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Abstract In Senegal, there are disparities in access to drinking water at several levels. There are major differences between urban and rural areas. In rural areas, poverty, the abundance or scarcity of water infrastructure, and the distance between the place of residence and the place of supply are, to some extent, factors in the disparity in rates of access to drinking water from one village to another and, within the same village, from one household to another. Determining the sources of variance between villages and households regarding access to drinking water is based on the identification of several explanatory variables, both at the aggregate level (village level) and at the individual level (household level). Multilevel analysis has shown that differences in household access to drinking water are due to several factors that can be grouped into two categories: contextual variables that vary from one village to another, and individual characteristics that differ from one household to another. The aim of this article is to analyze the factors that explain the disparity in access to drinking water in rural communes in the south of the Kaffrine region. The usefulness of multilevel analysis lies in its ability to solidify causal inference in the associations between the infrastructural levels of villages, in terms of water facilities, and their impact on the level of access to drinking water of rural households as reported (Bringe and Golaz in Manuel pratique d’analyse multiniveau, Ined Éditions, Aubervilliers, 2017), as reported (Diane et al., in Analyse multiniveau pour expliquer la prévalence d’impacts sanitaires néfastes autorapportés et l’adaptation lorsqu’il fait très chaud et humide en été dans les secteurs les plus défavorisés des neuf villes les plus populeuses du Québec en 2011, 2015).

Cemented paste backfill (CPB) is an innovative cementitious construction material widely used to stabilize underground mine structures and minimize the mine’s environmental impact. Understanding the factors that influence the self-healing efficiency of CPB is essential to optimize its design and improve its durability. In real-world applications, CPB structures are often exposed to varying curing temperatures, which can affect their self-healing ability. However, the specific impact of temperature on the self-healing capacity of CPB is not yet clearly established. This study experimentally investigates the effects of temperature (i.e., 2℃, 20℃, 35℃, and 50℃) on the self-healing performance of CPB. The self-healing efficiency was evaluated through observations of crack closure, mechanical strength tests, hydraulic conductivity measurements, and assessments of physical properties (i.e., porosity and void ratio). The results demonstrate that temperature significantly influences CPB’s self-healing performance. Elevated temperatures (35℃ and 50℃) enhance the self-healing process within the CPB matrix compared to room temperature (20℃), primarily due to accelerated binder hydration. The pre-cracked CPB specimens can restore their strength and achieve up to approximately 31 % higher strength than uncracked specimens after 28 days of self-healing. However, the pre-cracked specimens cured at low temperature (i.e., 2℃) exhibit low self-healing capacity, particularly at early ages. The low curing temperature significantly delays the onset of the self-healing process in CPB material. Moreover, analytical techniques reveal that an amount of healing products, mainly consisting of C-S-H, Ca(OH)2, and CaCO3, contribute to this promising self-healing performance. The findings from this paper have important practical implications for the design, mechanical stability, and durability of CPB structures, providing valuable insights for engineering practices.

This paper examines the influence of various factors, including the addition of nano-calcium carbonate particles (chemical processes, C) to CPBs, non-isothermal field curing temperatures (thermal factor, T), and field vertical curing stress (mechanical factor, M), on the self-desiccation capacity of CPB plugs. The assessment of self-desiccation involves the determination of pore water pressure (PWP) and volumetric water content (VWC) in the examined CPBs. Thermo-mechanical-chemical (TMC) column experiments were conducted to investigate the interaction among these factors and their collective impact on the evolution of PWP and VWC within the CPB plug. The findings underscore that each factor, both individually and in combination, significantly affects the magnitude and progression of self-desiccation in CPB plugs. Notably, the factors of elevated field temperature and the introduction of nano-calcium carbonate (NC) to the CPB exert the most substantial influence on the extent and enhancement of self-desiccation, whereas the impact of field curing stress in isolation is comparatively much weaker. The integration of nano-calcium carbonate, especially under non-isothermal conditions and concurrent field stress, emerges as a key contributor to enhanced PWP and VWC dissipation rates. The role of non-isothermal field curing temperature is underscored as a significant contributing factor in the self-desiccation of CPB plugs. The results presented in this paper will contribute to a more cost-effective design of CPB plugs and the improved optimization of CPB mixtures with nano-calcium carbonate particles.

Abstract To ensure that public infrastructure can safely provide essential services and support economic activities in seasonal frost regions, the design of their foundation systems must be updated and/or adapted to the impacts of climate change. This objective can only be achieved, if the impact of global warming on the soil thermal behaviour in Canadian seasonal frost regions is well-known and can be predicted. In the present paper, the results of a modeling study to assess and predict the effect of global warming on the thermal regimes of grounds in three Canadian seasonal frost regions (Ottawa, Sudbury, Toronto) are presented and discussed. The results show that future climate changes will significantly affect the soil thermal regimes in seasonal frost Canadian areas. The simulation results indicated a gradual loss in the frost penetration depth due to the climate change, in the three representative sites. The frost period duration will be shorter due to climate change in the three selected regions and will completely disappear in Ottawa and Toronto. However, the impact of climate change would not appear clearly in the first 40 years “up to 2060”. The response of the ground to the effect of climate change is a function of the geotechnical characteristics of the ground and the climate conditions. The numerical tool developed and results obtained will be useful for the geotechnical design of climate-adaptive transportation structures in Canadian seasonal frost areas.

Abstract Background One out of ten deaths of children under five are attributable to indoor air pollution. And Acute Respiratory Illness (ARI) is among the direct causes. Objective This study showed the possibilities of characterizing indoor air pollution in West African Economic and Monetary Union (WAEMU) area and it also made it possible to estimate its impact on the occurrence of ARI in children under five. Methods It has been a secondary analysis based on Demographic and Health Surveys (DHSs) from WAEMU countries’ data.. “Household level of air pollution” is the created composite variable, from questions on the degradation factors of indoor air quality (domestic combustion processes) which served to characterize indoor air pollution and to measure its impact by a logistic regression. Results Burkina Faso stands out with a greater number of households with a high level of pollution (63.7%) followed by Benin (43.7%) then Togo (43.0%). The main exposure factor "Household level of air pollution" was associated with ARI symptoms (Togo: prevalence = 51.3%; chi-squared test’s p-value

Diarrheal diseases are the second leading cause of child mortality worldwide, occurring in about one in every nine child deaths, and were associated with water, sanitation, and hygiene (WASH) access. In this study, we provided an overview of WASH indicators' evolution from 2000 to 2017 and their impact on the occurrence of diarrhea in children under 5 years old in Senegal. It was a retrospective cross-sectional study, in which we did a secondary analysis of data from the Joint Monitoring Program (JMP) for water supply and sanitation and from the Senegal Demographic and Health Survey 2018. Our results showed that access to safely managed services increased by 18.1 and 19.1%, respectively, for water and sanitation. The prevalence of diarrhea estimated at 18.16% was associated with straining water through a cloth (adjusted odds ratio (AOR) [95% confidence interval (CI)]: 1.21 [1.00–1.45]) and getting water supplies from a source not located in a dwelling (AOR [95% CI]: 1.59 [1.21–2.09]). The prevalence of diarrhea among children under 5 years old was still relatively high in Senegal and was significantly associated with a lack of WASH access. Although the latter continues to increase, additional efforts to make water safer to drink will significantly reduce the occurrence of diarrheal diseases among children under 5 years old in Senegal. HIGHLIGHTS WASH access has improved in recent years; however, the prevalence of diarrhea is still relatively high.; Diarrhea is associated with a lack of WASH access. Indeed, straining water through a cloth and getting water supplies from a source not located in a dwelling are associated with an excess risk of diarrhea among children under 5 years old.; Interventions to improve WASH are opportunities to save lives and are cost-effective measures.;

This paper presents an experimental study of the strength and suction development of cemented paste backfill (CPB), which is an innovative cementitious construction material for mining (made by recycling mine waste into a construction material), and modified with nanoparticle (NP) additives. The effects of different amounts of four types of NP additives, including nano-silica (SiO2), nano-calcium carbonate (CaCO3), nano-iron oxide (Fe2O3), and nano-aluminum oxide (Al2O3), on the key engineering properties of CPB are investigated. An ether-based polycarboxylate superplasticizer (SP) is added to the backfill to help the NPs to better disperse in the mixture. Ordinary Portland cement is used as the binder in the CPB mixture. Uniaxial compressive tests (UCS) are conducted to determine the strength of the CPB, while suction monitoring experiments are performed to evaluate changes in suction with time. To understand the effects of the NP additives, different microstructural analyses and tests, including thermal analyses (thermogravimetry (TG), differential thermogravimetry (DTG)), mercury intrusion porosimetry (MIP), and X-ray diffraction (XRD) are conducted on the nano-CPB and the cement paste of nano-CPB. The results indicate that the addition of NP additives in the absence of SP results in lower strength due to high likelihood of agglomeration. In contrast, samples with SP and NP additives show a higher UCS and more suction than the control sample at the early ages of curing. It has been observed that the addition of NP additives results in the generation of more hydration products which enhance the interparticle friction and packing density of the CPB structure. Higher strength is obtained by increasing the SP content (0.25%) with the same NP content (1%). Enhancement of the strength of CPB and increase in suction, particularly at early ages, can have great importance in speeding up the mining cycle and thus increasing mining productivity, which is obviously associated with financial benefits to the mine.

Compacted bentonite–sand (B/S) mixtures have been used as a barrier material in engineered barrier systems (EBSs) of deep geological repositories (DGR) to store nuclear wastes. This study investigates the individual and combined effects of different chemical compositions of deep groundwaters (chemical factor) at potential repository sites in Canada (the Trenton and Guelph regions in Ontario), heat generated in DGRs (thermal factor), dry densities and mass ratios of bentonite and sand mixtures (physical factors) on the swelling behavior and ability of bentonite-based materials. In this study, swelling tests are conducted on B/S mixtures with different B/S mix ratios (20/80 to 70/30), compacted at different dry densities (ρd = 1.6–2 g/cm3), saturated with different types of water (distilled water and simulated deep groundwater of Trenton and Guelph) and exposed to different temperatures (20 °C–80 °C). Moreover, scanning electron microscopy (SEM) analyses, mercury intrusion porosimetry (MIP) tests and X-ray diffractometry (XRD) analyses are carried out to evaluate the morphological, microstructural and mineralogical characteristics of the B/S mixtures. The test results indicate that the swelling potential of the B/S mixtures is significantly affected by these physical and chemical factors as well as the combined effects of the chemical and thermal factors. A significant decrease in the swelling capacity is observed when the B/S materials are exposed to the aforementioned groundwaters. A large decrease in the swelling capacity is observed for higher bentonite content in the mixtures. Moreover, higher temperatures intensify the chemically-induced reduction of the swelling capacity of the B/S barrier materials. This decrease in the swelling capacity is caused by the chemical and/or microstructural changes of the materials. The results from this research will help engineers to design and build EBSs for DGRs with similar groundwater and thermal conditions.

Abstract In this study, an instrumented thickened tailings deposit model was designed, built and employed to evaluate the behaviour of layered thickened tailings to dynamic loading by using a shaking table equipment. The thickened tailings were deposited subsequently in three thin layers in a flexible laminar shear box mounted on top of the shaking table. Cyclic loading with a peak horizontal acceleration of 0.13 g and a frequency of 1 Hz was applied to the layered tailings deposit. Different types of sensors were placed to monitor the accelerations, displacements, volumetric water content and pore water pressures at the intermediate depth of each layer. Results indicated that the acceleration for the bottom and middle layers were similar to that of the base of the shaking table; but, this was not the case for the top layer. The measurements of vertical displacements indicated that all layers of thickened tailings experienced initially contraction and subsequently dilation during the shaking. The excess pore water pressure ratios were found to exceed unity through all layers of thickened tailings when the shaking ended. In other words, the results showed that the layered thickened tailings are susceptible to liquefaction under the considered testing conditions. It is also found that upward pore water migration to the top layer and downward pore water flow to the bottom layer occurred in the thickened tailings deposit. This water migration generated additional pore water pressure and also impacted the vertical displacement and liquefaction susceptibility of the thickened tailings material. The results of this study give a better understanding of the dynamic behaviour of thickened tailings, which is crucial for the safety of thickened tailings systems as well as sustainable mining.

The aim of this study was to assess the integrity and kidney overall functional capacity of subjects exposed to landfill emissions. Urine and blood levels of Pb and Cd, and several of the newly biomarkers of nephrotoxicity (Kim Injury Molecule 1 (KIM-1), alpha-1 Microglobulin (α1 M), beta-2 Microglobulin (β2 M), Cystatin-C (Cyst C), Clusterin, alpha-glutathione S-transferase (GSTα), pi-glutathione S-transferase (GSTπ), Tissue Inhibitor of Metalloproteinase-1 (TIMP1), Calbindin, Neutrophil Gelatinase-Associated Lipocalin (NGAL), Osteopontin (OPN), (Retinol Binding Protein(RBP), Liver-type Fatty Acid-Binding Protein (FABP-1), Trefoil Factor 3 (TFF3), Collagen VI) were measured in order to assess glomerular and tubule damage in adults living near a landfill.Our results indicate glomerular dysfunction in exposed subjects, and supported evidence of necrosis of proximal and distal tubule epithelial cells as specific biomarkers began to appear in the urine.Positive correlation by Pearson test were obtained between : blood Pb and B-OPN, B-Cyst C, Calbindin, U-KIM-1, TIMP1, U-OPN, and U-Clusterin; and also, between urinary Cd and TIMP1, B-Clusterin, U-OPN, FABP-1, Albumin, and U-Clusterin. The relation between biomarkers of Cd/Pb exposure and early effect biomarkers in this study clearly predicts the future risk of severe kidney injury in subjects living close to the landfill.

Abstract Underground mined-out voids need to be backfilled for the stability of the surrounding rock and also to increase ore extraction from adjacent pillars. One of the relatively newer means is cemented paste backfilling, which has been extensively adopted in underground mining operations around the world. During and after the placement of cemented paste backfill (CPB) into stopes, complex multiphysics (thermal, hydraulic, mechanical and chemical) processes take place in the large mass of CPB and could affect its consolidation behavior. An analysis of the consolidation process in CPB mass is essential for the assessment of CPB behavior and cost-effective designs in practice. In this paper, multiphysics simulation of the consolidation behavior of CPB mass is performed under different conditions, including the mixture recipe, and backfilling, drainage, surrounding rock and curing conditions. It is found that the in situ consolidation behavior of CPB structures is a function of the multiphysics processes that occur in the cementing backfill mass. Moreover, the rock mass conditions, including the geometry and rock wall roughness, influence the consolidation process of CPB structures. Cement content, curing time and backfilling rate play a crucial role in the consolidation process of CPB. The obtained results can facilitate a better understanding of the consolidation behaviour of CPB for backfill designers and engineers, and thus contribute to enhance the engineering of CPB structures.

Abstract In this study, a simulation tool, based on the combination of Geographic Information System (GIS) and Grid-Based Regional Slope-Stability Model (TRIGRS), is developed to assess and predict the snowmelt-induced landslides in areas of sensitive marine clays in the Ottawa region (Canada). Topographic, geologic, hydrologic, and geotechnical information of the study area, in addition to snowmelt intensity data for different periods, was required to conduct this modeling study. Snowmelt intensity records for periods of 6–48 h, 3–15 days, 25 days, and 30 days, as well as the information on historical landslides in the study area, were used to examine both the timing and location of shallow landslides due to snowmelt across the Ottawa region. The developed tool is validated by comparing the predicted landslide-susceptible areas with the historical landslide maps in the study area. A good agreement between the predicted and recorded historical landslides was obtained, which suggests that the developed GIS-TRIGRS based tool can predict relatively well the snowmelt-induced landslide susceptibility in the sensitive marine clays. The modeling results show that high slope areas of sensitive marine clays are more prone to snowmelt-induced landslides. As a result, this simulation tool could be used to assess and/or predict snowmelt-induced landslides in different areas of the Ottawa region, which is an important means for decision-making processes with respect to protecting the population and infrastructure against snow-melt induced marine clay landslides.

In recent years, serious environmental problems induced by plastic wastes have drawn considerable attention across the world and new initiatives have been adopted to recycle plastic wastes into construction materials. One of the promising initiatives is the use of plastic waste as the only binding phase to make concrete/mortar-like construction materials. However, how key engineering properties of concrete/mortar-like materials with melted plastic as the only binder change with material composition and curing conditions are not well known. This paper aims to investigate the effect of curing conditions and granular material size on the mechanical properties (compressive and splitting tensile strengths) of a mortar with melted plastic waste (high density polyethylene (HDPE) and low density polyethylene (LDPE)) as the only binder (MPB: mortar with melted plastic waste binder). Moreover, it presents a study conducted in the city of Bamako (Mali) to evaluate the use of MPB to make interlocking paving blocks for use on non-traffic areas in residential or municipal construction projects. Two curing conditions, namely, air dry at ambient temperature and water curing were used for this research. Moreover, the size of the granular materials (sand and gravel) was varied in order to assess its impact on the properties of the corresponding MPB sample formulations with given plastic content and HDPE/LDPE (H/L) ratio. Granular material size and curing conditions were found to have significant impact on the mechanical strengths of the MPB materials. Regardless of age and H/L ratio, the MPB samples cured in water showed lower strength (compressive and tensile) than the specimens cured at ambient temperature under controlled laboratory conditions, while adding coarse granular materials helped to improve these strength properties. Furthermore, the mechanical performance of the proposed MPB-interlocking paver is superior to that of the interlocking Portland cement-based pavers that are commercially available on the Bamako’s market. Moreover, the cost of the Portland cement-less MPB-paver will be substantially lower than that of the Bamako’s commercial Portland cement-paver. The obtained results place this MPB material as a promising candidate for making interlocking pavers or other products, while reducing the amount of plastic waste to be managed and the cost of interlocking pavers.

A landfill biocover system optimizes environmental conditions for biotic methane (CH4) consumption that controls the fugitive and residual emissions from landfills. Research shows that wasted compost material has more (CH4) oxidation potential than other materials. Thus, in this study, the authors investigate the engineering properties of compacted compost to test its suitability for CH4 oxidation capacity. Different laboratory and analytical approaches are employed to attain the set objectives. The biochemical tests show that the studied material indicates the presence of methanotrophs with sufficient organic contents. The compacted compost also shows adequate diffusivity potential to free air space for a wide range of water content. The data also imply that compacting compost to low hydraulic conductivity can be accomplished for a wide range of water content, according to the suggested values for a landfill hydraulic barrier. Furthermore, the low thermal properties of compost as compared to other mineral materials seem more beneficial, as specifically, during the winter season, when the atmospheric temperature is low, low thermal conductivity enables it to sustain a stable temperature for the activities of the microbial organisms, which therefore extends the CH4 oxidation process right through a long period in the winter.

Abstract Objectives Disruption in HIV care provision may enhance the development and spread of drug resistance due to inadequate antiretroviral therapy. This study thus determined the prevalence of HIV-1 transmitted drug resistance (TDR) in settings of decentralized therapy and care in Senegal and, the Ebola outbreak in Guinea. Antiretroviral-naïve patients were enrolled following a modified WHO TDR Threshold Survey method, implemented in Senegal (January–March 2015) and Guinea (August–September 2015). Plasma and dried blood spots specimens, respectively from Senegalese (n = 69) and Guinean (n = 50) patients, were collected for direct sequencing of HIV-1 pol genes. The Stanford Calibrated Population Resistance program v6.0 was used for Surveillance Drug Resistance Mutations (SDRMs). Results Genotyping was successful from 54/69 (78.2%) and 31/50 (62.0%) isolates. In Senegal, TDR prevalence was 0% (mean duration since HIV diagnosis 4.08 ± 3.53 years). In Guinea, two patients exhibited SDRMs M184V (NRTI), T215F (TAM) and, G190A (NNRTI), respectively. TDR prevalence at this second site, however, could not be ascertained because of low sample size. Phylogenetic inference confirmed CRF02_AG predominance in Senegal (62.96%) and Guinea (77.42%). TDR prevalence in Senegal remains extremely low suggesting improved control measures. Continuous surveillance in both settings is mandatory and, should be done closest to diagnosis/transmission time and with larger sample size.

Abstract Cemented paste backfill structures are complex underground cementitious structures. After fresh cemented paste backfill (CPB; a mix of tailings, binder and water) is poured into underground stopes (mined-out voids), its strength which is a key mechanical design criterion of CPB structures, gradually develops with time. The development of CPB strength is governed by the coupled thermo-hydro-mechanical-chemical (THMC) processes in the CPB mass. Therefore, to assess and predict the changes to CPB strength and its distribution within the CPB mass, a multiphysics model on CPB strength is proposed in this study, and has been successfully validated against a series of experimental data. Then, the validated model is used to investigate the changes in the strength of CPB structure under various influential factors in the field (e.g., backfilling strategy, inclination angle of stope, and filling rate). The obtained results provide better insight into the process of the strength increase and spatial distribution in CPB structures as well as contribute to more cost-effective engineering designs of CPB structures.

Although a large number of previous researches have significantly contributed to the understanding of the quasi-static mechanical behavior of cemented tailings backfill, an evolutive porous medium used in underground mine cavities, very few efforts have been made to improve the knowledge on its response under sudden dynamic loading during the curing process. In fact, there is a great need for such information given that cemented backfill structures are often subjected to blast loadings due to mine exploitations. In this study, a coupled thermo-hydro-mechanical-chemical (THMC)-viscoplastic cap model is developed to describe the behavior of cementing mine backfill material under blast loading. A THMC model for cemented backfill is adopted to evaluate its behavior and evolution of its properties in curing processes with coupled thermal, hydraulic, mechanical and chemical factors. Then, the model is coupled to a Perzyna type of viscoplastic model with a modified smooth surface cap envelope and a variable bulk modulus, in order to reasonably capture the nonlinear and rate-dependent behaviors of the cemented tailings backfill under blast loading. All of the parameters required for the variable-modulus viscoplastic cap model were obtained by applying the THMC model to reproducing evolution of cemented paste backfill (CPB) properties in the curing process. Thus, the behavior of hydrating cemented backfill under high-rate impacts can be evaluated under any curing time of concern. The validation results of the proposed model indicate a good agreement between the experimental and the simulated results. The authors believe that the proposed model will contribute to a better understanding of the performance of hydrating cemented backfill under blasting, and also to practical risk management of backfill structures associated with such a dynamic condition.

In this paper, the hydro-mechanical behavior and physical properties of mature fine tailings (MFT) under atmospheric drying are investigated through a column study. In the study, evaporation takes place in the development of suction in the upper parts of the column and increasing suction leads to higher strength in the tailings. After 5 days, the suction in the first lift is around 17 kPa in the upper part of the column. When a second lift is added, the first lift initially loses strength but over a 30 days’ period, the strength is recovered to its prior value and suction in the second lift reaches 500 kPa. The vane shear strength values show a substantial increase in the strength of the MFT after 30 days under atmospheric drying and drainage. The 90% strength found in the column exceeds the threshold (5 kPa). The hydraulic-mechanical properties of the deposited tailings are closely coupled due to several mechanisms, such as evaporation, drainage, self-consolidation, suction and crack development. The findings of this study will provide a better understanding of the placement behavior of multiple lifts of MFT and thus contribute to reclamation design standards and reduce the use of dedicated disposal areas. Keywords: Tailings, Oil sand, Environment, Drying, Multi-lift deposition

Natural methane (CH4) oxidation that is carried out through the use of landfill covers (biocovers) is a promising method for reducing CH4 emissions from landfills. Previous studies on peat-based landfill covers have mainly focused on their biochemical properties (e.g. CH4 oxidation capacity). However, the utilization of peat as a cover material also requires a solid understanding of its geotechnical properties (thermal, hydraulic, and mechanical), which are critical to the performance of any biocover. Therefore, the objective of this context is to investigate and assess the geotechnical properties of peat-based cover materials (peat, peat–sand mixture), including compaction, consolidation, and hydraulic and thermal conductivities. The studied materials show high compressibility to the increase of vertical stress, with compression index (Cc) values ranging from 0.16 to 0.358. The compressibility is a function of sand content such that the peat–sand mixture (1:3) has the lowest Cc value. Both the thermal and hydraulic conductivities are functions of moisture content, dry density, and sand content. The hydraulic conductivity varies from 1.74 × 10−9 m/s to 7.35 × 10−9 m/s, and increases with the increase in sand content. The thermal conductivity of the studied samples varies between 0.54 W/(m K) and 1.41 W/(m K) and it increases with the increases in moisture and sand contents. Increases in sand content generally increase the mechanical behavior of peat-based covers; however, they also cause relatively high hydraulic and thermal conductivities which are not favored properties for biocovers.

This study allowed determining diverse roles of the mangrove in Delta du Saloum. To the ecological plan, the slightest environmental changes are harmful to mangrove (Ndour, 2005 ; Thomas and al., 1997 ; Blasco, 1983). The consequences are their degradation and the loss of the functions of nurseries, housing environment and niche ecological. In the socioeconomic aspects, mangrove exploitation resources make them playing the role of rampart of the livelihood of the coastal populations (Sène, 2007 ; Cormier-Salem, 1999). So, the goods and services which the mangrove procures to population, gets created divergent interests between the various actors ; what makes difficult their management. Among others obstacles, there is their sector-based management which implies at once several state services. This sector-based approach not facilitates harmonization of the measures of preservation. Otherwise, in spite of the existence of several plans of management, there is always no transfer of competence in fishery domain which prevents in a part the actors to play entirely their roles. In these conditions, perspectives of mangroves management should turn around the harmonization of the measures of protection, decision-making by the Ministry of fishery on marine resources, the elaboration of landscaping of classified forests and codes for good behavior in the area. This need also to promote joint management including the neighboring States sharing the same resources (Ndour, 2005).

The potential contamination of underground drinking water (UDW) caused by CO2 leakage is a critical decision input for risk assessment and management decision making. This paper presents an overview of the potential alterations to UDW quality caused by CO2 and the relevant quality guidelines on drinking water. Furthermore, a framework and numerical simulator have been developed to (i) predict and assess the potential consequences of CO2 leakage on the quality of UDW; and (ii) assess the efficiency of groundwater remediation methods and scenarios for various UDW leakage conditions and alterations. The simulator was applied to a Canadian CO2 disposal site to assess the potential consequences of CO2 leakage on groundwater quality. The information, framework, and numerical tool presented here are useful for successful risk assessments and the management of CO2 capture and sequestration in Canadian geological formations.