Značilnosti odnosa med napajanjem in praznjenjem kraškega vodonosnika v zaledju izvirov Vipave (Slovenija)

Povzetek

V opravljeni raziskavi sem iskala odgovore na vprašanji, kakšne so značilnosti odnosa med napajanjem in praznjenjem kraškega vodonosnika v zaledju izvirov Vipave in kaj lahko na osnovi ugotovljenih odnosov med vhodnim in izhodnim signalom kraškega sistema sklepamo o zakonitostih njegovega delovanja. Postavila sem več različnih modelov napajanje-praznjenje. Za vsakega sem pretvorbo vhodnega signala v odziv sistema definirala s funkcijami transferja, ki v matematični obliki odražajo razmere in procese v kraškem sistemu. Primerjava ustreznosti različnih postavljenih modelov je potrdila pomemben vpliv vegetacije ter procesov v ozračju in tleh na količino vode, ki dejansko vstopi v kraški vodonosnik in sem jo izrazila s funkcijo napajanja. Točnost simulacije pa se je povečala tudi z razčlenitvijo napajanja na počasno in hitro komponento, kar se ujema z dvojnim mehanizmom delovanja kraškega sistema: s hitrim pretokom skozi kraško drenažno mrežo in daljšim zadrževanjem v sistemu z uskladiščenjem v conah slabše prepustnosti.

In the presented research I tried to find answers to the following questions: what the characteristics of the relation between recharge and discharge of the karst aquifer in the background of the Vipava springs are and which conclusions about the functioning of the karst system can be made based on stated relations between its input and output signal. Several different models of the system recharge-discharge were set. For each the conversion of the input signal to the system response was defined by transfer functions, which express conditions and processes in the karst system in mathematical form. Based on the comparison of the suitability of these different models an important influence of vegetation and processes in atmosphere and soil on the quantity of water that actually enters the karst aquifer and is expressed as recharge function was proved. An increase in the accuracy of the simulation was obtained also by the temporal distribution of recharge in fast and slow component, which is in agreement with the double mechanism of the functioning of the system: fast flow through the karst drainage net and longer retardation in the system with storage of water in less permeable zones.