Pan-European Mapping of Underutilized Land for Bioenergy Production
Abstract
:1. Introduction
2. Study Area and Data
2.1. Study Area
2.2. Data
2.2.1. Satellite Imagery
2.2.2. Reference Data for Training
- The limited spatial extent per observation: “The “point” (or basic unit of observation) is in fact a circle with a radius of 1.5 m corresponding to an identifiable point on an orthophoto. As we have not only homogeneous classes that we would like to observe, for example forests (forest definition requires observing a certain area to define the crown coverage or canopy of the trees) or orchards (which may consist in more than one tree species, etc.), the LUCAS observation framework also specifies an observation area, the “extended window of observation” which is the area defined by a 20 m radius around the point, for specific classes.” [1].
- The point grid was not the same for all surveys, thus sometimes, there is only land use information for a specific year (e.g., 2015), but no information about the land use before or after.
- Sometimes a shift in the location between the same points can be observed in two different surveys.
- The last survey was conducted in 2018; the classification is done using image time series data from 2015 to 2019.
- High Resolution Layers (HRL) Forest, Imperviousness, and Water and Wetness
- CORINE Land Cover (CLC) 2018 agriculture classes “Arable land” (21), “Permanent crops” (22), and “Pastures” (23).
2.2.3. Data for Masking Specific Areas
- Forest areas (HRL Forest): Forest areas are considered to be used land. Changing forests to other land use types is usually critical in terms of carbon balance [26] and was therefore avoided. Especially in Eastern Europe and former Soviet Union countries, young forests are growing on abandoned agricultural farmland [27,28]. The re-cultivation of these lands is a major issue of discussion [29,30]. However, since forest areas provide higher potential for carbon sequestration, we do not consider these areas as “underutilized land”.
- Settlement areas (HRL Imperviousness, Open Street Map (OSM), and CORINE land cover): Settlements belong to the category of used land.
- Water and Wetland areas (HRL Water and Wetness): In addition to excluding water bodies, wetland areas were removed for two reasons: first, due to limitations in drivability for mechanized growing of bioenergy crops, and second, due to the high natural value and biodiversity potential entailed in wetlands [31].
- Protected areas (Natura2000): Protected areas are removed totally, although the consortium is aware that crops used for energy might be allowed in some protected areas (e.g., outer zones of national parks). However, due to missing European-wide spatial separation between allowed and restricted zones, all areas are removed to avoid critical land competition.
- Steep slopes (>15° slope in Shuttle Radar Topography Mission digital elevation model (SRTM)): Steep slopes with inclinations larger than 15° are also removed because mechanized land cultivation is typically not feasible.
- Other not usable areas (CORINE land cover): Other not usable areas like beaches, bare rocks, or glaciers (CLC classes 331, 332 and 335) are also eliminated.
- Areas permanently used for agriculture (CORINE land cover): From the agriculturally used areas, most classes (CLC classes 221, 222, 223, 231, 241, 242, and 244) are removed. The annual crops in CORINE land cover (CLC classes 211, 212, and 213) are not removed in order to detect abandoned farmlands.
3. Methodology
3.1. Method for the Classification of Underutilized Land
- minimum
- maximum
- standard deviation
- percentiles (10 and 90)
3.2. Method for Validation of the Results
- (1)
- Reliability: if VHR data of less than three of the five years was available in Google Earth or if the interpretation could not be done due to bad quality or winter imagery, this attribute was flagged as “not reliable”, which means the point is not interpretable with a high confidence.
- (2)
- Borders: if the point was located within 30 m of the border between classes, the attribute was flagged as “borders”.
- (3)
- Small stripes: if a point was located in an area of small structures, mainly agricultural areas or gardens, with a minimum width of less than 30 m, the attribute was flagged as “small stripes”.
4. Results
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Biogeographical Region | Study Area (ha) | Elimination Mask (ha) | Area of Interest (ha) |
---|---|---|---|
Alpine | 63,815,477 | 50,898,030 | 12,917,447 |
Atlantic | 86,135,597 | 53,133,180 | 33,002,417 |
Boreal | 89,317,815 | 60,034,485 | 29,283,330 |
Continental | 173,990,564 | 93,346,118 | 80,644,446 |
Mediterranean | 92,181,777 | 59,869,101 | 32,312,676 |
Pannonian | 12,901,241 | 5,121,331 | 7,779,910 |
Steppic | 28,226,727 | 6,233,216 | 21,993,511 |
Overall | 546,569,198 | 328,635,461 | 217,933,737 |
Biogeographical Region | Area of Interest (Ha) | UU Area (Ha) | UU from AOI (%) | Average Size per UU Patch (Ha) | Average Compactness Index per UU Patch |
---|---|---|---|---|---|
Alpine | 12,917,447 | 356,913 | 2.76 | 39.2 | 0.2102 |
Atlantic | 33,002,417 | 634,985 | 1.92 | 33.7 | 0.2218 |
Boreal | 29,283,330 | 61,408 | 0.21 | 28.5 | 0.2766 |
Continental | 80,644,446 | 1,336,876 | 1.66 | 29.9 | 0.1875 |
Mediterranean | 32,312,676 | 2,579,935 | 7.98 | 49.6 | 0.1940 |
Pannonian | 7,779,910 | 139,010 | 1.79 | 26.4 | 0.2287 |
Steppic | 21,993,511 | 200,392 | 0.91 | 23.2 | 0.2036 |
Overall | 217,933,737 | 5,309,519 | 2.44 | 32.9 | 0.2175 |
Biogeographical Region | Utilized | Underutilized | Total |
---|---|---|---|
Alpine | 111 | 50 * | 161 |
Atlantic | 286 | 74 | 360 |
Boreal | 258 | 50 * | 308 |
Continental | 700 | 155 | 855 |
Mediterranean | 262 | 300 | 562 |
Pannonian | 67 | 50 * | 117 |
Steppic | 92 | 50 * | 142 |
Overall | 1876 | 729 | 2605 |
Biogeographical Region | OA (%) (CI) | U: OE (%) (CI) | U: CE (%) (CI) | UU: OE (%) (CI) | UU: CE (%) (CI) |
---|---|---|---|---|---|
Alpine | 62.16 (8.82) | 1.17 (0.65) | 37.84 (9.06) | 95.55 (1.12) | 38.00 (13.59) |
Atlantic | 91.43 (2.31) | 0.37 (0.12) | 8.42 (2.33) | 92.24 (2.24) | 32.43 (10.57) |
Boreal | 90.62 (3.61) | 0.06 (0.03) | 9.69 (3.62) | 98.38 (0.63) | 24.00 (11.96) |
Continental | 90.62 (2.10) | 0.52 (0.13) | 9.06 (2.14) | 88.08 (2.65) | 27.74 (7.07) |
Mediterranean | 70.08 (5.19) | 1.74 (0.50) | 31.30 (5.63) | 80.75 (2.87) | 14.00 (3.93) |
Pannonian | 98.17 (2.88) | 0.40 (0.21) | 1.49 (2.93) | 51.61 (48.78) | 22.00 (11.60) |
Steppic | 85.28 (4.96) | 0.32 (0.14) | 14.58 (5.01) | 95.77 (1.53) | 30.00 (12.83) |
Overall | 85.52 (1.55) | 0.66 (1.55) | 14.27 (1.50) | 88.06 (1.32) | 22.77 (3.05) |
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Hirschmugl, M.; Sobe, C.; Khawaja, C.; Janssen, R.; Traverso, L. Pan-European Mapping of Underutilized Land for Bioenergy Production. Land 2021, 10, 102. https://doi.org/10.3390/land10020102
Hirschmugl M, Sobe C, Khawaja C, Janssen R, Traverso L. Pan-European Mapping of Underutilized Land for Bioenergy Production. Land. 2021; 10(2):102. https://doi.org/10.3390/land10020102
Chicago/Turabian StyleHirschmugl, Manuela, Carina Sobe, Cosette Khawaja, Rainer Janssen, and Lorenzo Traverso. 2021. "Pan-European Mapping of Underutilized Land for Bioenergy Production" Land 10, no. 2: 102. https://doi.org/10.3390/land10020102
APA StyleHirschmugl, M., Sobe, C., Khawaja, C., Janssen, R., & Traverso, L. (2021). Pan-European Mapping of Underutilized Land for Bioenergy Production. Land, 10(2), 102. https://doi.org/10.3390/land10020102