The aim of this study was the writing of PHP language program to analyze lineaments. To achieve this aim, a TXT file containing the start and end coordinates of 1620 lineaments extracted from four Landsat 8 scenes (with references 198_53, 198_53, 198_54, 199_53 and 199_54) was used. Geomorphological parameters such as minimum, maximum and average lengths, as well as the spatial parameters such as the density of lineaments and density of intersections were determined through the three modules of the program which are calculation of directions modules, calculation of lengths modules and calculation of intersections point’s modules. The minimum and maximum lengths of lineaments are respectively 3.95 Km and 15.90 Km and belong respectively to NW-SE and NE-SW directions. 43.9% of the lineaments are in the NE-SW direction, 28.6% are in the NW-SE direction, 11.8% in the E-W direction and 15.7% in the N-S direction. The values of the different proportions of the lineament density classes shows that the medium and high density classes represent 36.78% of the Denguélé District.
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.
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