The spatial and possess analyses of piping and gully head erosions using unmanned aerial vehicles (UAV) images

The main aim of this study is analyzing the spatial pattern of piping and headcut erosions and theirinteractions. The other aim is identification of susseptible areas and effective factors on these two soilerosion features. The present study is conducted using photogrammetric drones in an area ofapproximately ۲۷۰۰ hectares in the Loess-derived soils of the Golestan Province. According to the fieldsurveys, ۸۳۳ pipes and ۲۷۳ headcuts are recorded by GPS and orthophoto made from the UAV images. Inthis study, the topographic, hydrological, pedologic and biological factors are considered as independentvariables. The locations of piping and headcut are also defined as dependent variables. The univariate andbivariate statistics are used to investigate the spatial patterns of piping collapses and headcuts, and alsotheir spatial interaction. The random forest (RF) algorithm is used to prioritize the factors controlling theoccurrence of these two soil erosion features. The susceptibility maps of these two soil erosion features areprepared using the SVM, BRT, and ME models in the R software and validated using the receiver operatingcharacteristic (ROC) curves. Based on the results of the univariate summary statistics, the pipes has aclustered distribution and the pattern of headcuts is aggregate. Based on bivariate summary statistics,headcuts are positively related to pipes. The results of factor importance analysis have indicated that landuse, slope, and silt content are the most important factors in the occurrence of piping, whereas slopegradient, silt content, and distance to streams are the most important in headcut occurrence. SVMalgorithem has excellent accuracy, and is selected as the best calculator. Identification of the erosionallandforms, piping and headcut, and their spatial and process interactions through observations and highprecisiondata leads to an understanding of the natural processes underlying their spatial structure andprovides appropriate solutions for managing them in these areas.