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Površinska in podzemna voda sta med seboj tesno povezani. Razumevanje njunega medsebojnega odnosa je ključnega pomena za trajnostno upravljanje in varovanje. V Sloveniji je veliko sistemov za oskrbo s pitno vodo neposredno odvisnih od podzemne vode, ki se napaja s strani površinske vode in sta tako njena kakovost in količina povezani z interakcijo s površinsko vodo. Za preučevanje odnosa med površinsko in podzemno vodo smo si izbrali vodonosnik na območju Črneč pri Dravogradu, kjer imamo na majhnem območju na voljo veliko kvalitetnih podatkov. Območje obsega rečno teraso z rečno ravnico, reko Dravo na severu in potok v Črneškem grabnu na zahodu. Geološko podlago sestavljajo slabo prepustni metamorfne kamnine paleozojske starosti, preko katerih so odloženi dobro prepustni kvartarni nanosi reke Drave. Pri izdelavi numeričnega hidrogeološkega modela smo si pomagali s podatki o vodostaju reke Drave, pretoku bližnjega potoka in podatki o gladini podzemne vode iz štirih opazovalnih vrtin. Območje je veliko 330 m x 330 m, sestavljata pa ga dve plasti. Med kalibracijo je bilo določenih pet območji s koeficientom prepustnosti med 1,10 x 10-3 m/s in 9,50 x 10 3 m/s in neprepustno območje odlagališča. Rezultati simulacij modela z različnimi hidrološkimi in hidrogeološkimi stanji so pokazali odvisnost podzemne vode od količinskega stanja površinske vode in količine napajanja iz zaledja. Pri srednjem hidrogeološkem stanju je smer toka podzemen vode od juga proti reki na severu, pri zvišanju gladine reke Drave je z jugozahoda proti severu in nato nazaj proti jugovzhodu, zvišanje gladine potoka pa povzroči spremembo v smeri od zahoda proti vzhodu. Znižanje količine napajanja iz zaledja povzroči obrat toka v smeri od severa proti jugu. Pri ostalih scenarijih je prišlo do spremembe upada gladine podzemne vode. Model omogoča nadaljnje raziskave na področju dinamike podzemne vode in transporta snovi v podzemni vodi na območju Črneč pri Dravogradu. Surface water and groundwater are closely interconnected. Understanding their interaction is crucial for the management and protection of both natural resources. In Slovenia, many drinking water supply systems are directly dependent on the groundwater which recharges from surface water. Therefore its quality and quantity are related to the state of the surface water. To study this relationship, an aquifer near Črneče near Dravograd was selected, where a fair amount of quality data is available. The area comprises a river terrace, a river plain with Drava River to the north and a stream in the Črneški Graben to the west. The bedrock consists of poorly permeable metamorphic rocks with highly permeable alluvial deposits deposited over it. In the numerical hydrogeological model the water level data of the Drava River, the flow data from the stream and the groundwater level data from four observation boreholes was used. The model covers the area of 330 m x 330 m and consists of two layers. During calibration, five zones with a permeability coefficient between 1.10 x 10 3 m/s and 9.50 x 10 3 m/s have been determined, together with a zone representing the non permeable area of the landfill. The results of the model simulations with various hydrological and hydrogeological conditions show the dependence of the groundwater on the water levels of the surface water, as well as on the amount of water from recharge area. At medium groundwater levels, the flow direction is south north recharging the Drava River. When the water level in Drava River is raised, the flow changes directions to southwest-north-southeast. With the rise of water in the stream, the flow direction is from west to east. Lowering the amount of water from the recharge area causes the reversal of the flow direction from south-north to north-south. In other scenarios only the slope of the groundwater flow was changed. The model enables further research of the dynamics of the groundwater and the transport of the substance in the groundwater in the Črneče area near Dravograd. |
