Hersh Entezami; Sayed Kazem Alavipanah; Hamidreza Matinfar; Ali Darvishi; Kamran Chapi
Abstract
The importance of snow and its water equivalent in water resources supply has caused many studies and researches to measure snow characteristics and runoff. Conducted in the Saqqez Watershed, this research attempted to estimate snow–induced runoff in a mountainous area and the SRM Model was ...
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The importance of snow and its water equivalent in water resources supply has caused many studies and researches to measure snow characteristics and runoff. Conducted in the Saqqez Watershed, this research attempted to estimate snow–induced runoff in a mountainous area and the SRM Model was selected to simulate daily runoff from snow-melt. Based on the data and variables for four consecutive years of 2006 to 2009 collected and snowmelt runoff was estimated. MODIS satellite images were used to calculate the snow coverage area. After segregating the snow coverage from the images, the daily snow area was calculated using GIS, and along with the other variables, imported into the model. For better evaluation of efficiency of the model, the model was calibrated and validated. The process of calibration was led to the best estimate for each parameter. To evaluate the accuracy of model and comparing results with field data Nash-Sutcliffe coefficient and the percentage difference were used. The results of the Nash-Sutcliffe coefficient were between 0.90 to 0.94 and the differences in the volume were 6.8 to 7.2 percent, which indicates the high-performance of modeling.
Shirko Ebrahimi Mohammadi; Seyed Hamidreza Sadeghi; Kamran Chapi
Abstract
In this study, the seasonal variations of discharge and concentrations of soluble nitrite, nitrate, ammonium, orthophosphate and potassium and also the concentrations of these substances during baseflow and rainfall runoff in the seasonal and perennial rivers entering the Zarivar Lake were investigated. ...
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In this study, the seasonal variations of discharge and concentrations of soluble nitrite, nitrate, ammonium, orthophosphate and potassium and also the concentrations of these substances during baseflow and rainfall runoff in the seasonal and perennial rivers entering the Zarivar Lake were investigated. The results showed a great variation of discharge in the spring than the other months because of frequent rainfalls and the maximum discharge in this season. Despite the differences of the stream lake behavior and also the different nature of nutrients, generally, nutrients concentrations have different seasonally significant so that the maximum concentrations and the maximum concentration variations of soluble nitrite, nitrate, orthophosphate and ammonium were seen in summer. The results of the inter and intra storm variability analysis of nutrient concentrations indicated a significant differences between nitrite and nitrate during and between storm events with sig=0 and sig
