نتایج جستجو برای: water erosion

تعداد نتایج: 575644  

Journal: :تحقیقات جغرافیایی 0
احمد نوحه گر دانشگاه هرمزگان احمد نوحه گر دانشگاه هرمزگان احمد نوحه گر دانشگاه هرمزگان محمد کاظمی گروه آبخیزداری دانشگاه هرمزگان

in this research, the applicability of geographic information system (gis) and remote sensing (rs) techniques was tested to assess soil erosion risk with the icona erosion model. this study was carried out in the tange bostanak area because of its variety of diverse landforms, land uses and land covers. the erosion risk assessment phase of this model consists of seven steps that mainly use slop...

Journal: :Environment international 2003
R Lal

Soil erosion is the most widespread form of soil degradation. Land area globally affected by erosion is 1094 million ha (Mha) by water erosion, of which 751 Mha is severely affected, and 549 Mha by wind erosion, of which 296 Mha is severely affected. Whereas the effects of erosion on productivity and non-point source pollution are widely recognized, those on the C dynamics and attendant emissio...

Journal: :Journal of environmental management 2009
John Boardman Mark L Shepheard Edward Walker Ian D L Foster

Soil erosion on agricultural land is a growing problem in Western Europe and constitutes a threat to soil quality and to the ability of soils to provide environmental services. The off-site impacts of runoff and eroded soil, principally eutrophication of water bodies, sedimentation of gravel-bedded rivers, loss of reservoir capacity, muddy flooding of roads and communities, are increasingly rec...

2017
Lei wu Tong Qi Jin Zhang

Soil erosion is the main pathway of nutrients to fresh water in highly erodible regions. In this study, a dynamic erosion-type nonpoint source (NPS) pollution model was proposed to investigate spatiotemporal characteristics of adsorbed NPS total nitrogen (TN) load before and after returning farmland. Results indicate that: 1) the erosion-type NPS TN load showed a significant decreasing trend si...

2016
Florent Gimbert Victor C. Tsai Jason M. Amundson Timothy C. Bartholomaus Jacob I. Walter

Water that pressurizes the base of glaciers and ice sheets enhances glacier velocities and modulates glacial erosion. Predicting ice flow and erosion therefore requires knowledge of subglacial channel evolution, which remains observationally limited. Here we demonstrate that detailed analysis of seismic ground motion caused by subglacial water flow at Mendenhall Glacier (Alaska) allows for cont...

Journal: :Oral diseases 2011
Fj Wegehaupt N Günthart B Sener T Attin

OBJECTIVE The aim of this study was to evaluate the erosive/abrasive enamel wear after contact with orange juices modified with different dietary supplements. METHODS A total of 96 bovine enamel samples were prepared and allocated to eight groups (1-8; n = 12). Samples were eroded (120 s) in 200 ml of the following eight solutions: 1: water (control), 2: orange juice, 3: water + calcium effer...

Journal: :Ecological applications : a publication of the Ecological Society of America 2011
Jason P Field David D Breshears Jeffrey J Whicker Chris B Zou

Rangelands are globally extensive, provide fundamental ecosystem services, and are tightly coupled human-ecological systems. Rangeland sustainability depends largely on the implementation and utilization of various grazing and burning practices optimized to protect against soil erosion and transport. In many cases, however, land management practices lead to increased soil erosion and sediment f...

Journal: :Environmental Modelling and Software 2004
Robert Scott Van Pelt Ted M. Zobeck Ken N. Potter John E. Stout T. W. Popham

The wind erosion stochastic simulator (WESS) is a single event wind erosion model that is the core of the wind erosion submodel of the environmental policy integrated climate (EPIC) erosion model. WESS uses inputs of soil texture, erodible particle diameter, soil roughness, soil water content, crop residue, and 10 min average wind speeds to predict the erosion at several user-selected distances...

2005
James C. Ascough Lajpat R. Ahuja Dennis C. Flanagan

ABSTRACT. Current challenges in soil erosion research have created demand for integrated, flexible, and easily parameterized sediment transport models. Most of the existing monolithic erosion models (e.g., WEPP and WEPS) are not modular, thus modifications require considerable time, effort, and expense. In this paper, the feasibility and challenges of using the Object Modeling System (OMS) for ...

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