Change in Climate Extremes and Pan Evaporation Influencing Factors over Ouémé Delta in Bénin

Rita Hounguè,Sounmaila Moumouni,Agnidé Lawin,Akambi Afouda

doi:10.3390/cli7010002

Rita Hounguè, Sounmaila Moumouni + Show 2 more

Open Access

https://doi.org/10.3390/cli7010002

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Abstract

This work focuses on trend analysis of rainfall, evaporation, temperature, relative humidity, wind speed, and sunshine duration over the Ouémé Delta in Bénin. Eight temperature based indices and fifteen rainfall based indices are computed from 1960 to 2016. Moreover, maximum 1, 2, 3, 5, and 10 days precipitation indices were computed at the monthly scale. Trends are detected at 0.05 confidence level, using a combination of Mann-Kendall and prewhitened Mann-Kendall test. Partial correlation and stepwise regression are used to detect the set of meteorological variables that influence pan evaporation in Ouémé Delta. Results showed intensification of heavy rainfall over Ouémé Delta. Moreover, a significant increasing trend is detected in temperature. As consequence, diurnal temperature significantly decreases as proof of the global warming. Average pan evaporation showed a significant slither increasing trend over the area. Change in pan evaporation can be explained by wind speed and sunshine duration that hold almost 50% of pan evaporation variance. As future temperature is going to be increasing, pan evaporation may increase considerably. So, adaptation measures have to be reinforced in the Ouémé Delta area where farmer are used to rainfed agriculture for food security. Moreover, Ouémé Delta plan have to be developed for it resources sustainability.

Highlights

Quantifying impacts of changes in climatic patterns over natural resources in a given region is prominent at area level where micro climate is significant
We focused more on heavy rainfall during the high water period to assess its impacts on flood events
Results show at an annual scale that the prewhitening process did not add value to the trend analysis in the Ouémé Delta

Summary

Introduction

Quantifying impacts of changes in climatic patterns over natural resources in a given region is prominent at area level where micro climate is significant. This is important in the development of planning and management of water resources, to cater for everyday demand and supply of users, especially in developing countries where the economy is based on rainfed agriculture [1]. There are contrasting trends throughout seasonal variations of rainfall. Extreme rainfall is declining in Cote d’Ivoire [4] and annual precipitationtend to reduce in Nigeria [5]. No significant trends were detected in Ghana [6]

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