نتایج جستجو برای: sediment yield

تعداد نتایج: 229620  

2016
Charles Gyamfi Ramadhan W. Salim

Intensified human activities over the past decades have culminated in the prevalence of dire environmental consequences of sediment yield resulting mainly from land use changes. Understanding the role that land use changes play in the dynamics of sediment yield would greatly enhance decision-making processes related to land use and water resources management. In this study, we investigated the ...

Journal: :Science 1997
Trimble

Stream channel erosion has long been suspected as the major contributor to long-term sediment yield from urbanizing watersheds. For San Diego Creek in southern California, measurements from 1983 to 1993 showed that stream channel erosion furnished 10(5) megagrams per year of sediment, or about two-thirds of the total sediment yield. Thus, because channel erosion can be a major source of sedimen...

This study was aimed at identification and determination the spatial variations of sediment yield in Qarasu watershed located in Ardebil province, NW Iran, considering the negative consequences of erosion and sediment yield. In this regard, the monthly time scale, as the basis of work, was used to prepare the sediment rating curves. Preparation of monthly sediment rating curves based on sample ...

Journal: Desert 2015
A. Bahrami Ali Talebi, J. Mahjoobi M. Mardian

Managers always consider the precise estimation of sediments in watersheds due to various conditions, such assoil and water resources management, construction, infrastructure and economical and social issues. In this condition,an optimized determination of sediment rating equation (typical method until now for sediment yield estimation) isessential to investigate sediment yield in rivers. In th...

هاشمی, سید علی اصغر , عرب خدری, محمود ,

  In order to quantitatively evaluate the sediment yield in ungauged basins, it is necessary to use empirical models. The EPM model, as a model which is using in Iran, has sometimes been evaluated. Most evaluations have often been conducted by using river's sediment information and direct measurements of dam reservoir sedimentation have been less used, while the sediment measurement method on r...

2006
M. H. Nichols

Small watershed sediment yield data were evaluated for eight small watersheds ranging from 35.2 to 159.5 ha within the United States Department of Agriculture – Agricultural Research Service Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona, USA. Stock pond sediment accumulation measurements covering time periods from 30 to 47 years were combined with water level records and es...

ژورنال: علوم آب و خاک 2008
هاشمی, سید علی اصغر , عرب خدری, محمود ,

  In order to quantitatively evaluate the sediment yield in ungauged basins, it is necessary to use empirical models. The EPM model, as a model which is using in Iran, has sometimes been evaluated. Most evaluations have often been conducted by using river's sediment information and direct measurements of dam reservoir sedimentation have been less used, while the sediment measurement method on r...

Journal: :desert 2015
ali talebi a. bahrami m. mardian j. mahjoobi

managers always consider the precise estimation of sediments in watersheds due to various conditions, such assoil and water resources management, construction, infrastructure and economical and social issues. in this condition,an optimized determination of sediment rating equation (typical method until now for sediment yield estimation) isessential to investigate sediment yield in rivers. in th...

Journal: :journal of agricultural science and technology 2011
a. kouhpeima s. feiznia h. ahmadi s. a. a. hashemi

sediment yield data, collected for most regions in iran has been insufficient and not so reliable and there is still not any sufficiently reliable methodology available for sediment yield assessment in the country as a whole. on the other hand, an attainment of reliable sediment yield data is a must and key requirement for the design of effective sediment management as well as control strategie...

1985
ROBERT B. THOMAS

The "Selection At List Time" (SALT) scheme controls sampling of concentration for estimating total suspended sediment yield. The probability of taking a sample is proportional to its estimated contribution to total suspended sediment discharge. This procedure gives unbiased estimates of total suspended sediment yield and the variance of the estimate while automatically emphasizing sampling at h...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید