Translation of the CORINE Land Cover nomenclature to the Land Cover Meta Language using LCCS3

Transcription

1 Translation of the CORINE Land Cover nomenclature to the Land Cover Meta Language using LCCS3 Vasco Nunes Remote Sensing Group (GDR) Portuguese Geographic Institute (IGP) Coordinator: Mário Caetano

2 Index > Introduction > Specifications of CORINE Land Cover > Translation process > Questions and remarks > About the translation process > About the LCCS3 software > Final considerations 2

3 Introduction > Objectives - Evaluating the hability of the Land Cover Meta Language (LCML) to describe the classes of the CORINE Land Cover (CLC) -Evaluating the use of the Land Cover Classification System (LCCS) version 3 software 3

4 Specifications of CORINE Land Cover > Project CORINE Land Cover Co-ordination of Information on the Environment - Objective Produce Land Cover/Land Use cartography harmonised for all countries of the European Union; - Delimiting Homogeneous areas with polygons to obtain a vector spatial database; 4

5 Specifications of CORINE Land Cover - Technical specifications: - Scale: : 1: Minimum Mapping Unit (MMA): 25ha - Minimum Distance Between Lines (MDBL): 100m - Thematic accuracy: 85% - Nomenclature: Hierarquic,, 3 levels with 44 classes - Including several Generalization and Topology rules 5

6 Specifications of CORINE Land Cover > Nomenclature 3 hierachical levels 44 classes at most detailed level 6

7 CORINE Land Cover nomenclature Land Cover Classification System 3 (3rd level) 7

8 CODE Designation Adaptation to Portugal Translation User defined process structure 111 Continuous urban fabric Discontinuous urban fabric Industrial or commercial units Road and rail network and associated land 2 Yes 123 Port areas Airports Mineral extraction sites Dump sites Construction sites Green urban areas 2 Yes 142 Sport and leisure facilities Non-irrigated arable land 1 Yes Includes Drip irrigation type; 212 Permanently irrigated arable land Excludes irrigated permanent crops (e.g. Irrigated Orchard) Rice fields Vineyards Fruit trees and berry plantations Olive groves Pastures Annual crops associated with permanent crops Complex cultivation patterns Land principally occupied by agriculture, with significant areas of natural vegetation Agro-forestry areas Tree cover > 10% Broad-leaved forest Coniferous forest Mixed forest Natural grasslands Moors and heathland Geographic distribution Sclerophyllous vegetation Geographic distribution Transitional woodland/shrub Tree cover > 10% 3 Yes 331 Beaches, dunes and sand plains Bare rocks Sparsely vegetated areas Burnt areas Excludes burnt Glaciers and perpetual snow Unexisting in Portugal Inland marshes Peat bogs Salt marshes Salines Intertidal flats Water courses Water bodies Coastal lagoons Estuaries Sea and ocean 1 Difficulties/questions in the translation of CLC classes Straight forward translation Somewhat questionable translation Very questionable translation 8

9 Example of class Continuous urban fabric Most of the land is covered by structures and the transport network. Building, roads and artificially surfaced areas cover more than 80 % of the total surface. Non-linear areas of vegetation and bare soil are exceptional. Extension: 80 % of the total surface at least should be impermeable. The continuous urban fabric class is assigned when the urban structures and transport network (i.e. impermeable surfaces) occupies more than 80 % of the surface area. This coverage percentage pertains to real ground surface. Therefore, localisation of this cut-off-point requires particular attention to avoid confusion with the apparent vegetation (i.e. visible tree crowns) and permeable surfaces under trees. For example, in the streets bordered with trees, the real ground surface under the trees is mostly covered with asphalt or concrete. So, the vegetation percentage has to be estimated taking into account the shape structure and context visible on the satellite image. This heading includes: urban centre types and dense ancient suburbs where buildings form a continuous and homogeneous fabric; public services or local governments and commercial/industrial activities with their connected areas inside continuous urban fabric when their surface is less than 25 ha; interstices of mineral areas; parking lots, concrete or asphalt surfaces; transport network; small squares, pedestrian zones, yards; urban greenery (parks and grass areas) amounting to 20 % of the polygon area; unvegetated and vegetated cemeteries less than 25 ha located inside continuous urban fabric. 9

10 Example of class Continuous urban fabric Straight forward translation Should other descriptive details be included? 10

11 Example of class 244 Agro-forestry areas Annual crops or grazing land under the wooded cover of forestry species. Extension: This class includes Mediterranean agro-forestry systems (e.g. dehesa, montado). This heading includes: areas of forest trees imbricated with fruit trees/olive trees while neither of the two kinds of trees dominates; carob trees shading agricultural lands; agricultural land shaded by palm trees in Mediterranean context. 11

12 Example of class Agro-forestry areas Somewhat questionable translation Should other descriptive details be included? 12

13 Example of class 313 Mixed forest Vegetation formation composed principally of trees, including shrub and bush understoreys, where neither broad-leaved nor coniferous species predominate. Extension: Mixed forests with a crown cover of more than 30 % or a 500 subjects/ha density for plantation structure. The share of coniferous or broad-leaved species does not exceed 25 % in the canopy closure. This heading includes: mixed-forest wooded dunes; denuded spots and grassland; sporadically occurying shrub formations. 13

14 Example of class Mixed forest Very questionable translation Should 313 constitute a Mixed Class in LCCS?? Should mixed Broadleaved and Needleleaved constitute different patterns?? 14

15 Example of class 242 Complex cultivation patterns Juxtaposition of small parcels of diverse annual crops, pasture and/or permanent crops. Extension: This class includes juxtaposition of small parcels of annual crops, city garden pastures, fallow land and/or permanent crops eventually with scattered houses or gardens. This heading includes: mixed parcels of permanent crops (fruit trees, berry plantations, vineyards and olive groves); interstices of non-mineralised free spaces in discontinuous urban fabric < 25 ha; complex cultivation pattern areas with scattered houses inserted within a patchwork structure when built-up parcels cover less than 30 % of the patchwork area; summer settlement areas if infrastructure/road network is not visible; hobby/city gardens; parcels of grassland. 15

16 Example of class Complex cultivation patterns Very questionable translation Should other descriptive details be included, like scattered houses? 16

17 Example of class 324 Transitional woodland/shrub Bushy or herbaceous vegetation with scattered trees. Can represent either woodland degradation or forest regeneration/recolonisation. Extension: Areas of natural developmental forest formations (young broad leaved and coniferous wood species with herbaceous vegetation and dispersed solitary trees) for instance; in abandoned meadows and pastures or after calamities of various origin, part of this class may be also various degenerative stages of forest caused by industrial pollution, etc. This heading includes: arborescent mattorals which are pre- or post-formation of broad-leaved evergreen forest with a usually thick evergreen shrub stratum composed of evergreen oaks (Quercus suber/ilex/ rotundifolia), olive trees, carob trees or pines the crown cover density of which is less than 30 % of the surface; agricultural lands (classes 2xx) under recolonizing process with occurrence of forest trees which cover more than 30 % of the surface (scattered trees or small plots of forests); abandoned fruit tree plantations and orchards; clear cuts in forest areas; young plantations; forest nurseries inside forests areas; natural grassland areas with small forests < 25 ha and/or with trees intermixed which cover more than 30 % of the surface; open clear-felled or regeneration areas with regrowing during transition stage which last for maximum 5-8 years; forest burning areas which do not show black tones any more in the satellite image but are still visible; heavily damaged forests by wind, snow-brake or acid rains and other pollution with more than 50 % dead trees; marginal zones of bogs with a vegetation composed of shrubs and pine bogs which cover more than 50 % of the surface. 17

18 Example of class 324 Transitional woodland/shrub Very questionable translation Should this structure be different? 18

19 Example of class 324 Transitional woodland/shrub Very questionable translation Open forests Mixed class or Young plantations or Clear-cuts or Forest regeneration Another possibility 19

20 Questions and remarks about the conversion Regarding the translation of class 244 Agro-forestry areas, FAO used the following structure: In this case, though we agree it is a good translation, we still have 2 questions: a) isn t the concept of Herbaceous growth forms used for grazing included in Herbaceous Growth forms cultivated and Managed? b) this description is excluding the case of Permanent crops under storey of Forest Trees (e.g. Olive trees and Oak trees). We suggest this form: 20

21 Questions and remarks about the conversion When Land Cover class includes Horizontal pattern A and/or Horizontal pattern B, does Cover % have any influence? e.g. If Horizontal Pattern A covers 80% of the area, is Horizontal Pattern B limited to 20%? Shouldn t a Presence type property (e.g. Mandatory/optional) be included in Horizontal Patterns too? Example of Land principally occupied by agriculture, with significant areas of natural vegetation H.Pattern A + H.Pattern B <= 100%????? H.Pattern A & H.Pattern B Mandatory??? 21

22 Questions and remarks about the LCCS software It would be interesting to automatically compare the Cover percentages of given elements when validating the legend in order to prevent overlapping of definitions; The various windows of the software sometimes overlap hiding buttons and other important elements; It would be important for the user to be able do close some windows; It would be important for the user to be able to move classes up and down 22

23 Final considerations CLC LCML/LCCS3 CLC has some classes that are scale dependent (e.g. 242, 243) There is more than one correct form to describe a Land Cover class using LCCS Generally CLC classes have extensive descriptions Its not clear when to stop in detailing class descriptions Most classes can be discriminated using smaller descriptions The User defined structures are very helpful to better describe the CLC classes Some classes are the same as other but with an additional attribute. (e.g. 334 = burnt) Dealing with Horizontal and Vertical patterns is not very intuitive Software platform is quite functional but could include more validation mechanisms (e.g. compare cover percentages) 23

24 THE END 24