Conference PaperPDF Available

INVESTIGATION ABOUT THE RECHARGE SOURCES OF POÇEMI SPRINGS IN ALBANIA BY MEANS OF ENVIRONMENTAL HYDROCHEMICAL TRACERS

Authors:

Abstract and Figures

Because a connection between the Poçemi springs and Vjosa River in South Albania was suspected, the determination of the origin of springs was of a particular interest for the high dam proposed to be constructed on Vjosa River valley, about 2.0 km south to these springs. Environmental hydrochemical and isotope tracers are successfully applied to establish the possible connection between Poçemi springs and Vjosa River. A program of independent hydrochemical was conducted for a period of nearly two years. Sulfate ion (SO 4) was used as a specific tracer, but conductivity is also indicative. This was facilitated by the relatively high SO 4-concentration in Vjosa River than the SO 4 concentration of the karst groundwater recharging the local spring. It resulted that about of 80 % of the water discharged by the Poçemi springs is recharged from Vjosa River and about 20 % is locally recharged. The results of hydrochemical investigations are in very good harmony with the results obtained from the environmental isotope methods.
Content may be subject to copyright.
Investigation about the recharge sources of Pocemi springs be means of … 123
INVESTIGATION ABOUT THE RECHARGE SOURCES OF POÇEMI SPRINGS IN ALBANIA
BY MEANS OF ENVIRONMENTAL HYDROCHEMICAL TRACERS
EFTIMI R.1, DHAME L.2
1Private Consultant, Rr. Rreshit Collaku pll. 10/3/18 Tirana Albania, Eftimi@sanx.net
2Albanian Geological Service, Tirana - Albania
Proceedings of XVIIIth Carpathian-Balkan Geological Association, Sudar M. Ercegovac M. Grubić A., eds. Belgrade. p.p. 123-126.
Abstract. Because a connection between the Poçemi springs and Vjosa River in South Albania was suspected, the
determination of the origin of springs was of a particular interest for the high dam proposed to be constructed on Vjosa
River valley, about 2.0 km south to these springs. Environmental hydrochemical and isotope tracers are successfully
applied to establish the possible connection between Poçemi springs and Vjosa River. A program of independent
hydrochemical was conducted for a period of nearly two years. Sulfate ion (SO4) was used as a specific tracer, but
conductivity is also indicative. This was facilitated by the relatively high SO4 concentration in Vjosa River than the
SO4 concentration of the karst groundwater recharging the local spring. It resulted that about of 80 % of the water
discharged by the Poçemi springs is recharged from Vjosa River and about 20 % is locally recharged. The results of
hydrochemical investigations are in very good harmony with the results obtained from the environmental isotope
methods.
Key words: Environmental hydrochemical and isotope tracers, groundwater recharge, groundwater mixing, karst spring.
Introduction
The construction of a dam 110 m high was proposed on
Vjosa River, in southcentral Albania, to produce
electricity. The dam site was located in the south-western
corner of the Kremenara karst basin, in a narrow gorge of
Vjosa River. The future lake would be developed east to
the dam site widely contacting with high karstified rocks.
A group of springs, named Poçemi springs, issue from the
karstic massive, approximately 2.0 km north to the
proposed dam site, in downstream direction of the future
lake (Fig. 1).
Intensive hydrologic, hydrogeologic and geotechnical
investigations have demonstrated that the advanced
karstification of the carbonate rocks and the possibility of
karst groundwater flow from south to north, from Vjosa
River to Poçemi springs. The objective of this study is to
demonstrate the efficiency of natural hydrochemical tracers
on studying the origin of Poçemi springs and to compare
the results with those obtained by the environmental
isotope methods (AKITI at al., 1989).
Geology and Hydrogeology
The Poçemi springs emerge in the south-west of the
elliptical like carbonate structure of Kremenara with a total
surface of 35 km2. The core of the Kremenara structure
consists of Jurassic and lower Cretaceous limestones with
siliceous rocks, which are mainly jointed. Above them lay
Upper Cretaceous, Paleocene and Eocene stratified and
massive limestones jointed and strongly karstified; caves,
karst and other forms are common there (DAME, 1987).
Fig. 1. Geological Map of Kremenara karst basin and location
of sampling points. 1. Gravel; 2. Clay (terra rossa); 3. Siltstone
and sandstones; 4. Stratified and massive limestone; 5. Spring;
6. Gallery; 7. Projected dam site; 8. Elevation in m a.s.l.
The Kremenara carbonate structure is surrounded mainly
by Paleogene flysch formation and less by Tortonian
Investigation about the recharge sources of Pocemi springs be means of … 124
siltstones and sandstones. The Vjosa River valley which cut
the Kremenara structure in its south-western corner is filled
with Quaternary fluvial gravelly deposits which maximal
thickness is about 40 m.
The Poçemi springs consist of a line of springs about
700 m long, emerging from Paleogene limestone at a
distance about 1.5 km away from the right river bank of
Vjosa River. The average discharge of the springs is 1.7
m3/s. Some limestone hills divide the Poçemi springs from
the Vjosa River. The elevation of the springs is about 41 m
above sea level, while the elevation of the oscillating river
stage is between 42.5 and 48 m above sea level. Another
important spring of the Kremenara karst basin is one
issuing about 4.5 km north to Poçemi springs at elevation
about 60 above sea level and with a total discharge of 2 to 7
l/s (spring Nr 7). This spring is recharged by the infiltrated
in the Kremenara basin precipitation and is selected as a
local calibration spring.
Three hypotheses were advanced concerning the origin
of the Poçemi springs. The first hypotheses recognize as the
possible recharge sources for the Poçemi springs the
groundwater of Kremenara karst basin, according to the
second one the Poçemi springs are recharged by another
karst basin located south to the Kremenara one. According
to some sporadic hydrogeolgical indication LAKO (1971)
has supposed the possibility of the recharge of the Poçemi
springs from the Vjosa River. In case of the verification of
the existence of suspected karstic pathways, it would
become necessary to change the site of the dam, or to apply
very expensive engineering measures.
The Kremenara karst basin has a mean annual
precipitation of 870 mm and the mean yearly efficient
infiltration estimated applying the Kessler method results
about 420 mm. The total karst groundwater resources of the
basin result 14.7*106 m3 or 0.46 m3/s, and consisting 27 %
of the total discharge of Poçemi springs. This result
supports the hypothesis of the existence of another
additional recharge source for Poçemi springs.
Hydrochemical observations
The sampling points were seven (Fig. 1): three springs
(Nr 1, 2 and 3) and two galleries (Nr 4 and 5) represent
different issues of Poçemi springs; the other sampling
points were Vjosa River (Nr 6) and the local spring (Nr 7).
The local spring has not connection with the Vjosa River
and represents the groundwater of the Kremenara basin. In
the field the temperature, electric conductivity and pH of
the sampled surface or groundwater are measured.. The
samples are analyzed for the major ions.
Table 1 shows the summarized results of some selected
chemical components of the Poçemi springs, the Vjosa
River and the spring of local origin. The high SO4 concen-
tration in Vjosa River comes from some sulfate springs
draining in the upper part of this river, both in Albanian and
Greek territory. The average chemical analyses of the
Poçemi springs, of the Vjosa River and of the local spring
are presented on a Schœller diagram (Fig. 2).
Table 1. Mean values of some selected chemical data of the water
sampling points
SP - sampling point; T temperature; Cond conductivity; PS 1
to PS 5 sampling points of Poçemi springs; PS 1-5 summarized
representative value of Poçemi springs; σ standard deviation; VR
Vjosa River; LS Local spring.
Fig. 2. Schœller diagram of the mean chemical composition of the
Poçemi springs, of the Vjosa River and of the spring with local
recharge
The Vjosa River and the Poçemi springs have similar
chemical composition, whereas the chemical composition of
the locally recharged spring is different. This fact suggests
that at big proportion the Poçemi springs are recharged by
the Vjosa River. The similarity of the chemical composition
SP
Nr of
analyses
T
˚ C
Cond
μS/cm
Cl
SO4
mg/l
meq/l
mg/l
meq/l
PS 1
11
13.9
463
23.3
0.66
55.5
1.15
PS 2
11
13.8
452
22.7
0.64
52.2
1.09
PS 3
11
13.8
453
22.3
0.63
53.0
1.10
PS 4
10
13.8
453
22.7
0.64
54.2
1.13
PS 5
11
13.8
456
22.4
0.63
54.8
1.14
PS 1-5
σ
54
13.8
455
5.9
22.7
1.54
0.64
0.04
53.8
4.94
1.12
0.10
VR
σ
11
18.8
446
38.2
26.6
5.50
0.75
0.15
64.8
16.89
1.35
0.35
LS
σ
10
16.5
645
8.7
22.7
2.06
0.64
0.06
27.1
4.72
0.56
0.10
Investigation about the recharge sources of Pocemi springs be means of … 125
of two different waters is in general considered as an
indication of their possible similar origin (MAZOR, 1976).
The seasonal variations of the chemical composition of
five sampling points of Poçemi springs are relatively small,
this means that the water is well mixed into the aquifer
and a mean value could characterize these springs with a
very good statistical certainty. The chemical composition
of the local spring has small seasonal variations and clearly
differs from that of the Vjosa River, as well as of the
Poçemi springs. The Vjosa River has the biggest seasonal
variations; the standard deviation is usually more than two
times bigger than the analytical mistake of the
determination of different chemical elements. The mean
values of the chemical components could characterize
sufficiently also the Vjosa River.
Fig. 3. Variation in SO4 ion content of the Vjosa River, Poçemi
springs and a spring of local origin.
Particularly indicative are the seasonal variations of the
SO4 ion content in the observed water points, which are
shown on Figure 3. The SO4 content of the Vjosa River and
of the Poçemi springs is very similar, while the locally
recharged spring has lower content. The seasonal
fluctuations of the SO4 are bigger in the Vjosa River and
smaller in the local spring, while the Poçemi springs stay in
between (Fig. 4).
Fig. 4. Seasonal fluctuations vs. values of mean SO4 content for the
Vjosa River, Poçemi springs and of the local spring
From the above results, it is clear that the recharge of the
Poçemi springs is hardly of local origin. Most probably the
major part of the water issuing from the Poçemi springs
originates from another source with higher SO4 content.
This could be explained by seepage along the Vjosa River.
The proportion of the mixing of two different waters
could be determined comparing the amount of the so-called
conservative ions. A typical conservative ion is considered
Cl ion (SCHŒLLER, 1962) but SO4 is used too
(GUGLIELMI at al., 2000). In our case study the Cl ion can’t
be used as a specific tracer; its concentration in the Vjosa
River and in the Poçemi springs is nearly the same, but SO4
ion was successfully used.
In Table 2 the SO4 data used for the estimation of the
proportion of the mixing waters are shown. For Vjosa
River, it is calculated the weighted SO4 value, which
corresponds to the mean river level. Applying the input and
output functions the calculated portion of river water in
Poçemi springs resulted 77 % and the karst water of the
Kremenara basin consists 23 % of the recharge.
Table 2. Mean content and seasonal fluctuation of SO4 content
Sampling point
Mean content
mg/l
Seasonal fluctuation
mg/l
Vjosa River
64.75
46.10
Poçemi springs
53.75
21.13
Local spring
27.12
12.49
With the data of seasonal fluctuation of SO4, using the
hydraulic exponential model (MALOSZEWSKI and ZUBER,
1982) is calculated the mean residence time (To) of seeped
into limestone Vjosa Rivet water. The calculation formula is
the following:
To = (1/2π) * (1/f2 1)1/2
Where F= (SO4 output) / (SO4 input)
The calculated residence time resulted 0.31 years or
practically 120 days. For the mean distance between Vjosa
River and Poçemi springs of about 1500 m, the groundwater
flow velocity results 12 m/d, or 0.5 m/h.
Comparison of the hydrochemical and isotope data
The results of the hydrochemical investigations are in a
good agreement with the calculations made from the isotope
methods (AKITI et al., 1989). With the isotope methods it
is calculated that about 80 % of the water of the Poçemi
springs comes from the Vjosa River and about 20 % from
the karts water of Kremenara basin. Very indicative for the
relation of hydrochemical and of isotope methods of study
are the relations of the concentrations of the SO4 and of the
conductivity values with the O-18 concentration at the
investigated waters (Fig. 5 and 6). The relation between SO4
and O-18 is indirect; the Vjosa River has lower
concentration of O-18, but higher concentration of SO4 and
Investigation about the recharge sources of Pocemi springs be means of … 126
the local recharge has higher concentration of O-18 and
lower concentration of SO4. The O-18 and SO4 values of
the Poçemi springs stay in the mixing line of the Vjosa
River and the local recharge.
The relation between conductivity and O-18 is direct;
the Vjosa River has lower concentration of O-18 and lower
conductivity and the local recharge has higher
concentration of O-18 and higher conductivity. The O-18
and conductivity values of the Poçemi springs stay also in
the mixing line of the Vjosa River and the local recharge.
Using the conductivity data the contribution of the Vjosa
River to the recharge of the Poçemi springs would be about
95 %, which seems to be much exaggerated.
Fig. 5. Relationship between δ18O and sulfate concentration in
Vjosa River, Poçemi springs and a spring of local origin.
Fig. 6. Relationship between δ18O and electrical conductivity in
Vjosa River, Poçemi springs and a spring of local origin.
Observing the water level contours map of the right
bank of the Vjosa River (Fig. 6), where the river contact the
limestones, one could conclude that the river recharge the
Poçemi springs. The water flow from the river mixes with
the karst water of the Kremenara basin coming from the
north and east.
Conclusions
Environmental hydrochemical methods are used as an
independent method for the investigation of the origin of
the Poçemi springs in Albania. The sulfate ion was used as
a specific tracer. The Poçemi springs resulted to be
recharged by the Vjosa River at about 77 % and by the
karst water of Kremenara basin at about 23 %. The transit
time of the Vjosa River to the Poçemi springs is 120 days
and the groundwater flow velocity of the seeped Vjosa
River waters is 0.5 m/d.
Fig. 7. Skatch map of karstic flow pattern along the right bank of
the Vjosa River 1. Gravel; 2. Siltstone; 3. Carbonate rocks; 4.
Water level contours in m above sea level; 5. Karst water flow
direction; 6. Borehole; 7. Gallery; 8. Water level gouge; 9. Spring.
In parenthesis are given the water levels in m above sea level.
The results are in very good harmony with the
observations and calculations made from the
hydrogeological and environmental isotope methods (AKITI
at al., 1989) and (EFTIMI and DHAME (1990)
Reference
AKITI, T., EFTIMI, R., DHAME, L., ZOJER, H. and ZOETL, J.
1989: Environmental isotope study of the interconnection
between the Vjosa River and the Poçemi springs in Albania.
Memoirs of 22nd Congress of IAH, Vol. XXII: 452-458
DAME L., 1987: Karst and hydrotechnical construction Ph. Dr.
Thesis, Tirana.
GULIELMI, Y., BERTRAND, C., COMPAGNON, FOLLACCI, J. and
MUDRY, J., 2000: Acquisition of water chemistry in a mobile
fissure basement massif. Journal of Hydrology, 229: 138-148.
MALOSZEWSKI P. and ZUBER A., 1982: Determining the turnover
time of groundwater systems with the aid of environmental
tracers: Models and their applicability. Journal of Hydrology,
57: 207-231.
EFTIMI R. and DHAME L., 1990: About the origin of Poçemi
springs. Bul. Shkenc. Gjeol, 1: 121-133 (in Albanian).
MAZOR E. E., 1985; Tracing groundwater by chemical, isotopic
and physical parameters-Example: Schnzanach, Switzerland.
Journal of Hydrology, 76: 233-245.
LAKO A., 1971: Poçemi Springs, Tirana (in Albanian).
... The natural recharge is affected by many factors related to the land surface, surface water, soil zone, and unsaturated zone (Rushton and Ward 1979). Most widespread among recharge processes is the areal infiltration of precipitations directly to the carbonate rocks (autogenic, diffuse recharge), but the allogenic recharge from rivers or lakes water, or the inflows from shallow gravely aquifers of some karst aquifers of Albania, is present also (Eftimi and Dhame 2006;Eftimi et al. 2003Eftimi et al. , 2009a. ...
... The calculations based on the isotopic content (Akiti et al. 1989) indicate that Poçemi springs with 80% are recharged by the seepage of Vjosa River and with 20% by the Kremenara karst massif. Comparable results are obtained also based on SO 4 concentrations and on balance calculations (Eftimi and Dhame 2006;Eftimi et al. 2017). ...
... The natural recharge is affected by many factors related to the land surface, surface water, soil zone, and unsaturated zone (Rushton and Ward 1979). Most widespread among recharge processes is the areal infiltration of precipitations directly to the carbonate rocks (autogenic, diffuse recharge), but the allogenic recharge from rivers or lakes water, or the inflows from shallow gravely aquifers of some karst aquifers of Albania, is present also (Eftimi and Dhame 2006;Eftimi et al. 2003Eftimi et al. , 2009a. ...
... The calculations based on the isotopic content (Akiti et al. 1989) indicate that Poçemi springs with 80% are recharged by the seepage of Vjosa River and with 20% by the Kremenara karst massif. Comparable results are obtained also based on SO 4 concentrations and on balance calculations (Eftimi and Dhame 2006;Eftimi et al. 2017). ...
... The proportion of the mixing of two different waters could be determined comparing the amount of the so-called conservative ions. A typical conservative ion is considered Cl ion but SO 4 i o n is used also (Eftimi 2006). For the estimation of the mixing proportions contributing to Bistrica spring sulphate ion is used as a neutral ion. ...
Full-text available
Conference Paper
Bistrica spring is the source of Bistrica River and is the biggest spring of Albania. T hi s sp r i n g issues at the western side of Gjere Mountain karst massif; his mean discharge is 18.4 m 3 /s. In the eastern side the Gjere Mountain karst massif comes in contact with the abundant gravely basin of Drinos River. From the balance calculations results that only about 70 % of the groundwater resources of the massif could be recharged by the infiltration of the precipitation. Because Bistrica spring is located at elevation about 45 m lower than the mean elevation of gravely basin of Drinos River, it was supposed that the spring partially could be recharged by the gravely basin groundwater. A sampling program was applied during 1989-1990 with some additional sampling during 1996. There were analyzed the oxygen-18, deuterium as well as water chemical analyses were performed. The measurements were made at 6 springs in the karst area, at one borehole of Drinos River valley and at Drinos River. It was calculated that about 60-65 % of the water issuing from the Bistrica spring originate from the infiltrated precipitation in the karst massif and about 30-35 % represent the Drinos valley groundwater seepage into the massif. This result fit very well with the karst water balance study of the Gjere Mountain karst massif.
... The proportion of the mixing of two different waters could be determined comparing the amount of the so-called conservative ions. A typical conservative ion is considered Cl ion but SO 4 i o n is used also (Eftimi 2006). For the estimation of the mixing proportions contributing to Bistrica spring sulphate ion is used as a neutral ion. ...
Full-text available
Conference Paper
Bistrica spring is the source of Bistrica River and is the biggest spring of Albania. T hi s sp r i n g issues at the western side of Gjere Mountain karst massif; his mean discharge is 18.4 m 3 /s. In the eastern side the Gjere Mountain karst massif comes in contact with the abundant gravely basin of Drinos River. From the balance calculations results that only about 70 % of the groundwater resources of the massif could be recharged by the infiltration of the precipitation. Because Bistrica spring is located at elevation about 45 m lower than the mean elevation of gravely basin of Drinos River, it was supposed that the spring partially could be recharged by the gravely basin groundwater. A sampling program was applied during 1989-1990 with some additional sampling during 1996. There were analyzed the oxygen-18, deuterium as well as water chemical analyses were performed. The measurements were made at 6 springs in the karst area, at one borehole of Drinos River valley and at Drinos River. It was calculated that about 60-65 % of the water issuing from the Bistrica spring originate from the infiltrated precipitation in the karst massif and about 30-35 % represent the Drinos valley groundwater seepage into the massif. This result fit very well with the karst water balance study of the Gjere Mountain karst massif.
... An artificial tracer experiment carried out in 2002 physically demonstrated the underground connection between both lakes, and maximum karst underground flow velocity was about 700 to 2900 m/h (Amataj et al. 2005), which is much higher than reported velocities for other karst areas (Garašic 1997, Kogovšek et al. 1997. By a similar combined study it was established that the Poçem karst spring is replenished by the Vjosa River by about 80% (Akiti et al. 1989, Eftimi at al. 2006b). Through another environmental isotope and hydrochemical study it has been established that the Blue Eye Spring is replenished by the Drinos River gravelly aquifer (Fig. 6) by about 30 t0 35%, and the remaining quantity is replenished by the precipitation infiltrating into the Mali Gjere karst massif (Eftimi et al. 2007). ...
Full-text available
Article
This paper provides a comprehensive description of the hydrogeology of Albania based on the hydraulic type of the rocks. They result in porous aquifers, karstic and fissured aquifers, porous and fissured rocks with low productivity or rocks practically without groundwater. The porous aquifers are associated to gravelly deposits filling some plains of the Adriatic Basin, river valleys, as well as some intermoun-tain lowlands. For these aquifers the description includes their geometry , filtration parameters, well capacity, water quality, regimen and groundwater use. The water supply of Albania's largest cities is totally based on groundwater wells in porous aquifers. Karst aquifers crop out over an area of about 6,500 km 2. There are roughly 110 karst springs with average discharges exceeding 100 l/s. Of these, 17 have discharges exceeding 1,000 l/s. The average yearly discharge of the Blue Eye Spring, the biggest karst spring in Albania, is about 18.4 m 3 /s. The paper summarises the main characteristics of karst aquifers like the karst morphology, surface and underground network, effective infiltration, karst water quality, filtration parameters , application of trace methods of investigation, and vulnerability of karst water. Very important for the local water supply are the aquifers associated to some major basins filled with sedimentary molasses of different lithology, as well as the magmatic intrusive rocks. On both types of rocks the statistical treatment of short-term tests are used for char-acterising the aquifer filtration parameters and the capacity of wells. Shortly are described in the paper also the thermomineral waters of Albania and are assessed the total natural groundwater resources of the country separately calculated for the main aquifers. During the past decade, tourist expansion and population density have been particularly evident in Albania, and the problem of water availability has become the main obstacle to further development. Riassunto: L'Albania è situata nella parte orientale della Penisola Balcanica sulla costa est del mare Adriatico e Ionico. La superficie totale dell'Albania è 28.748 km 2 e la popolazione conta 3.2 milio-ni di abitanti. Questo lavoro dà una descrizione comprensiva della idrogeologia dell'Albania basata sulle caratteristiche idrauliche delle rocce. Queste si riscontrano negli acquiferi porosi, in quelli carsici e fessurati, nelle rocce porose e fessurate con una bassa produttività o in rocce praticamente prive di acque sotterranee. Gli acquiferi porosi sono associati ai depositi ghiaiosi che riempiono alcune pianure del Bacino Adriatico, le valli dei fiumi così come alcune pianure inter-montane; Il loro spessore massimo arriva a circa 300 m. Per questi acquiferi la loro caratteristica comprende la loro geometria, i parame-tri di infiltrazione, la potenzialità del pozzo, la qualità delle acque, il regime e l'uso delle acque sotterranee. Valori di trasmissività di oltre i 2000 m 2 /giorno riguardano ampie aree di acquiferi ghiaiosi e sono frequenti potenzialità dei pozzi di oltre 50 l/s. La chimica delle acque sotterranee indica con accuratezza le condizioni idrodinamiche gene-rali dell'acquifero ghiaioso. In alcuni di essi è ampiamente sviluppato anche il fenomeno del " naturale addolcimento delle acque sotterra-nee ". L'approvvigionamento idrico delle maggiori città dell'Albania è totalmente basato su pozzi di falde di acquiferi porosi. Gli acquiferi carsici affiorano su un area di circa 6.500 km 2. Ci sono approssimati-vamente 110 sorgenti carsiche con una portata media che supera i 100 l/s. Di queste, 17 hanno una portata che supera i 1000 l/s. La portata media annua della Sorgente Blue Eye, la più importatnte sorgente car-sica albanese, è circa 1,8 m 3 /s. L'articolo passa in rassegna le princi-pali caratteristiche degli acquiferi carsici come la morfologia carsica, la rete superficiale e sotterranea, l'infiltrazione efficace, la qualità del-le acque carsiche, i parametri di filtrazione, l'applicazione dei metodi di indagine con i traccianti, e la vulnerabilità delle acque carsiche. Le aree carsiche dell'Albania coincidono con le montagne più alte e la loro morfologia e particolarmente bella. La rete carsica viene controllata essenzialmente dalla realazione tra le aree di ricarica e quelle di deflusso e si sviluppano perfino perpendicolarmente ai piani di stratificazione. L'articolo mette in evidenza l'efficacia dell'applica-zione degli isotopi ambientali e dei metodi idrochimici con lo scopo di capire meglio i pattner relativi alla circolazione dell'acqua carsica come " pirateria di sottosuolo " o la valutazione delle fonti di ricarica. Molto indicative per la caratterizzazione della chimica delle sorgenti carsiche risulta il grafico di rCa/rMg rispetto a quello di rCa+rMg, così come il grafico di Sic e Sid. Molto importanti per la fornitura lo-cale di acqua sono gli acquiferi associati ad alcuni dei maggiori bacini riempiti da molasse sedimentarie di differenti litologie così come di rocce magmatiche intrusive. In entrambi i tipi di roccia i trattamenti statistici di tests a breve termine sono usati per la caratterizzazione dei parametri di filtrazione degli acquiferi e la potenzialità dei pozzi. Vengono descritte brevemente anche le acque termominerali dell'Al-bania e sono valutate le risorse naturali complessive delle acque sot-terranee del paese. Durante i dieci anni passati, l'espansione turistica e la densità della popolazione è diventata particolarmente evidente in Albania, e il problema della disponibilità delle acque è diventato il principale ostacolo ad un futuro sviluppo.
... Groundwater is saturated with calcite, which enables deposition of metals in the water due to their affinity with carbonates. Ions Cl and SO 4 are typical conservative ions (Eftimi 2006). Sulphate and chlorides concentrations are relatively low. ...
Full-text available
Article
Three karstic springs of the Gacka River were investigated: Tonkovića vrilo is included in the regional, and Klanac and Majerovo vrilo are included in the local water supply system. The purpose of the research was to investigate geochemical characteristics of the watershed with macroinvertebrate assemblages overview, type and water quality index (WQI) of the groundwater defining hydrochemical facies, presenting one of the most typical Dinaric karst areas in the world. Isotopic investigations were performed measuring the concentration of dissolved radon in the groundwater. The values ranged from 1.00 to 21.88 Bq L−1 which is much lower than the reference level between 100 and 1000 Bq L−1 set by the CD 2013/51/Euratom of 22 October 2013. According to the results of analyses of water from the investigated springs, only the values of microbiological indicators exceed the maximum allowed concentrations laid down by the Ordinance on compliance parameters and methods of analysis of water intended for human consumption [ Official Gazette No. 125 Croatian ordinance on compliance parameters and methods of analysis of water intended for human consumption (OG 125/2013), 2013]. WQI indicates an excellent water status. Hydrochemical facies belongs to the Ca–HCO3 type of water. The results show that the concentrations (mg kg−1, d.w.) of nickel (80.80) and TN (5900) in the sediment exceed values of the possible toxic effect, while the concentrations of molybdenum (max. 20.30) exceed the value for disposal of dredged sediments. Samples of benthic macroinvertebrates were collected with 38 taxa recorded, dominated by crustaceans and snails. According to investigations, anthropogenic activity still does not affect the quality of groundwater and spring sediments.
... and for dolomite (SId= -062). Comparing these values with values obtained for karst water of other areas, one could say that the referred spring waters are dominantly running over the limestone-dolomite bedrock (Petrik, 1969;Petrik, 1976;Filipović et all., 1991), as it is the case with water of karst springs of Albanian massifs (Eftimi & Dhame, 2006;Eftimi & Benderev, 2007;Eftimi, 2010). ...
Full-text available
Article
Key words: catchment area of the Upper Morača River, karst springs, water geochemistry, classification, purpose. SYNOPSIS The contents of spring waters of the referred catchment area was established for the first time during the low water level season, 2008. At the same time its classification was conducted, by means of establishing molar ratio Ca/Mg and other ionic types: SO 4 /Σ A , Cl/Σ A and SO 4 /Mg; % Mg in 0 dH, and on the basis of thermodynamic calculations: SIc and SId, in order to estimate their best purpose.
Full-text available
Article
oraz ich wykorzystanie. Albania jest położona w zachodniej części Półwyspu Bałkańskiego, na wschodnim wybrzeżu Morza Adriatyckiego i Jońs-kiego. Krajobrazy krasowe zajmują 24% powierzchni kraju. Odnawialne zasoby ogólne wód krasowych stanowią 80% wszystkich zasobów wód podziemnych Albanii. Około 70-80% ludności miast, łącznie ze stolicą Tiraną, oraz inne ważne miasta takie jak: Korcza, Pogradec, Berat, Vlora i Girokastra są zaopatrywane w wody krasowe. Zna-czna ilość wód krasowych jest także wykorzystywana do produkcji energii elektrycznej. Masowe wykorzystanie wód krasowych Albanii związane jest z ich szerokim rozprzestrzenieniem oraz bardzo dobrą jakością, jak również dominowaniem niedrogich grawitacyjnych systemów zaopatrzenia i względnie prostym magazynowaniem. Zrów-noważone wykorzystanie zasobów wód krasowych jest utrudnione ze względu na wysokie zróżnicowanie wodo-nośców krasowych w zakresie ich przepuszczalności hydraulicznej, prędkości ruchu wód, sposobów i wielkości zasilania oraz podatności na oddziaływanie człowieka. Эфтими Р., Андрейчук В., Щипек Т., Пухэйда В. Карстовые источники Албании и их использование. Албания расположена в западной части Балканского полуострова, на восточном побережье Адриатичес-кого и Ионического морей. Карстовые ландшафты занимают около 24% територии страны. Общие запасы возобновляющихся ресурсов карстовых вод составляют 80% всех запасов подземных вод Албании. Около 70-80% населения городов, включая столицу-Тирану, а также другие важные города такие как Корча, По-градец, Берат, Влора и Джирокастра водоснабжаются за счет карстовых вод. Значительные количества вод задействованы также в производстве электроэнергии. Массовое использование карстовых вод Албании свя-зано с их значительным количеством и преимущественно очень хорошим качеством, а также преоблада-нием недорогих гравитационных (самотечных) систем водоснабжения и относительно простым магазини-рованием. Стабильное использование ресурсов карстовых вод затрудняется высокой неоднородностью карстовых водоносных горизонтов в смысле типов и развитости их гидравлической проницаемости, ско-ростей течения, характера и объемов питания, качества карстовых вод, а также их высокой восприимчи-вости к воздействию человека. Keywords: karst morphology, karst springs, karst water quality, management of karst water, Albania. Słowa kluczowe: morfologia krasu, źródła krasowe, jakość wód krasowych, wykorzystanie wód krasowych, Albania Ключевые слова: морфология карста, карстовые источники, качество карстовых вод, использование карстовых вод, Албания 40 Abstract Albania is situated in the western part of Balkan Peninsula, on the eastern coast of the Adriatic and the Ionian Sea. The karst landscape in Albania covers nearly 24% of the countries territory. The total renewable karst water resources represent 80% of the groundwater resources of Albania. Nearly 70-80% of the population of the cities, including the capital Tirana, and other important are cities like Korça, Pogradec, Berat, Vlora and Gjirokastra are supplied by karst water; important resources are used for the production of the electricity, also. The massive use of karst waters in Albania is related to their abundant and mostly very good quality, as well as of the prevailing inexpensive gravity distribution systems and their relatively simple maintenance. The sustainable management of karst water resource is difficult due to the high heteroge-neity of karst aquifers in terms of type and development of hydraulic porosity, flow velocity, hydraulic head, recharge type and quantity, karst water quality, as well as to the high vulnerability to the human impact.
Full-text available
Article
Karst aquifers are characterized by high heterogeneity of groundwater flow. The classical study methods such as boreholes, pumping tests, and point observations give important data but cannot be extended to the entire aquifer. However the environmental hydrochemical and stabile isotope methods could give important information about large scale aquifer characterization. Some study examples from Albania, shown in this paper, demonstrate the successful application of the isotope methods, which are more powerful if applied in combination with hydrochemical ones, for the identification of the karst water recharge sources. Among the isotope methods the altitude effect seems to be more indicative for the solution of the problem concerned. For characterising the lithology of karst rocks and the physical aspects of karst aquifers (type of groundwater flow) the combined use of some hydrochemical parameters like the water conductivity, total hardness, ionic ratios rCa/ rMg, rSO4/r/mg, CO2 pressure and the indexes of calcite and (Sic) and of dolomite saturation (Sid), result very useful.
Full-text available
Article
Because a connection between Poçemi springs and Vjosa River in South Albania was suspected, the determination of the origin of Poçemi springs was of particular interest for the stability of a high dam proposed to be constructed on Vjosa River valley, about 1.5 km south to these springs. Independently, environmental hydrochemical and isotope tracers are successfully applied to investigate the possible connection between Poçemi Springs and Vjosa River. Sulphate ion (SO4--) was used as a specific tracer, but the conductivity resulted indicative, also. This was facilitated by the relatively high SO4-- concentration in Vjosa River, comparing to that of a local spring representing karst groundwater recharging water. The environmental isotope used to resolve the problem of connection between Vjosa River and Poçemi Springs are O18 and D. In this case it is supposed that Vjosa River water and the karst groundwater recharging water have different height and Poçemi Springs is expected to have an intermediate “height” in relation of the proportion of mixing recharge waters. Both applied methods, those of environmental hydrochemical and isotope conformed that about 80% of the water discharged by the Poçemi Springs is recharged from Vjosa River and about 20% is locally recharged. The gradient of the undground flow will become steeper by damming up the river level, open places for seepage will become multiplied and the sealing by a grouting curtain more difficult. As a result, the axes of the dam is relocated. This paper represents a slightly improved version of the above mentioned paper published in 1990. Për gjetjen e lidhjes së mundëshme ndërmjet Lumit Vjosa dhe Burimeve të Poçemit, të cilët ndodhen në pjesën jugore të Shqipërisë, u përdorën në mënyrë të pavarur metodat e gjyrmuesve mjedisorë hidrokimikë dhe izotopikë. Në përfundim doli se të dyja metodat e përdorura dhanë rezultate të përafërta: Burimet e Poçemit në rreth 80% të sasisë ushqehen nga Lumi Vjosa dhe në rreth 20% ushqehen nga ujërat karstike të massivit të Kremenarës. Si rezultat i këtij studimi, i cili plotësoi studimet shumë të detajuara gjeologo-inxhinierike të kryera nga Nd. Gjeologji-Gjeodezi e Tiranës, diga e lartë e planifikuar për tu ndërtuar në afërsi të burimeve të Poçemit u pezullua, për shkak të rrezikut të largimit të sasive të madhë të ujit nga liqeni ardhshëm drejt këtyre burimeve. Masat e mundëshme për të penguar filtrimin vlerësohen shumë të kushtueshme dhe s’kanë garanci të plotë, si frrjedhim aksi i digës së ardhëshme u çvendos drejt lindjes ku lugina e lumit Vjosa ndërtohet nga formacion flishore. Ky artikull është një përmirësim i artikullit të lartpërmendur publikuar më 1990.
Article
Dissolved ions, stable and radioactive isotopes, and physical data obtained from hydrologically related samples, may be processed as “anonym” and as “specific” tracers. Answers are obtained to questions pertaining to the number and proportions of inter-mixing water types, the properties of each end-member, its recharge altitude, depth of circulation, nature of the rocks passed and mode of flow. The methodology of the data processing is demonstrated on observations made over one year on a spring and a well at the spa of Schinznach, Switzerland. Two end-members are identified: (1) warm (39°C), saline (up to 85 meq l−1 total dissolved ions), circulating at a depth of over 640 m and passing through gypsum/anhydrite- and halite-bearing rocks; and (2) colder (21 ± 2°C), fresher (30 meq l−1 total dissolved ions), circulating at a depth of ∼ 240 m, passing through a sequence of gypsum/anhydrite-bearing carbonate rocks and flowing in a karstic mode. Both water types are recharged at an average altitude of 550 ± 100 m a.s.l., a value used in identifying the recharge area. The existence of a separate hotter water body at greater depth is possible.
Article
Groundwater flowpaths of the La Clapière landslide are studied by chemical and isotopic water analysis and modeling of the landslide springs. In our case, it appears that sulfate can be taken as a chemical tracer of the different flowpaths. On the gneissic slope of La Clapière, geochemical modeling explains sulfate concentrations from 0 to 130 mg/l by dissolution of sulfurous minerals present in the gneisses. Such a variability of the concentrations measured in the springs is due to different infiltration paths: direct paths through the basement or indirect path through superficial deposits like screes or fluvio-glacial terrains which cover the basement The high concentrations (600–800 mg/l) cannot be explained by thermodynamic geochemical simulations, and they reveal Triassic gypsum dissolution hidden under the studied slope. So, two main flowpaths are differentiated in the La Clapière landslide: (1) flow through low permeable Triassic deposits pinched under the foot of the landslide, (2) flow through a more permeable fissured basement with different flow paths; and, consequently, with different transit times due to the anisotropic nature of the top and the central part of the landslide.
Article
Three new lumped-parameter models have been developed for the interpretation of environmental radioisotope data in groundwater systems. Two of these models combine other simpler models, i.e. the piston flow model is combined either with the exponential model (exponential distribution of transit times) or with the linear model (linear distribution of transit times). The third model is based on a new solution to the dispersion equation which more adequately represents the real systems than the conventional solution generally applied so far.The applicability of models was tested by the reinterpretation of several known case studies (Modry Dul, Cheju Island, Rasche Spring and Grafendorf). It has been shown that two of these models, i.e. the exponential-piston flow model and the dispersive model give better fitting than other simpler models. Thus, the obtained values of turnover times are more reliable, whereas the additional fitting parameter gives some information about the structure of the system. In the examples considered, in spite of a lower number of fitting parameters, the new models gave practically the same fitting as the multiparameter finite state mixing-cell models.It has been shown that in the case of a constant tracer input a prior physical knowledge of the groundwater system is indispensable for determining the turnover time. The piston flow model commonly used for age determinations by the 14C method is an approximation applicable only in the cases of low dispersion.In some cases the stable-isotope method aids in the interpretation of systems containing mixed waters of different ages. However, when 14C method is used for mixed-water systems a serious mistake may arise by neglecting the different bicarbonate contents in particular water components.
Environmental isotope study of the interconnection between the Vjosa River and the Poçemi springs in Albania
  • T Akiti
  • R Eftimi
  • L Dhame
  • H Zojer
  • J Zoetl
AKITI, T., EFTIMI, R., DHAME, L., ZOJER, H. and ZOETL, J. 1989: Environmental isotope study of the interconnection between the Vjosa River and the Poçemi springs in Albania. Memoirs of 22 nd Congress of IAH, Vol. XXII: 452-458
Karst and hydrotechnical construction Ph
  • Dame L
DAME L., 1987: Karst and hydrotechnical construction Ph. Dr. Thesis, Tirana.