6355536861

136

GEOMORPHOLOGICAL AND HYDROLOGICAL EFFECTS OF UNMETALLED ROAD NETWORK FUNCTIONING ON THE EXAMPLE OF CIĘZKOWICKIE FOOTHILLS

Summary

The main target of this study was to recognizc the role of unmetalled roads in natural erwironment transformation, especially in agricultural areas. Cięzkowickic Foothills wcrc chosen as a rcsearch terrain. Two typical catchments were selected for detailed studies within the reascarch area.

The major work hypothesis assumes that unmetalled road nctwork supplcments natural drainage system and affects geomorphologic and hydrologie processes in a catchment. The hypothesis was vcrified by a GIS model. Catchment rcaction to rainfall and flood wave forma-tion were studied in two cases: 1) cxcluding the road network, 2) including the rod nctwork.

In the Carpathian Mountains historie, social, economical and psychological factors led to farmlands and forests disintegration. This proccss began in the 16 century with first mass cx-pulsions. In the middle of the 19 century farmlands division to plots took place. Due to “land shortage”, plots partition begun. With every ncw field a new road leading to it was created this situation developed an unmetalled road network of high density.

Today road network density on Carpathian Foothills, depending on the region is about 6 9 km/km². It is a significantly higher valuc in comparison o averagc density of natural drainage system in Polish Carpathians which is 3,5 km/ km²

ROAD DENSITY IN THE CIĘZKOWICKIE FOOTHILLS

In order to cvaluate the spatial diversity of the road density cartometric measurements were carried out on the basis of maps in scalę 1:10 000. The obtained average value for the area of Cięzkowickic Foothills was 8,8 km/km², which is one of the highest values for all regions in Polish Carpathians. Maximum measured values reached 16 km/km² they refer to areas with the best agricultural condition, settled in the first place. They are placed mostly in river valleys and spaces on the Foothills edge covercd with loss - like formations. The low-est road density was found in areas that were never inhabited (for cxample Brzanka-Liwocz Rangę) or thosc with limited colonization.

DifTercnces in road network density were observed between calculations bascd on maps and factual State. On the arabie lands these differenccs are insignificant. In the areas of big forest complexes actual road network density is three times higher than on the map.

Unmetalled roads account for 80% of all roads. Metalled roads (the remaining 20%) are localized in the citics, towns and suburban areas. In the country (especially in distant rural areas) metalled roads comprise 5% of all roads.