engleski

The flow characteristics estimation of a karstic ungauged catchment: The Sutina River case study, Croatia

The Sutina – Karakašica is an ungauged karst catchment in southern part of Croatia with relative small area, but with existing records of several events of flash flood that compromised the structures as bridge and roads along the stream. This work gives an overview of the creation of the experimental catchment and establishment of the hydrological monitoring system which has for a goal a better understanding of runoff processes within the experimental karst area as well as flash flood occurrence analysis. The studied catchment is located in Dalmatia, a region of Dinaric karst in the southern part of Croatia, . Although it is very difficult to determine catchment borders in the karstic terrain, for the porpoises of the study the area of the catchment is estimated to eighth km2. The length of the stream flow up to the control cross section is 4.4 km. The highest point of the studied catchment area is on the 941 m a.s.l. and the lowest at the 300 m a.s.l. The geological settings of the catchment are characterized by the sedimentary rocks, mostly limestone and dolomites with discontinuities (cracks, and fractures) filled up with terra rossa and breccia. The presence of mudstone patches in the surface ensures the continuous surface flow of the studied stream. Some caves are also to be found in the catchment area. In the karst watersheds the occurrence of flash floods can be registered due to the exceptional meteorologic events during the year. The intensive rainfall in the short time can trigger a flash flood that can induce over bank flow, immense changes in channel morphology and in sediment distribution. In order to produce a hydrological model that could predict the events of flash flood in the studied area, a continuous monitoring of meteorological and hydrological parameters in the catchment is established. The predictions of exceptional flooding events derived from a useful hydrological model based on the study site can be used further on to quantify the possible flooding risk. The study site can be useful by extrapolating procedure as well as obtained results to a larger scale.

karstic ungaged catchment; flash flood; flow characteristics

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