CwRS Site definition: demonstration of the use of LPIS. Aim, data and SW used

Transcription

1 CwRS Site definition: demonstration of the use of LPIS Olivier Leo, Csaba Wirnhardt 9th conference on Controls with Remote sensing Köln, November Institute for the Protection and Security of the Citizen Aim: Aim, data and SW used to demonstrate the use of LPIS information to improve CwRS site s selection data used: a subset of digital LPIS from the UK GIS SW tools: ArcView for manual analysis and display Arc/Info for automated analysis and statistics 2 1

2 Data used study area 0km x 0km parcels 3300 holdings unique link between holdings and reference parcels dataset only used for demo of tools & possible approaches (does not represent the way we expect UK will do its site selection!) 3 4 General approach defining the risk at holding level and map it at parcel level as opposed to mapping risk at commune level define rectangular windows as sites (similar to those recommended and most suitable for currently available VHR data, eg x20km or 30x30km) calculate statistics for these windows number of farms (having more than 80% of their area in window) mean risk per window net area of parcels / window area decision: size, location and number of sites fine tune final AOI within the site This is of course only one of the many possible approaches for using the digital LPIS and basic GIS tools for site selection 2

3 Mapping farm level risk Risk factor: calculated on farm level, mapped at parcel level present case - simulated farm area (r1: 1-5) random (r2: 1-5) Risk factor=r1+r2 Mapping risk at administrative unit level mean risk: Defining geographic targets for instance manual site interpretation example: x20 km windows 6 3

4 The GIS provides real time results 1. step: selecting all the parcels falling in window 1 Output of LPIS-GIS Output statistics 3 farms have parcels in window 1 7 mean risk: 6.55 net/gross: 65% The GIS provides real time results 1. step: selecting all the parcels falling in window 1 2. step: selecting parcels of farms having more than 80% of their area in window 1 3. step display histogram Output of LPIS-GIS whole region window 1 Output statistics Number of farms Number of farms farms have more than 80% area in window Risk Risk mean risk: 6.67 net/gross: 48% 4

5 Summary Manual approach preferences on the rough location of the sites predefined cluster centres fine-tune the final selection using the GIS tools modifying the centre, size and shape of the site to achieve enough number of dossiers, high mean risk and high net/gross area this can easily be done by using digital LPIS built-in GIS functions of offthe-shelf software 9 A step towards automated site selection Define moving windows over the target area pre-defined size, starting position, step in x, y direction Calculate statistics for each window Map and analyse results Select sites or adjust moving window parameters y step = ½ window size x step = ½ window size 5

6 Mean risk Mapping calculated statistics per moving windows 11 Mapping calculated statistics per moving windows Mean risk Number of farms 12 6

7 Mapping calculated statistics per moving windows Mean risk Number of farms Net/gross area 13 A step towards automated site selection Plotting the three variables calculated for each moving window Number of holdings with 80% area in window Mean risk per window size of circles represents net/gross area in window 14 7

8 A step towards automated site selection Selecting a set of windows with optimum parameters (eg. windows 25, 27 and 64) Number of holdings with 80% area in window Mean risk per window size of circles represents net/gross area in window 15 Using the results of the automatic approach selecting a set of optimum sites further manual analysis to refine output, eg. merge windows 25 and 27 and recalculate statistics define final AOI within window 16 8

9 Summary GIS functionalities allow to define dedicated procedures to optimise site selection Scenario could be drawn in order to fix a priori some parameters to obtain best location/answer Nb farms Risk Computation allow to trace and report on decision taken (risk analysis) Site dimension Nb sites % net/gross area in site 17 Thank you for your attention! 18 9