Estimation of Land-use Changes in Portugal. Methodology used in NIR 2013 JRC Workshop, February 2013

Transcription

1 Estimation of Land-use Changes in Portugal Methodology used in NIR 2013 JRC Workshop, February 2013

2 Land-use Changes in Portugal: General Approach 3 separate approaches for Portugal (9,22Mha) Portuguese Mainland (8,91Mha = 96,6%) Azores (0,23Mha = 2,5%) Madeira (0,08Mha = 0,9%) Mainland Madeira

3 Portuguese Mainland: General Approach Time-series based on NFI6 National Forest Inventory 6 covers all land uses and land-use changes (1995, 2005, 2010) Time-Series (re)constructed using auxiliary data: National Forest Inventories: NFI2 (1974), NFI3(1985) Total forest area Forest area per forest type General Census of Agriculture (1979, 1989, 1999, 2009) Total cropland and grassland area Crop area per crop type

4 NFI6 Methodology Land-use/cover data Use of Sample Points Systematic grid of 500m x 500m ( points) Land-use X attributed to a point if included in an area of X >0,5ha Interpretation of airborn imagery Full wall-to-wall country coverage False color near infrared imagery (1995, 2005, 2010) and true color imagery (2005, 2010) Spatial resolution 1m (1995) and 0.5m (2005, 2010) Use of Kyoto and UNFCCC compatible land-use classification ALL land uses (not just forest) Land-use Change data Comparison of land-use in each point in each temporal assessment Two land-use change matrices : and Annual data for land-use change estimated by dividing total land-use change by number of years in interval

5 Data production process National Sampling Grid Orthophotomaps 1995 Orthophotomaps 2005 Orthophotomaps 2010 Classified sampling points 1995 Classified sampling points 2005 Classified sampling points 2010 Auxiliary data Final classification

6 NFI6 Attribution of Land-use/cover A > 0.5ha Results calculated based on No. of plots per land use type 75ha B 25ha A A < 0.5ha or <20m width Results 100ha B B B A A

7 NFI6 Methodology web based interface

8 NFI6 Quality Control & Quality Assurance Mandatory training and accreditation of all photo-interpreters Software design limited data insertion errors Extensive use of hierarchical pop-down menus Alerts for improbable / impossible land-use conversions Field verification of dubious situations (e.g. for identification of tree species in new plantations) mandatory for a minimum 1% of all points Field verification of 5% of the territory Sub-contracted task (different contractor) Maximum allowed differences between field-checked land-use and reported land-use 10% ICNF (Institute for Nature Conservation and Forestry) control and helpdesk during production phase ICNF control of both photo-interpretation and field verification [additional 6% field verification when tree measurements and data collection take place in 2013]

9 Land use 2010 Afforestation Deforestation

10 Use of NFI6 for UNFCCC and KP Reporting Advantages Full wall-to-wall representation of the country Simultaneous interpretation of 3 points in time (land-uses are consistently interpreted and represented over time) Compliant with 1ha minimum data resolution Low cost compared to full mapping systems (about 20% of the cost) Faster production time compared to full mapping systems Systematic, permanent grid allows estimation of land-use change Methodology implemented will allow future updates, as new full country images become available

11 Use of NFI6 for UNFCCC and KP Reporting Difficulties encountered Sometimes what you see is NOT what you need to report Problems in land-use allocation for look-alike categories Difficult distinction between annual crops in long rotations, fallow land and grasslands Difficult distinction between areas that can be irrigated from areas that are actually irrigated Specific activities (e.g. no-till) can not be identified by aerial photography Problems in matching some land-uses, as observed in photography, with reported land-use categories Forest type allocation of areas under clear cuts or recently burned Application of the temporarily unstoked notion to forest types Observed spontaneous vegetation (including shrubs and possible natural regeneration) should be classified as forest NFI6 cropland and grassland totals tend to be higher than those from the General Census on Agriculture (GCA)

12 Changes to NFI6 raw data for UNFCCC and KP reporting 1. Allocation of forest clear cuts and forest burnt areas with unkown forest type to reported forest types Based % distribution of clear cut areas (or burnt forest areas) per forest type, where previous forest type is known 2. Re-estimation of Rainfed Annual Crops (RAC) and Grassland (GL) areas Based on RAC+GL total area of NFI6 and % distribution from the General Census on Agriculture

13 Approach for the time series Forest Land use of previous NFI data NFI2 (1974) and NFI3 (1985) totals per forest type considered = same trend as 1974/85; same share per forest type as 1974 Cropland + Grassland based on GCA and NFI data Trends in total area applied to NFI6 total area of cropland and grassland Allocation to cropland and grassland types according to share in GCA1979 and GCA considered = same trend as 1979/89; same share per cropland/grassland type as 1989 Settlements; Wetlands; Other land considered = 1995 Country totals maintained constant by adjusting the shrubland category

14 Assumptions in land use change Only Net-Changes per land-use type are available Land-uses loose area to land-uses that gain area Proportional to gains of area per land-use type Annual Gains P. pin Net Gains P. pinaster 0 0 Q. suber 0 0 Eucalyptus Q. rotundifolia 0 0 O. Quercus O. broadleaves P. pinea O. coniferous 0 0 Rain-fed crops Irrigated crops 0 0 Rice 2 36 Vineyards Olive O. permanent Grasslands Wetlands Settlements Shrubland 0 0 O. land Annual Losses

15 Total Areas per UNFCCC Land-use Category

16 Total Areas per Land Use Type Subcategories

17 Land-use Change Matrices Annual Gains P. pin Q. sub Eucal Q. rot O. Que O. Br P. pnea O. Com Rf crps Ir crps Rice Vine Olive O. Perm Grassl Wetl Settl Shrub O. land Net Gains P. pinaster Q. suber Eucalyptus Q. rotundifolia O. Quercus O. broadleaves P. pinea O. coniferous Rain-fed crops Irrigated crops Rice Vineyards Olive O. permanent Grasslands Wetlands Settlements Shrubland O. land Annual Losses

18 Land use and Land Use Change: UNFCCC Allocation of land use subcategories to IPCC categories Use of 20 year conversion period in all land uses (IPCC default) to differentiate: Land X remaining Land X = total in year land in conversion Land Y converted to Land X = sum of areas converted from Y to X over the last 20 years Sector IPCC LU category Subcategory 5A Forest Pinus pinaster Quercus suber Eucalyptus spp. Quercus rotundifolia Quercus spp. Other broadleaves Pinus pinea Other coniferous 5B Cropland Non-irrigated annual crops Irrigated annual crops (excluding rice) Rice paddies Vineyards Olive groves Other permanent crops 5C Grassland Grassland 5D Wetlands Wetlands 5E Settlements Settlements 5F Other land Shrubland Other land

19 Land Use and Land Use Change: UNFCCC

20 Land use and Land Use Change: KP Allocation of land uses to KP activities Criteria since 1990 for afforestation, reforestation and deforestation Land under AR in year X = Sum of land converted to forest from Year 1990 to Year X Afforestation & Reforestation harvested Only Eucalyptus are harvested (age 12) = Sum of all areas converted to Eucalyptus with age 12 Sector KP Activity Subcategory A.1.1 A.1.2 A.2 B.1 B.2 Afforestation not harvested Afforestation harvested Deforestation Forest Management Cropland Management B.3 Grassland Management Grassland Forest management = total forest area in Year X AR in Year X All cropland area in year X (X>2008) is cropland management Pinus pinaster Quercus suber Eucalyptus spp. Quercus rotundifolia Quercus spp. Other broadleaves Pinus pinea Other coniferous Non-irrigated annual crops Irrigated annual crops (excluding rice) Rice paddies Vineyards Olive groves Other permanent crops Except lands converted from forest to cropland (included as deforestation) Areas of cropland converted to other land uses (except forests or grasslands) from 2009 onwards are included as cropland

21 Land Use and Land Use Change: KP

22 KP and UNFCCC differences

23 KP and UNFCCC differences