A Commune-Level Groundwater Potential Map for the Republic of Mali

Groundwater represents an essential resource in sub-Saharan Africa, where several hundred million people rely on aquifers for domestic supply. This paper presents a method to map groundwater potential in the Republic of Mali based on a spatially-distributed database of 26,040 boreholes. The database includes exhaustive information on key parameters such as borehole location, success rate of borehole production, depth, yield, static groundwater level or water quality. Representative variables were classified and interpreted jointly to develop a groundwater potential index for each of the 703 communes in Mali. This provides a methodological novelty because groundwater potential studies typically rely on indirect indicators such as lineaments, slope, soil moisture and landforms. Also, such large borehole databases have seldom been used to estimate groundwater potential. The highest indexes were obtained for the areas in and around the River Niger’s Inner Delta, including southern Tombouctou and the central parts of the Ségou and Mopti Regions. The lower Precambrian formations, which include the country’s thoroughly populated southern plateau, had moderate scores. The lowest groundwater potential was found in the northern part of the Kayes and Koulikoro Regions, as well as in the entire region of Kidal. By providing results at the commune scale, these outcomes show that groundwater potential across the country’s geological and hydrogeological units can be highly variable, and that local and regional-scale information may be useful for groundwater management purposes. These results are policy-relevant in a context of rapid change and population growth, where groundwater resources can be expected to be increasingly relied upon in the coming years

Estudiando la sequía: una experiencia para el aula de informática

El agua es un recurso tan escaso como necesario. En regiones donde imperan los climas semiáridos, como es el caso de la mayor parte de la Península Ibérica, la disponibilidad de agua puede estar condicionada por la sequía. El estudio de este riesgo natural está íntimamente relacionado con diversas disciplinas de las Ciencias de la Tierra, como la meteorología o la hidrología. Este artículo describe paso a paso la aplicación de una de las muchas técnicas existentes para el estudio de la sequía: la curva de desviaciones acumuladas. El alumno descarga de internet los datos de precipitación de la ciudad donde reside y los analiza con ayuda de una hoja de cálculo, caracterizando las principales sequías con perspectiva histórica. Por último se proponen diversos ejercicios de interpretación. Con las oportunas modificaciones, este ejercicio es adecuado para un amplio rango de titulaciones

Water versus Wireless Coverage in Rural Mali: Links and Paradoxes

Water and wireless coverage were evaluated in a rural commune of southern Mali. All improved water sources in the area were checked for operability, accessibility, and water quality, while wireless coverage was tested by means of smartphones, phone calls, and instant messaging applications. Theoretical water coverage exceeded 82% of the total village surface area, thus beating the national and sub-Saharan African averages, but dropped to just 39% when considering only serviceable and contamination-free sources. In contrast, wireless coverage exceeded 90%. These outcomes highlight a triple paradox: (1) water from theoretically safe (i.e., improved) water sources is often unsafe to drink; (2) wireless access is better than water access even though water is essential for human survival and telecommunications are not; and (3) excellent Internet coverage does not help a large number of people, who lack the skills, devices, or need to access it. While telecommunications seem to be making inroads towards universal access faster than the water sector, a survey of water committees uncovered a hidden nexus between both resources, revealing that increased wireless access is actually contributing to underpin water coverage in a variety of ways

Manual Borehole Drilling as a Cost-Effective Solution for Drinking Water Access in Low-Income Contexts

Water access remains a challenge in rural areas of low-income countries. Manual drilling technologies have the potential to enhance water access by providing a low cost drinking water alternative for communities in low and middle income countries. This paper provides an overview of the main successes and challenges experienced by manual boreholes in the last two decades. A review of the existing methods is provided, discussing their advantages and disadvantages and comparing their potential against alternatives such as excavated wells and mechanized boreholes. Manual boreholes are found to be a competitive solution in relatively soft rocks, such as unconsolidated sediments and weathered materials, as well as and in hydrogeological settings characterized by moderately shallow water tables. Ensuring professional workmanship, the development of regulatory frameworks, protection against groundwater pollution and standards for quality assurance rank among the main challenges for the future

Mapping the Viability, Time, and Cost of Manual Borehole Drilling in Developing Regions

While access to water remains an issue in arid and semiarid regions across the world, aquifers have the potential to help millions of people out of poverty by providing a reliable source of drinking and irrigation water. Manual boreholes are increasingly advocated as a safe and cost-effective substitute to mechanized drilling, as well as to traditional excavation methods. This research banks on the assumption that field and remote sensing data can be integrated within a geospatial database in order to map the viability of manual boreholes based on factors such as rock type, water table depth, landforms, or water quality. The approach presents three main novelties in relation to methodological precedents: (1) outcomes are not only expressed in terms of technical feasibility, but also as a function of drilling time and cost; (2) maps refer to a specific drilling technique; and (3) results take into account borehole diameter, as this constrains both drilling time and cost. The method provides univocal outcomes that can be immediately useful for non-experts, donors, planners, or practitioners and that can be readily exported to other catchment-scale settings. Results were validated against geophysical data

Studying drought in the computer room

El agua es un recurso tan escaso como necesario. En regiones donde imperan los climas semiáridos, como es el caso de la mayor parte de la Península Ibérica, la disponibilidad de agua puede estar condicionada por la sequía. El estudio de este riesgo natural está íntimamente relacionado con diversas disciplinas de las Ciencias de la Tierra, como la meteorología o la hidrología. Este artículo describe paso a paso la aplicación de una de las muchas técnicas existentes para el estudio de la sequía: la curva de desviaciones acumuladas. El alumno descarga de internet los datos de precipitación de la ciudad donde reside y los analiza con ayuda de una hoja de cálculo, caracterizando las principales sequías con perspectiva histórica. Por último se proponen diversos ejercicios de interpretación. Con las oportunas modificaciones, este ejercicio es adecuado para un amplio rango de titulaciones.Water is as scarce as it is necessary. Water availability in semiarid regions is often constrained by droughts. The study of droughts pertains to several scientific disciplines, including meteorology and hydrology. This paper presents a step-by-step description of the cumulative rainfall curve, a common technique for drought analysis. Students download historical rainfall data for the town where they live. Thereafter, they carry out a spreadsheet-based analysis to characterize drought from a historical perspective. Finally, a series of additional interpretation exercises are proposed. This exercise is appropriate for a wide range of age groups and courses.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Fomento de la empleabilidad y el emprendimiento entre los alumnos de Grado en Geología

En la actualidad, el acceso al mercado laboral constituye un reto importante para un buen número de titulados universitarios. Esto se hace especialmente patente en aquellos sectores que, como la obra pública, el medio ambiente, la docencia o la investigación, han resultado fuertemente afectados por la crisis económica. Es el caso de los egresados del Grado en Geología, un colectivo que tradicionalmente encontraba acomodo profesional en algunos de estos campos y que se ha visto sumido en una situación de baja empleabilidad en España a lo largo de los últimos años. Esto ha redundado en que muchos de los geólogos de reciente titulación se han visto forzados a emigrar al extranjero. En tiempos recientes se ha observado una incipiente recuperación del mercado laboral nacional, lo que se viene traduciendo en más oportunidades de empleo para los geólogos. Sin embargo, entre los titulados a menudo se observa la ausencia de determinadas destrezas que resultan importantes a la hora de buscar trabajo, así como una cierta desorientación ante la realidad del mercado laboral. Este proyecto tiene por objeto contribuir a subsanar dichas carencias, fomentando con ello la empleabilidad de los egresados.Depto. de Mineralogía y PetrologíaDepto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEsubmitte

A survey of domestic wells and pit latrines in rural settlements of Mali: Implications of on-site sanitation on the quality of water supplies

On-site sanitation is generally advocated as a means to eradicate the health hazards associated with open defecation. While this has provided a welcome upgrade to the livelihoods of millions of people in low-income countries, improved sanitation facilities are increasingly becoming a threat to domestic groundwater-based supplies. Within this context, a survey of pit latrines, domestic wells and improved water sources was carried out in a large rural village of southern Mali. All households were surveyed for water, sanitation and hygiene habits. Domestic wells and improved water sources were georeferenced and sampled for water quality (pH, electric conductivity, temperature, turbidity, total dissolved solids, thermotolerant coliforms, chloride and nitrate) and groundwater level, while all latrines were inspected and georeferenced. A GIS database was then used to evaluate the proportion of water points within the influence area of latrines, as well as to underpin multiple regression models to establish the determinants for fecal contamination in drinking supplies. Moreover, an appraisal of domestic water treatment practices was carried out. This revealed that nearly two-thirds of the population uses bleach to purify drinking supplies, but also that domestic-scale treatment as currently implemented by the population is far from effective. It is thus concluded that existing habits could be enhanced as a means to make water supplies safer. Furthermore, population, well and latrine density were all identified as statistically significant predictors for fecal pollution at different spatial scales. These findings are policy-relevant in the context of groundwater-dependent human settlements, since many countries in the developing world currently pursue the objective of eliminating open defecation