that environmental, physical and socio - economic factors are at very high, high and medium priority respectively causing moderate to very high risk level. As a matter of fact, environmental factors and socio-economic make the highest and the least risk respectively.

This study aimed to evaluate the efficiency of EPM and MPSIAC in sediment, Razi catchment area with complex topography and diversity of climatic conditions, rock and vegetation. Part of the required data for the models were collected through laboratory studies, rats and other results (maps and reports) comprehensive study of the region that have already been made. Digital map maker and other data were entered computer and all necessary modifications and conversions were done (converting the coordinate system UTM), using GIS software. .According to the aforesaid method, all required data were gathered from digitized ones. Digitizing 100-meter digital elevation model (DEM), digitized model of height was prepared which was used to make slope map and some calculations. Then using GIS capacities and based on the structure of each model, arithmetic and processing operations, needed to produce maps, were done to determine sediment. The findings of the model show that this model can estimate (98%) of moderate intensity of observed sediment. However, EPM model can only calculate 69% of observed sediment basin .Based on the model results, class 2 and class 3 have most erosion and most sedimentation basin respectively.