Search results for "Watershed"

Potential for microbial diuron mineralisation in a small wine-growing watershed: from treated plots to lotic receiver hydrosystem

2009

BACKGROUND: Since biological degradation processes are known to be a major driver of the natural attenuation of pesticide residues in the environment, microbial communities adapted to pesticide biodegradation are likely to play a key environmental role in reducing pesticide exposure in contaminated ecosystems. The aim of this study was to assess the diuron-mineralising potential of microbial communities at a small-scale watershed level, including a diuron-treated vineyard (pollution source), its associated grass buffer strip (as a river protection area against pesticide runoff) and the lotic receiver hydrosystem (sediments and epilithon), by using radiorespirometry. RESULTS: Comparison of r…

Derivation of a Distributed Unit Hydrograph Integrating GIS and Remote Sensing

2007

The paper describes the results of a study based on the integration of remote sensing and geographical information system techniques to evaluate a distributed unit hydrograph model linked to an excess rainfall model for estimating the streamflow response at the outlet of a watershed. Travel time computation, based on the definition of a distributed unit hydrograph, has been performed, implementing a procedure using (1) a cell-to-cell flow path through the landscape determined from a digital elevation model (DEM); and (2) roughness parameters obtained from remote sensing data. This procedure allows the taking into account of the differences, in terms of velocity, between the hillslopes and t…

Advanced SVG Triangulation/Polygonalization of Digital Images

2005

Advanced SVG Rendering of Digital Images

2005

SVG Rendering by Watershed Decomposition

2005

DISCUSSION “Curve Number Derivation for Watersheds Draining Two Headwater Streams in Lower Coastal Plain South Carolina, USA” by Thomas H. Epps, Dani…

2015

Epps et al. (2013) derived Curve Number (CN) values for two forested headwater watersheds in the Lower Coastal Plain of South Carolina during the 2008-2011 period from rainfall-runoff data, resulting in 23 events for the Upper Debidue Creek (UDC) watershed and in 20 events for Watershed 80 (WS80). D’Asaro and Grillone analyzed the P, CN data of the UDC watershed finding an evident “complacent” behavior, characterized by a declining CN with increasing P but without approaching a stable value at large storms. In this case, the traditional runoff CN equation does not fit well with the rainfall-runoff data that indicate a partial source area watershed behavior and are more aptly modeled by the …

Sulphur Stored in Forest Soils and the Relative Importance of Organic and Inorganic Forms. Examples from Mont-Lozère (Southern Massif Central)

1995

From studies initiated in 1981, the mean annual hydrochemical budget established in three experiment watersheds at Mont-Lozere demonstrated that sulphur is retained in soils and in arenaceous formations (Lelong et al. 1990). Soils were developed on weathered granite materials that were strongly reworked by periglacial processes. One watershed is covered with grasses (Bassin de la Cloutasse) and the two others by forest. A beech coppice (Fagus sylvatica L.) and a Norway spruce forest (Picea abies (L.) Karst., hereafter shortened to “spruce”) occupy the Bassin de La Sapine (54 ha) and the Bassin of La Latte (20 ha), respectively. Unfortunately, as a result of a parasite attack, a large part o…

Predicting gully occurrence at watershed scale: Comparing topographic indices and multivariate statistical models

2020

In this study, the ability of five topographic indices to predict the gully trajectories observed in two adjacent watersheds located in Sicily (Italy) was evaluated. Two of these indices, named MSPI and MTWI, as far as we know, have never been employed to this aim. They were obtained by multiplying the stream power index (SPI) and the topographic wetness index (TWI), respectively, by the convergence index (CI). The predictive ability of the topographic indices was measured by using both cut-off independent (AUC: area under the receiver operating characteristic curve) and dependent statistics (Cohen's kappa index κ, sensitivity, specificity). These statistics were calculated also for 100 MAR…

Trans-boundary land cover changes and its influences on water crisis: Case study of the Aras River

2020

Abstract In a watershed, disturbing land covers (LCs) are one of the most important factors in the balance and flow rate of water. This study aimed to monitor and model LC changes in the upstream of the Aras River Basin in Turkey over 1984, 2002, 2010 and 2016. The main ground to conduct such an analysis was to mitigate severe economic, social and ecological consequences driven by agricultural activities and dam construction along with probable climate change, which would decrease the water flow from the Aras River to Caspian Sea. The study approach consisted of four main steps: 1) producing LC maps using Landsat satellite images, 2) performing the change analysis, 3) identifying the change…

Linking the Molecular Signature of Heteroatomic Dissolved Organic Matter to Watershed Characteristics in World Rivers

2015

Large world rivers are significant sources of dissolved organic matter (DOM) to the oceans. Watershed geomorphology and land use can drive the quality and reactivity of DOM. Determining the molecular composition of riverine DOM is essential for understanding its source, mobility and fate across landscapes. In this study, DOM from the main stem of 10 global rivers covering a wide climatic range and land use features was molecularly characterized via ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). FT-ICR mass spectral data revealed an overall similarity in molecular components among the rivers. However, when focusing specifically on the contributi…