نتایج جستجو برای: watershed

تعداد نتایج: 16406  

2012
X. Cui S. Liu

Quantifying the effects of forest changes on hydrology in large watersheds is important for designing forest or land management and adaptation strategies for watershed ecosystem sustainability. Minjiang River watershed, located in the upper reach of the Yangtze River basin, plays a strategic role in the environmental protection and economic and social well-being for both the watershed and the e...

Journal: :مرتع و آبخیزداری 0
اکرم عارفی اصل کارشناس ارشد آبخیزداری، دانشگاه علوم کشاورزی و منابع طبیعی گرگان علی نجفی نژاد استادیار گروه مرتع و آبخیزداری دانشگاه علوم کشاورزی و منابع طبیعی گرگان فرشاد کیانی استادیار گروه خاک شناسی دانشگاه علوم کشاورزی و منابع طبیعی گرگان عبدالرسول سلمان ماهینی دانشیار گروه محیط زیست دانشگاه علوم کشاورزی و منابع طبیعی گرگان

runoff and sediment measurement is difficult in mountain watershed because of many different problems such as time and financial limitations. so using simulation model is necessary in this regard. accuracy and precision evaluation of models for different watershed of iran is necessary. the aim of this study was the evaluation of swat model efficiency in simulation of runoff and sediment yield i...

Journal: :Journal of environmental management 2007
Mingqin Zhang Minghua Zhang

Ammonium nitrogen and total germanium are among the main pollutants in the wastewater discharged from the leather industry. The intake of high concentrations of ammonium nitrogen and/or total germanium harms human health and biological species, as is well documented in literature. This paper focuses on assessing the trends of ammonium nitrogen and total germanium concentrations through time in ...

2013
Pierre Y. Julien Mark L. Velleux Jaehoon Kim

Significant advances in upland erosion modeling have been achieved in the past decade. The TREX (Two-dimensional Runoff, Erosion, and Export) watershed model has been developed at Colorado State University for the simulation of surface runoff from spatially and temporally distributed rainstorms on watersheds. The model has been applied in several countries with different climatic conditions. TR...

2014
James C. Ascough Timothy R. Green Olaf David Gregory S. McMaster Manfred Fink Peter Krause Sven Kralisch

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quantified and modeled. This paper first provides a brief review of current challenges and advances i...

2010
Minha Choi Jennifer M. Jacobs

Soil moisture state and variability control many hydrological and ecological processes as well as exchanges of energy and water between the land surface and the atmosphere. However, its state and variability are poorly understood at spatial scales larger than the fields (i.e. 1 km2) as well as the ability to extrapolate field scale to larger spatial scales. This study investigates soil moisture...

Journal: :Water research 2007
Michele A Burford Suzanne A Johnson Andrew J Cook Timothy V Packer Bradley M Taylor E Robert Townsley

This study examined the correlations between watershed and reservoir characteristics, and water quality parameters related to algal blooms in seven subtropical reservoirs. Analysis of the dissimilarity of physico-chemical parameters resulted in separation of the reservoirs into three main groups: four reservoirs with the highest proportion of agriculture and/or urban land use in their watershed...

2016
Janis L. Thomas Katarina D. M. Pintar Peter M. Wallis Norman F. Neumann

Three tributaries of the Grand River watershed (Ontario, Canada), each representing different watershed types (urban, agricultural/rural, and mixed land-use) were examined to understand the spatial, temporal, and host-source distribution of the waterborne pathogen, Cryptosporidium. Cryptosporidium was frequently found throughout the study (73%, 65/89) with occurrence and concentrations observed...

2012
Mark A. Hanson Brian R. Herwig Kyle D. Zimmer John Fieberg Sean R. Vaughn Robert G. Wright Jerry A. Younk

Constraints on lake communities are complex and are usually studied by using limited combinations of variables derived from measurements within or adjacent to study waters. While informative, results often provide limited insight about magnitude of simultaneous influences operating at multiple scales, such as lake- vs. watershed-scale. To formulate comparisons of such contrasting influences, we...

2015
Jake J. Beaulieu Heather E. Golden Christopher D. Knightes Paul M. Mayer Sujay S. Kaushal Michael J. Pennino Clay P. Arango David A. Balz Colleen M. Elonen Ken M. Fritz Brian H. Hill Andrew C Singer

Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in...

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