Using kites for 3-D mapping of gullies at decimetre-resolution over several square kilometres: a case study on the Kamech catchment, Tunisia

摘要: Monitoring agricultural areas threatened by soil erosion often requires decimetre topographic information over of several square kilometres. Airborne lidar and remotely piloted aircraft system (RPAS) imagery have the ability to provide repeated decimetre-resolution and-accuracy digital elevation models (DEMs) covering these extents , which is unrealistic with ground surveys. However, various factors hamper dissemination technologies in a wide range situations, including local regulations for RPAS cost airborne laser systems medium-format imagery. The goal this study investigate low-tech kite aerial photography obtain DEMs resolution accuracy that permit 3-D descriptions active gullying cultivated To end, we developed assessed two-step workflow. First, used both heuris-tic experimental approaches field numerical simulations determine conditions make photogram-metric flight possible effective kilometres consumer-grade camera. Second, mapped characterised entire gully test catchment 3-D. We showed numerically experimentally using thin light line key complete coverage thus obtained DEM 3.18 km 2 mean error standard deviation +7 22 cm respectively, hence achieving accuracy. With data set, high-resolution detection characterisa-tion an high level detail overall 74 % compared independent survey. Kite simple but appropriate equipment alternative tool has been proven be valuable surveying gullies sub-metric details square-kilometre-scale catchment. This case suggests access on scales can given community, may help facilitate better understanding processes within broader spectrum conditions.