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PRACTICAL APPLICATIONS FOR CONSTRUCTION AND THE BUILT ENVIRONMENT


Innovation & Research


Issue No. 69


IN THIS ISSUE Buildings


Super-insulated buildings Construction Futures


Thermal crack control in concrete Fibre-reinforced concrete


Dredging


Impacts of offshore dredging Environment


Building roads into the landscape Impacts of offshore dredging


Highways Building roads into the landscape 2


Information Award for Highways Agency 5 IT


Information Award for Highways Agency 5 Materials


Thermal crack control in concrete Fibre-reinforced concrete Super-insulated buildings


Structures Impacts of Part L Research & Innovation


Women ‘CORE’ to construction research 3 Construction research project showcase 2 Promoting innovation in the built environment


Water & Sanitation


Water in low-income countries Wind engineering


Wind turbine aerodynamics 6 3 4 5


6 7 8


5


2 5


8


Women ‘CORE’ to construction research 3 Design


6 7


Also at www.innovationandresearchfocus.org.uk


Trend analysis for beach & sea-bed management


Improving our understanding of beach and near-shore sea-bed evolution often involves the collection of very large amounts of data. This inevitably covers large areas, and necessitates frequent and repeated surveys. Responding to the need to present this information in a form that is quickly understandable and can readily inform decision making about possible interventions, TRENDAMaT (Trend Analysis and Management Tool) is GIS-based Trend Analysis software recently developed by HR Wallingford.


G


IS is commonly used by coastal man- agers to manage, display and analyse coastal, estuarine and riverine data. It is an ideal tool to deal with the spatial vari- ability of the data. However, most landforms within these environments also experience temporal variation, and this makes time trend analysis an important requisite if coastal land- form evolution is to be understood. However, GIS techniques have not tradition- ally been able to calculate the change in values over time and, instead, a simple but perhaps misleading technique has been used (where a Digital Terrain Model (DTM) created for a given survey is subtracted from an earlier one). The net result of this calculation is purely the differ- ence in levels between two "snapshots" of bathymetries or beaches in time. It gives no indication of the variation of the levels between these two snapshots, and yet is often misinter- preted to illustrate the time trend of the data. One way to avoid this problem is to extract the levels for each DTM at each individual cell, plot them in a graph and perform a lin- ear regression analysis on them. Clearly this is very time-consum- ing, particularly since many DTMs consist of over 10,000 data cells, and this method does not indicate the spatial distribution of the time trends.


The new trend tool combines time trend analysis with the GIS spatial distribution and shows the changes in bed-level (or any other


parameter) both spatially and temporally. This provides new information on coastal landform evolution, as shown in the figure below. The TRENDAMaT tool uses colours to map the trends it has calculated for tens of thou- sands of individual data points across the area of interest. Whilst this indicates the areas of high variability, the tool actually calculates the rate at which the levels are changing. Designed for use by for coastal practitioners, it provides a time-saving, analytical means of processing datasets of ever increasing size.


For further information, please contact: Jonathan Kemp, HR Wallingford (01491 822412, fax 01491 832233; E-mail jak@hrwallingford.co.uk).


Trend analysis for a Newhaven shingle beach May 2007


www.innovationandresearchfocus.org.uk Innovation & Research Focus Issue 69 MAY 2007


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