Deltas on the move; Making deltas cope with the effects of climate c

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KvR report 001/2006<strong>Deltas</strong> on the move5. Data on deltasAs outlined in our introduction, the objective of this study is to provide an accessibleoverview of compiled information on deltas across the world. We based our study ondatasets that already provided a comprehensive set of parameters for a bunch ofdeltas. This approach allows providing a consistent overview of the incorporateddeltas, but as a consequence, we also missed some deltas. This chapter shows howwe checked and used the available data to link deltas with system-basedapproaches.5.1 How to characterize deltas?There is physical and socio-economic data available on deltas. The information isavailable in different formats, in quantitative and qualitative databases, in maps andimages and as GIS-material. Together, all this information will be used tocharacterize deltas according to:1. physical vulnerability (for example to erosion, e.g. due to sea-level rise);2. societal stocks at risk, i.e. socio-economic indicators of the delta and itsimmediate hinterland;3. the potential for ‘soft’ system-based approaches.In this way, a wide audience of potential users may find the compilation useful.The present chapter explains where this information was obtained and how it wasprocessed. We identify two main data sources. These databases are described, andan overview is presented of potentially useful variables in each. The allocation ofindicators to the above three categories is carried out in section 5.5. Subsequently,observed variation among deltas was used to select the indicators that are useful inthe present context.The steps taken in the selection process are given in detail in Annex 1, whichincludes an overview of the major patterns of variability in indicators that can bedistinguished among deltas. The indicators selected are then included in the projectwebsite as explained in Chapter 6.5.2 Sources of informationFor the present pilot study, we have limited ourselves to data sources for whichlarger sets of data were available in freely accessible form. Furthermore, our interestwas both in geomorphological features of a delta and its surrounding coast, as wellas in socio-economic aspects of adjacent human society. In addition, it was thoughtpreferable that remote sensing imagery would be available of selected deltas. Thishas put constraints on the sources of information available.Most fortunately, we could depend on two major compilations of information, theWorld Delta Database (WDD, www.geol.lsu.edu/WDD/), and the DIVA-tool, recentlyfinalized by the DINAS-COAST consortium (www.dinas-coast.net/). Together, thesetwo sources contain a wealth of information that can be used to carry out preliminary,but quantitative evaluations of vulnerability, stocks at risk and the potential for new,soft engineering solutions along the world’s deltas.4243
KvR report 001/2006We adopted a three-step approach in the selection of deltas. First, we selected thosedeltas from the WDD for which data availability was high and for which also satelliteimagery of some form was available. This led to a list of 42 deltas (section 5.3).Then, we matched those to the data available in DIVA. The DIVA tool allowsmodeling of plausible future SRES scenarios (e.g. Lorenzoni et al., 2000) along theworld’s coast. Its structure and content will be briefly explained in section 5.4. Finally,possible indicators for the potential of applying system-oriented coastal engineeringare introduced, and matched to the contents of these databases.5.3 The World Delta DatabaseStudies by Hart & Coleman (2004) resulted in the open on-line World <strong>Deltas</strong>Database (http://www.geol.lsu.edu/WDD/). The purpose of the WDD is to facilitatethe development and use of a public domain distributed knowledge base on modernglobal deltaic systems. The WDD contains two sub-databases that are particularlyuseful for the physical characterization of deltas in our project:A. For 43 deltas, geomorphological, hydrological and oceanographical variableswere summarized in an excel file (Coleman & Huh, 2004);B. For 54 deltas, satellite pictures and a description of physical characteristics weregiven in a pdf file on the WDD site in “Appendix A: The Major River <strong>Deltas</strong> Of TheWorld” (Huh et al., 2004).For 42 <strong>Deltas</strong> both A and B were available. A list of physical characteristics resultsfrom close examination of the content of A and B (Table 5.1).The information can easily be combined using location (coordinates), delta name (oran ID). Location (latitude and longitude) also allows the link with DIVA output. Aselection of variables from the WDD may be suitable for assessment of coastalvulnerability (mainly physical vulnerability) and possibly soft engineering potential.This will be addressed in section 5.5.Table 5.1:Variables for 42 deltas in the two subsets of the WDD.<strong>Deltas</strong> on the moveVariables DB AVariables DB BGeneric DELTA (name) Selected High Quality ImagesLATLONGClassified Ex. of Delta TypesArea X 103LocationDrainage Basin Stream Length Landmass DrainedReliefOcean Basin of DepositionAve El (USGS)ClimateMax ElAir TemperatureMin ElTideDrainage DensityDischarge (water & sediment)# Days Freeze IDAve RainfallMax RainfallMin RainfallAve Monthly Rainfall (MM)Annual Ave DischargeMax DischargeMin. DischargeDelta Delta AreaSubaerial/SubaqueousAbandoned/ActiveShoreline# River MouthsDistributary DensityReceiving basinForm-ProcessOffshore SlopeSpring TideWave PowerShoreline RMSWave HeightDrainage Basin Area x Delta Arearelationships An. Ave Discharge x Delta AreaOffsh. Slope x Wave Power Shoreline4445
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Deltas on the move; Making deltas cope with the effects of climate c

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