نتایج جستجو برای: runoff volume

تعداد نتایج: 328486  

2014
Z. H. He J. Parajka F. Q. Tian G. Blöschl

Degree-day factors are widely used to estimate snowmelt runoff in operational hydrological models. Usually, they are calibrated on observed runoff, and sometimes on satellite snow cover data. In this paper, we propose a new method for estimating the snowmelt degree-day factor (DDFS) directly from MODIS snow covered area (SCA) and ground-based snow depth data without calibration. Subcatchment sn...

2005
J. G. Arnold K. N. Potter K. W. King P. M. Allen

Seasonal cracking of the soil matrix results in poor estimates of runoff and infiltration by simulation models due to the changing soil storage conditions. In this study, soil surface elevation changes were measured every two weeks and soil crack volume was calculated for a two-year period at the USDA-Agricultural Research Service, Riesel Y-2 watershed in central Texas. Soil anchors were placed...

Runoff assessment and estimation is crucial for watershed management as it provides information that is needed to expedite the course of watershed planning and development. The most commonly used model due to its simplicity and versatility in runoff estimation is the soil conservation service curve number developed by the United States Department of Agriculture. The study estimates the surface ...

2013
Usman T. Khan Angus Chu Jianxun He

Bioretention cells are an urban stormwater management technology used to address both water quality and quantity concerns. A lack of region-specific design guidelines has limited the widespread implementation of bioretention cells, particularly in cold climates. In this paper, experimental data are used to construct a multiple linear regression model to predict hydrological performance of biore...

Journal: :Journal of environmental quality 2009
Anthony R Buda Peter J A Kleinman M S Srinivasan Ray B Bryant Gary W Feyereisen

Phosphorus (P) losses from agricultural landscapes arise from the interaction of hydrologic, edaphic, and management factors, complicated by their spatial and temporal variability. We monitored sites along two agricultural hillslopes to assess the effects of field management and hydrology on P transfers in surface runoff at different landscape positions. Surface runoff varied by landscape posit...

2008
BARBRO JOHANSSON Barbro Johansson

A conceptual model is used to calculate the weekly and monthly runoff for about 400 ungauged catchments in the southernpart of Sweden. To improve the performance of the model, a relationship is sought between model parameters and catchment characteristics. In a special study, 11 basins with a mixed geology and land use but with a low lake percentage are investigated. They are all in an area tha...

Journal: :مرتع و آبخیزداری 0
شهرام خلیقی استادیار دانشکدة منابع طبیعی دانشگاه تهران، کرج محمد رستمی خلج دانشجوی دکتری آبخیزداری، دانشکدة منابع طبیعی دانشگاه تهران، کرج محمد مهدوی استاد دانشکدة منابع طبیعی دانشگاه تهران، کرج علی سلاجقه استاد دانشکدة منابع طبیعی دانشگاه تهران، کرج

large impervious surfaces and man-made waterways are the characteristic of urban area. increasing urbanization and rapid growth of cities in recent decades towards the upstream watershed, has been severely affected on rainfall-runoff processes in urban area. therefore, to computer models in order to illustrate these processes the proper design or assessment of urban drainage systems has special...

The process of precipitation – runoff of each basin, is influenced by hydrologic, geomorphology conditions, geological formation and vegetation. There are different methods in drainage basins. One way to estimate the runoff height is Curve Number (CN) method. That reperesents the hydrological behavior of basin. data were collected for statistics of climate and then topographic map of 1: 25000 a...

2014
Jing Qian Li-Ping Zhang Wen-Yan Wang Qiao Liu

In order to evaluate the effects of different slope lengths (1, 2, 3, 4, and 5 m) and different vegetation coverage ratios (20%, 45%, 60%, and 90%) on the mechanisms of nutrient loss and runoff producing processes, we have conducted 14 simulated rainfall experiments. The results show that N and P loss are decided by the concentration and the runoff volume, but when the amounts of N and P in top...

Different factors affect the runoff and sediment production during storm conditions. Among different soil properties, clay content is one of the most important bonding agents for aggregation and infiltration. Rock fragments also affect hydrological and erosional processes, but these relationships in various soil clay contents or surface rock fragments may be positive or negative, thus examinati...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید