Geodetski Vestnik (Jan 2013)

Algoritem za prepoznavanje kraških kotanj na podlagi digitalnega modela reliefa ; Algorithm for karst depression recognition using digital terrain models

  • Jaroš Obu,
  • Tomaž Podobnikar

Journal volume & issue
Vol. 57, no. 2
pp. 260 – 270

Abstract

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Algoritem samodejnega prepoznavanja kraških kotanj deluje na podlagi digitalnega modela reliefa (DMR) in večinoma temelji na analizah s premikajočim se lokalnim oknom velikosti 3 x 3 celice. Razdeljen je na štiri dele: računanje porečij, omejevanje kotanj, omejevanje kotanj višjega reda in izločanje nekraških kotanj. Jedro izdelanega algoritma je, da so kotanje omejene z višino najnižje robne celice porečja. Kotanje višjega reda pa so prepoznane z algoritmom zalivanja predhodno prepoznanih kotanj. Uspešnost algoritma je bila preizkušena na testnem območju Krasa na DMR-jih s prostorsko ločljivostjo 12,5 metra in 3 metre. Pokazalo se je, da so rezultati precej odvisni od več lastnosti in kakovosti DMR-ja, predvsem od prostorske ločljivosti ; An algorithm of automated karst depression recognition uses a digital terrain model (DTM) and mainly applies the methods of a moving window with a kernel size of 3 × 3 cells using focal functions. It is divided into four parts: watershed calculation, depression delineation, higher level depression delineation and elimination of non-karst depressions. The essential part of the algorithm is the delineation of depression by the elevation of the lowest border cell of watershed. Depressions at higher levels are recognised by filling previously recognised depressions. The performance of algorithm was tested on test area in the Kras region (Slovenia) using DTMs with a spatial resolution of 12.5 m and 3 m. The results mainly depend on the DTM characteristics and quality, especially of their spatial resolution.

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