Des destins croisés : regards sur 30 ans de recherches en grande hydraulique

La " grande hydraulique " fut un modèle scientifique et centralisateur d'aménagement par l'irrigation, conçu et géré par des corps d'ingénieurs bâtisseurs depuis la deuxième partie du XIX e siècle. Traversant plusieurs crises, elle a constitué de ce fait un champ de recherche exceptionnel, inspirant une multitude d'écoles de pensée. Au cours des 30 dernières années, trois paradigmes forts fondés sur l'action prééminente de l'Etat, puis sur l'action collective, et plus récemment sur l'action individualiste et la régulation par le marché, ont fortement influencé les programmes de recherche mais aussi les politiques publiques sur l'irrigation. Si l'enrôlement de la recherche au service d'Etats aménageurs, ou de bailleurs de fonds, a été très marquant pour le domaine de l'irrigation, le propos pourrait être sans doute élargi à d'autres domaines (sciences agronomiques, par exemple) et à d'autres acteurs. La proximité croissante entre la recherche et la société constitue en même temps une opportunité pour une recherche vivante opérant dans un double souci de rigueur et de pertinence. Ceux-ci s'opposent au quotidien, mais peuvent se conjuguer dans le temps. (Résumé d'auteur

Agriculture in motion: Intertwined geographical and socio-professional mobilities in North Africa's groundwater economy

In this paper, we examine the greenhouse horticulture in Algeria's Sahara, which is one illustrative example of the agricultural transitions that have taken place in North Africa on the new irrigation frontiers created through groundwater use. The entrepreneurial farming systems in the region are characterized by considerable mobility. Geographic mobilities of people, ideas, capital, information, and objects and socio-professional mobilities are intrinsically intertwined, whereby skilled sha-recroppers and laborers move sometimes over hundreds of kilometers, attracted by the opportunities of quick monetary gains and by the opportunities of rapid so-cio-professional upward mobility. This paper analyzes, first the different forms of socio-professional and geographical mobilities associated with the groundwater-ba-sed farming systems in Algeria's Sahara, with a particular focus on mobile young farmers; then focuses on the multiple borders that these young farmers crossed on their trajectory; and their return journey after they quit the Sahara

Rapid assessment for prioritisation of trachoma control at community level in one district of the Kaolack Region, Senegal.

The objective of this study was to use a modified Lot Quality Assurance Sampling methodology to classify communities according to prevalence of active trachoma and to estimate the prevalence of trachoma and trichiasis in Nioro department, Kaolack Region, Senegal. A survey was conducted using two-stage cluster sampling to select 50 children aged 2-5 years in each of 33 clusters. In total 1,648 children were examined for active trachoma. Information on trachoma risk factors was collected through interviews with the mother or the household head of the child. Adults (>40 years) with trichiasis were identified through case finding. Nineteen clusters had a low prevalence of active trachoma in children aged 2-5 years (40%). The prevalence of active trachoma in children aged 2-5 years was 17.4% (95% CI 12.9-21.8%). Multivariate-adjusted predictors of active trachoma were: age, facial cleanliness, hygiene practices and keeping cattle in the household. The prevalence of trichiasis in adults aged over 40 years was 1.77% (95% CI 1.24-2.51), equating to 985 adults (95% CI 765-1250) with trichiasis in Nioro department. In conclusion, a survey using rapid methodology showed that trachoma is a problem of public significance in Nioro department, Senegal

Prospective of groundwater overexploitation through participatory approaches: Saiss plain in Morocco

In the Saiss plain, groundwater overexploitation is often explained by two phenomena. The first one is a natural phenomenon (droughts), which seems therefore uncontrollable; the other one is human as groundwater is largely used by the agricultural sector. The main issue of groundwater governance is to find an acceptable balance in the use of the water resource without compromising the socio-economic development generated by this resource. Our study aims to contribute to understanding the differential contribution of different categories of groundwater users and the socio-economic and agrarian dynamics impacted by the overuse of groundwater. We adopted a participatory approach to explore with the different actors involved in the management and use of groundwater to identify the different viewpoints on the issue of overexploitation and to engage prospective and collective thinking of present situation of groundwater overexploitation. We organized multi-stakeholder workshops and designed a role-playing game to identify and qualify the existing links between the water resource, and the economic and social dynamics in order to better understand the human behavior to economic and environmental crises and the adaptive strategies of farmers confronted with an increasingly scarce groundwater resource. Our results showed considerable differences in the viewpoints of different categories of farmers regarding overexploitation. Agricultural investors who arrived over the past 5 years in the area practicing arboriculture consider themselves modern farmers using precise and water-saving irrigation technologies (drip irrigation, especially) who cannot be blamed for overexploitation of groundwater resources. Lessees practicing horticulture put considerable pressure on water resources, but were not interested in debates on overexploitation and the sustainability of groundwater resources. In fact, they did not turn up for the workshops. Finally, the local small-scale farmers who have very limited access to groundwater due to declining groundwater tables were shown to be the most concerned about groundwater overexploitation, especially the youngsters. These results show that not only different categories of users contribute differently to groundwater overexploitation, but also the direct effects of overexploitation are asymmetrically supported by different categories of users. These results can thus provide the basis for a user-oriented debate on groundwater governance involving the different categories of users and public institutions, by making the differential contribution and impacts of groundwater overexploitation visible. (Texte intégral

Biophysical and economic water productivity of dual-purpose cattle farming

This study analyzes key factors influencing water productivity in cattle rearing, particularly in contexts characterized by water scarcity. This was done through year-round monitoring of on-farm practices within five smallholder farms located in the Saïss area (northern Morocco). The on-farm monitoring protocol consisted of characterizing: (i) volumes of water used for fodder production and distinguished by source (rainfall, surface irrigation and groundwater), (ii) virtual water contained in off-farm feed resources, (iii) total forage biomass production, (iv) dietary rations fed to lactating cows and their calves and (v) milk output and live weight gain. Findings reveal a mean water footprint of 1.62±0.81 and 8.44±1.09 m3/kg of milk and of live weight gain, respectively. Groundwater represented only 13.1% and 2.2% of the total water used to get milk and live weight gain, respectively, while rainfall represented 53.0% and 48.1% of the total water for milk and live weight gain, respectively. The remaining water volumes used came from surface irrigation water (7.4% for milk and 4.0% for live weight gain) and from virtual water (26.5% for milk and 44.7% for live weight gain). The results also revealed a relatively small gross margin per m3 of water used by the herd, not exceeding an average value of US $ 0.05, when considering both milk and live weight. Given the large variability in farm performances, which affect water productivity in cattle rearing throughout the production process, we highlight the potential for introducing a series of interventions that are aimed at saving water, while concurrently improving efficiency in milk production and live weight gain. These interventions should target the chain of production functions that are implemented throughout the process of water productivity in cattle rearing. Moreover, these interventions are of particular importance given our findings that livestock production depends largely upon rainfall, rather than groundwater, in an area afflicted with sustained droughts, overexploitation of groundwater resources and growing water scarcity. (Résumé d'auteur