Light Detection and Ranging (LIDAR) is a new technology that offers a potential alternative to fi... more Light Detection and Ranging (LIDAR) is a new technology that offers a potential alternative to field surveying and photogrammetric techniques for the collection of elevation data. It has the advantages of being rapid accurate and able to map areas that are difficult to access. LIDAR has demonstrated the capability to accurately estimate important vegetation structural characteristics such as forest canopy height. For these reasons, airborne LIDAR data were used to compare vegetation height determinations with field observations on one selected transect in the vicinity of Lake Hatchineha in Florida, USA. The approach was based on the LIDAR and field measurements. The results showed that the lowest height (0 cm) appeared to be open water and barren fields. Vegetation heights of 0-30 cm corresponded to short grassy areas and 90-180 cm corresponded to medium height plants. Tall plants were determined to be vegetation heights ranging from 180 to 365 cm and very tall plants were determined to range from 365 to 600 cm. In addition, vegetation heights ranging from 600 to 1200 cm and from 1200 to 1700 cm corresponded to low and medium-height trees, respectively. Sources of potential error in determining forest tree canopy height were found to evolve from the fact that medium-height tree branches were sometimes reflected and recorded as a first hit and so were incorrectly classified as either low tree or tall plant classes. The results showed that, in most cases, while field and photogrammetric methods fail to determine tree and other plant heights, they could be accurately detected by using LIDAR classification in the wetlands where the ground is not visible. The next step will be to try to find a correlation between LIDAR vegetation heights and water boundaries.
Land cover is one of the key terrestrial variables used for monitoring and as input for modelling... more Land cover is one of the key terrestrial variables used for monitoring and as input for modelling in support of achieving the United Nations Strategical Development Goals. Global and Continental Land Cover Products (GCLCs) aim to provide the required harmonized information background across areas; thus, they are not being limited by national or other administrative nomenclature boundaries and their production approaches. Moreover, their increased spatial resolution, and consequently their local relevance, is of high importance for users at a local scale. During the last decade, several GCLCs were developed, including the Global Historical Land-Cover Change Land-Use Conversions (GLC), the Globeland-30 (GLOB), Corine-2012 (CLC) and GMES/ Copernicus Initial Operation High Resolution Layers (GIOS). Accuracy assessment is of high importance for product credibility towards incorporation into decision chains and implementation procedures, especially at local scales. The present study builds on the collaboration of scientists participating in the Global Observations of Forest Cover—Global Observations of Land Cover Dynamics (GOFC-GOLD), South Central and Eastern European Regional Information Network (SCERIN). The main objective is to quantitatively evaluate the accuracy of commonly used GCLCs at selected representative study areas in the SCERIN geographic area, which is characterized by extreme diversity of landscapes and environmental conditions, heavily affected by anthropogenic impacts with similar major socio-economic drivers. The employed validation strategy for evaluating and comparing the different products is detailed, representative results for the selected areas from nine SCERIN countries are presented, the specific regional differences are identified and their underlying causes are discussed. In general, the four GCLCs products achieved relatively high overall accuracy rates: 74–98% for GLC (mean: 93.8%), 79–92% for GLOB (mean: 90.6%), 74–91% for CLC (mean: 89%) and 72–98% for GIOS (mean: 91.6%), for all selected areas. In most cases, the CLC product has the lower scores, while the GLC has the highest, closely followed by GIOS and GLOB. The study revealed overall high credibility and validity of the GCLCs products at local scale, a result, which shows expected benefit even for local/regional applications. Identified class dependent specificities in different landscape types can guide the local users for their reasonable usage in local studies. Valuable information is generated for advancing the goals of the international GOFC-GOLD program and aligns well with the agenda of the NASA Land-Cover/Land-Use Change Program to improve the quality and consistency of space-derived higher-level products.
Light Detection and Ranging (LIDAR) is a new technology that offers a potential alternative to fi... more Light Detection and Ranging (LIDAR) is a new technology that offers a potential alternative to field surveying and photogrammetric techniques for the collection of elevation data. It has the advantages of being rapid accurate and able to map areas that are difficult to access. LIDAR has demonstrated the capability to accurately estimate important vegetation structural characteristics such as forest canopy height. For these reasons, airborne LIDAR data were used to compare vegetation height determinations with field observations on one selected transect in the vicinity of Lake Hatchineha in Florida, USA. The approach was based on the LIDAR and field measurements. The results showed that the lowest height (0 cm) appeared to be open water and barren fields. Vegetation heights of 0-30 cm corresponded to short grassy areas and 90-180 cm corresponded to medium height plants. Tall plants were determined to be vegetation heights ranging from 180 to 365 cm and very tall plants were determined to range from 365 to 600 cm. In addition, vegetation heights ranging from 600 to 1200 cm and from 1200 to 1700 cm corresponded to low and medium-height trees, respectively. Sources of potential error in determining forest tree canopy height were found to evolve from the fact that medium-height tree branches were sometimes reflected and recorded as a first hit and so were incorrectly classified as either low tree or tall plant classes. The results showed that, in most cases, while field and photogrammetric methods fail to determine tree and other plant heights, they could be accurately detected by using LIDAR classification in the wetlands where the ground is not visible. The next step will be to try to find a correlation between LIDAR vegetation heights and water boundaries.
Land cover is one of the key terrestrial variables used for monitoring and as input for modelling... more Land cover is one of the key terrestrial variables used for monitoring and as input for modelling in support of achieving the United Nations Strategical Development Goals. Global and Continental Land Cover Products (GCLCs) aim to provide the required harmonized information background across areas; thus, they are not being limited by national or other administrative nomenclature boundaries and their production approaches. Moreover, their increased spatial resolution, and consequently their local relevance, is of high importance for users at a local scale. During the last decade, several GCLCs were developed, including the Global Historical Land-Cover Change Land-Use Conversions (GLC), the Globeland-30 (GLOB), Corine-2012 (CLC) and GMES/ Copernicus Initial Operation High Resolution Layers (GIOS). Accuracy assessment is of high importance for product credibility towards incorporation into decision chains and implementation procedures, especially at local scales. The present study builds on the collaboration of scientists participating in the Global Observations of Forest Cover—Global Observations of Land Cover Dynamics (GOFC-GOLD), South Central and Eastern European Regional Information Network (SCERIN). The main objective is to quantitatively evaluate the accuracy of commonly used GCLCs at selected representative study areas in the SCERIN geographic area, which is characterized by extreme diversity of landscapes and environmental conditions, heavily affected by anthropogenic impacts with similar major socio-economic drivers. The employed validation strategy for evaluating and comparing the different products is detailed, representative results for the selected areas from nine SCERIN countries are presented, the specific regional differences are identified and their underlying causes are discussed. In general, the four GCLCs products achieved relatively high overall accuracy rates: 74–98% for GLC (mean: 93.8%), 79–92% for GLOB (mean: 90.6%), 74–91% for CLC (mean: 89%) and 72–98% for GIOS (mean: 91.6%), for all selected areas. In most cases, the CLC product has the lower scores, while the GLC has the highest, closely followed by GIOS and GLOB. The study revealed overall high credibility and validity of the GCLCs products at local scale, a result, which shows expected benefit even for local/regional applications. Identified class dependent specificities in different landscape types can guide the local users for their reasonable usage in local studies. Valuable information is generated for advancing the goals of the international GOFC-GOLD program and aligns well with the agenda of the NASA Land-Cover/Land-Use Change Program to improve the quality and consistency of space-derived higher-level products.
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