The Niger River plays an important role for all riparian countries, especially Mali because many irrigated areas use this resource for their daily activities. Climate change, leading to a reduction in rainfall, may have a negative impact on the Niger River. Therefore, it is useful for researchers to study this natural resource to address climate risks. The main goal of this current study is to characterize the river flow with the evolution of rainfall over the Niger River at the scale of Mali. To achieve this objective, hydroclimatic data were collected and analyzed. The statistical method was applied for the analysis and interpretation of the collected data. The results show that there is a weak correlation between rainfall and river flow for all four stations considered. From 1980 to 2020, the overall results show a slight increase in the hydroclimatic parameters. But for the recent 10 years (2007 - 2016), it is clear that the trend changed by decreasing the rainfall and discharge. This decrease in the climatic parameters affects negatively all economic sectors in the study area. Key words: Niger River, Mali, hydroclimatic, climate change.
Rural communities in low-income countries rely on intermittent water supply, defined as access to water for less than 24 h a day.The path to continuous water supply requires electricity as well as water infrastructures, which in turn requires the necessary finance for investment.We show that a sample of 16 Least Developed Countries (as classified by the UN) do not yet meet the minimum conditions necessary to implement continuous water supply, mainly because they do not have the finance.Building up an infrastructure requires investments, using earned foreign exchange or loans, to build up electricity capacity, water treatment plants and a distribution pipe network.But once a country has the electricity infrastructure and the basic water mains, its remote areas can then be served through lowcost investment into a system called "trickle fill."Vietnam, having developed fast through export earnings, was able to increase its electricity production and expand its drinking water infrastructure.But there are still people in rural Vietnam without access to drinking water.We show that where there are water mains, continuous supply can be extended further through "trickle fill."We describe a freely available user-friendly decision-making tool for a feasibility study for a trickle fill solution and describe countries where this solution has been successfully implemented.For developing countries, we show that there is no shortcut to converting intermittent water supply to continuous water supply without adequate foreign exchange earnings which can then be invested in electricity and water infrastructure.
Globally, diarrhoea is considered as a major threat to human health and remains a leading cause of mortality and morbidity. Several studies have shown that incidence of diarrhoea is influenced by source of drinking water and mediated by some compositional and contextual factors. However, not much is known about how mediating factors interact with source of drinking water to influence incidence of diarrhoea in Ghanaian adults. This study was carried out to investigate how compositional and contextual factors interact with source of drinking water to influence incidence of diarrhoea. A survey was carried out in fourteen regions of Ghana. A multivariate regression model was used to determine how compositional and contextual factors mediate the effect of drinking water source on incidence of diarrhoea. The results showed that source of drinking water and geospatial (regional) disparities are the two main factors that affect incidence of diarrhoea in Ghana. Households that depended on river as a source of drinking water were 64% more likely to have diarrhoea compared to those who drink from pipe-borne water. Upper West Region recorded the highest incidence of diarrhoea (37%) and Volta Region recorded the least incidence of diarrhoea (less than 1%). Escherichia coli bacteria was detected in all water sources . Streptococcus was detected in all the water samples except dam water. Some of the causes of diarrhoea were found to be beyond the control of individuals warranting the need for government intervention and policy to improve the sanitation in the country.
Many rural households do not have access to treated drinking water. However, some households may be in regions where a water treatment plant has excess capacity to supply some additional households. In such circumstances, small diameter low-pressure supply systems can be connected to major transmission lines to give these households access to water. These typically occur in locations that do not belong to recognized municipal or other local government. Such supply systems, commonly referred to as “trickle fill,” have been implemented in South America, Africa and Canada. This paper explains the concept of trickle fill supply systems. A user-friendly decision-making framework is proposed to assist the decision maker to determine whether the implementation of a trickle fill system is economically feasible for a given rural area. The decision-making assessment template (DMAT) takes into projects the economic, energy and carbon footprint changes. A case study for a rural municipality in the province of Alberta, Canada is presented to illustrate the value of the DMAT and the feasibility of trickle fill water supply as a solution. In this case study, a trickle fill water supply solution is found to be technically and economically viable and would reduce energy consumption and the carbon footprint. It is shown that trickle fill solution can be implemented, resulting in an average cost of water to be $165 per month per household. This is higher than the affordability threshold of 2% of the median household income, but comparable to the cost that the end users currently pay for drinking water in the area. A capital grant from a higher level of government, or low interest rate financing, would reduce the end user costs to the level of the affordability criterion mentioned here. Hence, a trickle fill solution is worth investigating for some rural residents. Key words: Rural water systems; economic feasibility; carbon footprint, small diameter water distribution pipelines.
Droughts are part of extreme meteorological phenomena that generate serious social, economic and environmental consequences. This study seeks to characterize the historical (1976-2019) and projected (2021-2050) meteorological drought in the Niger River Basin in Benin. To achieve this, the present study used daily rainfall observations and simulations of two regional climate models (RCM) (HIRHAM and REMO) from fifteen (15) rainfall stations installed around the basin. We used standardized precipitation indices (SPI) at 12 and 36 months’ time steps. To have a normal distribution, the data were transformed according to the Gamma distribution. The results revealed that over the historical period (1976-2019), SPI showed increasing trends with near-normal droughts occurring about 90% and the other drought classes around 10%. At the 12- and 36-month SPI scales, there are average durations of 17 and 32 months respectively and peaks of -1.52 and -1.12. In the future, according to the average representative concentration pathway of the RCM, the trends remain very low (1/1000 per decade) with near-normal droughts occurring at about 80 and 20% for the other classes. For SPI-12 and SPI-36 months, there are likely mean drought durations of 19 and 40 months respectively with likely mean peaks of -1.5 and -1.6. The changes assessment shows the decrease in near-normal droughts and the increase in moderate and severe droughts on average compared to the baseline period. Drought durations are also expected to increase with smaller peaks. These changes remain non-significant according to the Student's test. Key words: Meteorological, drought, standardized precipitation index (SPI), Beninese Niger River Basin.
The shortages in the distribution of drinking water from the public network in the municipality of Jacqueville lead the population of the peri-urban villages of the said municipality to turn to well water, the quality of which remains a concern.The objective of this study is to evaluate the hygienic quality of well water used by the population for their domestic needs.The measurement and sampling were carried out on eleven wells in three peripheral villages of the commune.The analysis covered ten physico-chemical parameters (T, pH, EC, Turbidity, salinity, NO 3 , NO 2 , NH 4 , PO 4 and SO 4 ) and three microbiological parameters (total coliforms, Escherichia coli and faecal streptococci).Principal component analysis (PCA) was applied to the data to highlight the phenomena causing the degradation of the water.The calculation of the fecal contamination index (FCI) revealed three classes of water quality: Uncontaminated wells, moderately contaminated wells, and heavily contaminated wells.The study of the general quality shows that most of the wells studied had warm, turbid water with a high population of pathogenic microorganisms.This study highlighted the health risk incurred by the population when consuming the water from these wells without prior treatment.
This work aims to study the uncertainties in the rainfall-runoff process using a stochastic approach derived from the deterministic hydrological model based on the least action principle (ModHyPMA). The stochastic formulation of ModHyPMA allows for consideration of both the dynamics and stochastic nature of the hydrological phenomenon. The main assumption is that uncertainties in the hydrological process are modelled as Gaussian white noise. It is assumed that hydrological systems are nonlinear dynamical systems that can be described by stochastic differential equations (SDE). From this SDE, we deduce the associated Fokker-Planck equation (FPE). The FPE is a partial differential equation that cannot be solved analytically due to its complexity. We therefore investigated a numerical solution to this equation by using the finite differences and finite volumes methods. The results show that the stochastic model improves the simulations of discharges in Ouémé at Savè Basin (NSE = 0.89, R2 = 0.90, RMSE = 113 and MAE = 76) compared to the deterministic model (NSE = 0.78, R2 = 0.78, RMSE = 123 and MAE = 51). The plots of the solutions (the density probability of discharges) always coincide when the investigated numerical solutions are compared, except when the number of meshes is very small (100 meshes). The two solutions are convergent. This numerical solution provides information about the distribution of discharges in the Ouémé at Savè Basin. Key words: Uncertainty, stochastic approach, Fokker-Planck equation (FPE), ModHyPMA, numerical solutions, density probability.
