نتایج جستجو برای: watershed depend on river system
تعداد نتایج: 9406183 فیلتر نتایج به سال:
Quantifying the effects of watershed management projects is a first step in the evaluation of their efficiency. Selecting suitable index for evaluation is an important concern in an evaluation process and is determined on the basis of project type, evaluation method, required accuracy, and available data. Watershed management projects have been initiated in Goosh-Bahreh Watershed, Khorasan...
Objective: Mashhad metropolis as the second largest religioncity in the world and the second largest metropolis of Iran with an annual 3 million pilgrims have significant direct and indirect effects on the watershed leading to the city and surrounding over the past four decades. There is no collection system and sanitation disposal network in towns and villages within the Torghabeh River. Meth...
The purpose of this study was to determine the relationships between precipitation at the seasonal and annual scale and water discharge per surface area for seven contiguous firstand second-order tributaries of the Rhode River, a small tidal tributary to Chesapeake Bay, Maryland, USA. The goal was to quantify the effects of a wide range of precipitation, representative of interannual variations...
Geographic information system (GIS) has had a great progress in river engineering in recent years. Most of new developed softwares in this area have the GIS abilities or are able to interact with GIS software. The application of GIS in this area is mostly for pre and post processing of input and output data. In this research, water flow of river has been estimated in an ungaged point using ArcV...
We used the Sacramento-San Joaquin River Delta CA (Delta, hereafter) as a model system for understanding how human activities influence the delivery of sediment and total organic carbon (TOC) over the past 50-60 years. Sediment cores were collected from sites within the Delta representing the Sacramento River (SAC), the San Joaquin River (SJR), and Franks Tract (FT), a flooded agricultural trac...
A freshwater fish inventory was conducted from March through August, 2002 in the Alagnak Watershed. The objectives of the inventory were (1) to document species that were expected yet undocumented and (2) to provide initial descriptions of the distributions, abundance, and biologic characteristics of these species. Minnow traps, minnow seines, beach seines, snorkel gear, hand nets, fyke nets, t...
karkhe watershed (kw) with more than 5 million hectares recently encountered many problems in the natural, social and man-made habitats. unsuitable use of land, soil erosion and lack of rainfall are the most destructive factors in this watershed affecting the whole region fundamentally. as expected, these problems have caused a considerable fall in biodiversity in fauna and flora, a decrease in...
Contour filter strips planted with perennial vegetation can be used to improve surface and ground water quality by reducing pollutant, such as NO3-N, and sediment outflow from cropland to a river or lake. Meanwhile, the filter strips of perennial grass with biofuel potentials also have economic benefits of producing ethanol. In this study, The Soil and Water Assessment Tool (SWAT) model was app...
A study coupling sedimentcore incubation and microelectrode measurement was performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19-1.41 g/(m²·d) with an average of 0.62 g/(m²·d) were obtained by core incubations, and diffusive oxygen flux value...
among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...
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