Hydrological Processes · 2004 · 171 citations · 20 references
Environmental MonitoringEngineeringGeomorphologyHydrologic EngineeringNetwork AnalysisQuantitative GeomorphologyNetwork‐index‐based VersionContinuous SaturationEarth ScienceSocial SciencesData ScienceCatchment ScaleTopographic MappingClassic TopmodelTopographic IndexSurveyingGeographyNetwork ModelingHydrologyNetwork ScienceWater ResourcesSurface-water HydrologyRemote SensingLand SubsidenceHigh-dimensional NetworkHydrological ScienceFlood Risk ManagementData Modeling
The study develops a network‑index modification of TOPMODEL to better represent saturated areas in high‑resolution topographic data. The modification counts saturated cells only when continuous saturation exists along a flow path to a stream, and it incorporates an enhanced pit‑hollow handling routine. Applying the original TOPMODEL to 2‑m LIDAR data revealed many saturated zones disconnected from the drainage network, a problem worsened by high resolution; the network‑index and pit‑hollow improvements mitigate this issue, with implications for ongoing methodological and substantive research. © 2004 John Wiley & Sons, Ltd.
Abstract This paper describes the preliminary development of a network‐index approach to modify and to extend the classic TOPMODEL. Application of the basic Beven and Kirkby form of TOPMODEL to high‐resolution (2·0 m) laser altimetric data (based upon the UK Environment Agency's light detection and ranging (LIDAR) system) to a 13·8 km 2 catchment in an upland environment identified many saturated areas that remained unconnected from the drainage network even during an extreme flood event. This is shown to be a particular problem with using high‐resolution topographic data, especially over large appreciable areas. To deal with the hydrological consequences of disconnected areas, we present a simple network index modification in which saturated areas are only considered to contribute when the topographic index indicates continuous saturation through the length of a flow path to the point where the path becomes a stream. This is combined with an enhanced method for dealing with the problem of pits and hollows, which is shown to become more acute with higher resolution topographic data. The paper concludes by noting the implications of the research as presented for both methodological and substantive research that is currently under way. Copyright © 2004 John Wiley & Sons, Ltd.
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