نتایج جستجو برای: catchments of velayatroud
تعداد نتایج: 21164525 فیلتر نتایج به سال:
Streamwater was sampled at high flows from 14 catchments with different (0-78%) percentages of broadleaf woodland cover in acid-sensitive areas in the UK to investigate whether woodland cover affects streamwater acidification. Significant positive correlations were found between broadleaf woodland cover and streamwater NO3 and Al concentrations. Streamwater NO3 concentrations exceeded non-marin...
In urban catchments of arid central Arizona, we investigate how the export of mineral and organic nitrogen (N) in storm runoff is regulated by interactions between local landscape characteristics and broader scale storm features. First, we test whether N export is more a function of (1) processes that affect N concentration in runoff or (2) the propensity of the catchment to convey rainfall as ...
Numerous methods are used in the investigation of floods in catchments such as regional flood frequency analysis. Regional flood frequency analysis relies on physical, climatic and ecological characteristics of catchments and applies statistical methods to study flow records. Hosking and Wallis developed Probability Weighted Moments and presented L-moments statistics as a new tool for flood fre...
Following the decline in sulphur deposition in Europe, sulphate dynamics of catchments and the reversibility of anthropogenic acidification of soils and freshwaters became of major interest. Long-term trends in sulphate concentrations and fluxes in precipitation/throughfall and freshwaters of 20 European catchments were analysed to evaluate catchment response to decreasing sulphate deposition. ...
The volume and duration of groundwater discharge following extreme winter recharge events in permeable catchments can often be more disruptive than the peak discharge. An estimation procedure for annual maxima flood series in permeable catchments is extended to annual flood volumes for different durations. Growth factors for durations of 1 to 30 days and return periods of up to 250 years are de...
Regional flood frequency studies are initialized by the delineation of the homogeneous catchments. This study was based on "Region of Influence" concept, aiming to find the similar catchments in the south of Caspian Sea. The methodology utilized the Particle Swarm Optimization Algorithm, PSO, to optimize the fuzzy system over a dataset of catchment properties. The main catchment variables in re...
In this paper, the characterization of catchments extracted from multiscale digital elevation models (DEMs) is performed. First, the lifting scheme is employed to generate multiscale DEMs. The catchments extracted from the generated multiscale DEMs are then characterized based on their numbers. A power law relationship is derived between the number of extracted catchments and the kernel size. T...
Multiple stressors threaten stream physical and biological quality, including elevated nutrients and other contaminants, riparian and in-stream habitat degradation and altered natural flow regime. Unconventional oil and gas (UOG) development is one emerging stressor that spans the U.S. UOG development could alter stream sedimentation, riparian extent and composition, in-stream flow, and water q...
The objective of this paper is to assess the performance of methods that predict low flows and flood runoff in ungauged catchments. The aim is to learn from the similarities and differences between catchments in different places, and to interpret the differences in performance in terms of the underlying climate-landscape controls. The assessment is performed at two levels. The Level 1 assessmen...
Remote Sensing techniques with GIS were used to study the two sub-catchments of the upper catchment of Sukri River, Luni River basin. The measurement and analysis for the two sub-catchments were carried by using GIS for linear, areal and relief aspects. Both sub-catchments have low permeability, high surface run-off, and control of geologic structure. The morphometic analysis and measurements a...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید