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Dobrogea’s Underground Water Supplies

Colaborator Greenly — Mon, 09 Feb 2015 10:44:28 +0000

Notwithstanding its cultural and touristic significance, Dobrogea offers plenty of “study material” for other sciences as well, such as geology, speleology, geography, history and so on. The lands of Dobrogea are rich in historical sites, tourist resorts, extremely old rock formations and spectacular caves. One of the more recent discoveries occurred in 2011, when workers on a railway project had to blow up a limy hill. After the explosion, the resulting crater revealed the shimmer of water. Dozens of dump trucks filled with stone were used to try and cover up the hole, but to no avail – the crater seemed to swallow up any amount of rubble. Next, the engineers tried to divert the route, but another explosion opened up a new water-filled cave. An ever greater detour was made but, after a while, the railroad’s embankment began to sink. Not long after, the caverns were explored by speleologists, who discovered an impressive cave, featuring stalagmites and various other geological formations, with a pretty complex topography.
Nevertheless, local legends speak of a true subterranean river, which flows in an opposite direction compared to normal rivers, from the valley towards the hills, and with a flow that could easily surpass the Danube. If, today, you visit Constanța County and you ask about an “underground river”, you will surely find those that know about such a thing. And people have seen water bursting from the ground every time the earth was drilled. It is even more peculiar to see such phenomena in a county as dry and lacking in fresh water reserves as Constanța.
Scientists believe that the flow of such an underground river is more likely closer to that of Olt River. To the north of Constanța, at Palazu Mare, there is a high quality iron ore deposit, at a depth of 500 to 1000 meters. Legend has it that this deposit was discovered by sailors whose compasses were disturbed when they sailed near the shore. After the first prospective drillings, the quality of the ore was confirmed and plans were made to begin extraction. The mining operation failed because above the deposit there are layers of limestone filled with cavities through which water circulates. Therefore, this was the first time when the existence of an “Olt”-sized river was established. The iron ore could not be extracted because the mining galleries would be flooded with water; this was also an opportunity to measure the flow of this underground water.
The aquifer is a complex made up of permeable rocks and water. Where does this water come from? In Dobrogea, there are four sources of underground water – water coming from the Prebalcanic Plateau, located in Bulgaria (this is the main source), water coming from the Danube, in the Ostrov-Cernavoda area, and also rainwater and irrigations.
“The source extends for at least 200 square kilometers under Bulgaria and 80 square kilometers under Romania, at a depth of several hundred meters”, says Camelia Dumitrache, Manager of Water Resources for DADL Constanța.
A significant portion of this flow of underground water drains into the Black Sea, directly beneath sea level, and is thus impossible to see. According to specialists, the exact volume of water of this subterranean river cannot be precisely determined, and the only way of monitoring it is by calculating it on the basis of flows measured during drillings. The input of underground water from Bulgaria is nevertheless demonstrated through clear evidence. Thus, in the heart of Dobrogea, the flow of water is around one liter per second, whereas in the “flooded” south, the measured values reach tens of liters per second.
“The aquifer beneath Constanța County drains through two natural drains in the Siutghiol Lake and Mangalia Pond. In terms of volume contained, this is the most important aquifer in Romania”, tells us Adrian Chera, who works for the Dobrogea-Littoral Water management Agency.
It is paradoxical that farmers face droughts every year, yet they sit upon a subterranean lake. “In 2012, there were few chances for us to use irrigations, because of the high cost of water. Unfortunately, the existing adduction canals are severely degraded nowadays. The solution brought forward by farmers was to combat the phenomenon of desertification by filling the irrigation canals with water, in an environmental program that will result in an solution which is both eco-friendly and advantageous for farmers and rural communities” adds Constantin Iancu, president of the League of Farmers’ Associations local branch. Experts say that the underground water volume can remain constant if this reserve is used exclusively to provide the population with potable water.
“Extreme temperatures and droughts have not reduced the volume of water and we do not believe such a reduction will occur in the following years. The amount of water currently extracted from the aquifer can be doubled without significantly affecting the volume of water” affirms Călin Costache, an environmental specialist.
Carmen-Alina Gherghina- claims, in her doctoral thesis presented at the Faculty of Geography of the Bucharest University, that “in the context of a non-existent natural drainage, the influence of irrigations on the hydro-geological processes intensifies, determined by a decrease of underground discharge. There are also a number of additional issues, such as the incorrect use of irrigations, wrong techniques and the losses in the adduction and distribution network, and a poor exploitation”.
“Getting to know these underground waters could lead to better water management in Dobrogea. Because of such resources, the Romanian littoral does not run out of water in summer, when its population triples and consumption is enormous. During this period, water is pumped from the underground deposits” – Cristian Lascu, speleologist and chief editor of national Geographic Romania.

Sources:

http://portal.tfm.ro/legenda-fluviului-subteran-de-sub-dobrogea/

http://www.mondonews.ro/Fluviul-subteran-care-strabate-Dobrogea-confirma-teoria-lui-Herodot+id-41771.html

http://www.natgeo.ro/explorari/speologie/9054-misterul-apelor-pierdute-din-dobrogea

http://www.romanialibera.ro/exclusiv-rl/reportaj/legenda-fluviului-subteran-de-sub-dobrogea-articol-integral-252520.html

http://deltadunarii.fotodelta.ro/?p=2372

http://www.recolta.eu/paradoxul-dobrogean-desi-se-confrunta-an-de-an-cu-arsita-agricultorii-stau-pe-un-lac-subteran/

Photo source:
http://www.groundwater.org/kc/whatis.html

http://greenly.ro/apa/rezervele-de-apa-din-adancul-dobrogei

Article written by Razvan Spiridon and translated by Mihail Mitoseriu.

Rezervele de apa din adancul Dobrogei

Razvan Spiridon — Mon, 19 Mar 2012 08:32:49 +0000

Pe langa importanta culturala sau turistica, Dobrogea ofera „material de studiu” si altor stiinte, cum ar fi geologia, speologia, geografia, istoria ș.a. Teritoriul dobrogean abunda in vestigii istorice, statiuni turistice, roci de varsta foarte inaintata sau pesteri spectaculoase. Una din cele mai recente descoperiri a fost facuta in urma cu un an, cand muncitorii de la o cale ferata au fost nevoiti sa dinamiteze o colina calcaroasa. Dupa explozie a rezultat un crater, pe fundul caruia se putea distinge luciul unei ape. Zeci de bascule cu piatra au fost turnate acolo, dar in zadar; golul parea capabil sa inghita orice cantitate de balast. Inginerii au proiectat o deviere, dar o noua bubuitura a avut ca rezultat deschiderea unei noi caverne cu apa. S-a facut un ocol si mai mare si astfel calea ferata a fost finalizata, dar dupa cativa ani, terasamentul a inceput sa se taseze. Nu dupa mult timp, cavernele au fost cercetate de speologi, care au gasit acolo o impresionanta pestera cu stalagmite si alte formatiuni, avand o topografie destul de complexa.

Legendele locale insa vorbesc de un adevarat fluviu subteran care curge invers decat apele obisnuite, de la vale la deal, cu un debit ce l-ar depasi cu mult pe cel al Dunarii. Daca te duci astazi in judetul Constanta si intrebi de „fluviul subteran”, sigur vei gasi oameni care sa-ti spuna ca au auzit de asa ceva. Cu atat mai mult cu cat lumea a vazut apa cum tasneste din pamant, ca o fantana arteziana, cu ocazia fiecarui foraj. E cu atat mai ciudat sa se intample acest lucru intr-un judet precum Constanta, care dintotdeauna a suferit din cauza lipsei resurselor de apa potabila.

Oamenii de stiinta sunt de parere ca debitul ar fi mai degraba comparabil cu Oltul decat cu Dunarea. La Nord de Constanta, la Palazu Mare, exista la adancimi de 500 – 1000 m, un zacamant de fier de o calitate superioara. Legenda spune ca acest zacamant a fost descoperit de marinari pentru ca le deruta busolele cand se apropiau de sol. Cand s-au facut primele foraje, s-a ajuns la concluzia ca este vorba de un minereu exceptional de bogat si s-a vrut exploatarea acestuia. Nu s-a reusit insa deoarece pe acest zacamant sunt calcare pline de goluri prin care circula apa. Deci „Oltul” acela atunci a fost pentru prima data pus in evidenta. Nu se putea exploata minereul de fier pentru ca galeriile ar fi fost inundate de apa; atunci s-a masurat debitul apei de-acolo.

Acviferul este un complex de roca permeabila impreuna cu apa pe care o gazduieste. De unde vine aceasta apa ? In cazul Dobrogei exista patru surse de alimentare pentru apele subterane – din Podisul Prebalcanic, localizat pe teritoriul Bulgariei (sursa principala), apoi mai este o componenta de alimentare din Dunare, in zona Ostrov-Cernavoda, dar si din precipitatii sau irigatii.

„Sursa se intinde pe o suprafata de cel putin 200 de kilometri pe teritoriul Bulgariei si in jur de 80 km in Romania, la cateva sute de metri adancime” a declarat Camelia Dumitrache, director Resurse de Ape in cadrul DADL Constanta.

O mare parte din debitul acestor ape curgatoare are ca punct de drenaj (varsare) „batranul” Pont Euxin, direct sub nivelul marii, astfel incat fenomenul nu poate fi observat. Potrivit specialistilor, volumul de apa al asa-zisului „fluviu” nu poate fi estimat cu exactitate, singura modalitate de supraveghere fiind aceea de calcul al debitelor de foraj. Aportul apelor subterane venite din Bulgaria este insa demonstrat prin cifre clare. Astfel, in centrul Dobrogei debitul apei este de aproximativ un litru pe secunda, in timp ce, in Sudul „inundat”, cifrele indica valori de zeci de litri pe secunda.

„Acviferul din subsolul judetului Constanta se descarca prin doua drenuri naturale in Lacul Siutghiol si in Balta Mangaliei. Volumul de apa cantonat in acest acvifer este cel mai important din Romania” spune inginerul Adrian Chera de la Directia Apelor Dobrogea Litoral.

E paradoxal faptul ca agricultorii se confrunta an de an cu seceta, desi stau pe un lac subteran. „In anul 2012, exista slabe sanse sa putem iriga, din cauza costurilor foarte mari cu apa. Din pacate, canalele de aductiune existente se afla in acest moment intr-un stadiu avansat de degradare. Solutia propusa de fermieri a fost aceea de a combate fenomenul de desertificare prin umplerea canalelor pentru irigatii cu apa, printr-un proiect de mediu, astfel incat aceasta masura sa fie prietenoasa cu mediul si avantajoasa pentru agricultori si zonele rurale“, spune si Constantin Iancu, presedintele unei filiale a Ligii Asociatiilor Producatorilor Agricoli din Romania. Specialistii sustin ca volumul de apa poate ramane constant in conditiile in care aceasta rezerva este utilizata exclusiv pentru alimentarea cu apa potabila a populatiei. „Temperaturile extrem de ridicate si seceta nu au dus la scaderea volumului de apa si nici nu credem ca se va intampla acest lucru in urmatorii ani. Debitul de apa exploatat la ora actuala din acvifer poate fi dublat fara sa fie inregistrate oscilatii semnificative ale volumului de apa” spune Calin Costache, specialist de mediu.

Carmen-Alina Gherghina, in cadrul tezei sale de doctorat de la Facultatea de Geografie – Bucuresti, sustine ca „in conditiile lipsei drenajului natural, influenta irigatiilor asupra proceselor hidrogeologice se intensifica, determinate de micsorarea scurgerii subterane. La acestea se adauga aplicarea irigatiilor in conditii necorespunzatoare, aplicarea unor norme de udare gresite, pierderi din reteaua de aductiune si distributie, exploatare deficitara.”

„Cunoașterea acestor ape subterane poate sa duca la o mai buna administrare a surselor de apa din Dobrogea. Datorita acestor surse de apa, litoralul romanesc nu duce lipsa de apa vara, cand se tripleaza populatia, iar consumul este enorm. Atunci se pompeaza din aceste depozite de apa subterana.” Cristian Lascu, speolog, redactor şef Naţional Geographic România

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