Z zagadnień systematyki i oceny zasobów wód podziemnych

Abstract

W artykule przedstawiono niektóre aspekty metodyczne dotyczące map hydrogeologicznych podstawowych, stanowiących punkt wyjścia schematyzacji poziomów wodonośnych na mapach zasobów, oraz wydzielania bloków obliczeniowych. Cechą szczególną map podstawowych było podanie maksymalnej ilości informacji typu ilościowego (miąższość, wodoprzewodność, wydajność potencjalna, izohipsy stropu i hydroizohipsy), przy rezygnacji ze ścisłych oznaczeń wieku :i genezy poziomów wodonośnych. Na mapach zasobów obok charakterystyki ilościowej przedstawiono podział regionalny i strefy kontaktów oraz przepływów między użytkowymi poziomami wodonośnymi. Omówiono systematykę zasobów wód podziemnych oraz koncepcję ich podziału, zastosowaną w prognozie ogólnokrajowej. Porównano wyniki oceny zasobów w ZSRR, Bułgarii i Polsce, głównie w aspekcie metodycznym.SOME PROBLEMS OF SYSTEMATICS AND ESTIMATION OF GROUNDWATER RESOURCESIn connection with the Atlas of Groundwaters of Poland, recently prepared by the research team of the Geological Institute, the paper presents some aspects of cartographic interpretation, methodology of calculations and discussions of the results obtained.The basic hydrogeological maps which are the starting point for estimating groundwater resources are characterized by predominance of spatial data on aquifers (thickness, permeability, top, depth, potential output, hydroisohypses) at the expense of accurate dating and reconstruction of origin of aquifer horizons and documentation of entrance data such as those on intake, drainage earthworks or hydrochemical anomalies. The maps of renewable and exploitational resources present both the modulus of resources and their subdivision into hydrogeological units.The resource prognosis covered only exploitable aquifer horizons from the zone of active water exchange and with mineralization below 1 g/l. Besides a general subdivision into renewable, unrenewable and exploitable resources, there is introduced a subdivision into potential and actual renewable resources. The potential renewable resources are characterized by a total infiItration of precipitation waters, and the actual ones - by a supply to exploitable horizons covered by the prognosis.The data obtained in the course of the works on the Atlas were compared with the results of similar prognoses made in the USSR and Bulgaria. Potential renewable resources were evaluated on the basis of analysis of oscillations in soil retention and infiltration index in Poland, and with the use of the hydrogeological method in the USSR and Bulgaria. Despite of these methodological differences the results obtained in Poland are close to or slightly higher than those obtained elsewhere. The actual renewable resources were calculated on the basis of hydrodynamic flow. They present about 50-60% of mean underground flow and are almost twice higher than the mean values obtained for the USSR and Bulgaria with the use of arbitrary conventional reducing coefficient.The prognosis for Poland was primarily limited to potential - overall - exploitational resources. The prognosis neglected marginal infiltration resources as well as so-called perspective resources estimated according to conventional schemes of large, combined groundwater intakes. In estimating the' perspective resources the deeper-seated aquifer horizons are preferred. Their high permeability and poorer capability to renew result in some under estimations, similarly as in the case of too low entrance parameters, saving schemes and twice longer prognosis period (50 years).The utilization of resources given in the prognosis made for the whole country depends on progress in: a - amelioration of the quality of surface waters, b - run-off control, c - artificial increasing of groundwater resources, d – national and selective exploitationand conservation of groundwaters, and e – cooperation with neighbouring countries.