New type of ponds? Changing of quantity and function of water bodies in rural built-up areas (Pilsen Region, Czechia)

This study is focused on the changing of areas of water bodies in selected villages of the Pilsen Region (Czechia). We researched several different types of rural settlements and three time horizons with the help of old maps, orthophoto maps and GIS tools. To capture the influence of their location within the urban system, we chose 15 places from four categories (inner suburban area, outside suburban area, rural area, periphery rural area) depending on their distance to the core of the Pilsen agglomeration. There is no significant change in the amount of water bodies between the first reference period (1838-1839) and the second period (1957-1963) in the selected settlements. However, the third period (2013-2015) is characterized by the emergence of a large number of small water bodies - swimming pools and garden ponds. Based on the results of our research we identified the declining importance of public water bodies in some of the settlements. However, we have identified a notable prevalence of garden ponds which have a more positive ecological impact than pools. The proportion of private water bodies (covered and uncovered pools and garden ponds) in the total area of water bodies in the rural settlements in most cases is less than 20%, in the suburban settlements up to 100%. Peripheral settlements have a below-average share of these water bodies. The difference between the number of pools in different settlements is related to the proportion of newly built houses there. Although there are relatively fewer pools in rural settlements, the difference compared to the situation in suburban settlements is not pronounced due to the change in lifestyle in rural areas and the change in functions of some villages to recreational areas. Influence of pools on water consumption is dependent on the individual exchange technology of water in swimming pools. Filling of the pool before the season can overload the capacity of the local water supply.