Evaluation of geological sites in a park environment for the needs of the Bulgarian geoparks, nature parks, and national parks

The experience in the scientific evaluation of geological sites in the Bulgarian geoparks shows insufficient efficiency of the generalized criteria used for the evaluation of geotopes for the purposes of the Register and Cadastre of the Bulgarian geological phenomena. Here is proposes a new assessment methodology freed from some common criteria included in the expert card for national assessment of geosites. It includes the main evaluation criteria of the ‘scientific value’ category (representativeness, integrity, rarity), and ‘additional values’ – scenic/didactic potential, ecological, cultural, and geotourism impact. Due to the fundamentally different themes of the Bulgarian geoparks, the approach of ‘thematic geodiversity’ has been adopted, which defines one major theme expressing the identity of the geopark within its entire territory, and numerous secondary themes complementing the geodiversity of the area. One of the new criteria included in the expert card reflects the relation of a geosite with the main geopark theme and gives priority to outcrops representing key geological features for its understanding. At the same time, the possible identification of global cycles and events of special scientific interest, which can be presented to the general public in an attractive form, predetermines the high numerical indicator of the ‘scientific, research and educational value’. The main purpose of the expert card is to cover as wide a range of geological features as possible and to make the assessment less subjective by using a standard set of criteria against which specific examples can be compared. It is also important to minimize the possibility of interpretation of the explanatory text to the individual indicators. It includes 12 criteria of different weights with 4 to 7 indicators, the numerical expression of which starts from zero, corresponding to a complete lack of geoconservation value. The minimum number of 12 points (of total 48) required to pass the ‘threshold of significance’ is formed by the first six criteria. It provides the necessary rate of superiority over which the site must be considered geologically significant and deserves to be included in the geopark inventory. The scale of significance grades from local (12–20) to regional (21–30), national (31–40), and international (41–48). Geodiversity sites are of great importance for the geopark initiatives, so the weight of the ‘scenic (aesthetic) value’ corresponds to the weight of the ‘scientific, research and educational value’ (6) versus (3) or (4) of the other criteria to better reflect their geotourism significance. Geosites with high interpretive potential, especially where the relationship between geology and human history/culture/spirituality can be demonstrated, should also be prioritized for inclusion in the geopark list.