Volume XXI |

Geodiversity Assessment by Application of Geoinformation Approach (on the Example of Golo Bardo Mountain, Western Bulgaria)

Abstract: Geodiversity is considered as a complex indicator of the abiotic environment. On the example of information about Golo Bardo Mountain (Western Bulgaria), the article emphasizes the need to develop methods for quantitative assessment of the geodiversity of an area to minimize the subjective nature of the assessment by defining clear criteria that can be quantified. The complex geodiversity assessment of the investigated area was made based on the analysis of lithology, soils, topographic features and drainage network. The analysis is done in a GIS environment. Topographic settings are analysed on the base of digital elevation model with a cell size of 30 m using Spatial Analyst Tools. The elevation model is used for calculating the terrain roughness, slope gradients and aspects of the slopes. Geological component is evaluated considering the petrographic composition of the area. The variety of the abiotic components is calculated by application of grid method (cell size 1000 x 1000 m), using Focal statistics tool, neighborhood type “Variety”. Fuzzy logic is suggested to be used for comparison of areas located in different regions and with different landscape conditions.
The results of the geodiversity assessment show that most of the area of the Golo Bardo mountain has moderate geodiversity index. The method used in the article gives reliable results with minimal subjectivity, that can be used for assessment of the distribution of the geodiversity on a particular area and allow to compare different territorial units. The results obtained in the current study show good correlation between areas with high and moderate geodiversity index, and areas with high biodiversity values. The applied methodology and the visualization of the geodiversity index allow for easy understanding of geodiversity by a wide range of stakeholders, even non-geoscientists, and can be successfully applied in the planning of geotourism activities.

Volume XV |

Modelling of Ecosystem Indicators in Geographic Information System Environment (A Case Study of the Sweet Chestnut Forest, Belasitsa Mountain, Bulgaria)

Abstract: The aim of the present research is to show the possibilities of applying computer technology in ecosystem investigations. The object of the research is the chestnut forests located on the Northern slopes of Belasitsa mountain (Southwest Bulgaria). Three study areas are determined for detailed investigation of structural and functional parameters (indicators) of chestnut ecosystems. These areas are located in forests with different ages (45-120 years old), different forestry management and different state. Ecosystem indicators are modeled on the base of field investigation and available published data, and the assessment of the forest state is done by spatial interpolation (inverse distance weighted) in geographic information system (GIS) environment (ArcGIS). Resulting model values are verified and validated by field investigations. An output layer showing the state of the chestnut forest in the investigated region is generated on the base of the raster surfaces, result of the interpolation and application of map algebra. Also, weight coefficients to the assessment values of the different indicators are used which makes the spatial analysis more correct. Created mapping model shows significant matching areas of forests in poor condition and forests in good conditions compared to the relevant determined on the base of forest management plan. The research confirms the advantages of GIS technology in processing large and varied data for assessing the impact of many factors on forest vegetation.