Modeling diffuse pollution with a distributed approach

2002 ◽  
Vol 45 (9) ◽  
pp. 149-156 ◽  
Author(s):  
L.F. León ◽  
E.D. Soulis ◽  
N. Kouwen ◽  
G.J. Farquhar
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Geographical Information Systems ◽  
Diffuse Pollution ◽  
Geographical Information ◽  
Nutrient Concentrations ◽  
Source Modeling ◽  
Response Unit ◽  
Distributed Approach ◽  
Group Response

The transferability of parameters for non-point source pollution models to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse pollution modeling. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modeling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. The distributed approach for the water quality model for diffuse pollution in agricultural watersheds is described in this paper. Integrating the model with data extracted using GIS technology (Geographical Information Systems) for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve non-point source modeling at the watershed scale level.

Consequences of diffuse pollution on the water quality of rivers in the watershed of the lagoon of Venice (Italy)

1999 ◽  
Vol 39 (3) ◽  
pp. 113-120 ◽  
Author(s):  
G. Bendoricchio ◽  
L. Calligaro ◽  
G. M. Carrer
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Nitrogen Concentration ◽  
Monitoring Program ◽  
Diffuse Pollution ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
Lagoon Of Venice ◽  
Point Source Pollution ◽  
Monitoring Programs

The results of three water quality monitoring programs implemented in the watershed of the Lagoon of Venice are presented. The programs focus on nutrient discharge because of its critical effect on eutrophication of the Lagoon. One of these programs is concerned with the long term variation of water quality. It shows the positive effect induced by the interventions on point source pollution of urbanised areas. It results in the reduction of ammonia concentration and in the increase of dissolved oxygen downstream of major cities. It also shows the negative effect of increases in corn crops in upland areas on the nitrate nitrogen concentration at the sources of major rivers. The short term monitoring program shows the quick variation of nutrient concentrations during rain events in the rivers, and the close relation between the diffuse pollution sources and the deterioration of water quality. The total nutrient loads measured at the monitored river outlets confirm the loads predicted by mathematical models for the whole basin, and the importance of the diffuse pollution loads on the global loads discharged into the Lagoon. The progress in reduction of point source pollution increases the role of the diffuse sources, and demands for urgent and strong intervention on those to reach the final goal of stable mesotrophic conditions in the water body. Finally, data analysis of the monitoring programs also indicates an effective strategy for further monitoring of the river basin focused on the effectiveness of the pollution abatement program, and the real time control of water quality for the management of the Lagoon of Venice.

A geographic information system screening tool to tackle diffuse pollution through the use of sustainable drainage systems

2014 ◽  
Vol 69 (10) ◽  
pp. 2066-2073 ◽  
Author(s):  
Zorica Todorovic ◽  
Neil P. Breton
Keyword(s):  
Water Quality ◽  
Information System ◽  
Flood Management ◽  
Diffuse Pollution ◽  
Geographical Information ◽  
Drainage Systems ◽  
Wide Range ◽  
Diffuse Pollutant Sources ◽  
Traditional Approaches ◽  
Sustainable Drainage Systems

Sustainable drainage systems (SUDS) offer many benefits that traditional solutions do not. Traditional approaches are unable to offer a solution to problems of flood management and water quality. Holistic consideration of the wide range of benefits from SUDS can result in advantages such as improved flood resilience and water quality enhancement through consideration of diffuse pollution sources. Using a geographical information system (GIS) approach, diffuse pollutant sources and opportunities for SUDS are easily identified. Consideration of potential SUDS locations results in source, site and regional controls, leading to improved water quality (to meet Water Framework Directive targets). The paper will discuss two different applications of the tool, the first of which is where the pollutant of interest is known. In this case the outputs of the tool highlight and isolate the areas contributing the pollutants and suggest the adequate SUDS measures to meet the required criteria. The second application is where the tool identifies likely pollutants at a receiving location, and SUDS measures are proposed to reduce pollution with assessed efficiencies.

scholarly journals Water quality assessment of the Triassic aquifer, SE Tunisia, for drinking water supply

2019 ◽  
Vol 98 ◽  
pp. 09002
Author(s):  
Meriem Ameur ◽  
Fadoua Hamzaoui-Azaza ◽  
Moncef Gueddari
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Chemical Composition ◽  
Water Samples ◽  
Geographical Information Systems ◽  
Water Quality Assessment ◽  
Geographical Information ◽  
Multivariate Statistical ◽  
Aquifer System

The Triassic aquifer is located in southereastern Tunisia, in the Medenine region, and being part of Jeffara's multilayer aquifer system. The aquifer is currently overexploited with an exploitation rate of 163%, which led to a generalized drop in the piezometric level in the order of 20 cm/year. This study applied conventional techniques such as hydrochemical compositions, multivariate statistical methods and Geographical Information Systems (GIS). To better identify the processes controlling the hydrogeochemical evolution of groundwater quality of Triassic aquifer and its suitability for drinking uses, 14 well water samples from the Triassic aquifer were analysed for physical character and chemical composition. In the groundwater, the respective order of cation and anion concentration was Na>Ca>Mg>K and SO4>Cl>HCO3. The chemical data of water samples from the study area presented by plotting on a Piper diagram reveals the predominance of two hydrochemical types: a Na-Ca-Mg-SO4 facies and a Na-Ca-Mg-Cl-SO4 facies. Analytical results demonstrate that the chemical composition of groundwater in Triassic aquifer is strongly influenced by residence time and flow path. Water quality deteriorates going from southwest to northeast across the region, coincident with the appearance a clay layer limiting the infiltration of rainwater. The majority of ions are above the maximum desirable limits recommended for drinking water by WHO guidelines and Tunisian Standards (NT.09.14). Based on the Water Quality Index (WQI), 36% of water samples of the Triassic aquifer are classified as "poor water" and they cannot be used for drinking purposes without prior treatment.

The Simulation Research on Non-Point Source Pollution in Lianshui Watershed

2012 ◽  
Vol 209-211 ◽  
pp. 2018-2022
Author(s):  
Yuan Nan Long ◽  
Chang Bo Jiang ◽  
Shi Xiong Hu ◽  
Bei Chu
Keyword(s):  
Water Quality ◽  
Point Source ◽  
Assessment Tool ◽  
Coefficient Of Determination ◽  
Dominant Factor ◽  
Nutrient Concentrations ◽  
Point Source Pollution ◽  
Time Step ◽  
Temporal And Spatial Distribution ◽  
Non Point Source Pollution

Non-point source pollution (NPSP) is an important factor that affects water quality. To study the effect of the pollution on water quality, the Soil and Water Assessment Tool (SWAT) is applied to simulate runoff and nutrient concentrations in the Lianshui Watershed. In the monthly time step, the model’s Nash-Sutcliffe coefficient and the coefficient of determination indicated that the values of simulated runoff, nutrient concentrations are acceptably closer to the measured data. Then, the study concluded that NPSP is the dominant factor affecting the water quality of the Lianshui River. Finally, the study also explored the temporal and spatial distribution characteristics of NPSP in the watershed.

scholarly journals Influence of Anykščiai City on Šventoji River Water Quality

2017 ◽  
Author(s):  
Lina Bagdžiūnaitė-Litvinaitienė ◽  
Andrius Litvinaitis ◽  
Laurynas Šaučiūnas
Keyword(s):  
Water Quality ◽  
Point Source ◽  
River Water ◽  
Anthropogenic Activities ◽  
River Water Quality ◽  
Nutrient Concentrations ◽  
Point Source Pollution ◽  
Investigation Period ◽  
The Impact

Increasing migration of nutrients in the river water is a major factor in determining the quality of river water due to anthropogenic activities. In order to preserve the good water quality in rivers and other surface water bodies, it is necessary to take preventive measures that can be scientific water quality research and analysis. According to research carried out in kind, the article analyses the Anykščiai city as point source pollution, and the influence of it to the water quality of Šventoji river. Also, based on the statistical information a nutrient concentrations trend analysis of the meteorological and hydrological con-ditions influence was carried out. Investigations were carried out in July-September of 2016. Concentrations of ammonium (NH4-N), nitrite (NO2-N), nitrate (NO3-N), phosphate (PO4-P) and dissolved oxygen (O2) was analysed. In order to determine the impact of point source pollution on river water quality, the changes in concentration before and beyond Anykščiai city were evaluated, according to the meteorological and hydrological conditions. It was found that total nitrogen (Nb) and total phos-phorus (Pb) concentrations during the investigation period respectively, increases in 6% and 8%.

scholarly journals The Challenges of Regulating Diffuse Agricultural Pollution to Improve Water Quality

2017 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Ronlyn Duncan
Keyword(s):  
Water Quality ◽  
Agricultural Land ◽  
National Policy ◽  
Predictive Modelling ◽  
Diffuse Pollution ◽  
Nutrient Concentrations ◽  
Policy Reforms ◽  
Lag Effects ◽  
Legal Provisions

Worldwide, the cumulative effects of diffuse pollution arising from a range of human activities are diminishing the quality and ecosystem capacity of lakes, rivers, estuaries, and oceans. Devising effective ways to regulate the causes and effects of diffuse pollution is a fraught legal, political, policy, and management challenge given the difficulties in identifying and measuring who is responsible for what, where, and when. In 2011, under its Resource Management Act, 1991, the South Pacific nation of New Zealand introduced national policy to arrest diffuse pollution with a requirement for local government to institute enforceable water quality and quantity limits on all freshwater bodies. The blueprint for these national freshwater policy reforms comes from its South Island region of Canterbury. Canterbury's regional council has adopted a catchment load approach whereby an overarching limit on nutrient losses from agricultural land is calculated and linked to land use rules to control property-scale agricultural activities. With a focus on the Canterbury region, this case study examines two approaches to establishing a catchment load for diffuse nutrient pollution to link to legal provisions in its regional plan. One is based on a river's nutrient concentrations and the other relies on predictive modelling. The case study opens important questions about measuring and regulating diffuse pollution and the difficulties faced by policy-makers and regulators in linking numbers to legally binding compliance and enforcement mechanisms, e.g. how to account for lag effects when establishing ‘in-stream’ limits and how to address changes in software when relying on ‘modelled’ limits?

Vulnerability to diffuse pollution and average nitrate contamination of european soils and groundwater

1995 ◽  
Vol 31 (8) ◽  
pp. 159-165 ◽  
Author(s):  
C. R. Meinardi ◽  
A. H. W. Beusen ◽  
M. J. S. Bollen ◽  
O. Klepper ◽  
W. J. Willems
Keyword(s):  
Atmospheric Deposition ◽  
Groundwater Recharge ◽  
Land Surface ◽  
Geographical Information Systems ◽  
Groundwater Age ◽  
Diffuse Pollution ◽  
Nitrate Contamination ◽  
Geographical Information ◽  
Nitrogen Compounds ◽  
Aquifer Type

From the Atlantic Ocean to the Ural Mountains, European soils are threatened by diffuse pollution from modern agriculture and increased atmospheric deposition. The vulnerability of the soil to diffuse pollution depends on land cover, topsoil features, net precipitation, aquifer type, groundwater recharge and age. The elaboration of the various elements was realized by applying Geographical Information Systems (GISs). Precipitation and the actual evapotranspiration were estimated using meteorological data. The resulting net precipitation is discharged by groundwater recharge and surfacial runoff, with the division of net precipitation in groundwater recharge and surfacial flow following from climate and soil features. The average groundwater age was based on aquifer depth, porosity and the recharge. The vulnerabilities of the soil and groundwater were estimated by establishing a ranking of the combined risks of a diffuse contamination for the topsoil and for groundwater in aquifers. Nitrogen compounds in soils are caused mainly by manuring and fertilization of agricultural lands and atmospheric deposition. The varying doses of fertilizer and manure and the atmospheric deposition of nitrogen compounds were assessed for an actual situation. Only part of the applied doses leached into the soil. The leaching of nitrate to a level of 1 m below land surface was estimated by applying empirical relations derived from the northwest European experience, based on land use, features of the topsoil and net precipitation. The subsequent leaching to deeper strata and a further denitrification also depend on groundwater recharge and aquifer type. The average nitrate concentration in the various aquifers was assessed by estimating the nitrogen doses to European soils in the course of time in combination with the groundwater age. Results, attained using GIS and presented in the form of maps, show the leaching of nitrate concentrations to a level of 1 m below land surface and also the average concentration in the upper aquifer system.

Applicability of modelling tools in watershed management for controlling diffuse pollution

2007 ◽  
Vol 56 (1) ◽  
pp. 147-154 ◽  
Author(s):  
A. Erturk ◽  
M. Gurel ◽  
M.A. Baloch ◽  
T. Dikerler ◽  
A. Ekdal ◽  
...  
Keyword(s):  
Geographical Information Systems ◽  
Agricultural Practices ◽  
Diffuse Pollution ◽  
Geographical Information ◽  
Water Quality Modelling ◽  
High Resolution Data ◽  
Diffuse Sources ◽  
Watershed Models ◽  
Sources Of Pollution ◽  
Mountainous Country

Diffuse pollution is hard to analyze, control and manage by its nature. Watershed models and Geographical Information Systems (GIS) are recently developed tools that aid analysis of diffuse sources of pollution. However, their applications are not always easy and straightforward. Turkey is a typical example of a mountainous country rich in rivers and streams. Due to the complex geomorphology, land-use and agricultural practices in most of the watersheds in Turkey, modelling, analyzing and managing diffuse pollution has been a challenge. The complex watershed structure forces the modellers to work with spatially high resolution data. Apart from the data, the models themselves may also cause operational problems. These issues and their probable solutions form the basis of the discussions in this paper. It acts as a guideline for modelling and analyzing diffuse pollution by emphasizing the referred problems and difficulties. Design of an Information Technology-based system tool for watershed and/or water quality modelling, which would be suitable for countries having watersheds with similar structure and problems to those of Turkey, is also outlined.

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