Curvature and Radius of Curvature Variation in the Characterization of an Area Affected by Anthropogenic Mining Activities

Abstract This study analyzed the curvature and radius of curvature in order to characterize an area affected by anthropogenic coal mining activities. The study took place in an area located in Jiu Valley, Romania. 16 control points were considered (CP1 – CP16), for which the quota values were determined (X,Y,Z system) at the moment of analysis (T1) in relation to a reference moment (T0). The differences in quota were calculated (XYZ) between moments T1 and T0. Curvature (Curv) and radius of curvature (RadC) values were calculated. Strong correlation was recorded between Curv and Z(T1-T0), r = -0.847***, between Curv and Dg (diving the ground), r = 0.847***, and between Curv and Ls (land slope), r = 0.891*** (*** p < 0.001). Weak correlation was recorded between RadC and Y(T1-T0), r = 0.586***. Spline type mathematical models described the variation of curvature, and Radius of curvature in relation to the control points (XYZ values), under conditions for curvature, respectively for radius of curvature. According to the multivariate analysis, the PCA diagram resulted, in which PC1 explained 50.737% of variance, and PC2 explained 49.263% of variance. The cluster analysis generated the dendrogram in which the control point CP16 was positioned separately, and the other control points were grouped in a cluster based on similarity (Coph.corr = 0.998). The ranking of the control points, in relation to the values recorded for the Curv and RadC parameters, was done in the form of Scaling dendrogram.