Оцінка ризиків втрати екосистемної послуги з регулювання ерозії міськими зеленими зонами

Abstract

The paper presents the methodology and results of assessment the amount of erosion control ecosystem service (ES) and the risks of it loss. Quantitative risk assessment was carried out on the basis of the fact that the green zone is currently performing or will provide its service in the future in smaller volumes. Accordingly, the assessment consisted of: a) determining the loss of ES today and b) calculating the probability of loss in the future. For the assessment, the factors that affect the volume of ES have been determined and a set of relevant estimation parameters has been substantiated. They were included as attributes to the database of Kyiv green areas. The assessment of ES volumes was based on the comparison of erosion rates caused by natural and anthropogenic factors with the rate of soil formation. Estimation of risk probabilities was calculated based on Harrington desirability function adapted to the ecosystem services assessment. The source materials in the work were vector geodata sets: “Soils”, “Vegetation”, a digital elevation model. The sets were created based on information about city landscapes, remote sensing data, field and laboratory research. The assessment was carried out for 50 urban Kyiv green spaces. As a result of geodata analysis, it was determined that most of the studied objects provide their maximum ES and, accordingly, have very low risks of loss it today. However, 30% studied areas have medium risks of ES loss in the future. The assessment can be an effective tool in environmental decision-making. Firstly, it allows to identify the areas that need the most active actions to improve the possibilities of providing ES today. Secondly, the presented methodology allows to determine the factors that are cause a danger to ES, and therefore the risks of it loss in the future. Thus, this assessment, unlike others, is aimed at solving the issue of ensuring the sustainable functioning of green areas. Thirdly, this methodology is applicable to any territory and is a necessary component in the process of determining the total amount of ES provided by urban green zones. After all, the “separate” methods of each ES calculating when converting indicators into normalized values make it possible to avoid difficulties in the general assessment of ES, which arise due to the diversity and incomparability of measurement units.