Definition of catchment area in karst: case of the rivers Krčić and Krka, Croatia

Abstract

The study area consists of the spring zones of the Krčić, Krka and Cetina river catchments located in the Dinaric karst, Croatia. Classical hydrological approaches and some newer time and frequency domain methods are used in order to validate the existing hypotheses both qualitatively and quantitatively, and these contribute to factual information about the hydrological behaviour of the catchments. The groundwater recharge rates are calculated by a mathematical model based on Palmer's soil-moisture balance method. The values of parameters of the groundwater recharge model are estimated by the spectral method. The calculated monthly and annual groundwater recharge rates form the basis for estimating the hydrological catchment areas of the spring zones and also for the determination of quantitative relationships between the catchments.Key words catchment area; Croatia; effective rainfall; groundwater recharge; karst hydrology; karst spring Définition de l'aire d'un bassin versant karstique: cas des rivières Krčić et Krka (Croatie)Résumé La zone d'étude correspond aux zones de sources des bassins versants des rivières Krčić, Krka et Cetina dans le karst des Dinarides. Les méthodes hydrologiques classiques, ainsi que certaines nouvelles méthodes dans les domaines temporel et fréquentiel, sont utilisées afin de valider qualitativement et quantitativement les hypothèses existantes, et de contribuer à la caractérisation factuelle du fonctionnement de ces bassins versants. Les taux de recharge hydrogéologique sont calculés au moyen d'un modèle mathématique basé sur la méthode du bilan de l'humidité du sol de Palmer. Les valeurs des paramètres du modèle de recharge hydrogéologique sont estimées par méthode spectrale. Les taux de recharge mensuels et annuels calculés sont à la base de l'estimation des aires des bassins versants des zones de sources, ainsi que de la détermination de relations quantitatives entre les bassins.Mots clefs aire de bassin versant; Croatie; pluie efficace; recharge hydrogéologique; hydrologie karstique; source karstique

Microbial mats as shelter microhabitat for amphipods in an intermittent karstic spring

“…Krčić is a small intermittent stream situated in the middle of Dinaric karst of the southern Croatia, confined mostly to the External Dinarides, which consists predominantly of Triassic, Jurassic and Cretaceous limestones and dolomites (Bonacci et al, 2006;Hajna et al, 2010). The study area falls within a continental climate influenced by the mid-Mediterranean climate with the average annual temperature of 13°C.…”

“…The summers are hot, with maximum temperature above 30°C, whilst winters are cold with temperatures as low as À10°C. The catchment area of Krčić covers 157 km 2 with the surface flow of 10.5 km from the springhead to the waterfall in the Krka River (Bonacci et al, 2006). The spring and the mouth of the river lie between latitudes 44°1 0 32 00 N and 44°2 0 31 00 N and longitudes 16°19 0 53 00 E and 16°14 0 7 00 E, respectively (Fig.…”

“…1). Strong river bed karstification causes significant water losses along the stream causing alternating surface and subsurface flow (Bonacci, 1987(Bonacci, , 1993Bonacci et al, 2006). Krčić functions as a descending karstic spring (Jukić and Denić-Jukić, 2006) and dries up regularly every year from June to September, usually when springwater discharge of Krka River (below the mouth of Krčić) drops below 4.20 m 3 s À1 (Bonacci et al, 2006).…”

Identification of glacial meltwater runoff in a karstic environment and its implication for present and future water availability

“…Predictions are complex, as meltwater drainage from the glaciers is subject to diurnal variability (Schuler et al, 2004) and may evolve during the melting season due to enhanced melting (Covington et al, 2012) and glacial lake outbursts (Werder et al, 2009). In karstic environments such projections become even more difficult as runoff paths are underground and therefore difficult to observe and assess (Bonacci et al, 2006;Siemers and Dreybrodt, 1998). In many situations the proportion of water from a glacier to a karst spring is unknown, and, conversely, the number of springs fed by a glacier is difficult to estimate (Jobard and Dzikowski, 2006;Gremaud et al, 2009;Gremaud and Goldscheider, 2010).…”

Diurnal pattern of the drying front in desert and its application for determining the effective infiltration

“…Afore mentioned studies are mainly focused on the rate at which the infiltrated rainfall recharges the groundwater, which could be called the effective infiltration or the effective rainfall (Wu et al, 1997;Bonacci et al, 2006). However, the effective infiltration or rainfall could also be defined as the amount of rainfall stored in the shrub root zone, excluding the fraction that runs off the soil surface or passes through the root zone that does not contribute to shrub growth and the fraction that evaporates (Wang et al, 2007).…”