Analysis of Geologically Fractured Terrain Using Remote Sensing and GIS

Sumanjit Aich
Department of Earth Sciences, Florida International University
Miami, Florida, USA
E-Mail : saich002@fiu.edu

Fractures play an important role in the subsurface movement of water, hydrocarbons and contaminants. My objective is to characterize the spatial heterogeneity of fracture networks in sedimentary rocks using innovative Remote Sensing and GIS techniques. The purpose is to develop new approaches to analyze the spatial distribution of fracture networks, investigate methods for mapping fractures from aerial photos and portray spatial distribution of heterogeneity within fracture networks with the aid of a Geographic Information System. The project focuses on quantifying the two-dimensional distribution of fractures and characterizing the geometric attributes of fracture populations in terms of fracture density and connectivity, two important factors that influence fluid flow in fractured rock.

The study area is in Arches National Park of Utah. An aerial photograph in the form of Digital Orthophoto Quadrangle (DOQ) is treated as source data. The methodology includes digitizing fracture traces from air photos within a GIS environment, creating fracture distribution, fracture intensity and distance buffer maps, overlaying maps for quantitative analysis and generating fracture backbone maps. Field work will be carried out for fracture scanline survey to measure fracture length, spacing and orientation, as well as to corroborate with the fracture traces mapped from aerial photos.

Characterizing the spatial distribution of fractures is essential, as fractures significantly change the hydrological character and stability of a rock mass. Furthermore, zones of high fracture intensities serve as major pathways for fluid flow, which is of great importance for groundwater exploration and in research fields related to modeling of hydrocarbon reservoirs.