In Côte d'Ivoire rice cultivation is practiced in rainy conditions and remains sensitive to climatic uncertainties. This study is conducted to analyze the variation of climatic parameters and their impact on rice production in the high Sassandra region. The daily climatic parameters (rainfall and temperature) recorded over the period from 1976 to 2005 and the agronomic characteristics of two rice varieties (NERICA 1 and IDSA 85) were used for yield simulation using SARRA-H model. The results showed that the rainy season generally begins in March while instability is observed at the end of the rainy season (between 15 July and 9 October). Overall, the annual rainfall recorded remains potentially appropriate to meet rice water requirements. However, rice cycle shortens when the temperature rises; besides it lengthens when the photoperiod is high. Regardless of sowing date, the total requirements are essentially the same for both rice species. The best yields, 17,161 kg/ha for NERICA1 and 20,048 kg/ha for IDSA85 are obtained when sowing on 5th April. On the other hand, the date of 15th March gives the lowest yields. These results constitute a significant contribution in the redefinition of the rice agricultural calendar in the high Sassandra region.

The sensitivity of subtropical African river basins to possible future climate change is a matter of some concern. In Ivory Coast, previous works on climate change impacts predict a decrease in annual average water resource by the 2080s between 6.9% and 8.4%. This is a potentially serious issue because of a series of historical resource management decisions that have increased dependence upon water use, such as through major dam building schemes. This paper focuses upon the Buyo Lake catchment, a central resource for the Ivorian people with the aim of providing future water resource scenarios, under climate change so as to develop appropriate adaptation policies. The study applied simulations from the UKMO climate model, HadGEM1 from the ENSEMBLES project 2009, with the A1B emissions scenario in continuous simulation. Daily climate data such as rainfall, temperature, wind speed and relative humidity were input to the SWAT hydrological model. The simulations were performed after model calibration. Analysis focuses on the periods 1950-1979 (baseline), 2035-2064 (2050 horizon) and 2064-2093 (2080 horizon).The results showed that the entire basin of Buyo could experience a serious temperature elevation of +1.34