In this work, we present a study of heat transfer through the different layers of a frequency modulated pavement structure. Solving the heat equation for the different layers obtained the temperature and the heat flux density of each layer (from the wearing course to the base layer) of the structure. The expression of the equivalent thermal impedance of the wearing course in crushed plastic bag waste and sugar cane residue, found by thermal electrical analogy, allowed to study the diagrams of Bode, its phase and his portrayal of Nyquist. These studies are carried out in the illumination zone and in the shaded zone.

In this article, we propose a study of heat transfer through a flexible pavement, the wearing course of which is composed of bitumen modified with sugar cane fibers (bagasse). The expressions for temperature and heat flux density are obtained from the heat equation established by Fourrier. The influence of extrinsic parameters such as the convective and radiative heat exchange coefficient on pavement deformations are presented in order to quantify the thermal behavior of the bituminous mixture under lighting and shade.

The objective of the present work is to contribute to the study and the numerical modelling of the hydric erosion in the plateau of Thiès: through an application to the watershed of Kissane, according to the USLE (Universal Soil Loss Equation) model. The establishment of the USLE model requires data on the topography, the land use, the climatology and the pedology. One of the major difficulties in the elaboration of the model was the collection of relevant data. Indeed, the rural commune of Noto more exactly the village of Kissane is relatively little informated by the scientific bibliography. The geographical reference data on the topography, the precipitation, the land use either non-existent, or incomplete or obsolete on a small scale and the geo-referenced digital data are even rarer. The study, the combination of the data and in the modelling were operated in a Geographical Information System (GIS). Every factor is a digital estimation of a precise component that affects the gravity of the soil erosion in a given place. The realization of the land use map from the visual interpretation assisted by GIS, from the satellite imaging Landsat that covers the watershed of Kissane facilitated the extraction of the vegetation cover map, what allowed defining with more precision the most sensitive areas with erosion risk.

The Niayes area is an agricultural region where market gardeners use a lot of fertilizers and pesticides. With irrigation, water infiltration can lead with it chemicals that can reach the groundwater that is used for drinking by the population and other domestics activities. The study presented in this paper is to assess the risk of contamination of the groundwater consecutive to the use of chemicals in the Niayes area. To perform this, we used the HYDRUS-1D software to model and visualize the spread of flow concentration of the constituent considered as pollutant from the soil surface to the water table. For pollutants we considered in our simulations, urea and NPK 46% mainly used in the Niayes area. The amounts of fertilizer considered in the simulations are those recommended by the Regional Agriculture Center of Thi