Determination of the Landscapes Regulation Capacity and Their Role in the Prevention of Catastrophic Events: A Case Study from the Lom River Upper Valley, Bulgaria

Floods are among the most dangerous natural disasters that threaten large territories in Bulgaria. The assessment of flood risk provides valuable information for environmental management. An important part of this assessment is the determination of landscapes flood regulation capacity. The study area is a small basin in the upper valley of the Lom River. The capacities of the landscapes to regulate floods were assessed through investigations of water retention functions of different natural components. Features of vegetation, land use, soil, orohydrography, and relief were considered. Each feature influencing the landscape regulatory functions was given a weight coefficient. To achieve more precise assessment, we combined field methods and remote sensing. The MODIS NDVI 250 m Multi-Temporal Imagery Dataset for the period 2008–2014 and widely accepted indices such as NDVI (Normalized Difference Vegetation Index), NDWI (Normalized Difference Water Index), and VCI (Vegetation Condition Index) were also applied. Thematic maps showing the regulating service capacity of each of the investigated components and that of the landscapes were generated, and a final assessment was made. In the study area, the natural landscapes of the Biosphere Reserve “Chuprene” and landscapes with different degrees of anthropogenic load occur as well. This work contributed the comparative characteristics of these two major landscape classes to be performed so that the main factors affecting their surface runoff regulation capacity could be determined.