Error propagation analysis of DEM‐based drainage basin delineation

Abstract

GIS analysis‐based drainage basin delineation has become an attractive alternative to traditional manual delineation methods since the availability and accuracy of Digital Elevation Models (DEMs) and topographic databases has been improved. To investigate the uncertainty in the automatic delineation process, the present study represents a process‐convolution‐based Monte Carlo simulation tool that offers a powerful framework for investigating DEM error propagation with thousands of GIS‐analysis repetitions. Monte Carlo‐based probable drainage basin delineations and manual delineations performed by five experts in hydrology or physical geography were also compared. The results showed that automatic drainage basin delineation is very sensitive to DEM uncertainty. The model of this uncertainty can be used to find out the lower bound for the size of drainage basins that can be delineated with sufficient accuracy.

Acknowledgements

This project was funded by the Ministry of Forestry and Agriculture, Finland. In addition, the authors express their gratitude to Prof. Matti Tikkanen, Prof. Jukka Käyhkö and Ph.Lic. Olli Ruth from the Department of Geography, University of Helsinki and Mr Matti Ekholm and Mr Jaakko Suikkanen from the Finnish Environment Institute, who kindly performed the manual drainage basin delineations.