Change in Heavy Rainfall Characteristics over the Ouémé River Basin, Benin Republic, West Africa

Abstract

Abstract:Climate change has severe impacts on natural resources, food production and consequently on food security especially in developing countries. Likely accentuated by climate change, flooding is one of the disasters that affects people and destroies agricultural land and products. At different governance levels and scales, appropriate responses are needed. Cluster analysis using scaled at-site characteristics was used to determine homogeneous rainfall regions. A methodology for detecting change was applied to heavy daily rainfall of 34 stations across the Ouémé basin, Benin, in order to assess potential change in its characteristics. The spatial variability of the detected changes in return periods was analyzed using the kriging interpolation method. For this analysis, up to 92 years of rainfall data were used. Three homogeneous regions were found by the cluster analysis. For all studied return periods, 82% of the stations showed statistically significant change in daily precipitation, among which 57% exhibited a positive change and 43% negative change. A positive change is associated with an increase in heavy rainfall over the area of concern. An analysis of the interpolated change in heavy rainfall of different return periods revealed an east-west gradient from negative to positive along the lower Ouémé basin (Region 2). From the middle to the upper Ouémé (Region 1 and 3), a decreasing tendency of heavy rainfall is dominant mainly for the non-homogeneous period. This result of the complex pattern of changes could be veritable information for decision makers and consequently for development of appropriate adaptation measures.

Modelling blue and green water availability under climate change in the Beninese Basin of the Niger River Basin, West Africa

“…The economy of this region is mainly based on rainfed agriculture, and any change in the climate regime would directly affect the income at the country level as well as the livelihood of local populations (Läderach, Martinez‐Valle, Schroth, & Castro, ; Schroth, Läderach, Martinez‐Valle, Bunn, & Jassogne, ; Sultan & Gaetani, ). The high sensitivity of the West African region to climate hazards is illustrated by the severe consequences of the drought of the 1970s and 1980s (Amogu et al, ; Badou, Kapangaziwiri, Diekkrüger, Hounkpè, & Afouda, ; Lebel et al, ) and the floods at the end of the 2000s and the beginning of the 2010s (Aich et al, ; Descroix et al, ) on agricultural production and livelihoods of local population (Bonou, ; Hounkpè, Diekkrüger, Badou, & Afouda, ; Liersch et al, ).…”

Decreasing Past and Mid-Century Rainfall Indices over the Ouémé River Basin, Benin (West Africa)

“…Even though an effort has been made in [21], 15 years after the end year considered (2000), it is necessary to evaluate the new trends of climate indices using the recent World Meteorological Organization (WMO) reference period 1981-2010. Hounkpè et al [22] conducted a study devoted to changes in heavy rainfall characteristics over the Ouémé River Basin (Benin). The main finding is the positive change associated with an increase in heavy rainfall over the area of concern.…”

“…This study analyzed well the heavy historical precipitation for the period 1960-2012 but based on the uncommon climate indices used in impact studies. Indeed, the thresholds established by WMO to define extreme rainfall are of relevance to particular applications such as flood and drought early warning systems contrary to the three thresholds used in [22]. These two studies devoted to climate indices in Benin didn't prospect the future trends of the precipitations index nevertheless pertinent for the future development and sustainable management of water resources.…”

Statistical Analysis of Recent and Future Rainfall and Temperature Variability in the Mono River Watershed (Benin, Togo)

“…Consequently, high fatality rates are recorded in developing countries because of their high reliance on natural resources and their limited coping capacities [6]. Several authors highlighted that, since the 1970s, the number of natural disasters (flood, drought, windstorm, epidemic and famine) has been increasing in sub-Saharan Africa [7][8][9]. In 2012, central and western Africa were hit by severe floods which affected 1,538,242 people and caused 340 deaths as of September of that year.…”