drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

River flow forecasting plays an important role in planning, management and operation of water resources. To achieve this goal and according to the phenomenon of global warming, it is necessary to simulate the daily time series of rainfall and runoff for future periods. Therefore, it is important to survey the detection of climate change event and its impact on precipitation and runoff in the ba...

  Soil erosion is one of the most threatening issues for crop production and environmental qualities, especially for soil and water resources. Appropriate knowledge about total soil loss and runoff is valuable in order to perform soil and water conservation practices in watersheds. EUROSEM, "a single event, dynamic and distributed model," was developed to simulate soil loss, sediment transporta...

  Soil erosion is one of the most threatening issues for crop production and environmental qualities, especially for soil and water resources. Appropriate knowledge about total soil loss and runoff is valuable in order to perform soil and water conservation practices in watersheds. EUROSEM, "a single event, dynamic and distributed model," was developed to simulate soil loss, sediment transporta...

Today, increase in flood frequency and intensity, and flash flood events have caused environmental issues and increased human and economic losses. As a result, numerous tools and new programs for flood forecasting systems and risk management programs are being used in the relevant period. There are models that make it easy to be used for this purpose. In this research, MISDc model was applied t...

چکیده روش های متعددی برای برآورد رواناب حاصل از بارش در حوضه های آبریز وجود دارد. یکی از این روش ها استفاده از مدل های هیدرولوژیکی است. با استفاده از مدل های هیدرولوژیکی و شبیه سازی فرآیندهای هیدرولوژیکی می توان با صرف کمترین زمان و هزینه، رواناب و مولفه های دیگر چرخ? هیدرولوژیکی را برآورد کرد. از آنجا که در حوضه های آبریز اندازه گیری تمام کمیت های مورد نیاز برای تحلیل رواناب ممکن نیست، انتخاب...

This study aims to simulate runoff and runoff quality of Zarrineh river basin by SWAT model. Calibration and verification were done respectively with monthly runoff statistics in SWAT CUP by SUFI2 method for 1992-2013, for 12 sub basin, 226 HRU and monthly nitrate data for 2006-2009. The highest runoff sensitivity and runoff quality with minimum Pvalue and maximum absolute value Ttest belong to...

   Hydrological models are simplified representation of the real basin system, which helps to assess basin function in response to different inputs and better understanding of hydrological processes. The HEC-HMS model is one of the most important hydrological models for Flood estimating volumes and discharge in watersheds. In this research, the HEC-HMS hydrologic model was used to simulate the ...