Statistical and Geostatistical Analysis of Lineaments Network Mapped in The Precambrian Basement: Case of Divo-Oume Region (Southern Cote d’Ivoire)

Abstract

The high populated and dense agricultural region of Divo-Oumé, in the southern part of Côte d’Ivoire, periodically faces drinking water scarcity and lack of reliable water resources management tools. This study presents a statistical and geostatistical analysis of lineaments network, conducted in Divo-Oumé region, in order to contribute to a better understanding of local Precambrian basement aquifer. Fractures network has been characterized through the analysis of the attributes of lineaments derived from conjoint Radarsat and Asar images. The average length of lineaments is 2.15 km and around this value, high dispersion is observed (CV = 133%). A total of 3,559 cross-points (CP) are identified and most of spacing values (84.3%) are less than 2 km. The statistical distribution of lineaments lengths, cross-points and spacing follow power law, highlighting the fractal nature of fractures network. Also, the variation coefficient (CV = 51%) of lineaments spacing and the characteristic exponent of power law in the case of lineament lengths (α = 2.55) would indicate respectively, fracturing process is intense in the region and fracture network reach a mature stage of development. The geostatistical analysis showed that the variograms of lineaments cumulative lengths (CL) and cross-points (CP) are structured. These variograms have the same behavior, reflecting the intrinsic character of CL and CP. However, the correlation ranges of CL are higher than those of CP. These results could be useful for understanding groundwater flow and the establishment of water resource management tools.