This study aims to explain the dynamics of the local climate in southwestern of Côte d'Ivoire in a context of strong human pressure and climate variability. The methodological approach, based on the use of climate data an opportunity to discuss the impact of environmental change on natural resources. Southwestern Côte d'Ivoire has suffered a sharp change in vegetation cover. Since the climate out of 1970, the region observed spatiotemporal variation of rainfall regularly changing down. She sees an emphasis on the occurrence of extreme weather events, especially in terms of temperatures. These changes have resulted in a reduction of consecutive wet months and threatening storm agriculture practice in this area.
A DEM is a numerical and mathematical sketch of an area in terms of elevation (Charleux , 2001). Thus this source of information is used in many areas of daily life (mapping, defense, development and urban planning, civil engineering, telecommunications, geomorphology, hydrology, etc.).The results of its use often contain errors that are not generally perceived by the user. In this study, contours of topographic map were used to create two test digital elevation models (DEM) by using two interpolation methods the TIN (Triangulated Irregular Networks) method and the IDW (Inverse Distance Weight) method. These two models were then compared to a reference DEM, product of interferometry radar technology (SRTM images) to detect major errors on our test DEMs. It is clear from this analysis that: On the interpolated DEMs, summit areas are affected by underestimation of altitude and thalweg areas are affected by overestimation of altitude. However, these errors are not impacted on the overall quality of the DEM.
This study aims to assess the evolution of water balance parameters watershed Comoe in a context of climate change. Using the GR2M hydrological model, climate data from the climate model RegCM3 under the A2 emission scenario were simulated to get infiltration, runoff and evaporation and plant transpiration for the periods 1991-2000, 2031-2040 and 2091-2100. Similarly, monthly hydrological and climatic data were used to calibrate the parameters of GR2M hydrological model over the period 1961-1990.
The calibration of the hydrological model gave Nash values between 57% to 72%. At validation, Nash criterion varies from 51% to 75%.
The results of projection, revealed a decrease in runoff of 18.8% to 34% in 2031-2040 and 40% to 73% in 2091-2100 horizon in different localities. Refills of sheets that are through infiltration could decrease by 7% to 13% in 2031-2040 horizon and 49.3% to 70% in 2091-2100. The decrease in these two consecutive hydrological parameters is, firstly, to falling precipitation of 7.17% and, secondly, an increase in the evaporation and plant transpiration via the temperature increase of 3.6
Pesticides used for intensive agricultural production threaten natural resources and human health. The aim of this study is to analyze the use of pesticides in the Marahou
This work aims to test the polygons' method of Thiessen, initially used to evaluate the average rainfall for assessing a groundwater recharge. The study concerns the groundwater of Terminal Continental, the main source of water alimentation of Abidjan population. The database is constituted by rainfall (three stations) and piezometric data (ten piezometers). This method has been tested on both cases: in surface for calculating the total recharge and in saturated zone for assessing the true recharge. The results showed that the ground water of Abidjan total recharge is estimated to 252 mm.year-1; the one estimated in saturated zone is equivalent to 158 mm.year-1 in 2006, that is to say 12 pc of the total infiltration. The taking account of "land use" factor in the approach underlined the fact that the quick ongoing urbanization of Abidjan city is reducing the infiltration zones.
The present study is led on the Gourou watershed, in the autonomous district of Abidjan. Many quantities of sands and macroelements stream to this watershed's exutory in rainy season, blocking drainage canals and invading decantation basin. The objective of this work is to determine the origins of the sands in order to make map. To do it, we update the watershed's limits according to water separation lines. Then, we make a map of erosion zones susceptible to give up sands. The processing of all these data reveals a plurality of this sand blocking origins; the most producing zones being the ones situated near the road arteries. Sands come mainly from numerous bare zones of the watershed, from disorderly installed human activities and from the canals of the drainage network poor maintenance; some canals are being broken by place.
Manganiferous soils have high contents of manganese, which, combined with trace elements could affect the physico-chemistry of the soil and lead to serious hazard on the environment and human. This study aims to assess the levels of trace elements on manganiferous soils of C
This study aims to show the effect of the climatic variability on the productions of coffee and cocoa of the area of Daoukro which is the principal producing area in the Ivory Coast. The methodological approach is summarized in two steps: first, the characterization and analysis of the impact of climate variability on water resources second monitoring developments in the production of coffee and cocoa (1964-2005) through statistical analysis. The centered and reduced index shows a great interannual variability of rainfalls which is organized in two climatic periods, a humid period (1956-1970) and a dry period (1971-2009). The rainfall deficit evaluated in the area of Daoukro reaches an average of 11% and fluctuated between 5% and 15%. Analysis of the average rainfalls of the wettest four months (March-June) every 10 years during five decades of Daoukro station shows that the period of the great season of rains fell from 4 months to 3 months. The decrease of the rainfall consecutive with the effects of the dryness involved a decrease of the agricultural production (the production of coffee and cocoa). The climate variability from 1964 to 2005 caused interannual fluctuation of the production of coffee and cocoa. Cocoa production in 2004-2005 is only 36% of that of 1981-1982 and that of coffee 43% of the production of 1981-1982.
The access to drinking water, in particular in the rural areas and semi-rural in Ivory Coast, constitutes a paramount factor in economic development, the improvement of the standard of living of the populations and their stabilization. The present study aims to raise the unequal distribution of the water supply points for the area of Daoukro and to make a contribution in the research of the zones favorable with the establishment of the productive water supply points in order to allow a good cover of the water needs. The adopted methodological approach is summarized in two stages: initially design of the chart of the water requirements (the access to drinking water) which highlights the zones of deficits followed by the cartography of the sites of establishment of the future water supply points. The knowledge of the space distribution of the population and amongst water supply point by locality made it possible to calculate the access to drinking water of the populations. The analysis of the chart set of themes of the storage areas reveals that nearly 80% of the total surface areas are occupied by zones favorable to the existence of groundwater. The various suitable zones with the establishment of work to large flows were charted and more than 150 sites favorable to the future establishments were selected.