The management of agro-pastoral waste remains a major concern in countries with high agricultural potential such as Côte d’Ivoire, due to the pollution of environmental components resulting from its poor management. This work aims to identify the different types of agro-pastoral waste generated in the departments of Soubré, Issia, Sassandra and Daloa. It also aims to provide information on the quantities of residues available and to identify the management method for this waste. To do this, some fields of observations were made to identify the different types of waste then based on agricultural statistical data from the Ministry. The quantities of agro-pastoral residues were estimated. A survey was also conducted from a survey sheet of agropastoral residue holders to identify the management method. It appears that in these localities, we find as crop residues, rice straw and husk, stalks, cobs and pobs of maize and cassava, bunches and palm shells, cocoa fibers and pods, shells of coffes. Livestock waste is made up of slurry, liquid manure, manure, bones, feathers and droppings and comes from animals such as cattle, sheep, goats, pigs and poultry. The quantities of crop residues estimated are 236,123.3 t/year in Daloa, 255,000 t/year in Issia, 290,000 t/year in Soubré and 198,221.4 t/year in Sassndra. Livestock waste is 728.8 t/year in Daloa, 3,606.1 t/year in Issia, 2,442.6 t/year in Soubré and 873.4 t/year in Sassndra. In these localities, 85% of planters abandon their residues in the fields, 12% of planters incinerate them in the open air and 3% compost them.

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.

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.