MULTIDIMENSIONAL MODELING OF THE FOREST AREAS AROUND WATER SOURCES IN BULGARIA

In Bulgaria, the number of water sources and facilities for drinking and domestic water supply from surface and underground water is about 7,480. They are surrounded by sanitary protection zones (SPZ). Each SPZ has 3 belts, which are organised according to an accepted methodology. With the help of a designed geographic information system, it was found that in Bulgaria forest territories that belong to SPZ around water sources and water supply facilities for drinking and domestic needs have a total area of 576,117 ha and 49.837 million cubic meters of total growing stock. The importance of sanitary protection zones for water protection, health and life quality of the population is indisputable. Due to this the goal of the present paper is to systemize forests around water sources with protection functions in Bulgaria in homogenous groups. The systematization is done on the basis of K-means cluster analysis, which is applied for coniferous, coppice and high-stem forests for each of the three SPZ in 28 regions from level NUTS-3 in Bulgaria and three variables, which characterize forests, namely � forest area (ha), mean annual increment (m3/ha), total growing stock of forest territories (m3). On this ground it has been established that high-stem, coniferous and coppice forests from the three SPZ can be systemized in 6, 6 and 7 homogenous clusters respectively. The variables, which contribute to a high extent for cluster formation, are as follows: area of high-stem forests from belt 3; area of coniferous forests from belt 2; and area of coppice forests from belt 3.