CATCHMENT-WIDE, SECTIONAL AND LOCAL ASPECTS IN SEDIMENT TRANSPORT MODELLING AND MONITORING

1.INTRODUCTIONOVerthelastdecadesmuchprogresshasbeenmadeconcerningsedimenttransPOrtmodellingandmonitoring.Thedifferelltiationincatchmeflt-tvide,sectionalandlocalaspectsreflectsthefactthatmanysedimenttransportandpredictionmodelsaredealingwithspecialpartsofriverSystems,mainlydifferinginscale.Overthepastyears,scaleissuesinhydrologyhaverapidlyincreasedinimportance(BLoSCHL,1996).Onalargescaletheapplicationoffractals,self-similarityanalysistolandscapeorganizationandoptimalchannelnetlvorks(O…

CATCHMENT-WIDE, SECTIONAL AND LOCAL ASPECTS IN SEDIMENT TRANSPORT MODELLING AND MONITORING

The aim of this paper is to analyse the relevance of different scales for the methods and reliability of sediment transport modelling and monitoring techniques. Both deterministic as well as stochastic approaches allow to derive specific results in different scales whereaby the deterministic, physically based methods are mostly limited to local and sectional aspects. The larger the scale becomes the more stochastic compnents enter the system. At the same time basic features in the larger scales line catchments show a fractal nature and a scale independent behaviour. Throughout the paper a framework for sediment transport modelling and monitoring in different scales is discussed. Starting with catchment-wide analysis using optimal channel network (OCN-) techniques etc. based on digital elevation maps (DEMs) a downscaling process leads to the analysis of local structures like meander-modelling. Based on the point- and local scale an upscaling procedure allows to derive overall conclusions for the catchment and management measures.