Abdou Moumouni University

About: Abdou Moumouni University is a education organization based out in Niamey, Niamey, Niger. It is known for research contribution in the topics: Population & Agriculture. The organization has 796 authors who have published 808 publications receiving 17478 citations. The organization is also known as: University of Niamey & Abdou Moumouni Dioffo University.

Modeling climate change impact on the hydropower potential of the Bamboi catchment

Abstract: Understanding climate change impacts helps adaptation efforts in the energy sector. This study evaluates the impact of future climate change on the hydropower potential (HPP) of the Bamboi catchment in West Africa combining the HBV-light rainfall-runoff model and a hydropower generation model. Two regional climate simulation datasets MPI-ESM-REMO and WASCAL under RCP 4.5 were applied to the validated HBV light to simulate the catchment discharge. Based on reference and future simulated discharges, a 1.3 MW run-of-river hydropower plant was designed to evaluate the HPP of the catchment. Hydrological and HPP changes were expressed as the difference between two future periods (2020–2049 and 2070–2099) and a reference period (1983–2005). The climate datasets projected a mean annual precipitation increase by 8.8% and 7.3% and discharge increases by 11.4% and 9.735% for the 2020–2049 and 2070–2099 periods, respectively. However, an overall decrease of hydropower generation by − 9.1% and − 8.4% for the 2020–2049 and 2070–2099 periods, respectively, was projected. These results stem from an increase in discharge for the rainy season not convertible into hydropower, combined with a decrease in discharge during the dry months that leads to important HPP losses.

Perception et observation : les principaux risques agro-climatique de l’agriculture pluviale dans l’ouest du Niger

Abstract: La variabilite et le changement climatiques constituent un defi pour l’agriculture pluviale au Sahel. L’objectif de cette etude etait d’identifier et de hierarchiser les risques agroclimatiques, leurs impacts et les strategies d’adaptation, a travers la perception communautaire et l’analyse des donnees observees. Une enquete a ete conduite au Niger aupres de 361 chefs de menage de 12 villages des zones saheliennes et sahelo-soudaniennes. Les donnees de precipitations et de vents de 2 stations meteorologiques ont ete analysees. Les resultats montrent que les communautes sont conscientes de l’existence des risques agroclimatiques, a savoir la fin precoce des pluies, les vents de sable en debut de saison et les sequences seches qui sont les evenements meteorologiques les plus frequents et les plus severes. Les perceptions sur les vents et les sequences seches s’accordent avec les resultats de l’analyse des donnees observees, alors qu’en ce qui concerne la fin precoce des pluies, l’analyse des donnees observees revele un retour a une meilleure situation, qui demeure cependant non perceptible par les communautes, du fait de la forte variabilite intra et interannuelle. Les impacts immediats sont les pertes de semis et de recoltes et le developpement des ravageurs de cultures. Ces impacts entrainent a leur tour l’affaiblissement des animaux et l’insecurite alimentaire. Bien qu’elles developpent des strategies d’adaptation, telles que les varietes ameliorees et les techniques de conservation des eaux et de defense et de restauration des sols, les communautes semblent etre desarmees par le phenomene. Dans l’immediat, la proposition de strategies d’adaptation face aux risques identifies par les communautes aiderait a faire face aux effets des variabilites et changements climatiques sur l’agriculture pluviale au Sahel.

Uncertainties in Plot-Scale Mass Balance Measurements Using Aeolian Sediment Traps

Abstract: Modified Wilson and Cooke (MWAC) sediment catchers are commonly used for quantifying aeolian sediment transport in the saltation layer. The accuracy of aeolian mass flux and mass balance estimates using MWAC catchers has, however, not been reported in detail so far. By combining analytical error propagation equations and Monte Carlo simulation, this study tested a random error propagation scheme that incorporates six sources of uncertainty: sediment mass, MWAC inlet diameter, vertical position of the catchers, trapping efficiency, horizontal spacing between catcher arrays, and wind direction. For a weighing uncertainty of 0.01 g, the relative uncertainty in the cumulative mass flux of sediment reached up to 140%, but this generally affected only the highest catchers. The relative error in the measured unit mass transport was much less, ranging between 2 and 20%, with an average of 10%. The relative uncertainty in the corrected cumulative unit sediment mass transport, however, was found to be 32%, on average, because of the high relative uncertainty in the trapping efficiency of 31%. The relative uncertainty in the plot-scale mass balances ranged between 32 and 80%. Uncertainty in the trapping efficiency and the measured unit mass transport contributed most to the mass balance uncertainty, but the uncertainty in the wind direction sometimes also contributed substantially. The high uncertainties that potentially affect the sediment mass transport and mass balances highlight the need for their systematic reporting in future studies. We also investigated possible pathways for reducing the uncertainty.

Aspects ultrastructuraux et cytochimiques du tapis staminal chez Calotropis procera (Asclepiadaceae)

Abstract: Les transformations ultrastructurales et les modifications cytochimiques des cellules des assises nourricieres staminales ont ete etudiees parallelement a l'elaboration de la pollinie chez Calotropis procera (Ait.) Ait. (Asclepiadacaea). Le tapis se differencie durant la phase premeiotique et conserve son integrite jusqu'a l'anthese. Au cours de cette periode, les cellules tapetales binucleees sont caracterisees par: 1) le developpement restreint du reticulum endoplasmique et de l'appareil de Golgi; 2) l'absence de reserve a l'etat figure; 3) un cytoplasme dense, riche en ribosomes et parseme de petites vacuoles; 4) le developpement transitoire de spherules cavulees au voisinage du noyau; 5) une abondante population de plastes polymorphes dans lesquels se developpent des globules lipidiques; 6) enfin, au stade microspore, la secretion, principalement sur leur face interne, d'importants depots d'un melange de substances glucidiques et proteiques. Il ne se forme pas d'orbicule et, peu avant l'anthe...