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 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.

Regional-scale screening of groundwater pollution risk induced by historical mining activities in Serbia

2016 ◽  
Vol 75 (16) ◽  
Author(s):  
Nebojša Atanacković ◽  
Veselin Dragišić ◽  
Vladimir Živanović ◽  
Sunčica Gardijan ◽  
Sava Magazinović
Keyword(s):  
Groundwater Pollution ◽  
Regional Scale ◽  
Mining Activities ◽  
Pollution Risk ◽  
Historical Mining

scholarly journals Translating the agricultural N surplus hazard into groundwater pollution risk: Implications for effectiveness of mitigation measures in nitrate vulnerable zones

2021 ◽  
Vol 306 ◽  
pp. 107204
Author(s):  
Maria do Rosário Cameira ◽  
João Rolim ◽  
Fernanda Valente ◽  
Marta Mesquita ◽  
Ulrike Dragosits ◽  
...  
Keyword(s):  
Groundwater Pollution ◽  
Mitigation Measures ◽  
Pollution Risk ◽  
Vulnerable Zones

scholarly journals Modelling temporal dynamics of Culicoides Latreille (Diptera: Ceratopogonidae) populations on Reunion Island (Indian Ocean), vectors of viruses of veterinary importance

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yannick Grimaud ◽  
Hélène Guis ◽  
Frédéric Chiroleu ◽  
Floriane Boucher ◽  
Annelise Tran ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Temporal Dynamics ◽  
Control Strategies ◽  
Host Density ◽  
Environmental Drivers ◽  
Hurdle Model ◽  
Reunion Island ◽  
Annual Variations ◽  
Réunion Island ◽  
Set Up

Abstract Background Reunion Island regularly faces outbreaks of epizootic haemorrhagic disease (EHD) and bluetongue (BT), two viral diseases transmitted by haematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae) to ruminants. To date, five species of Culicoides are recorded in Reunion Island in which the first two are proven vector species: Culicoides bolitinos, C. imicola, C. enderleini, C. grahamii and C. kibatiensis. Meteorological and environmental factors can severely constrain Culicoides populations and activities and thereby affect dispersion and intensity of transmission of Culicoides-borne viruses. The aim of this study was to describe and predict the temporal dynamics of all Culicoides species present in Reunion Island. Methods Between 2016 and 2018, 55 biweekly Culicoides catches using Onderstepoort Veterinary Institute traps were set up in 11 sites. A hurdle model (i.e. a presence/absence model combined with an abundance model) was developed for each species in order to determine meteorological and environmental drivers of presence and abundance of Culicoides. Results Abundance displayed very strong heterogeneity between sites. Average Culicoides catch per site per night ranged from 4 to 45,875 individuals. Culicoides imicola was dominant at low altitude and C. kibatiensis at high altitude. A marked seasonality was observed for the three other species with annual variations. Twelve groups of variables were tested. It was found that presence and/or abundance of all five Culicoides species were driven by common parameters: rain, temperature, vegetation index, forested environment and host density. Other parameters such as wind speed and farm building opening size governed abundance level of some species. In addition, Culicoides populations were also affected by meteorological parameters and/or vegetation index with different lags of time, suggesting an impact on immature stages. Taking into account all the parameters for the final hurdle model, the error rate by Normalized Root mean Square Error ranged from 4.4 to 8.5%. Conclusions To our knowledge, this is the first study to model Culicoides population dynamics in Reunion Island. In the absence of vaccination and vector control strategies, determining periods of high abundance of Culicoides is a crucial first step towards identifying periods at high risk of transmission for the two economically important viruses they transmit.

scholarly journals The sub-annual calibration of hydrological models considering climatic intra-annual variations

2017 ◽  
Author(s):  
Binru Zhao ◽  
Huichao Dai ◽  
Dawei Han ◽  
Guiwen Rong
Keyword(s):  
Time Scale ◽  
Temporal Dynamics ◽  
Model Performance ◽  
Optimal Time ◽  
Temperature Pattern ◽  
Climate Conditions ◽  
Fcm Algorithm ◽  
Calibration Scheme ◽  
Annual Variations ◽  
Improve Model

Abstract. Changing climate leads to change of temporal dynamics of hydrological systems by affecting the catchment conditions. Considering climatic variations when calibrating a hydrological model can improve model performance, which allows parameter sets to vary according to sub-periods with different climate conditions. This study has explored climatic intra-annual variations by using two classification approaches to recognize the sub-periods with similar climatic patterns, Calendar-Based Grouping (CBG) method and Fuzzy C-Means (FCM) algorithm. The model performances of the sub-annual calibration schemes based on these two approaches are compared using the conceptual model IHACRES. The effect of time scales on sub-annual calibration schemes was also studied. Results indicate that the sub-annual calibration scheme based on CBG method performs better than that based on Rainfall-dominated FCM algorithm, since the CBG method has a better performance in recognizing temperature pattern, and the main source of catchment change is from the change of vegetation, which is mainly affected by temperature in the study site. The optimal time scale is dependent on the sub-annual calibration scheme, with bimonthly for CBG method and Temperature-dominated FCM algorithm and seasonal for Rainfall-dominated FCM algorithm. Overall, when using sub-annual calibration schemes, the selection of the partitioning method and time scale is very important to model performances

scholarly journals Modeling of Quaternary Groundwater Pollution Risk by GIS and Multicriteria Analysis in the Southern Part of Abidjan District (Côte d’Ivoire)

2013 ◽  
Vol 04 (11) ◽  
pp. 1213-1223 ◽  
Author(s):  
Innocent Kouassi Kouame ◽  
Aristide Gountôh Douagui ◽  
Kouadio Koffi ◽  
Brou Dibi ◽  
Lazare Kouakou Kouassi ◽  
...  
Keyword(s):  
Groundwater Pollution ◽  
Multicriteria Analysis ◽  
Pollution Risk

scholarly journals Temporal Dynamics of Jellyfish Pelagia noctiluca Stranded on the Mediterranean Coast of Morocco

2020 ◽  
Vol 21 (02) ◽  
pp. 87-94
Author(s):  
Bilal Mghili ◽  
Mohamed Analla ◽  
Mustapha Aksissou
Keyword(s):  
Atmospheric Pressure ◽  
High Frequency ◽  
Temporal Dynamics ◽  
Winter Season ◽  
Mediterranean Coast ◽  
The Other ◽  
Economic Activities ◽  
Annual Variations ◽  
Effective Strategies ◽  
Pelagia Noctiluca

Seasonal dynamics of the scyphomedusa Pelagia noctiluca were studied along with their relation to certain environmental factors between the study period that extends from January 2018 to December 2019. During 2018, stranded individuals of P. noctiluca appeared throughout this year, but their high frequency was reported in the summer. While in contrast, P. noctiluca in 2019 was reported in a very low number only during the winter season and had not been detected in the other seasons of this year. The overall results revealed that the inter-annual variations in the abundance of jellyfish were not significantly (P<0.05) correlated with water temperature, relative humidity and atmospheric pressure. Our results showed easterly winds as a significant predictor of P. noctiluca strandings. The bell diameters of examined jellyfish ranged from 30 to 130 mm, with mean of 72 mm. Stranded mature jellyfish individuals as well as young ones were recorded throughout the year 2018. The size distribution indicated that P. noctiluca can reproduce all around the year, with its more intense activityduring the spring. The continuing presence of P. noctiluca in the Moroccan Mediterranean makes it necessary to set effective strategies in order to prevent and minimize their impact on economic activities.

scholarly journals Discovery of continental-scale travelling waves and lagged synchrony in geometrid moth outbreaks prompt a re-evaluation of mountain birch/geometrid studies

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 128 ◽  
Author(s):  
Olle Tenow
Keyword(s):  
Temporal Dynamics ◽  
Travelling Waves ◽  
Mountain Birch ◽  
Epirrita Autumnata ◽  
Operophtera Brumata ◽  
Temporal Behaviour ◽  
Continental Scale ◽  
Northern Fennoscandia ◽  
Early Results ◽  
Spatio Temporal

The spatio-temporal dynamics of populations of two 9-10 year cyclic-outbreaking geometrids, Operophtera brumata and Epirrita autumnata in mountain birch forests in northern Fennoscandia, have been studied since the 1970´s by a Swedish-Norwegian research team and, during the last decade, by Norwegian and Finnish research teams. Some of the early results have been challenged by the Norwegian team. To examine the base for disagreements, five of the papers published by the Norwegian team (2004-2011) are reviewed. It is found that conclusions in these papers are questionable or data could not be interpreted fully because two decisive traits in the spatio-temporal behaviour of outbreaks of the two species were not considered.

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