scholarly journals Challenges of groundwater pollution and management in transboundary basins at the African scale

2021 ◽  
Vol 384 ◽  
pp. 69-74
Author(s):  
Issoufou Ouedraogo ◽  
Marnik Vanclooster
Keyword(s):  
Land Use ◽  
Water Table ◽  
Groundwater Pollution ◽  
Statistical Models ◽  
Nitrate Contamination ◽  
Geographical Information ◽  
Pollution Risk ◽  
Continental Scale ◽  
Deep Aquifers ◽  
Vulnerability Indicator

Abstract. We address the significant knowledge gap for groundwater pollution in Africa methods by assessing groundwater pollution risk at the African scale. To do so, we compiled the most recent continental-scale information on soil, land use, geology, hydrogeology, and topography in a Geographical Information System at the resolution of 15 × 15 km and the 1:60 000 000 scale. We produced a vulnerability map by using the generic DRASTIC vulnerability indicator. This map revealed that groundwater is highly vulnerable in Central and West Africa groundwater basins, where the water table is shallow. In addition, very low vulnerability classes are found in the large sedimentary basins of Africa deserts where groundwater is situated in very deep aquifers. The generic groundwater pollution risk map is obtained by overlaying the DRASTIC vulnerability indicator with current land use. The northern, central, and western parts of the African continent are dominated by high vulnerability classes and very strongly related to water table depths and the development of agricultural activities. Given the availability of data, we concentrate first on nitrate vulnerability mapping. To this end, groundwater nitrate contamination data are compiled in literature using meta-analysis technic and used to calibrate as well linear and nonlinear statistical models; the latter performing much better as compared to simple linear statistical models. This study will help to raise awareness of the manager's International Basin Authorities or Transboundary Basin Organizations in Africa and in particular on transboundary groundwater pollution issues.

Groundwater pollution risk assessment methodology

2003 ◽  
Vol 47 (9) ◽  
pp. 1-7 ◽  
Author(s):  
L. Lytton ◽  
S. Howe ◽  
R. Sage ◽  
P. Greenaway
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Risk Score ◽  
Groundwater Pollution ◽  
Quality Data ◽  
Risk Scores ◽  
Assessment Methodology ◽  
Pollution Transport ◽  
Pollution Risk ◽  
Risk Assessment Methodology

A generic groundwater pollution risk assessment methodology has been developed to enable the evaluation and ranking of the potential risk of pollution to groundwater abstractions. The ranking can then be used to prioritise risk management or mitigation procedures in a robust and quantifiable framework and thus inform business investment decisions. The risk assessment considers the three components of the pollution transport model: source - pathway - receptor. For groundwater abstractions these correspond to land use (with associated pollutants and shallow subsurface characteristics), aquifer and the abstraction borehole. An hierarchical approach was chosen to allow the risk assessment to be successfully carried out with different quality data for different parts of the model. The 400-day groundwater protection zone defines the catchment boundary that forms the spatial limit of the land use audit for each receptor. A risk score is obtained for each land use (potential pollution source) within the catchment. These scores are derived by considering the characteristics (such as load, persistence and toxicity) of all pollutants pertaining to each land use, their on-site management and the potential for the unsaturated subsurface to attenuate their effects in the event of a release. Risk scores are also applied to the aquifer characteristics (as pollutant pathway) and to the abstraction borehole (as pollutant receptor). Each risk score is accompanied by an uncertainty score which provides a guide to the confidence in the data used to compile the risk assessment. The application of the methodology has highlighted a number of problems in this type of work and results of initial case studies are being used to trial alternative scoring methods and a more simplified approach to accelerate the process of pollution risk assessment.

scholarly journals Sustainability of Groundwater Resources of Weathered and Fractured Schists in the Rural Areas of Galicia (Spain)

2021 ◽  
Author(s):  
Javier Samper ◽  
Acacia Naves ◽  
Bruno Pisani ◽  
Jorge Dafonte ◽  
Luis Montenegro ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Table ◽  
Rural Areas ◽  
Groundwater Pollution ◽  
Fractured Rock ◽  
Groundwater Resources ◽  
Nitrate Contamination ◽  
Quality Data ◽  
Balance Model ◽  
Groundwater Supply

Abstract Water supply deficits in droughts, groundwater pollution and climate change are the main challenges for the sustainability of groundwater resources from hard rock aquifers in the rural areas of Galicia (Spain). Here we address the sustainability of groundwater resources of weathered and fractured schists in the rural areas of Abegondo municipality. The conceptualization of the hydrogeology of the study area includes: 1) The regolith, 2) The fractured rock layer; and 3) The underlying fresh bedrock. Groundwater flows mostly through the regolith and the fractured rock. Rainfall infiltration is the source of aquifer recharge. Groundwater discharges in seepage areas, springs and along creeks and valleys. The water table is generally shallow and shows seasonal oscillations of up to 4 m. The equivalent transmissivity ranges from 15 to 35 m2/d. Electrical resistivity tomography identifies a shallow water table and attests that the contact of the fractured rock and the fresh bedrock is highly heterogeneous. Groundwater resources were quantified with a hydrological water balance model. The mean annual recharge is approximately equal to 185 mm. Groundwater recharge at the end of the 21st century could decrease from 6% to 10% due to climate change. The decline in groundwater table could aggravate the shortages during droughts. Groundwater quality data show bacteriological and nitrate contamination due to a poor management of the manure in the fields and occasional discharges of slurry from pig and mink farms. Groundwater management and protection actions are proposed to prevent groundwater pollution and achieve a sustainable groundwater supply in the study area.

scholarly journals Spatial mapping for Groundwater Vulnerability to Pollution Risk Assessment Using DRASTIC Model in Ponnaiyar River Basin, South India

2021 ◽  
Vol 30 (2) ◽  
pp. 355-364
Author(s):  
Ingershal G. Ravindranath ◽  
Venugopal Thirukumaran
Keyword(s):  
Risk Assessment ◽  
Groundwater Contamination ◽  
River Basin ◽  
Groundwater Pollution ◽  
Risk Index ◽  
Geographical Information ◽  
Drastic Model ◽  
Pollution Risk ◽  
Contamination Risk ◽  
Ponnaiyar River

Groundwater is the principle source of drinking water and protection of groundwater quality is an important issue meets out the increasing population and agricultural practices. The present research an attempt made to develop DRASTIC model to understand the groundwater contamination risk in Ponnaiyar River Basin (PRB), Tamil Nadu, India using geographical information system (GIS). GIS have been shown to be useful tools for assessing groundwater pollution hazard. According to Central Ground Water Board reports the PRB categorized by semi-critical groundwater development. In view of the extensive reliance on this basin, contamination of PRB groundwater became an alarming issue. To assess groundwater contamination risk in the PRB the parameters such as Groundwater depth, Net recharge, Aquifer media, Soil media, Topography, Impact of vadose zone and Hydraulic conductivity were selected. Based on the importance of groundwater contamination all the parameters were assigned to rank and weights. Then all the themes were integrated and classified into five categories such as very low (9.33%), low (26.54%), moderate (34.77%), high (22.38%) and very high (6.98) risk. To validate the DRASTIC model, nitrate concentration was selected and found that it is 81.53% accurate which reflects that, DRASTIC model is appropriate to understand groundwater pollution risk assessment. In the GSB groundwater is contaminated mainly due to extensive use of groundwater extraction for agriculture purpose. Groundwater risk index assessment is an effective tool for groundwater management in the PRB.

scholarly journals Modelling the Temporal Dynamics of Groundwater Pollution Risks at the African Scale

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1406
Author(s):  
Issoufou Ouedraogo ◽  
Arthur Girard ◽  
Marnik Vanclooster ◽  
François Jonard
Keyword(s):  
Groundwater Pollution ◽  
Temporal Dynamics ◽  
Nile Delta ◽  
Lake Victoria ◽  
Risk Modelling ◽  
The Sustainable Development ◽  
Pollution Risk ◽  
Annual Variations ◽  
Continental Scale ◽  
Sustainable Development Goal 6

Groundwater pollution risk modelling is an important asset to improve groundwater management and protection. In this study, we assess the temporal dynamics of groundwater pollution risk at the continental scale, using the DRASTIC model. The approach was developed using continental-scale data on soil properties, topography, land use, geology, hydrogeology, and climate with a resolution of 15 × 15 km2. We compared continental-scale groundwater pollution risk for the years 1990, 2000, and 2010. The results showed significant inter-annual variations of the spatial distribution of pollution risk. Changes were mainly concentrated in the area of the Nile Delta, around the Lake Victoria, in North Africa, and in coastal West Africa (predominately in Nigeria). We found that the increase in pollution risk was mainly related to the increase in the population density in these regions. The proposed methodology for modelling the temporal dynamics of groundwater pollution risk could support the monitoring of the Sustainable Development Goal 6, which focus in particular on the preservation of the freshwater resources against future threats.

scholarly journals Groundwater pollution risk in Africa (2016)

2017 ◽  
Author(s):  
Chloé Meyer
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Groundwater Pollution ◽  
Additive Model ◽  
Soil Surface ◽  
Groundwater Vulnerability ◽  
Land Use Land Cover ◽  
Pollution Risk ◽  
Vulnerability Model ◽  
Drastic Method

Groundwater pollution risk is determined both by the intrinsic vulnerability of the aquifer and the existence of potentially polluting activities at the soil surface. This raster has a resolution of 15*15 km. It was generated by combining a groundwater vulnerability model (based on the DRASTIC method) with land use/land cover (from the GlobCoverdatat set) using an additive model. Exposure Groundwater Pollution Risk

Assessment of land-use change in coastal areas through geographical information systems

2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Verónica Lango-Reynoso ◽  
Karla Teresa González-Figueroa ◽  
Fabiola Lango-Reynoso ◽  
María del Refugio Castañeda-Chávez ◽  
Jesús Montoya-Mendoza
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Geographical Information Systems ◽  
Design Methodology ◽  
Scientific Information ◽  
Coastal Ecosystems ◽  
Coastal Areas ◽  
Geographical Information ◽  
Coastal Zones ◽  
Computer Based

Objective: This article describes and analyzes the main concepts of coastal ecosystems, these as a result of research concerning land-use change assessments in coastal areas. Design/Methodology/Approach: Scientific articles were searched using keywords in English and Spanish. Articles regarding land-use change assessment in coastal areas were selected, discarding those that although being on coastal zones and geographic and soil identification did not use Geographic Information System (GIS). Results: A GIS is a computer-based tool for evaluating the land-use change in coastal areas by quantifying variations. It is analyzed through GIS and its contributions; highlighting its importance and constant monitoring. Limitations of the study/Implications: This research analyzes national and international scientific information, published from 2007 to 2019, regarding the land-use change in coastal areas quantified with the digital GIS tool. Findings/Conclusions: GIS are useful tools in the identification and quantitative evaluation of changes in land-use in coastal ecosystems; which require constant evaluation due to their high dynamism.

Analisis Perubahan Tata Guna Lahan di Kabupaten Bantul Menggunakan Metode Global Moran’s I

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Matheus Supriyanto Rumetna ◽  
Eko Sediyono ◽  
Kristoko Dwi Hartomo
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Spatial Autocorrelation ◽  
Land Use Changes ◽  
Geographical Information ◽  
Moran’S I ◽  
Complete Spatial Randomness ◽  
Moran's I ◽  
Global Moran’S I ◽  
Spatial Randomness

Abstract. Bantul Regency is a part of Yogyakarta Special Province Province which experienced land use changes. This research aims to assess the changes of shape and level of land use, to analyze the pattern of land use changes, and to find the appropriateness of RTRW land use in Bantul District in 2011-2015. Analytical methods are employed including Geoprocessing techniques and analysis of patterns of distribution of land use changes with Spatial Autocorrelation (Global Moran's I). The results of this study of land use in 2011, there are thirty one classifications, while in 2015 there are thirty four classifications. The pattern of distribution of land use change shows that land use change in 2011-2015 has a Complete Spatial Randomness pattern. Land use suitability with the direction of area function at RTRW is 24030,406 Ha (46,995406%) and incompatibility of 27103,115 Ha or equal to 53,004593% of the total area of Bantul Regency.Keywords: Geographical Information System, Land Use, Geoprocessing, Global Moran's I, Bantul Regency. Abstrak. Analisis Perubahan Tata Guna Lahan di Kabupaten Bantul Menggunakan Metode Global Moran’s I. Kabupaten Bantul merupakan bagian dari Provinsi Daerah Istimewa Yogyakarta yang mengalami perubahan tata guna lahan. Penelitian ini bertujuan untuk mengkaji perubahan bentuk dan luas penggunaan lahan, menganalisis pola sebaran perubahan tata guna lahan, serta kesesuaian tata guna lahan terhadap RTRW yang terjadi di Kabupaten Bantul pada tahun 2011-2015. Metode analisis yang digunakan antara lain teknik Geoprocessing serta analisis pola sebaran perubahan tata guna lahan dengan Spatial Autocorrelation (Global Moran’s I). Hasil dari penelitian ini adalah penggunaan tanah pada tahun 2011, terdapat tiga puluh satu klasifikasi, sedangkan pada tahun 2015 terdapat tiga puluh empat klasifikasi. Pola sebaran perubahan tata guna lahan menunjukkan bahwa perubahan tata guna lahan tahun 2011-2015 memiliki pola Complete Spatial Randomness. Kesesuaian tata guna lahan dengan arahan fungsi kawasan pada RTRW adalah seluas 24030,406 Ha atau mencapai 46,995406 % dan ketidaksesuaian seluas 27103,115 Ha atau sebesar 53,004593 % dari total luas wilayah Kabupaten Bantul. Kata Kunci: Sistem Informasi Georafis, tata guna lahan, Geoprocessing, Global Moran’s I, Kabupaten Bantul.

scholarly journals Mapping Groundwater Potential for Irrigation, by Geographical Information System and Remote Sensing Techniques: A Case Study of District Lower Dir, Pakistan

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 669
Author(s):  
Abid Sarwar ◽  
Sajid Rashid Ahmad ◽  
Muhammad Ishaq Asif Rehmani ◽  
Muhammad Asif Javid ◽  
Shazia Gulzar ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Table ◽  
Groundwater Potential ◽  
Geographical Information ◽  
Groundwater Potential Zone ◽  
Potential Zone ◽  
Relative Significance ◽  
High Good ◽  
Groundwater Potentiality ◽  
Very High

The changing climate and global warming have rendered existing surface water insufficient, which is projected to adversely influence the irrigated farming systems globally. Consequently, groundwater demand has increased significantly owing to increasing population and demand for plant-based foods especially in South Asia and Pakistan. This study aimed to determine the potential areas for groundwater use for agriculture sector development in the study area Lower Dir District. ArcGIS 10.4 was utilized for geospatial analysis, which is referred to as Multi Influencing Factor (MIF) methodology. Seven parameters including land cover, geology, soil, rainfall, underground faults (liniment) density, drainage density, and slope, were utilized for delineation purpose. Considering relative significance and influence of each parameter in the groundwater recharge rating and weightage was given and potential groundwater areas were classified into very high, high, good, and poor. The result of classification disclosed that the areas of 113.10, 659.38, 674.68, and 124.17 km2 had very high, high, good, and poor potential for groundwater agricultural uses, respectively. Field surveys for water table indicated groundwater potentiality, which was high for Kotkay and Lalqila union councils having shallow water table. However, groundwater potentiality was poor in Zimdara, Khal, and Talash, characterized with a very deep water table. Moreover, the study effectively revealed that remote sensing and GIS could be developed as potent tools for mapping potential sites for groundwater utilization. Furthermore, MIF technique could be a suitable approach for delineation of groundwater potential zone, which can be applied for further research in different areas.

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