among different models for runoff estimation in watershed management, the soil conservation services-curve number (scs-cn) method along with its modifications have been widely applied to ungauged watersheds because of quickly and more accurate estimation of surface runoff. this approach has been widely accepted by hydrologists, water resources planners, foresters, and engineers, as well. theref...

abstract optimal management of water and nutrient could consider as effective on farm method to reduce pollution because agriculture is none point pollution. in this research, an optimal model was presented to reduce nitrate loss in furrow fertigation. the optimal model contains four simulation models for predicting runoff, deep percolation, nitrate concentration in runoff and nitrate concentra...

This study describes and interprets the evolution of grain-size distribution of sediment yields generated in an experimental soil flume subjected to downstream and upstream moving rain storms. Results of laboratory experiments show that downstream moving storms cause more soil loss than do upstream moving storms. The pattern of sediment grain-size evolution in time during a runoff event exhibit...

In this research, The boundaries of the Koya catchment area have been delineated, and valley paths in region were drawn by using Water Modeling System (WMS) software, Analysis morphometric information indicated that characteristics watersheds contribute to floods. average surface runoff depth depends on curve number values are determined based types soil cover class according Harmonized World S...

The usefulness of a hydrologic model is directly related to its application and how well it is calibrated. Calibration is a subjective exercise where model parameters are adjusted to reduce discrepancies between measured data and modeled predictions. Automated calibration can be used to accelerate the model calibration process, minimize modeler bias, and increase the goodness of fit between mea...

arid and semi-arid regions of the world are confronted with limited water resources. a large part of iran is arid and semi-arid and rainfall in arid and semi-arid regions is typically meager, irregular and highly variable. this irregularity affects the hydrological cycle and water resources. investigating the hydrology of the arid and semi arid regions is essential to know this environment and ...