SHORT HISTORY of the HYDROGEOLOGICAL INVESTIGATIONS of the KARST in ROMANIA by Iancu ORÃªEANU Romanian Association of Hydrogeologists, [email protected]

SHORT HISTORY of the HYDROGEOLOGICAL INVESTIGATIONS of the KARST in ROMANIA by Iancu ORÃªEANU Romanian Association of Hydrogeologists, Ianora@Hotmail.Com

SHORT HISTORY OF THE HYDROGEOLOGICAL INVESTIGATIONS OF THE KARST IN ROMANIA by Iancu ORÃªEANU Romanian Association of Hydrogeologists, [email protected]

Investigation of karst areas is a multi-discipli- EM. PROTOPOPESCU-PACHE, in his nary approach, which is the reason why in these studies undertaken in Mangalia area, sets the wa- areas the efforts of landforms investigators, cavers, ter drainage to the springs of sulphurous bath in geologists, hydrologists and hydrogeologists inter- the South, as well as the springs placed to the East, penetrate, one being unable to specify exactly towards the sea, to Constanta highway, by mark- where some of them start, and where others end. ing with uranite the waters overflown from Kara- This is also the case of the research performed in Oban lake in the nearby ponor (R. COCÂRDEL, karst areas of Romania, where the first information EM. PROTOPOPESCU-PACHE, 1955). on karst springs and groundwater flow has been The first systematic hydrologic investigation provided by geographers, geologists and cavers. of the landforms in the karst areas of Romania has In the year 1863, the Austrian geographer A. been performed by the Institute of Speleology SCHMIDL has published in Vienna the work “Emil Racovita” (ISER) and by the Institute of “Das Bihar Gebirge and der Grenze von Ungarn Geography. Starting from the very first papers und Siebenburgen”, the first extensive geographi- published by the scientists of those two institutes, cal study addressing the karstology and the speleol- M. ªERBAN, D. COMAN and I. VIEHMAN ogy of an area within the territory of our country. (Bihor Mountains, 1957), T. RUSU, GH. The author provides a detailed description of the RACOVIÞÃ and D. COMAN (Bihor Moun- karst in the mountains Bihor, Vlãdeasa and Codru tains, 1970), I. VIEHMAN (Bihor Mountains, Moma, of the main karst springs, of the mineral 1958, 1966), V. SENCU, (Anina area, 1970, and thermal springs in those mountain bodies and 1978, 1986), T. RUSU (Pãdurea Craiului Moun- in Beiuº basin. tains, 1960-1988), V. TRUFAª (Sebeº Moun- In the year 1901, the Romanian geologist S. tains, 1965) and from ISPIF, BIªIR and M. MIHUÞIA has performed the first tracer testing PASCU (Cerna area, 1967, 1969), there can be of an underground stream course in Romania. By noticed their obvious concern for identifying the labeling the water of Þarina stream with charcoal groundwater flow paths, fluorescein tracer tests powder, he outlined the hydrologic connection being performed in this respect. between Câmpeneasca cave, in Vaºcãu karst pla- Over the time interval 1960-1988, the teau, and the Boiu spring, next to Vaºcãu town (S. Pãdurea Craiului Mountains karst areas have been MIHUÞIA, 1904). subject to detailed karst topography and hydrology In 1908, Marghitaº and Buhui dams are built investigations conducted by T. RUSU, who per- on Buhui stream, the lakes being the only ones in formed a multitude of fluorescein tracer tests, by Romania placed on limestones. Downstream which he outlined the main karst flow directions. Buhui lake, controlled water by the dam is then The integral publication of those results occurred distributed in the limestones area and feeds, to- in the year 1988. gether with Certej spring, the underground flow The Institute of speleology “Emil Racoviþã”, of Buhui cave. At the end of the cave there is an specifically its research worker I. POVARÃ, has artificial underground lake, its water supply Anina carried out over the period 1965-2007 an exten- town through an artificial gallery, of 1.3 km long sive activity of investigating the karst hydrogeology (V. SENCU, 1967). of Cerna stream catchment area, of Mehedinþi

19 Mountains and Plateau, West Jiu area and South In order to delineate the groundwater flow Dobrogea. T. CONSTANTINESCU performed paths, the company Prospecþiuni S.A. has per- tracer tests in Piatra Craiului Massif, G. formed about 170 tracer tests, many of them in DIACONU in Motru Sec area and I. POVARÃ cooperation with the Tracer group of Institute of and V. HOROI in Ardeu watershed. The chem- Physics and Nuclear Energy (IFIN) led by E. istry of the karst waters in Pãdurea Craiului, Cerna GAªPAR. For these tracer tests, there have been trough and Mangalia area made the object of very initially used radioactive tracers (Iodine-131, Bro- detailed studies signed by C. MARIN. mide-82), and after the year 1980, activable trac- In 1974, M.BLEAHU publishes “Karstic ers (In-EDTA, Dy-EDTA, La-EDTA), fluorescent morphology”, an encyclopaedia about the karst tracers (fluorescein, rhodamine B) and whitening and its genesis, a work of a highly positive impact optic agents (stralex). To some of the tracer tests on researching the karst in Romania. performed in Apuseni Mountains, there has also Starting from the year 1970, the Hydro- taken part a group from the High School Institute geological survey department of Prospectiuni S.A. in Baia Mare, led by I. POP. company has carried out a constant activity aimed In 1970, D. I. SLÃVOACÃ, I. ORÃªEANU, at investigating the carbonate rocks areas, in order E. GAªPAR and AL. BULGÃR (1985), confirm to complete hydrogeological maps, to compute the the continuity of limestone in the Danubian Unit water budget, to assess the groundwater resources, under crystalline schists in Motru Sec- Baia de to delineate the main karst flow paths and to out- Aramã by labelling with Iodine-131, demonstrating line the groundwater chemistry. Those investiga- thus, based on a hydrogeological method, the pres- tion projects addressed most karst areas in Roma- ence of the Gettic Nappe. A marking done 29 years nia, being performed by: G. SIMION (Mehedinþi later, in 1998, by G. & RÃDIÞA BANDRABUR, Mountains, Cerna-Jiul de Vest area), I. LAZU D. C. & RUXANDRA SLÃVOACÃ (1998-1999), (Mehedinþi Mountains), M. FERU (Mangalia in between the lost Prejna river at Balta and Bârza area), NICOLLE & I. ORÃªEANU (Pãdurea spring, supports the continuity to South-West of Craiului, Codru Moma, Bihor Vlãdeasa, Trascãu the same tectonic structure. Another labelling, con- Mountains, Poieni plateau, Rapolt crystalline tributing to confirming regional geological struc- limestones outcrop, Dâmbovicioara Pasasage, tures, was done in Bihor Mountains, the hydrologi- Postãvarul Massif, Reºiþa-Oraviþa area, Teliuc- cal connection between the losses at Valea Seacã Ghelar zone, Mangalia area), E. ANGHEL stream and the spring of Criºu Bãiþa stream con- (Moneasa and Teliuc-Ghelar areas), A. firming the continuity of the Bihor Unit limestones IURKIEWICZ (Pãdurea Craiului and Vâlcan under the permian sandstones of Arieºeni Nappe at Mountains, Reºiþa-Moldova Nouã area), N. Tapul peak (I. ORÃªEANU, E. GAªPAR, I. POP. TERTELEAC (Codru Moma, Dâmbovicioara T. TÃNASE, 1991). Passage), GH. PONTA (Codru Moma, The National Institute of Hydrology and Cerniºoara-Jiul de Vest area), ELENA & R. Water Management (INHWM), specifically its re- STRUSIEVICI (Cerniºoara-Jiul de Vest area), search workers P. NIÞÃ, AL. BULGÃR, P. MIÞÃ, RUXANDRA & D. C. SLÃVOACÃ (Vâlcan and DIACONU V., OANCEA V. performed hydro- Bucegi Mountains, Mehedinþi Mountains and logic investigations, together with tracer tests. The Plateau, Cerniºoara-Jiul de Vest area), RÃDIÞA & group in INHWM, including A. ÞENU, F. D. G. BANDRABUR (Petreºti-Tureni area, Babadag DAVIDESCU and ANA SLÃVESCU, has com- Basin, Poiana Ruscã Massif, Mehedinþi Mountains pleted investigations addressing the karst water dy- and Plateau, Sebeº Mountains, Parâng and namics by means of environmental isotopes. De- Cãpãþânii Mountains, Cerniºoara-Jiul de Vest tailed studies addressed the investigation of the karst area), MIRELA & C. PANAITESCU (Perºani aquifers in South Dobrogea, Valachian Platform Mountains), G. DRAGOMIR (Hãghimaº Moun- and the origin of the thermal water at Geoagiu and tains), G. DRAGOMIR and C. NAN (Reºiþa- Felix-1 Mai Spa. Anina area), A. ROTARU (Anina-Nera area), A. The tracer labellings performed by Institute ANGHELI (Nera-Dunãre area) and E. of Study and Design for Land Reclamation CÃPRARU (SW Vaºcãu Plateau). (ISPIF), especially by M. Pascu, highlight the un-

20 derground connexion between losses in Jiul de there are following researchers: R. CATILINA, S. Vest watershed and Cerna spring and between CRÃCIUN, LUCREÞIA DINESCU, R. losses in flow of Motru Sec river and springs in GAªPAR, M. MIDOIU, MARIA PASCU, B. Baia de Aramã area. Were also established sanitary PÃUNICÃ, G. POPOVICI, C. STANCA, P. and hydrogeological protection areas of Runcu and STÃNESCU, T. TÃNASE, L. TIMOFTE. Jaleº springs in Vâlcan Mountains (R. PASCU, E. GAªPAR is the author of “Modern trends DANA VELICIU, 2000). in tracer hydrology” (1987) and “Tracers in aquifer The investigation of the karst aquifers in South systems” (1994), reference books in using tracers in Dobrogea focused the interest of a multitude of hydrology. He has also published, on his own or scientists, among which we mention: R. with other co-authors, several articles on results of CIOCÂRDEL and EM. PROTOPOPESCU- tracer tests and was constantly interested in finding PACHE (1955), C. DRAGOMIRESCU (1971), I. new labelling technologies and new tracers to ex- NAINER (1971-1973), N. PITU (1980), plore the dynamics of underground waters. V. MOLDOVEANU (1987-1988), F. Hydrogeological research of karstic areas to ZAMFIRESCU, A. DANCHIV, M. ALBU, M. point out still waters is the topic of articles pub- ENÃCHESCU and V. MOLDOVEANU (1993), lished by M. PASCU, C. MOISSIU and ALINA F. ZAMFIRESCU, V. MOLDOVEANU, C. MOISESCU in 1984 (Scropoasa supplies, Izvorul DINU, N. PITU, M. ALBU, A. DANCHIV and Minunilor at Stâna de Vale, Bârza-Topleþ and H. NASH (1994). Murighiol), EUGENIA PÂRVÃNESCU and A. Contributions to the investigation of PÂRVÃNESCU in 1991 (“ªapte Izvoare Reci”, Mangalia area are due to GH. VASILESCU and Scropoasa area), ILEANA TIÞA and V. MICULA SILVIA MATEI (1967), A. ÞENU and G. in 1998 („Hera spring” in Vlãdeasa Massif) and I. NEACªU (1968), I. NIÞÃ (1971), M. FLORIAN ORÃªEANU the same year (Bihor Vlãdeasa and and GABRIELA POPESCU-DUMITRESCU Codru Moma mountains). (1972), I. IANCULESCU (1980), E. GAªPAR Starting with 1983, the review “Theoretical and and I. ORÃªEANU (1987), I. ORÃªEANU Applied Karstology” is being published, with works (1993, 1994), V. MOLDOVEANU, C. DINU, presented at seminars on this topic, organised by Emil P. GEORGESCU and V. NICULESCU (1988- Racoviþã Institute of Speology and S.C. Prospecþiuni 1990), M. FERU and ANA CAPOTÃ (1991), M. S.A. In 1987, E. GAªPAR and I. ORÃªEANU pub- FERU (1993), I. POVARÃ (1994), C. MARIN lish in this series an article about natural and artificial and TUDORA NICOLESCU (1993), T. tracers used in the study of karst hydrodynamics, A. PARKER (1994). IURKIEWICZ and A. MANGIN publish in 1994 Consistent data regarding geological structure a synthesis of using the systemic analysis in the study and hydrogeology of karst reservoirs has brought of karstic aquifers in Vâlcan mountains, while in by drilling wells performed by Foradex SA (former 1995, A. ÞENU and F. DAVIDESCU publish an- ISEM company), Enterprise for Driling and Spe- other synthesis on using the environmental isotopes cial Geological Works (ISLGC) and Institute of in the study of carbonate karstic aquifers in Romania. Balneology and Physiotherapy (IBF) In 1991 and 1996, I. ORÃªEANU publishes in the Starting with 1970, the Institute of Atomic same review hydrogeological maps at 1:50,000 scale, Physics, later named Institute of Physics and Nu- of Pãdurea Craiului and Bihor Vlãdeasa Mountains. clear Energy, has brought major contributions, by In 1985, the Geological Institute of Romania the team led by E. GAªPAR, to developing and ap- publishes the Vaºcãu sheet of the hydrological map plying marking technologies with radioactive and of Romania, at 1:50,000 scale, drafting by GH. activable tracers in the study of karstic aquifers. In PONTA, M. BLEAHU, S. PANIN and I. a permanent cooperation with researchers from in- ORÃªEANU. stitutes involved in the study of karstic areas, the In 2002, A. ISTRATE, in the “Hydrokarstic team of tracers took part in a large number of mark- systems of Bucegi Mountains” publishes the results ings, highly contributing to knowing the dynamics of his research in the high watershed of Ialomiþa river. of underground waters in all areas of carbonate The knowledge of karstic hydrographs of Apuseni waters in Romania. In this team there were and Mountains was supported by a major contribution of

21 works undertaken by L. VÃLENAª, B. ONAC, P. References COCEAN, E. SILVESTRU and P. E. DAMM. Bandrabur Gh., Slãvoacã D., Bandrabur Rãdiþa, We also need to mention the key contribu- Slãvoacã Ruxandra (1998-1999): Considéra- tion in exploring and researching the karst in Ro- tions hydrodynamiques sur le système karstique mania of amateur speleologists. In many cases, the de Bârza (Monts et Plateau de Mehedinþi, Ro- caves and avens they have found supported the mania). Theor. Appl. Karst., 11-12, pp. 133- researchers in exploring this invaluable asset. 138, Bucharest. Hydrogeological knowledge of karst areas Bleahu M., Decu V., Negrea St., Pleºa C., Povarã were the object of PhD Thesis performed by T. I., Viehmann I. (1976): Peºteri din Romania. RUSU (1979), A. ÞENU (1979), N. PITU (1981), Ed. ºtiinþificã ºi enciclopedicã, Bucureºti, 415p. I. POVARÃ (1997), V. MOLDOVEANU (1999), Bretoteanu M., Þenu A. (2000): Scurtã privire I. ORÃªEANU (2000), G. ISTRATE (2001), A. asupra activitãþii de hidrogeologie desfãºuratã în IURKIEWICZ (2004), and A. ROTARU (2009). cadrul Institutului Naþional de Meteorologie ºi The largest karst springs in the Carpathian Hidrologie. Lucrãrile Simpozionului “100 de Orogene have 1-2 m3/s average flow rates (table 1), ani de hidrogeologie modernã în România”, their occurrence being related to the presence of 24-26 mai 2000, Bucureºti, p. 117-129. unary karst type systems, with homogeneous lime- Bulgãr A., Diaconu V., Oancea V. (1984): Mod- stone bodies extending over large surfaces (the ern methods in karst hydrological research. Ap- springs in downstream gorges of Dâmboviþa stream, plication to some principal karst systems from Ochiu Beiului spring in Banat Mountains, Boiu the Southern Carpathians. Theoretical and Ap- spring in Vaºcãu Plateau), or to of a widely developed plied Karstology, 1, 215-224, Bucharest. non-karst catchment area within the binary karst sys- Cineti A. F. (1990): Resursele de ape subterane ale tems (Cerna spring, Bârza spring, springs in Vâlcan României. Ed. Tehnicã., 296 p., Bucureºti. Mountains). In Apuseni Mountains, although car- Ciocârdel R., Protopopescu Pache Em. (1955): bonate rocks extend over large areas, the tectonic Consideraþii hidrogeologice asupra Dobrogei. structural pattern to which they had been subjected St. Tehn. Ec., seria B, nr. 3, Bucureºti. has resulted in a kaleidoscope-like structure, where Davidescu F. D., Þenu A., Slãvescu Ana (1991): carbonate deposits are scattered within the bulk of Environmental isotopes in karst hydrology. A other deposits. This structural framework did not lay-out of problems with exemplifications in favor the development of large extent karst systems, Romania: Theoretical and Applied Karstology, so that flow rates of the most important springs do v. 4, p. 77-86, Bucharest. not exceed 500-600 l/s as mean annual discharge. Gaºpar E. (1994): Trasori în sisteme acvifere. The largest distance between sinking points Ed.Academiei Române, Bucureºti. 234 pages. and outlets, recorded as a result of the tracer tests Gaºpar E., Orãºeanu I. (1987): Natural and arti- performed in Romania so far, is 23.6 km (table 2). ficial tracers in the study of the hydrodynam- It was reached along the connection between losses ics of the karst. Theoretical and Applied Kars- of Cerna river in Bobotului gorges and Neptun tology 3, 31-107, Bucharest. springs in Bãile Herculane spa (G. SIMION, E. Istrate A. (2001): Hidrogeologia carstului din zona GASPAR, 1976). The flow path between the sink- Cheile Tãtarului - Scropoasa, Masivul Bucegi, ing point of Prejna stream in Mehedinþi Plateau cu privire la evaluarea resurselor exploatabile de and Bârza spring in Mehedinþi Mountains is 22.0 ape subterane, pe baza datelor de regim ale km long (G. BANDRABUR et al,1998-1999), debitelor izvoarelor. PhD Thesis, University of thus being the second longest. Bucharest. The higher difference in level recorded as a Istrate A. (2002): Sisteme hidrocarstice din Masi- result of the performed tracer tests is 775 m between vul Bucegi. Ed. Cetatea de Scaun, Târgoviºte, Balta Cerbului ponor and Seven Cold Springs in 222 P. Mehedinþi Mountains (I. POVARÃ, 1980), fol- Iurkiewicz A. (2004): Analiza sistemicã în investi- lowed by 700 m elevation drop between Scorota garea hidrodinamicã a acviferelor carstice (ex- ponor in Retezat Mountains and Cerna spring in emple semnificative din Romania). PhD The- Godeanu Mountains (G. PONTA et al., 1984). sis, University of Bucharest, 280 p. 22 , base flow index (the ratio between Qmean of the drought month and Q mean annual). f data processing in Podu Dâmboviþei and Rucãr hydrometric sections. expeditionary measurements; (Qmax /Qmin); B )

cumulated flow; , ) v ) * ** *** Table 1. Largest springs in Romanian Carpathian Orogene karst areas (mean annual discharge more than 300 l/s) n

23 e karst areas EDTA. resurgence; T-time of first anu, A. Bulgãr; (3) I. arrival of tracer; V-apparent velocity. Tracers: T= Tritium; F=Fluoresceine, R=Rhodamine B, I=I-131,In= In-EDTA, Dy=Dysprosium *) Unpublished report. Authors of labellings: (1) G. Ponta, E. Gaºpar, R. Strusiewicz; (2) D. I. Slãvoacã, Orãºe Orãºeanu, E. Gaºpar, T. Tãnase, Gh. Ponta, N. Terteleac, G. Halasi; (4) I. Orãºeanu, E. Gaºpar, Pop, T. Tãnase Table 2. Largest lengths (A) and difference in level (B) recorded tracing operations performed Romanian Carpathian Orogen H-elevation, in meters a.s.l., L-horizontal distance between losses and Spring s, DH-Difference level insurgence 24 Iurkiewicz A., Mangin A. (1994): Utilisation de onului “100 de ani de hidrogeologie modernã l’analyse systémique dans l'étude des aquiferes în România”, 24-26 mai 2000, Bucuresti, p. karstiques des Monts Vâlcan, Theoretical and 134-139. Applied Karstology, 7, Ed. Academiei Române, Pitu N. (1981): Contribuþii la studiul miºcãrii Bucureºti, pp 9-96. apelor subterane în roci fisurate, cu particular- Iurkiewicz A., Orãºeanu I. (1995): Karstic terraines izare la complexul acvifer din zona litoralului. and major karsic systems in Romania. Karst PhD Thesis, University of Bucharest, 163 p. Water Resources (Proceedings of the Ankara- Ponta G., Strusiewicz R., Simion G., Gaºpar E. Antalya Symposium, July, 1995) A.A.Balkema/ (1984): Subterranean stream piracy in the Jiul Rotterdam/ Brookfield/ 1997, 471-478. de Vest - Cerniºoara karst area, Romania. The- Maieru Cornelia, Orãºeanu I., Palcu M. (2000): oretical and Applied Karstology, v. 1, p. 235- 50 de ani de hidrogeologie la S.C. Prospecþiuni 238, Bucureºti. S.A. Lucrãrile Simpozionului “100 de ani de Povarã I. (1980): Note sur la circulation souter- hidrogeologie modernã în România”, 24-26 raine des eaux dans les calcaires du bassin de mai 2000, Bucureºti, p. 107-116. Cerna. Trav. Inst. Speol. „E. Racovitza”, t. XIX, Moldoveanu V. (1999): Studiul condiþiilor hidr- p. 237-241, 1 tab., Bucureºti. ogeologice ale Dobrogii de Sud pentru reeval- Povarã I. (1997): Studiu fizico geografic al bazinu- uarea resurselor exploatabile. PhD Thesis, Uni- lui hidrografic Cerna, cu privire specialã asupra versity of Bucharest, 164 p. hidrologiei carstice (1997). PhD Thesis, Orãºeanu I. (1991): Hydrogeological map of the Bucharest University, 216 p. Pãdurea Craiului Mountains, (Romania). The- Povarã I., Rãdulescu D., Stãnescu I., Gaºpar E., oretical and Applied Karstology 4, 97-127, Bulgãr Al. (1987): Aquiferous interconnexions Bucharest. in the Motru-Izvarna-Tismana-Bistriþa karst Orãºeanu I. (1996): Contributions to the hydro- area, Theoretical and Applied Karstology, 3, geology of the karst areas of the Bihor-Vlãdea- Bucharest, p.199-214. sa Mountains. Theoretical and Applied Karstol- Rotaru A. (2009): Contribuþii la simularea ogy 9, 185-214, Bucharest. regimului de curgere al izvoarelor carstice cu Orãºeanu I. (2000 a): Contribuþii la cunoaºterea aplicaþii la sistemul carstic Motru Sec-Baia de hidrodinamicii sistemelor acvifere carstice din Aramã. PhD Thesis, University of Bucharest, Munþii Apuseni. PhD. Thesis, University of 154 p. Bucharest, 256 p. Rusu T. (1979): Carstul din Munþii Pãdurea Orãºeanu I. (2000 b): Consideraþii privind cerce- Craiului. PhD. Thesis, 199 p., Univ. din Cluj- tarea hidrogeologicã a arealelor carstice din Napoca. România. Lucrãrile Simpozionului “100 de ani Rusu T. (1988): Carstul din Munþii Pãdurea de hidrogeologie modernã în România”, 24-26 Craiului. Pe urmele apelor subterane. Editura mai 2000, Bucureºti, p. 117-129. Dacia, Cluj-Napoca, 254 p. Orãºeanu I., Bulgãr A., Gaºpar E., Terteleac N. Sencu V., 1986, Field measurements relating to (1984): Hydrogeological study of Dâmbovicio- the subterranean runoff of karst waters in the ara Passage. Theoretical and Applied Karstolo- Anina Mountains, Z. Geomorph. N.F., p.59- gy 1, 153-164, Bucharest. 68, Berlin, Stuttgart. Orãºeanu I., Gaºpar E., Pop I., Tãnase T. (1991): Slãvoacã I. D., Orãºeanu I., Gaºpar E., Bulgãr A. Tracers experiments in the karst area of Bihor (1985): Hydrogeological contributions for the Mountains (Romania). Theoretical and Ap- existence of the Getic Nappe in the Motru Sec- plied Karstology 4, 159-172, Bucharest. Baia de Aramã region.Theor. Apply. Karst., 2, Orghidan T., Negrea St., Racoviþã Gh., Lascu C. pp.175-181, Bucharest. (1984): Peºteri din Romania. Ghid turistic. Ed. Þenu A. (1979): Studiul geochimic ºi izotopic al sport-turism, 454 p, Bucureºti. zãcãmintelor de ape hiprtermale din partea de Pascu M. R., Veliciu Dana. (2000): 50 de ani de nord-est a Depresiunii Pannonice. PhD Thesis, Hidrogeologie la I.S.P.I.F. Lucrãrile Simpozi- 255 p.

25 Þenu A., Davidescu F. (2000): Treizeci de ani de Zamfirescu F. (2000): Un secol de hidrogeologie hidrogeologie izotopicã în România. Lucrãrile în România. Lucrãrile Simpozionului “100 de Simpozionului “100 de ani de hidrogeologie ani de hidrogeologie modernã în România”, modernã în România”, 24-26 mai 2000, 24-26 mai 2000, Bucureºti, p. 1-8. Bucureºti, p. 82-96.