Soghra Malekpurlarki; Zohre Khorsandi kouhanstani; Mohammad Faraji
Abstract
Conservation and utilization of water resources are principles of sustainable development of each country. Surface waters or rivers are one of the most important water resources which have important role in supplying water demands in different sectors such as agriculture, industry, drinking water and ...
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Conservation and utilization of water resources are principles of sustainable development of each country. Surface waters or rivers are one of the most important water resources which have important role in supplying water demands in different sectors such as agriculture, industry, drinking water and energy. Shavoor River which is one of the effective rivers in Shoosh City is important due to its quality in water urban and agricultural usages. Land use and its changes have important effects on river water quality. In this research, the effect of land use change is investigated in water quality of Shavoor River in 1985-2015. For this reason, land use maps of 1985 and 2015 were prepared by satellite imageries and land use changes were investigated. Results showed an increase in residential and agricultural lands and a reduction in rangelands and forests. Also, the changing trend of water quality factors in Shavoor River was studied with Mann-Kendall test and graphs. Results demonstrated that the changes overall trend of Hco3, Cl, TDS, EC, Ca, Mg and So4 were increasing in the period. According to meaningful changes of parameters, it can be concluded that the increase in residential and agricultural lands and reduction in rangelands and forests cause the water quality of Shavoor River in the study period.
nasim arman; Ali Shahbazi; mohammad faraji; somaieh dehdari
Abstract
Water harvesting and surface runoff control systems are the important components of urban planning and development and ignoring these issues is likely to raise crisis. In order to decrease the urban flood damages, the urban runoff is needed to be evaluated correctly. Today some of models are developed ...
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Water harvesting and surface runoff control systems are the important components of urban planning and development and ignoring these issues is likely to raise crisis. In order to decrease the urban flood damages, the urban runoff is needed to be evaluated correctly. Today some of models are developed for urban runoff simulation. One of the most important models in evaluating and management of urban runoff is SWMM. The aim of this study is to evaluate SWMM efficiency on urban runoff simulation in Izeh urban basin. To define design rain, concentration time was computed while considering the duration of the cloudburst as equal to this time. Also three performance indexes of Nash-Sutklif, errors sum of squares and Bias were used in order to model calibration and validation. Moreover, areas of high susceptibility were determined for two, five, 10, 20 and 50 years of return periods. Later, it was found that the principle reason of inundation is the lack of sufficient capacity of water ways. In some points, even with sufficient capacity, inundation occurs, confirmed by model. In these cases the causes stem from the improper design and construction of bridges which has lessen the size of water ways and caused junk clogging. Three rainfall events were recorded on March 13, 2017, March 28, 2017 and April 6, 2017 which were considered in order to calibrate and evaluate the model performance. Along with that, the discharge, depth and velocity of water at the outlet were considered as well. The results of the SWMM application gave indication of a good matchup between discharge, depth and the velocity of runoff for observed and estimated data. In this case, this model could be utilized to well predict the inundation hazard, design and the estimation of the cost and volume of drainage systems, management of watershed and prioritization of region to address flooding issues.
Zahra Faghfouri; Nasim Arman; Mohammad Faraji; Zohreh Khorsandi
Abstract
Whereas investigation of effective factors in soil erosion and sediment yield, we can`t introduce specific factors basically as a main factors in water erosion. In fact, erosion condition in an area is a result of contract effect of impressive factors collection in erosion. In order to identify the effective ...
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Whereas investigation of effective factors in soil erosion and sediment yield, we can`t introduce specific factors basically as a main factors in water erosion. In fact, erosion condition in an area is a result of contract effect of impressive factors collection in erosion. In order to identify the effective factors in soil erosion and sediment yield in Seied Abad Basin, interrill erosion was determined by average intensity (30 min, 10 year: 40 mmhr-1) using rain simulator in 33 plots. Also, factor analysis, multivariate regression, logistic and Scalogram model were used. Using factor analysis (principal component analysis), between 15 effective variables in sediment ratio, six factors were selected. They were runoff coefficient, sand, rocks susceptibility, soil texture and land use that illustrate %82.009 of variation of data (KMO=0.53). The results of multivariate regression model were almost the same with factor analysis and the results of the Scalogram model confirmed this. Finally, runoff volume (0.02), rock susceptibility (0.001) runoff coefficient (0.00005), and sand percentage (0.00002) were effective factors in soil erosion and sediment yield. In this regard, regarding to these factors, we can conduct policy and planning for decreasing soil erosion and sediment yield.
