The Experts below are selected from a list of 299373 Experts worldwide ranked by ideXlab platform
Carolann K Maslanka - One of the best experts on this subject based on the ideXlab platform.
-
the potential contribution of urban Runoff to surface sediments of the passaic river sources and chemical characteristics
Chemosphere, 1999Co-Authors: William J Walker, Richard P Mcnutt, Carolann K MaslankaAbstract:Abstract Urban Runoff has been reported as the second most frequent cause of surface water pollution in the United States. Due to the incidence of Runoff in urban areas, it was of interest to estimate the impact Runoff may have to recent sediment quality within the lower reaches of the Passaic River. Study objectives included i) review of recent urban Runoff studies to determine the occurrence and pattern of distribution of chemicals in Runoff; ii)comparison of the “fingerprints” from urban Runoff studies to the contaminant distributions in surface sediments from the River; and iii) estimation of mass loadings to the surface sediments using surrogate data. The analyses showed that metals and PAH distributions in the sediments were similar to those observed in Runoff from diverse locations, suggesting that urban Runoff composition within the Passaic watershed is similar to other urban areas. Mass loading calculations demonstrated that urban Runoff is a significant source of the metals observed in the sediments, and that PAH and DDT sediment loadings could, in some cases, be accounted for by urban Runoff. Observed sediment loads for PCBs, however, were significantly higher than were estimated from urban Runoff.
Eric F Wood - One of the best experts on this subject based on the ideXlab platform.
-
global Runoff anomalies over 1993 2009 estimated from coupled land ocean atmosphere water budgets and its relation with climate variability
Hydrology and Earth System Sciences, 2012Co-Authors: Simon Munier, Hindumathi Palanisamy, Philippe Maisongrande, Anny Cazenave, Eric F WoodAbstract:Whether the global Runoff (or freshwater discharge from land to the ocean) is currently increasing and the global water cycle is intensifying is still a controversial issue. Here we compute land–atmosphere and ocean–atmosphere water budgets and derive two independent estimates of the global Runoff over the period 1993–2009. Water storage variations in the land, ocean and atmosphere reservoirs are estimated from different types of data sets: atmospheric reanalyses, land surface models, satellite altimetry and in situ ocean temperature data (the difference between altimetry based global mean sea level and ocean thermal expansion providing an estimate of the ocean mass component). These data sets are first validated using independent data, and then the global Runoff is computed from the two methods. Results for the global Runoff show a very good correlation between both estimates. More importantly, no significant trend is observed over the whole period. Besides, the global Runoff appears to be clearly impacted by large-scale climate phenomena such as major ENSO events. To infer this, we compute the zonal Runoff over four latitudinal bands and set up for each band a new index (combined Runoff index) obtained by optimization of linear combinations of various climate indices. Results show that, in particular, the intertropical and northern mid-latitude Runoffs are mainly driven by ENSO and the Atlantic multidecadal oscillation (AMO) with opposite behavior. Indeed, the zonal Runoff in the intertropical zone decreases during major El Nino events, whereas it increases in the northern mid-latitudes, suggesting that water masses over land are shifted northward/southward during El Nino /La Nina. In addition to this study, we propose an innovative method to estimate the global ocean thermal expansion. The method is based on the assumption that the difference between both Runoff estimates is mainly due to the thermal expansion term not accounted for in the estimation of the ocean mass. We find that our reconstructed thermal expansion time series compares well with two existing data sets in terms of year-to-year fluctuations but somewhat differs on longer (multi-year) time scales. Possible explanations include non negligible steric variations from the deep ocean.
-
Global Runoff anomalies over 1993–2009 estimated from coupled Land–Ocean–Atmosphere water budgets and its relation with climate variability
Hydrology and Earth System Sciences, 2012Co-Authors: Simon Munier, Hindumathi Palanisamy, Philippe Maisongrande, Anny Cazenave, Eric F WoodAbstract:Whether the global Runoff (or freshwater discharge from land to the ocean) is currently increasing and the global water cycle is intensifying is still a controversial issue. Here we compute land–atmosphere and ocean–atmosphere water budgets and derive two independent estimates of the global Runoff over the period 1993–2009. Water storage variations in the land, ocean and atmosphere reservoirs are estimated from different types of data sets: atmospheric reanalyses, land surface models, satellite altimetry and in situ ocean temperature data (the difference between altimetry based global mean sea level and ocean thermal expansion providing an estimate of the ocean mass component). These data sets are first validated using independent data, and then the global Runoff is computed from the two methods. Results for the global Runoff show a very good correlation between both estimates. More importantly, no significant trend is observed over the whole period. Besides, the global Runoff appears to be clearly impacted by large-scale climate phenomena such as major ENSO events. To infer this, we compute the zonal Runoff over four latitudinal bands and set up for each band a new index (combined Runoff index) obtained by optimization of linear combinations of various climate indices. Results show that, in particular, the intertropical and northern mid-latitude Runoffs are mainly driven by ENSO and the Atlantic multidecadal oscillation (AMO) with opposite behavior. Indeed, the zonal Runoff in the intertropical zone decreases during major El Niño events, whereas it increases in the northern mid-latitudes, suggesting that water masses over land are shifted northward/southward during El Niño /La Niña. In addition to this study, we propose an innovative method to estimate the global ocean thermal expansion. The method is based on the assumption that the difference between both Runoff estimates is mainly due to the thermal expansion term not accounted for in the estimation of the ocean mass. We find that our reconstructed thermal expansion time series compares well with two existing data sets in terms of year-to-year fluctuations but somewhat differs on longer (multi-year) time scales. Possible explanations include non negligible steric variations from the deep ocean.
-
evaluating gcm land surface hydrology parameterizations by computing river discharges using a Runoff routing model application to the mississippi basin
Journal of Applied Meteorology, 1994Co-Authors: Glen E Liston, Y C Sud, Eric F WoodAbstract:Abstract To relate general circulation model (GCM) hydrologic output to readily available river hydrographic data, a Runoff routing scheme that routes gridded Runoffs through regional- or continental-scale river drainage basins is developed. By following the basin overland flow paths, the routing model generates river discharge hydrographs that can be compared to observed river discharges, thus allowing an analysis of the GCM representation of monthly, seasonal and annual water balances over large regions. The Runoff routing model consists of two linear reservoirs a surface reservoir and a groundwater reservoir, which store and transport water. The water transport mechanisms operating within these two reservoirs are differentiated by their time scares, the groundwater reservoir transports water much more slowly than the surface reservoir. The groundwater reservoir feeds the corresponding surface store and the surface stores are connected via the river network. The routing model is implemented over the GEW...
Benoit Sarrazin - One of the best experts on this subject based on the ideXlab platform.
-
Detecting surface Runoff location in a small catchment using distributed and simple observation method
Journal of Hydrology, 2015Co-Authors: Judicael Dehotin, Pascal Breil, Isabelle Braud, Alban De Lavenne, Mickael Lagouy, Benoit SarrazinAbstract:Surface Runoff is one of the hydrological processes involved in floods, pollution transfer, soil erosion and mudslide. Many models allow the simulation and the mapping of surface Runoff and erosion hazards. Field observations of this hydrological process are not common although they are crucial to evaluate surface Runoff models and to investigate or assess different kinds of hazards linked to this process. In this study, a simple field monitoring network is implemented to assess the relevance of a surface Runoff susceptibility mapping method. The network is based on spatially distributed observations (nine different locations in the catchment) of soil water content and rainfall events. These data are analyzed to determine if surface Runoff occurs. Two surface Runoff mechanisms are considered: surface Runoff by saturation of the soil surface horizon and surface Runoff by infiltration excess (also called hortonian Runoff). The monitoring strategy includes continuous records of soil surface water content and rainfall with a 5 min time step. Soil infiltration capacity time series are calculated using field soil water content and in situ measurements of soil hydraulic conductivity. Comparison of soil infiltration capacity and rainfall intensity time series allows detecting the occurrence of surface Runoff by infiltration-excess. Comparison of surface soil water content with saturated water content values allows detecting the occurrence of surface Runoff by saturation of the soil surface horizon. Automatic records were complemented with direct field observations of surface Runoff in the experimental catchment after each significant rainfall event. The presented observation method allows the identification of fast and short-lived surface Runoff processes at a small spatial and temporal resolution in natural conditions. The results also highlight the relationship between surface Runoff and factors usually integrated in surface Runoff mapping such as topography, rainfall parameters, soil or land cover. This study opens interesting prospects for the use of spatially distributed measurement for surface Runoff detection, spatially distributed hydrological models implementation and validation at a reasonable cost. (C) 2015 Elsevier B.V. All rights reserved.
Narayan C. Ghosh - One of the best experts on this subject based on the ideXlab platform.
-
Normalized Antecedent Precipitation Index Based Model for Prediction of Runoff from Un-Gauged Catchments
Water Resources Management, 2021Co-Authors: Narayan C. Ghosh, Rahul Kumar Jaiswal, Shakir AliAbstract:The ‘Normalized Antecedent Precipitation Index (NAPI)’ model developed based on water balance equation was found capable to predict Runoff yields from ungauged catchment when its parameters estimated from the gauged catchment are updated using the linear relationship of geomorphologic parameters of an ungauged to that of the gauged catchment, and cumulative geomorphologic index (CGI). The CGI was developed by assigning a relative weight on each geomorphologic parameter multiplied by the ratio of characteristic value of that parameter of the ungauged and gauged catchment. Influence of land-use and land-cover (LULC) on the model’s parameters was also analyzed by developing an index for LULC. The NAPI model has three parameters and its mathematical structure has rational form and the parameters possessed resonance with curve number (CN) of the SCS (Soil Conservation Services) model. The NAPI model demonstrated ability to simulate rainfall-Runoff events both as direct and inverse problem. Performances of the model to predictions of Runoffs from ungauged catchments were also tested with the data of two observation sites of the Bina basin in Madhya Pradesh (India) considering the data of one site as the Runoffs from the ungauged catchment. The results exhibited a close match between the computed and observed values when the model’s parameters were also updated by the index of LULC.
-
Urban stormwater Runoff treatment of Nainital Lake's catchment: an application of ballasted sand flocculation technology
Water Supply, 2018Co-Authors: Sumant Kumar, Absar Ahmad Kazmi, Narayan C. Ghosh, Vinod Kumar, Ankur RajpalAbstract:Abstract Stormwater Runoffs are one of the primary causes for deteriorating water quality in the Nainital Lake, India – a prominent tourist attraction and the sole drinking water source for the habitants of Nainital City. Treatment of fluctuating Runoffs and contaminant influxes before mixing with the lake's water by conventional methods would require a large land footprint, which is a big constraint in the Nainital because of the hilly region. Ballasted sand flocculation (BSF) technology requires much less land footprint; a full-scale 1 MLD capacity pilot plant was applied for treatment of stormwater Runoffs of the Nainital Lake. Twenty-eight storm events were monitored for Runoff characterization and for evaluating the performance of BSF technology. The Runoff water showed marked variation especially for total suspended solids (TSS), total phosphorus (TP), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total coliform (TC) and fecal coliform (FC) with maximum concentrations of 964 mg/l, 2.35 mg/l, 520 mg/l, 299 mg/l, 21 × 105 MPN/100 ml and 14 × 104 MPN/100 ml. The performance analyses results of the pilot plant revealed that the contaminants including trace metals in the stormwater Runoff were reduced appreciably and the pollutant removal efficiencies were found to be largely unaffected by fluctuation of the influent contaminants' concentration.
William J Walker - One of the best experts on this subject based on the ideXlab platform.
-
the potential contribution of urban Runoff to surface sediments of the passaic river sources and chemical characteristics
Chemosphere, 1999Co-Authors: William J Walker, Richard P Mcnutt, Carolann K MaslankaAbstract:Abstract Urban Runoff has been reported as the second most frequent cause of surface water pollution in the United States. Due to the incidence of Runoff in urban areas, it was of interest to estimate the impact Runoff may have to recent sediment quality within the lower reaches of the Passaic River. Study objectives included i) review of recent urban Runoff studies to determine the occurrence and pattern of distribution of chemicals in Runoff; ii)comparison of the “fingerprints” from urban Runoff studies to the contaminant distributions in surface sediments from the River; and iii) estimation of mass loadings to the surface sediments using surrogate data. The analyses showed that metals and PAH distributions in the sediments were similar to those observed in Runoff from diverse locations, suggesting that urban Runoff composition within the Passaic watershed is similar to other urban areas. Mass loading calculations demonstrated that urban Runoff is a significant source of the metals observed in the sediments, and that PAH and DDT sediment loadings could, in some cases, be accounted for by urban Runoff. Observed sediment loads for PCBs, however, were significantly higher than were estimated from urban Runoff.
