This site will be closing down on 10 September 2014.

Griddle is a system of fast, approximate analysis of vector geographic region data via mid-mif files. It grew out of a simple request for a headline figure for the percentage overlap of 2 highly detailed and very large data sets. It consists of a Griddle Builder and a Griddle Analyser.

This site also includes updates for several MapInfo MBX packages.





 

Background

Griddle is the result of a simple request made a few years ago for a reasonable estimate, as a percentage figure, of the coverage of English Nature's designated Sites of Special Scientific Interest over their RAMSAR (international wetland) sites. The answer was wanted within the hour to satisfy a Government department. Using MapInfo, the quickest the answer could be determined was a few hours.

A taster version is available for download from the Access Griddle Demo Routines.

  

All files and tables used are available for download from Natural England's website and cannot be used for commercial purposes.

 Both sets of sites are highly detailed. The SSSI set has 8468 objects and the RAMSAR set has 1138 objects.

 The Griddle Analysis is:

 Load Time: 0 Minute(s)            0 Second(s)

Inputs Summed Area (1) Cover (2) Mean  SD
SSSI_Data 1077318.75 107691989 1.0003704 0.1299173
RAMSAR_Data 374319.09 37493732 0.9983511 0.0395569
         
Overlap: 330872.7 Hectare(s) for 6507 Common 1Km squares analysed from 16714 squares
         
       Type    Full Area      Overlap  Percentage  
                     HA           HA            %  
 SSSI_Data 1076919.9 330872.7 30.7  
RAMSAR_Data 374937.3 330872.7 88.2  

Analysis Time: 0 Minute(s)        1 Second(s
Thus 30% of SSSIs also cover RAMSARs and 88 % of RAMSARS are covered by SSSIs.

Summed Area (1): Actual Area of Data Set with Overlaps
Cover (2): Derived Ground Coverage

 An alternative form of analysis, listing the coverage of each RAMSAR gives:

UK11002, 2534, 2533.6, 100, 0.2
UK11004, 530.4, 530.4, 100, 0
UK11005, 1391.4, 1390.3, 99.9, 0.1
UK11006, 2283.9, 2283.7, 100, 0.2
UK11007, 4403.5, 4404.2, 100, 0.4
UK11008, 1203.9, 1203.7, 100, 0.1
UK11010, 5510, 5509.6, 100, 0.5
UK11012, 747.5, 747.2, 100, 0.1
UK11013, 5811, 5810.9, 100, 0.5
UK11014, 112.4, 112.4, 100, 0
UK11015, 2714.2, 2714.7, 100, 0.3
UK11016, 1745.3, 1744.9, 100, 0.2
UK11017, 981.1, 981.2, 100, 0.1
UK11018, 3133.9, 3134.3, 100, 0.3
UK11019, 158.2, 158.2, 100, 0
UK11021, 6697.7, 6677.9, 99.7, 0.6
UK11022, 6780, 6779, 100, 0.6
UK11024, 139.2, 139.2, 100, 0
UK11025, 2367, 2367.3, 100, 0.2
UK11026, 10987.9, 10937.4, 99.5, 1
UK11027, 422.2, 422.1, 100, 0
UK11028, 2185.8, 2185.7, 100, 0.2
UK11030, 28.1, 28.1, 100, 0
UK11031, 14962.5, 14962, 100, 1.4
UK11032, 778.8, 778.6, 100, 0.1
UK11033, 401.6, 398.1, 99.1, 0
UK11034, 451.3, 451.3, 100, 0
UK11035, 129.7, 129.5, 99.9, 0
UK11036, 3704.3, 3704.7, 100, 0.3
UK11037, 922, 921.8, 100, 0.1
UK11038, 286.7, 286.5, 99.9, 0
UK11039, 119.8, 119.7, 100, 0
UK11040, 4734.6, 4699, 99.2, 0.4
UK11041, 5023.5, 5023.6, 100, 0.5
UK11043, 512.4, 512.5, 100, 0
UK11044, 2009, 2009, 100, 0.2
UK11045, 36985.5, 36986.6, 100, 3.4
UK11046, 1509.6, 1510.1, 100, 0.1
UK11047, 28013.6, 27984.1, 99.9, 2.6
UK11048, 7861.2, 7861.6, 100, 0.7
UK11049, 1060.1, 1059.8, 100, 0.1
UK11051, 2513.6, 2513.4, 100, 0.2
UK11052, 629.1, 629.2, 100, 0.1
UK11053, 3585.6, 3585.2, 100, 0.3
UK11054, 2480.4, 2485.2, 100, 0.2
UK11055, 1249.7, 1249.5, 100, 0.1
UK11056, 127.1, 127.1, 100, 0
UK11057, 13491.3, 13491.4, 100, 1.3
UK11060, 79.8, 79.7, 99.9, 0
UK11061, 195.3, 195.4, 100, 0
UK11062, 1333.4, 1333.5, 100, 0.1
UK11063, 5306.8, 5304.5, 100, 0.5
UK11064, 6328, 6394.6, 100, 0.6
UK11065, 829.6, 829.4, 100, 0.1
UK11066, 481.3, 481.3, 100, 0
UK11067, 3672.6, 3672.8, 100, 0.3
UK11068, 1250.5, 1249.5, 99.9, 0.1
UK11069, 5553.6, 5553.7, 100, 0.5
UK11070, 2182.7, 2177.4, 99.8, 0.2
UK11071, 6510, 6509.6, 100, 0.6
UK11072, 62044, 62035.8, 100, 5.8
UK11074, 267.8, 267.6, 99.9, 0
UK11076, 53.4, 53.4, 99.9, 0
UK11077, 255, 255.1, 100, 0
UK11078, 208.7, 208.6, 100, 0
UK11079, 43656.1, 14097.6, 32.3, 1.3
UK11080, 1594.1, 821.1, 51.5, 0.1
UK11081, 23357.7, 17154.3, 73.4, 1.6
UK11082, 12029.3, 5240.2, 43.6, 0.5

 

Analysis Time: 0 Minute(s)        1 Second(s)

 The 5th column is the percentage of the total of SSSIs that that RAMSAR covers. A flag has been set in the solution that only allows RAMSARs that have SSSI coverage to be printed; UK11058 has no SSSI coverage.