Identifying Selected Man-made Surface Changes Using Lidar Data

Človek s svojim delovanjem načrtno in nenačrtno spreminja okolje. Na razgibanem površju je ena izmed nenačrtnih sprememb tudi pospešena erozija, do katere zaradi teptanja in odstranjevanja vegetacije pride na območju poti in cest. V pričujoči nalogi smo ocenili količino odnesenega gradiva z območij poti in cest na petih proučevanih območjih, kar smo dosegli z GIS-ovskim modeliranjem in uporabo obstoječih lidarskih podatkov za Slovenijo. Med terenskim delom smo merili višino ugreza poti v okoliško površje in opazovali natančnost interpretacije poti na senčenih modelih reliefa, kar nam je omogočilo opredeliti natančnost modeliranih izračunov višine odstranjenega gradiva. Potrdili smo, da je bilo modeliranje kolikor se le da natančno, saj so več kot štiri petine terenskih meritev od modeliranih izračunov odstopale za manj kot 15 cm, kolikor znaša tudi vertikalna natančnost uporabljenih podatkov. Hkrati smo ugotovili, da je identifikacija poti na lokalnem in senčenih modelih reliefa v nekaterih primerih celo enostavnejša kakor pa s terenskim delom, kar je značilno za opuščene in zaraščene poti.Human agency may bring about environmental changes either wittingly or unwittingly. One of the unwitting changes typical of undulating hilly areas is the acceleration of erosion as a result of trampling or vegetation removal near roads or pathways. This thesis made use of GIS modelling and lidar data for Slovenia to estimate the amount of material eroded from pathways and roads for five selected areas of interest. During fieldwork, measurements of how much the path has sunk into local surface were taken and compared with lidar shaded relief interpretation, which made it possible to determine the precision of the model used. The model was confirmed to be remarkably precise as more than 80% of fieldwork measurements deviated by less than 15 cm – the vertical accuracy of the data used – from values obtained from the model. It was also discovered that using the local model and shaded relief model is easier than fieldwork in some cases, namely for the abandoned and overgrown pathways