نتایج جستجو برای: catchments

تعداد نتایج: 4452  

2010
J. Temnerud J. Fölster I. Buffam H. Laudon M. Erlandsson K. Bishop

Small streams with catchment areas <2 km2 make up the majority of all stream length and are of great ecological importance. Surveys of first and second order streams reveal great spatial and temporal variability in the water chemistry of these headwaters, but their assessment presents a serious challenge since systematic, representative data are usually only collected in larger streams and rive...

2015
M. Staudinger M. Weiler J. Seibert

Meteorological droughts like those in summer 2003 or spring 2011 in Europe are expected to become more frequent in the future. Although the spatial extent of these drought events was large, not all regions were affected in the same way. Many catchments reacted strongly to the meteorological droughts showing low levels of streamflow and groundwater, while others hardly reacted. Also, the extent ...

Journal: :Environmental Modelling and Software 2004
Walter Boughton

The Australian water balance model (AWBM) is a catchment water balance model that calculates runoff from rainfall at daily or hourly time increments. The daily version iss used for water yield and water management studies; the hourly version is used for design flood estimation. This paper describes the origin and development of the AWBM beginning with elementary modelling components of saturati...

2011
C. J. Harman P. A. Troch M. Sivapalan

[1] Assessing the sensitivity of annual streamflow to precipitation is challenging due to the complexity of the processes that control the water balance. A low-dimensional model can be useful to interrogate data in regional assessments of a large number of catchments, and can provide insights into the broad similarities and differences between catchments’ behaviors. This work assesses the sensi...

2001
B. Reynolds C. Neal D. A. Norris

An acid waters sensitivity map has been widely used as a background resource for assessing potential impacts of forest management on stream water acidity within Wales. The validity of this approach has been explored by comparing predicted acid sensitivity with the observed acid neutralisation capacity (ANC) in stream runoff using data sets from two regional surveys of a major area of acidificat...

Journal: :Journal of environmental quality 2010
Christian Leu Manuel K Schneider Christian Stamm

The prediction of diffuse herbicide losses to surface waters using process-based models is data and time demanding. There is a need for simpler and more efficient catchment screening tools. We developed and tested a new proxy for screening catchments for their vulnerability to diffuse herbicide losses relying on widely available river flow data only. The proxy combines the fast flow index (FFI)...

2009
ANDREW L. SHELDON MELVIN L. WARREN

1. We collected adult stoneflies periodically over a 1-year period at 38 sites in two headwater catchments in the Ouachita Mountains, Arkansas, U.S.A. The 43 species collected were a subset of the Ozark-Ouachita fauna and the much larger fauna of the eastern U.S.A. We estimated 78–91% species coverage in the two catchments using jackknife extrapolation of species richness from our survey. 2. Ma...

2003
J. HOLDEN

1 Runoff production in blanket peat catchments of the northern Pennine hills, UK was measured through monitoring and experimentation at the plot, hillslope and catchment scale. Water flow from soil pipes was measured in one of the study catchments and overland flow, throughflow and water table were measured in runoff plots; rainfall simulation and tension-infiltrometry provided information on i...

Journal: :Ecological applications : a publication of the Ecological Society of America 2012
Travis S Schmidt William H Clements Richard B Wanty Philip L Verplanck Stanley E Church Carma A San Juan David L Fey Barnaby W Rockwell Ed H DeWitt Terry L Klein

Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as "historically mined" or "unmine...

2017
Hatim O. Sharif Muhammad Al-Zahrani Jun Xu

A physically-based, distributed-parameter hydrologic model was used to simulate a recent flood event in the city of Hafr Al Batin, Saudi Arabia to gain a better understanding of the runoff generation and spatial distribution of flooding. The city is located in a very arid catchment. Flooding of the city is influenced by the presence of three major tributaries that join the main channel in and a...

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