Impacts of Climatic Disturbances on the Agricultural Sector at the Scale of the Department of Hills (Benin, West Africa)

Resume Les populations du departement sont particulierement vulnerables aux effets nefastes des variations hydroclimatiques en raison des ressources limitees dont elles disposent. La presente etude analyse les impacts des perturbations hydroclimatiques sur l’agriculture a l’echelle du departement des Collines. La demarche methodologique a consiste en la determination des aleas lies a la variabilite hydro-climatique a travers les donnees climatologiques (pluie, ETP) et hydrometrique (debits) de 1971 a 2017, l’etude des indices de precipitations standardisees et l’analyse des series pluviometriques et hydrometriques appuyes par les observations de terrain et les investigations socio-anthropologiques. Par ailleurs, la matrice de sensibilite a servi de base a l’analyse des impacts risqueshydro climatiques sur les activites agricoles dans le secteur d’etude. L’etude de la variabilite saisonniere du regime hydrologique, des hauteurs pluviometriques et les ETP sur la periode 1971-2017 et les donnees socio-anthropiques recueillies, montre que le departement des Collines est sous la menace des catastrophes hydro climatiques. Ainsi, l’analyse de la vulnerabilite de l’agriculture montre que, les cultures maraicheres, la culture de mais et d’igname sont les plus vulnerables aux risques hydroclimatiques identifies avec un indice d’exposition de 77 % que les cultures de patate douce (71 %), du riz (68 %), de manioc (68 %), et d’anacardier (66 %) qui semble etre la culture la moins exposee aux risques. Le systeme agricole n’est donc pas a l’abri des effets pervers des risques hydroclimatiques dans le departement des Collines. Face a une telle situation la mise en œuvre des strategies appropriees et efficaces doit etre prises pour reduire la vulnerabilite de l’agriculture aux phenomenes hydroclimatiques. Mots cles : Departement des Collines, Perturbations climatiques, Impacts, Risques hydroclimatiques, Agriculture, vulnerabilite Abstract The populations of the department are particularly vulnerable to the harmful effects of hydroclimatic variations due to the limited resources at their disposal. This study analyzes the impacts of hydroclimatic disturbances on agriculture across the Collines department. The methodological approach consisted in determining the hazards linked to hydro-climatic variability through climatological (rain, ETP) and hydrometric (flow) from 1971 to 2017, the study of standardized precipitation indices and the analysis of pluviometric and hydrometric series supported by field observations and socio-anthropological investigations. In addition, the sensitivity matrix was used as a basis for the analysis of hydro-climatic risk impacts on agricultural activities in the study sector. The study of the seasonal variability of the hydrological regime, rainfall levels and ETPs over the period 1971-2017 and the socio-anthropic data collected, shows that the Collines department is under the threat of hydro-climatic disasters. Thus, the analysis of the vulnerability of agriculture shows that market gardening, corn and yam crops are the most vulnerable to hydroclimatic risks identified with an exposure index of 77% than sweet potato crops. (71%), rice (68%), cassava (68%), and cashew tree (66%) which seems to be the crop least exposed to risks. The agricultural system is therefore not immune to the perverse effects of hydroclimatic risks in the Collines department. Faced with such a situation, the implementation of appropriate and effective strategies must be taken to reduce the vulnerability of agriculture to hydroclimatic phenomena.