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Brandt, Steffen 
  
COMBINED APPLICATION OF AEROPHOTOGRAMMETRY, LASER SCANNING AND 
DYNAMIC SEGMENTATION TO RECONSTRUCT THREE-DIMENSIONAL WATERCOURSE 
NETWORKS 
Steffen BRANDT, Peter VOSEN 
Deutsche Steinkohle AG (DSK), Germany 
Department of Geoinformation Services (DG) 
steffen.brandt(@dg.deutsche-steinkohle.de 
peter.vosen(g)dg.deutsche-steinkohle.de 
KEY WORDS: Analytical and Digital Photogrammetry, Airborne Laser Scanning, Digital Terrain Model, GIS, 
Dynamic Segmentation, Watercourse Networks. 
ABSTRACT 
The data generation of highly detailed digital terrain models including an integrated 3D watercourse network is a 
requirement of the extensive approval and monitoring process within the environmental assessment for German coal 
mining. This paper provides an overview of the evaluation methodology of the application of photogrammetry in 
conjunction with GIS, and discusses the application of modern surveying procedures. 
1 INTRODUCTION 
Since the Department of Geoinformation Services (DG) at the DSK was set up in 1996, all GIS activities — particular in 
the field of environmental planning — for the entire DSK area (approx. 1500 knr) are centrally managed. 
From an environmental planning aspect, the extraction of hard coal is subject to extensive approval and monitoring 
procedures by the relevant authorities. Of particular significance is the general operation planning process, of which the 
assessment of environmental compatibility is an integral part. The environmental impacts on the population, animals, 
plants and their surroundings, ground, water, climate/air, landscape, heritage and property are investigated in GIS- 
supported environmental compatibility studies. 
2 WATER AS A PROTECTED RESOURCE IN THE ASSESSMENT OF ENVIRONMENTAL 
COMPATIBILITY 
Water as a protected resource, in the form of near-surface ground water, rivers, streams and lakes, plays a central role in 
the environmental assessment of underground hard coal extraction. The mining of hard coal produces a cavity which is 
largely filled by the overlying strata within a period of usually less than 1 to 2 years. This ground movement continues 
up to the surface, where a subsidence cavity develops above the extraction area. The subsequent ground movements 
(subsidence and shifting) influence the natural environment — particularly the ground water and surface drainage. 
Therefore, in addition to the environmental assessment involving ecological investigations, a separate study from a 
water resource and ecological aspect is being carried out. This involves the recording of the initial status in the fields of 
hydrology, surface waterways and hydrogeology. Among other things, it is based on a digital terrain model (DTM) with 
an integrated three-dimensional watercourse network and a ground water flow model. Using the initial status as a basis, 
the result forecast investigates changes in flowing and still waters (e.g. gradient change, gradient reversal, overflowing) 
as well as the ground water conditions (e.g. changes in the ground water isobath, waterlogging) which would arise from 
mining — if the required regulation measures were not implemented. In the subsequent program, regulating measures 
(e.g. bed deepening, stream displacement) will be developed for those watercourses and terrestrial areas influenced by 
the mining and their effectiveness checked with simulation calculations, taking into account existing water resource and 
ecological objectives. From this investigation, measures or alternatives will be suggested, which should be put into 
practice within the context of a monitoring program regarding scope and starting date. 
The three areas of near-surface ground water, flowing and still waters are closely interconnected. This study, however, 
describes only flowing waters — under special consideration of the combined application of photogrammetric evaluation 
techniques and GIS methods. 
This began with a two-dimensional watercourse network, determined on the basis of official topographical maps, aerial 
photographs etc. The course, direction of flow and description (name and abbreviation) of the individual waterways 
were clearly identified. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 213