Characterization and Trend of Heat waves in Burkina Faso

The Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC, 2013) reports that an increase in the frequency of extremely high temperatures and heat waves is very likely (> 90% of probability). Burkina Faso, a West African country without access to the sea, is particularly vulnerable in both health and economic terms. This research project aims to contribute to the improvement of knowledge on the evolution of extreme temperatures as well as the extreme phenomena associated with them in Burkina Faso.It is also intended to contribute to the research program ACASIS (Alerte aux Canicules Au Sahel et à leurs Impacts sur la Santé, ANR10 LABX56), one of the objectives of which is to establish a pre-operational warning system for heat waves in Burkina Faso. For this purpose the data of ten meteorological stations of Burkina Faso over the period 1961-2014 were used. Taking into accountcurrent recommandations on climatological practices, the first part of this work was devoted to data processing. This consisted mainly of the quality control and validation, imputation of missing values and homogenization of the data. The second was dedicated on the trend analysis of extreme temperatures by Mann Kendall method. Whether on the seasonnal or annual, the trend towards higher temperature is general but more noticeable on minimum temperatures. This trend is significative over all the stations and on most of the seasons. In the last part, the issue of heat waves was discussed. A three-step approach wasused. First, the characterization of these events on all the months of the year using a moving percentile (P90) made it possible to highlight the months of occurrence of predilection of these phenomena.In addition, the use of an index (HeatWave Magnitude Index daily, HWMId) made it possible to identify the heat waves of a particular severity that affected the country. Then the behavior of these phenomena on two warm seasons (spring and autumn) have been studied.Finally the trend of these events on these seasons during the period was eveluated. This allowed us to show an overall upward trend of these events as well as some characteistics associated with them.