Inland-coastal demographic transformations in a karst area: a case study of the surroundings of Krka National Park (Croatia)

According to geographic possibilism, environment does not determine socio-economic development. However, the environment sets certain constraints and limitations for development. How do natural settings influence population dynamics? In this study, we examine this question using the example of Sibenik-Knin County, which includes Krka National Park (NP) with a GIS-based statistical approach. The following parameters represent natural factors: elevation, slope, distance from water, and proportion of karst areas. In addition, distance from Krka NP was also added as an independent semi-natural factor (despite the fact that it is a social construction). The dependent social parameters are population density for selected historical dates, population change, year of maximum population, natural increase, migration, and age index. The analysis units are the 199 settlements found in the county, and the 20 local administrative units (LAU2). The study period can be divided into five phases: from the first census in 1857 to 1921, there was a slow increase in most settlements; then a relatively constant phase up to 1961 (some settlements began shrinking in this period); a slow decrease until 1991; a rapid decrease during the next decade; and relative stabilisation to present day. These processes were also accompanied by significant inner and outer migrations. As for the relationships between natural and demographic factors, we found that although the coastal-inland area dichotomy is dominant in the study area, elevation has the highest correlation with most population parameters. However, distance from water is also significantly correlated with population change and migration in certain periods. In the inland areas, there are statistically significant differences between the demographic processes of fully-karstic and partially-karstic areas, while in the coastal zone, the karst effect is overshadowed by other social processes. The impact of Krka NP on the demographic characteristics of the surrounding settlements was statistically not detectable. Our final conclusion is that correlations between natural and population parameters are low or moderately strong but statistically significant in many cases, thus the basic principles of geographic possibilism are valid for the area