assessment of groundwater problems of the quaternary aquifer...
TRANSCRIPT
1
"Assessment of groundwater problems of the Quaternary aquifer in the area
between El Salhia El Gidida-Abu Sweir, East Nile Delta, Egypt"
فبراير ( 42-42)وشمال افريفيا المؤتمر العالمى الثانى للثروات الطبيعية فى الشرق األوسطمصر -جامعة القاهرة 4002
(V.II, P. 329-353)
Assessment of groundwater problems of the Quaternary aquifer in the area
between El Salhia El Gidida - Abu Sweir, East Nile Delta, Egypt
Dahab, K. A.*, El Abd, E. A.
**, Fattah, M. K.
* and El Osta, M. M.
**
* Minufiya University, Shebin El-Kom, Egypt & **Desert Research Center, Matarya, Cairo, Egypt
Emails: [email protected], [email protected] & [email protected]
ABSTRACT
The present study discusses groundwater problems of the Quaternary aquifer in the area
between El Salhia El Gidida-Abu Sweir, east Nile Delta, Egypt. To achieve the purposes of
the present work, the hydrogeological condition and groundwater quality of the Quaternary
aquifer will be considered. The Quaternary aquifer in the study area is a natural extension of
the Nile Delta aquifer. It is mainly composed of sand and sandstone with clay and shale
intercalation, which show appreciable increase toward east direction (Abu Sweir area).
Ismailia and El Salhia canals and their branches as well as excess irrigation water are the main
recharge resources of the Quaternary aquifer in the study area, while groundwater extraction
through productive wells represents the main discharge resources. The study showed that the
groundwater flow system has been changed and local groundwater flow directions were
occurred. Moreover, local closure depleted groundwater level areas were dedected under the
new reclaimed areas that located in the middle part. On the other side, water logging and soil
salinization problems were appeared at the new reclaimed areas that located northeast abu
Sweir. So, the majority of the new reclaimed areas occupying such localities were completely
destroyed.
Groundwater quality of the Quaternary aquifer has a wide range from fresh to brackish
water, which is unsuitable for different purposes at many localities. Groundwater pollution
was studied. The results showed that the groundwater of the Quaternary aquifer is highly
polluted with phosphate and nitrate, they cause sever environmental and healthic problems.
Groundwater vulnerability was also studied. The results showed that the middle and eastern
part of the study area have high vulnerability level (not protected areas) while the western and
southern parts have moderately vulnerability level (poorly protected areas).
1. Introduction
The area of study occupies a portion of the Desert belt of Egypt. Its climate is
characterized by a hot summer and a short rainy winter. The relative humidity is higher in
winter than in summer, while the evaporation intensity is generally higher in summer than
that in winter. The total annual rainfall intensity ranges between 4.2 to 37 mm/year at El
Salhia. The maximum and minimum values were recorded in March and September. The
investigated area is a portion from east of the Nile Delta province. It is located north Ismailia
canal and bounded by latitudes 30º 32′ and 30º 40′ N and longitudes 31º 50′ and 32º 12′ E,
2
with the total area of 510 km2
(Fig 1). The study area is one of the land reclamation projects in
which surface and groundwater were used. The agricultural activities in southern and northern
parts of the study area depend mainly up on surface water of Ismailia and El Salhia canals and
their branches while, the agricultural activities in the middle parts depend mainly up on
groundwater of the Quaternary aquifer. The uncontrolled use of the surface and groundwater
cause serious environmental problems, which include water logging, soil salinization and
change in groundwater quality.
The present work aims to evaluate the impact of agricultural and human activities on
groundwater levels and water quality of the Quaternary aquifer. To achieve this purpose, field
and laboratory measurements were carried out. Inventory of water levels, depth to water and
field observation of hazard areas were done during field trips of September 2005 and 2006.
Collecting of groundwater samples was also done. Detailed chemical analyses for measuring
major ions and some trace elements such as nitrate, phosphate, iron, manganese and zinc were
carried out. Chemical analyses were carried out in the laboratories of Desert Research Center
(DRC) and Minufiya University using atomic absorption, spectrophotometer and flame
photometer. The Data were presented using numerical and graphical methods.
2. Geologic Setting
Geology and hydrogeology of the eastern part of the Nile Delta including the study
area had attracted the attention of many authors. Among them are the works of Shukri and
Ayouty (1956), Said and Beheri (1961), Shata (1965), El Fayouny (1968), Shata and El
Fayoumy (1970), El Shazly et al. (1975), El-Dairy (1980), Hefny (1980), Sallouma (1983),
Moussa (1990), Korany et al (1993), Gad (1995) and El-Fakharany (2004). It is concluded
that the study area occupies a part of Belbies-El Tell El-Kabier-El Salhia old deltaic plain
(Fig. 2). It occupies the low relief areas lying to the east of the Nile Delta flood plain, and
extending to the Suez Canal district to the east, it is bounded from the south by Ankabia-
Iwaibid structural plain and G.Mokattam–Ataqa structural plateau and Lake El-Manzala and
lacustrine plain in the North.
Lithostratigraphyically, the area east of the Nile Delta is essentially occupied by a
sedimentary succession belonging to Tertiary and Quaternary rocks. Tertiary rocks are
exposed on the surface south of the study area (Fig. 3), they represented by Eocene,
Oligocene, Miocene and Pliocene rocks. Eocene rocks are formed of shallow marine
fossiliferous chalky, dolomitic sandy and marly limestones; it belongs to the Middle and
Upper Eocene. Oligocene rocks are exposed in the area between Cairo and Suez at Gebel
Umm El Ragm and Gebel Umm Qamar, they are formed of continental sands and gravels as
well as volcanic basalts with variable thickness ranging from 45 m at Gebel Iwiebid to 100 m
at Gebel El Nassuri area. Miocene rocks are represented by El Shatt Formation (south of the
Bitter lakes) and El Hommath Formation (west of the Gulf of Suez), they are composed of
sandy limestone and sandy marls of shallow marine origin. Pliocene rocks are exposed in the
area northwest of Cairo along the margins of the Heliopolis Basin. Quaternary rocks have a
wide distribution over the study area, they are represented by old deltaic deposits which are
composed of fluviatile coarse quartz sand, cherty flinty pebbles and igneous fragments with
few occasional fossil wood remains and young aeolian deposits composed of fine to coarse
quartz sand with remarkable variable thickness. In the subsurface, sedimentary succession is
also built of Tertiary and Quaternary rocks, Tertiary rocks include Miocene sandy limestone
water bearing formation and Pliocene shale and clay confined beds. The Quaternary
sediments represent the main water bearing formation in the study area; they are composed of
sand and sandstone with clay and shale intercalation.
3
Structurally, the sedimentary succession in the study area is strongly affected by
structural elements. Faults and folds are the most conspicuous structural elements affecting
the landscape in the study area. Faults are dominantly represented by NE-SW and NW-SE
normal faults with downthrown side toward northeast direction (Fig. 4). The vertical
displacement along these faults ranges from few meters to hundred meters northeast direction.
This led to increase the thickness of the Quaternary water bearing formation of 3 m/km
towards northeast direction (Gad, 1995). The relationships between subsurface lithological
rock units in the study area are shown in the subsurface geologic cross section A-A’ and BB’
(Fig. 5). They illustrate that the western and middle parts are strongly affected by deep-seated
normal faults. Saline water of Miocene aquifer moves upward along the fault planes (Gad,
1995). Surface folds are detected out the area of study at Gebel Shubrawit, Gebel Iwiebid and
Gebel Umm Ragm. In the subsurface, folds are detected by geophysical methods in the Abu
Hammad and Abu Sultan deep wells.
.
El Manzala Lake
Mediterranean Sea
Port Said
El Qantara
El Ismailia
BitterLakes
GulfofSuez
Bahr El B
aker D
rain
El Ism
ailia C
anal
Cairo -
El Ism
ailia D
eser
t Road
El S
hark
aw
iya C
an
al
Cairo 3000
3030
3100
3130
31 30 32 00 32 30
Dem
itta
Branch
0 10 20 30 Km.
ScaleArea of study
Fig. (1) Location map of the study area. Fig. (2) Geomorphological map of the eastern
part of Nile Delta (Compiled from different
authors)
Mediterrabean SeaEl M
anzala
Lake
El Ismailia
BitterLakes
Gulf of Suez
Legend: G. Mokattum - Ataqa structural plateau Coastal El Ankabia-Iweibid Structural plain plain Bitter lakes, Isthmus plain Belbies El Tell El Kabier El Salhia plain Wadi El Tumilat depression Nile Delta flood plain Lake El Manzala and lacustrine plain Desert dry drainage
0 25 50 Km.
Scale
3000
3030
3100
3130
32 3032 0031 3031 00
Studied area
4
Mediterrabean Sea
El M
anzala Lake
El Ismailia
BitterLakes
Port Said
Q Q
Tn Tn
Tn
TnTn Tn
Tn
Tn
Tn
ToTo To
To
To
ToTo
Te
Te
Te
Te
Te
TvTv
Tv
Tv
K
Te
Legend: Quaternary Surfacal deposits Unddifferentiated Neogene Sand dunes Extrusive rocks Sabkhas Oligocene Tertiary Unddifferentiated Cretaceous Eocene
Q
Te
Tn
TvTo
K
0 20 40 60Km
Scale
3000
3030
3100
3130
32 00 32 3031 3031 00
Studied area
31
30
El Mansoura
El Zagazig
0 5 10 15 km
Scale
31
00
30
30
30
00
323032003130
Legend: D
UFault line Syncline Anticline
Fig. (6): Compiled structural map of the studied area. (After El-Dairy, 1980)
Studied area
Fig. (3) Compiled geological map of the East
Nile Delta (After geological map of Egypt, 1971).
Fig. (4) Compiled structural map of the East
Nile Delta (After El-Dairy, 1980).
5
40 m
Sea level
-40
-80
-120
-160
-200
0 1 2 km
H.Scale
Legend: Sand
Sand & Gravel
Sandy clay
Clay
Limestone1 5 10 km
Scale
C
C'
Ismailia Canal
3020
3030
32153145
OB
1
PW
5
PW
3 OB8 OB2
Ism
ail
ia
Can
alC
N
C'S
B B'
-80
-40
40
-120
160
200
-240
OB
7
E4
OB
1BW
B'E
0 1 2km
H.Scale
0Sealevel
0
Fig. (5) Geological cross sections B-B
- & C-C
- in El Salhia
El Gidida–Abu Sweir area (after Gad, 1995).
3. Hydrogeologic Setting
The Quaternary water bearing formation constitutes the main source of groundwater in
the study area. It is mainly composed of sand and gravels intercalated with clay and shale
lenses. They rest directly on Pliocene clay and Miocene sandy limestone (Fig. 6). The
thickness of Quaternary aquifer is strongly affected by normal faults with downthrown sides
towards the northeast, this increases the thickness toward north and northeast, it ranges from
300 m to 400 m in the study area while it reaches more than 900 m near the Mediterranean
Sea (Fig. 7). The Quaternary aquifer is hydraulically connected with the underlain Miocene
saline water aquifer through deep-seated normal faults (Gad, 1995). Groundwater of the
Quaternary aquifer occurs under free water condition. Semiconfined and confined conditions
were occurred at the eastern and northeastern parts (East Abu Sweir area), this is attributed to
the increase of shale and clay interecalation cap beds under such localities (Fig. 6).
Depths to water and groundwater levels were measured of forty-eight drilled wells
tapping the Quaternary aquifer at different depths (Table 1 and Fig. 8). Depth to water shows
wide range. It depends mainly up on the topography of the ground surface, it shows relatively
large values at the western and middle parts of the study area ranging from 20 to 34 m while it
shows small values at the low topography areas ranging from 6 to 2 m, it reaches less than
one meter at some areas that located northeast Abu Sweir (Fig. 9). Moreover, groundwater
occurs on the surface at some localities.
6
W61
E4W79W78W10040
20
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
-200
SeaLevel
D m
W
D'
E
Miocene aquifer Quaternary aquifer
Legend: Sand Sand & gravel Sandy clay Clay Limestone Water level
1 2 3 4 km
H. Scale
10078
79E4
61
D'D
Ismailia Canal
32 0031 45 32 15
3035
3030
3025
3020
0 10 km
ScaleKey Map
Fault
Ground surface
Fig. (6) Hydrogeological cross section D – D
- existing in E – W direction
(after Gad, 1995).
3000
3030
3100
3130
31 00 31 30 32 00 32 30
Cairo
100
200
300
400
500
600
700 800
900
San El Hagar
Port Said
El Qantara
El Ismailia
El Suez
Abu SultanBitter lake
E5
P4E1
E7E6
Stndbis
Abu Hammad
Abu KabierSalhiya
Mediterrabean Sea
20 0 20km
Scale
Studied area
Fig. (7) Quaternary aquifer thickness contour map of the East Nile
Delta (after Hefny, 1980).
Table (1) Hydrogeological data of the wells tapping the Quaternary aquifer (September,2006).
7
Well
N0.
Ground
Elevation
(m)
Total
Depth
(m)
Depth to
Water
(m)
Water level
(m)
+msl
Well
N0.
Ground
Elevation
(m)
Total
Depth
(m)
Depth to
Water
(m)
Water level
(m)
+msl
1* 16 25 9 7 25 35 120 28.5 6.5
2 13 58 5.75 7.25 26 34 150 28 6
3* 10 31 1.75 8.25 27 26.5 90 20 6.5
4* 5 32 0.5 4.5 28 28 65 21.5 6.5
5* 7 30 1.5 5.5 29 22 60 15 7
6* 7.5 29 1.5 6 30* 19 45 12 7
7* 7.3 36 1 6.3 31 26.5 60 20 6.5
8* 13 30 6.5 6.5 32 38 72 31.5 6.5
9 23 75 17 6 33 33 75 25 8
10* 19.75 51 14 5.75 34 35 75 27 8
11* 10.5 35 5 5.5 35 41 80 33.5 7.5
12 18.75 55 13 5.75 36 41 72 34 7
13* 10 21 4 6 37 42 90 33.5 8.5
14* 13 50 6.5 6.5 38 38.5 85 32.5 6
15* 12 13 5.3 6.7 39 26 60 19.5 6.5
16* 14 40 8 6 40 28 65 21 7
17* 14 30 7.75 6.25 41* 22.5 20 15 7.5
18* 17 42 10.25 6.75 42 21 60 12.5 8.5
19* 10.5 13 2 8.5 43 25 60 17 8
20* 23 36 16 7 44 41 75 33.5 7.5
21* 16.5 35 9 7.5 45 40 70 32.75 7.25
22* 15.5 42 8 7.5 46 40 65 32.75 7.25
23* 15 18 7 8 47 37 80 29.5 7.5
24* 16 46 9 7 48 40 82 32 8
* Shallow depths wells (<50 m).
2
9 12
2526
27
28
29
31
3233
34 35
36
37
38
39
4042
43
44
4546
47
48
1
3
4
567
8
11
13
141516
1718
19
20
212223
24
30
41
10
El Salhia El Gidida
El QassasinAbu Sweir
El Ismailiacanal
El Salhia Canal
0 2 4 6
Scale
El Q
antara
Cai
ro
El Zagazig
31 50 32 00 32 10
3035
3040
14 Well number Shallow well Irrigation canals Main roads
16 15
14
910
Deep well
El Kassara Canal
Fig. (8) Well location map of El Salhia El Gidida–Abu Sweir area, east Nile Delta, Egypt.
Groundwater levels and recharge resources were also discussed, Ismailia and El
Kassara canals and their branches as well as excess irrigation water represent the main
8
recharge resources of the Quaternary aquifer in the study area. The absolute groundwater
levels range from +9 (amsl) in the south (close Ismailia canal) and +8 (amsl) in the north
(close El-Kassara canal), while it ranges from +5 m to + 4 m (amsl) in the middle and eastern
parts of the study area (Fig. 10). The comparison between the groundwater flow map of
Sepmtamber- 2006 with that constructed by Sallouma (1983) and Gad (1995) (Figs. 11 & 12)
showed that the groundwater flow system had been changed and many local groundwater
flow direction were occurred. Moreover, many local closure depleted groundwater level areas
were detected under the new reclaimed areas that located in the middle parts; this is attributed
to the intensive groundwater extraction for agricultural activities in such parts. On the other
hand, there are increasing in groundwater levels under the reclaimed areas located close
Ismailia canal in the south and El-Kassara canal in the north, it ranges from 3 m to 4 m. this is
also attributed to lateral seepage from surface water and vertical downward of excess
irrigation water.
El QassasinAbu Sweir
El Ismailiacanal
El Kassara Canal
0 2 4 6
Scale
El Q
antara
Cai
ro
El Zagazig
31 50 32 00 32 10
3035
3040
Irrigation canals Main roads10 Contour line (m)
El Salhia
El Gidida
El Salhia Canal
Fig. (9) Depth to water contour map of the Quaternary aquifer in El Salhia
El Gidida–Abu Sweir area, east Nile Delta, Egypt (September, 2006).
El Qassasin Abu
SweirEl Ismailiacanal
El Kassara canal
Cair
o -
El
Ism
ail
ia R
oad
waterlogging
0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canals Main roads8 Flow directionContour line (m)
El Salhia Canal
Fig. (10) Water levels and flow net map of the Quaternary aquifer in El Salhia El
Gidida–Abu Sweir area, east Nile Delta, Egypt (September, 2006).
(2(September, 2006).
9
1
2
3
4
5
6
7
76
3
4
58
899
1011
121314
1516
Mideterranean
SeaEl M
anzala
Lake
El Ismailia
Cairo
1
2
3030
3100
3100
3000
31 30 32 00
31 30 32 00
3030
3100
3100
3000
Legend: Contour line (m) Flow direction Studied area
Dem
itta
bran
ch
records of 1975
0 20km Scale
4
Fig. (11) Water level contour map and flow net of the Quaternary
aquifer direction in the East Nile Delta (after Sallouma, 1983).
Ismailia canal
El Ismailia
Suez fresh water canal
El Manaiel canal
Great Bitter lake
31 45 32 00 32 15
30 35
30 30
30 25
30 20
31 45 32 00
30 35
30 30
30 25
30 20
32 15
4
5
5
67
89
98
7
7
65
4
45
6
7
810th of Ramagancity
0 5 10 km
Scale
Contour line (m) Irrigation canals Flow direction
Legend:
5
Studied area
Fig. (12) Water level contour map and flow net of the Quaternary aquifer, east Nile
Delta, Egypt (After Gad, 1995).
4.Water Logging Problem
11
Water logging and water ponding represent serious environmental problems under the
new reclaimed areas that located northeast Abu Swier area (Izbet Abazzah, Izbet El-Karamat
and Izbet El-Arab) (Figs. 13). The land surface slopes towards these localities (Fig. 14)
where, ground surface elevation reaches less than +10 m under such localities while it ranges
from +20 to +15 m (amsl) at the surrounding areas (Fig. 13). So, these areas receive the
excess irrigation water and groundwater seepage from the western and northern parts (Fig. 9
& 10). Moreover, the lack of advanced drainage system, use of traditional irrigation system
and the presence of shale and clay confining beds at shallow depths under such localities (Fig.
14) led to raising the water table under such localities and groundwater occurs on the surface
at some localities forming what is called water logging and water ponding. So, the majority of
the new reclaimed areas that located northeast Abu Sweir district will completely destroyed.
< 10 m +msl(Water logging)
Water pond
10 - 15 m +msl
15 - 20 m +msl
20 - 25 m +msl
25 - 30 m +msl
30 - 40 m +msl
> 40 m +msl
El Kassara Canal
El Salhia El Gidida
El Qassasin Abu Sweir
El Ismailia canal0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canalsMain roads
Legend:
El Salhia Canal
Fig. (13) Orographic map of El Salhia El Gidida – Abu Sweir
area, east Nile Delta, Egypt (September, 2006).
0
10
10-
20-
30-
m Well No. 8
Well No. 7
El Salhia Canal
IsmailiaCanal
AbuSuwayr
0 2 4 6
Scale
32 00 32 10
3035
3040
87
65
4
Iz-Abazah
Iz-Al-Arab
E
E'
Legend:
Sand Water level
Flow direction 4Clay Well location & No.
EE'
Water pondWater logging
Well No. 6Well No. 4
Well No. 5
Sealevel
Fig. (14) Hydrogeological cross section E – E
- northeast Abu Sweir area, east Nile
Delta, Egypt (September, 2006).
5. Hydrochemical Aspects
11
Hydrogeochemical characteristics of the Quaternary aquifer in the study area are
discussed through the chemical analysis of forty-eight groundwater samples collected during
September 2006 (Fig. 8 and Table 2). The chemical analyses deals with the determination of
major cations (Na+, K
+, Ca
++ and Mg
++) and anions (CO3
--, HCO3
-, SO4
-- and Cl
-) in addition
to some minor and trace elements (PO4, NO3, Fe, Mn and Zn). The analytical data were
interpreted using numerical and graphical methods.
5.1 Salinity distribution (TDS)
Groundwater quality of the Quaternary aquifer has wide range from fresh to brackish
water (Chebotarev 1955) where, salinity content ranges from 447.6 mg/l (well No. 19) close
irrigation canals to 7043.4 mg/l in the middle part of the study area (well No. 47). The salinity
distribution maps of the shallow and deep wells were constructed (Fig.16 and 17). The
salinity distribution maps of the shallow wells (Fig.15) shows relatively low salinity contents
at areas close El Ismailia and El Kassara canals and their branches (well Nos. 3, 19 & 41),
salinity contents range from 447.56 mg/l to 3728.84 mg/l. Low salinity contents (447.56 to
870.43 mg/l) (Table 2) recorded near the irrigation canals suggest recharge from the surface
water while high Salinity content (1236.3 to 3728.84 mg/l) (Table 2) recorded at the eastern
parts is attributed to downward seepage of excess irrigation water and lack of drainage system
as well as leaching processes of clay and lagoonal deposits dominating at the shallow depths.
Salinity contents of deep wells range from 664.7 mg/l to 7043.36 mg/l (Table.2)
Relatively high salinity contents (from 1106.77 to 7043.36 mg/l) recorded at the reclaimed
areas that located in the middle part of the study area and the appearance of high salinity
closure areas is attributed to over pumping of groundwater for agricultural activities and
probable mixing of deep saline water of Miocene aquifer along fault planes.
The comparison of salinity values of some wells for September 2006 and those values
of August 2005 indicates that there is considerable increase of water salinity contents for all
wells under comparison ranging from 15 mg/l (well No. 11) to 262.5 mg/l (well No. 28) (Fig.
17). This needs a proper management for groundwater of Quaternary aquifer to minimize
more deterioration of groundwater quality in the future.
Table (2) The results of chemical analyses of the investigated groundwater samples in El Salhia El
Gidida - Abu Sweir area (September 2006).
12
Well
No.
pH Ec
µmhos
/cm
TDS
mg/l
Cations (mg/l) Anions (mg/l) Minor & trace elements (mg/l)
Ca++
Mg++
Na+ K
+ HCO3
- SO4
-- Cl
- Fe Mn Zn PO4 NO3
1* 8.4 2650 1801.11 44 2.43 630 8 346.5 300 643.4 0.04 0.01 0.11 30 80
2 8.03 4140 2519.04 116 34.3 750 10 378 620 800 0.02 0.01 0.10 25 65
3* 8.18 1020 639.22 104 41.3 70 4 378 135 95.87 0.02 0.01 0.10 22 68
4* 8.03 1490 870.43 16 2.43 315 3 378 160 185 0.02 0.01 0.10 27 40
5* 8.25 2350 1568.75 16 24.3 545 4 409.4 220 554.6 0.04 0.01 0.10 23 8
6* 8.20 4210 2654.15 68 12.1 900 5 378 600 880 0.01 0.02 0.10 22 60
7* 8.43 3980 2511.42 50 20.6 860 6 409.5 500 870 0.01 0.01 0.11 39 62
8* 8.72 2540 1628.94 40 24.3 530 3 299.2 385 497 0.01 0.01 0.20 24 120
9 7.75 3370 1987.45 88 19.4 650 5 472.5 190 798.7 0.01 0.01 0.20 23 65
10* 7.85 4250 2619.84 116 41.3 800 5 409.5 512 940.7 0.53 0.02 0.50 111 61
11* 7.85 4010 2481.53 84 12.1 820 8 409.5 545 807.6 0.04 0.01 0.30 27 63
12 8.08 1950 1221.72 24 9.72 420 5 378 290 284 0.3 0.01 0.10 20 7
13* 7.75 2000 1236.30 116 29.1 300 5 472.5 158 291.8 0.24 0.01 0.10 42 60
14* 8.21 2260 1400.92 108 31.6 360 8 315 300 435.8 0.04 0.01 0.10 41 63
15* 7.95 1210 714.38 80 21.8 150 6 283.6 155 159.75 0.05 0.02 0.10 17 42
16* 8.15 1310 809.42 92 4.86 200 6 346.5 178 155.31 0.03 0.01 0.10 30 52
17* 7.95 5840 3728.84 136 41.3 1150 4 315 1100 1140 0.03 0.03 0.10 48 64
18* 7.72 5050 3007.47 140 36.4 920 6 350 600 1130 0.03 0.02 0.11 63 135
19* 8.12 780 447.56 64 24.3 70 6 346.5 60 50 0.03 0.02 0.12 31 13
20* 8.42 2650 1696.03 68 12.1 535 3 315 450 470.4 0.03 0.01 0.11 19 48
21* 8.03 3470 2243.98 74 31.6 700 4 200 580 754.3 0.01 0.01 0.10 49 32
22* 8.02 3670 2294.14 72 19.4 750 3 315 560 372.1 0.06 0.02 0.11 41 42
23* 7.9 4521 2909.18 116 26.7 890 3 236.2 890 865.3 0.04 0.02 0.10 39 60
24* 8.05 3870 2459.72 80 12.1 800 5 252 660 776.5 0.04 0.02 0.20 23 44
25 7.88 1960 1266.34 64 14.5 390 7 472.5 235 319.5 0.03 0.03 0.20 23 9
26 7.9 2200 1346.78 64 12.1 430 10 472.5 195 399.3 0.06 0.01 0.40 38 8.8
27 8.01 1530 950.11 44 4.86 310 6 378 130 266.25 0.03 0.01 0.35 38 12.5
28 8.12 4810 3080.41 184 65.6 850 9 283.6 640 1190 0.03 0.01 0.11 42 63
29 7.95 4250 2587.39 92 43.7 805 4 315 500 985.12 0.01 0.01 0.11 24 70
30* 8.54 2760 1739.29 64 7.29 570 4 252 400 568 0.02 0.01 0.10 28 61
31 8.68 2310 1436.57 48 21.8 455 4 283.5 300 465.93 0.06 0.02 0.10 32 44
32 8.7 1000 664.70 92 19.4 123 7 220.5 100 213 0.02 0.01 0.11 30 18
33 8.8 2160 1326.80 160 29.1 285 8 283.5 197 505.87 0.05 0.04 0.40 30 21
34 8.72 2780 1719.93 172 55.9 370 9 283.5 350 621.25 0.02 0.03 0.70 37 51
35 8.05 3870 2284.95 280 99.7 400 12 315 395 940.75 0.08 0.95 1.10 33 62
36 8.45 1610 1063.76 88 21.8 260 5 315 345 186.37 0.01 0.01 0.11 32 58
37 8.5 5200 3557.78 184 89.9 970 12 441 945.3 1136 0.02 0.26 0.11 23 62
38 8.51 1810 1106.77 104 7.29 300 4 393.7 210.6 384 0.01 0.02 0.20 26 63
39 8.66 2060 1344.13 112 19.4 365 5 409.5 220.8 417.12 0.02 0.02 0.21 28 45
40 8.56 2090 1350.27 56 17.0 430 4 441 250 372.75 0.03 0.01 0.20 23 30
41* 8.55 1030 668.47 32 12.1 200 3 252 140 155.31 0.02 0.03 0.21 17 28
42 8.67 2360 1454.27 56 17.0 460 4 378 320 408.25 0.04 0.01 0.20 3 62
43 8.75 2224 1469.62 64 21.8 450 4 315 306.3 465.93 0.04 0.03 0.20 18 59.5
44 8.69 5810 3740.08 336 97.2 850 17 378 1030.5 1220.3 0.02 0.03 0.23 - 61
45 8.64 3760 2389.86 160 58.3 605 18 157.5 600 869.75 0.03 0.12 0.20 23 39
46 8.35 3580 2194.58 108 46.2 630 5 189 450 860.87 0.04 0.09 0.20 19 60
47 8.74 10920 7043.36 620 85.1 1800 9 157.5 1550 2900.5 0.02 0.04 0.20 19 60.8
48 8.08 4330 2872.97 128 63.2 800 9 220.5 875 887.50 0.03 0.03 0.21 - 58
CO3-- concentration equal zero in all samples (-) not measured (*) Shallow wells
13
El Salhia El Gidida
El Qassasin Abu Sweir
El Ismailiacanal
El Kassara Canal
0 2 4 6
Scale
El Q
antara
Cai
ro
El Zagazig
31 50 32 00 32 10
3035
3040
Salinity contour line in (mg/l) Well location
Irrigation canals Main roads500
El Salhia Canal
Fig. (15) Iso – salinity contour map of shallow wells in El Salhia El Gidida-
Abu Sweir area, east Nile Delta, Egypt (September 2006).
El Salhia El Gidida
El Qassasin Abu Sweir
El Ismailiacanal
El Kassara Canal
0 2 4 6
Scale
El Q
antara
Cai
ro
El Zagazig
31 50 32 00 32 10
3035
3040
Salinity contour line in (mg/l) Well location
Irrigation canals Main roads500
El Salhia Canal
Fig. (16) Iso – salinity contour map of deep wells in El Salhia El Gidida -
Abu Sweir area, east Nile Delta, Egypt (September 2006).
Sali
nit
y (
TD
S)
in m
g/l
1 9 11 13 27 28 30 33 45
Well No.
TDS in 9/2006TDS in 8/2005
Legend:
3000
2500
2000
1500
1000
500
Fig. (17) Hydrograph showing the change in salinity contents with time
Salhia El Gidida - Abu Sweir area, east Nile Delta, Egypt
14
5.2 Major ions distribution
Regarding major cations, sodium is mostly predominant cation followed by calcium
and magnesium. Sodium concentration ranges from 70 mg/l (well No. 3) to 1800 mg/l (well
No. 47). High sodium concentration is possibly due to leaching processes of clay and shale
present in aquifer materials. Calcium concentration ranges from 16 mg/l (well No. 4) to 620
mg/l (well No. 7). Magnesium concentration ranges from 2.43 mg/l (well No. 1) to 99.7 mg//
(well No. 35). Concerning major anions, sulphate and chloride are mostly predominantly over
bicarbonate. Sulphate concentration ranges from 60 mg/l (well No. 19) to 1550 mg/l (well
No. 47). High sulphate concentration reflects dissolution of terrestrial deposits of gypsiferous
shale and gypsum in the aquifer materials. Chloride concentration ranges between 50 mg/l
(well No. 19) and 2900.5 mg/l (well No. 47). High values of Cl- content is mainly attributed
to dissolution of chloride–bearing deposits evaporates and clay minerals within the aquifer
materials. Bicarbonate concentration ranges between 157.5 mg/l (well No. 45) and 472.5 mg/l
(well No. 45).
The relation between salinity (TDS) and major ions were statistically illustrated (Fig.
18). This diagram shows correlation between salinity contents and concentration of ions of
groundwater of the Quaternary aquifer. Sodium, sulphate and chloride show high correlation
coefficients (R2) with salinity contents, the values of correlation coefficients (R
2) of these ions
are 0.8966, 0.8939 and 0.9464 respectively, this indicates that, the factors, which govern the
distribution of salinity in the different localities, are the same factors controlling the
distribution of sodium, sulphate and chloride. The factors controlling the distribution of such
elements include upward leakage of of Miocene saline water and leaching processes of clay
and lagonaal deposits present in aquifer materials. On the other hand, calcium and magnesium
show low correlation coefficient (R2) with salinity compared with that of sodium, sulphate
and chloride, it is 0.2864 and 0.2564 respectively. Bicarbonate shows no correlation with
salinity, it displays correlation coefficient (R2) 0.0501.
5.3 Groundwater Origin
The hydrochemical coefficients are used as a tool for detecting the origin of
groundwater and helped in discovering the previous hydrochemical processes affecting water
quality such as leaching, mixing and ion exchange. The hydrochemical coefficient rNa/rCl,
rSO4/rCl, rCa/rMg and (rCl-rNa)/rCl were calculated (Table 3). The value of rNa/rCl for the
analyzed groundwater samples ranges between 0.667 and 2.64. This values indicates
predominance of sodium over chloride in all groundwater samples except for well Nos. 32,
33, 34 and 47 in the western part, this reflect the effect of upward leakage of Miocene
groundwater in this locality. The increase in the concentration of Na+ ion than Cl
- in the other
parts of the area is mainly attributed to the evaporate salts which are considered the main
source of sodium ion in groundwater of Quaternary aquifer. The value of hydrochemical
coefficient rSO4/rCl ranges between 0.175 and 1.366. High value of this coefficient is mainly
due to the dissolution processes of local terrestrial sulphate minerals present in aquifer
materials. The hydrochemical coefficient rCa/rMg shows also high values varying from 0.399
to 10.97, which is more, related to rainwater value (3.08) than normal sea water (0.21). The
high values of this coefficient may indicate evaporites dissolution (gypsum and anhydrite) or
ion exchange. This could be attributed to the composition of the Quaternary aquifer, which is
essentially made up of clayey sandy and lagoonal facies. The value of (rCl-rNa)/rCl
coefficient is always negative in most the studied groundwater samples which indicates an
active ion exchange process. The only exception positive value is recorded in well Nos. 32,
33, 34, 35 & 47 at the western part due to the effect of upward leakage of Miocene aquifer.
Finally, these coefficients confirm the meteoric water origin and geochemical processes as
well as the recharging from surface water canals and the upward leakage from the Miocene
aquifer to groundwater of the Quaternary aquifer in the study area. More confirmation of this
15
concept is the occurrence of NaCl, Na2SO4, Na HCO3, Ca(HCO3)2, Mg(HCO3)2, MgSO4,
CaSO4, and MgCl2 in groundwater (Table 3). The presence of marine
0 2000 4000 6000 80000
50
100
150
200
250
300
350
400
450
500
550
600
650
TDS Vs Ca
Ca
(m
g/l
)
TDS (mg/l)
R = 0.28642
0 2000 4000 6000 8000
150
200
250
300
350
400
450
500
HC
O3
(m
g/l
)
TDS (mg/l)
TDS Vs HCO3
R = 0.05012
0 2000 4000 6000 8000
0
10
20
30
40
50
60
70
80
90
100
Mg
(m
g/l
)
TDS (mg/l)
TDS Vs Mg
R = 0.25642
0 2000 4000 6000 8000
0
250
500
750
1000
1250
1500
SO
4 (
mg
/l)
TDS (mg/l)
TDS Vs SO4
R = 0.89392
0 2000 4000 6000 8000
0
250
500
750
1000
1250
1500
1750
2000
Na
(m
g/l
)
TDS (mg/l)
TDS Vs Na
R = 0.89662
0 2000 4000 6000 8000
0
500
1000
1500
2000
2500
3000
Cl
(mg
/l)
TDS (mg/l)
TDS Vs Cl
R = 0.94642
Fig. (18) Salinity – major ions relationship in the groundwater of the Quaternary aquifer
in El Salhia El Gidida - Abu Sweir area.
16
salts of MgSO4, CaSO4 and MgCl2 is mainly due to the dissolution of these salts encountered
in the Quaternary water bearing sediments, return flow of irrigation water and salt water
encroachment as a result of over pumping specially at the western portion.
Table (3) Hydrochemical parameters of the investigated groundwater samples in El Salhia El
Gidida-Abu Sweir area (September 2006).
Well
No.
SAR
Ion ratio Hypothetical salts
Na/Cl SO4/Cl Ca/Mg Cl-Na/Cl NaCl Na2SO4 NaHCO3 MgCl2 MgSO4 Mg(HCO3)2 CaSO4 Ca(HCO3)2
1* 25.02 1.52 0.34 10.9 -0.52 60.3 20.81 11.09 0 0 0.67 0 7.32
2 15.73 1.45 0.57 2.06 -0.46 54.15 25.13 0 0 5.85 0.9 0 13.95
3* 1.46 1.16 1.03 1.52 -0.16 23.09 3.72 0 0 20.28 8.69 0 44.22
4* 19.38 2.64 0.63 3.99 -1.64 35.38 22.59 35.27 0 0 1.35 0 5.41
5* 20.03 1.52 0.29 0.39 -0.52 58.08 17.01 14.39 0 0 7.52 0 3
6* 26.40 1.58 0.50 3.39 -0.58 57.04 28.71 4.19 0 0 2.29 0 7.77
7* 25.81 1.53 0.42 1.46 -0.53 58.9 24.99 9.06 0 0 4.07 0 5.98
8* 16.30 1.64 0.57 0.99 -0.64 52.03 29.76 3.47 0 0 7.38 0 7.36
9 16.32 1.26 0.17 2.74 -0.26 65.81 11.36 5.4 0 0 4.65 0 12.77
10* 16.22 1.31 0.40 1.70 -0.31 60.43 18.73 0 0 5.55 2.16 0 13.13
11* 22.12 1.57 0.49 4.19 -0.57 55.78 27.79 3.79 0 0 2.44 0 10.21
12 18.27 2.29 0.75 1.49 -1.29 39.57 29.83 20.8 0 0 3.92 0 5.87
13* 6.44 1.60 0.65 2.41 -0.60 38.65 23.11 0 0 2.05 9.19 0 27.1
14* 7.83 1.29 0.51 2.07 -0.29 51.86 14.64 0 0 14.78 10.9 0.82 21.79
15* 3.83 1.48 0.71 2.21 -0.48 36.39 17.15 0 0 8.92 5.52 0 32.02
16* 5.50 2.02 0.84 11.4 -1.02 31.82 26.92 5.2 0 0 2.89 0 33.17
17* 22.15 1.55 0.71 1.99 -0.55 53.39 8.33 0 0 5.64 0 2.69 8.57
18* 17.90 1.26 0.39 2.32 -0.26 63.61 16.47 0 0 5.98 0 2.49 11.45
19* 1.88 2.26 0.88 1.59 -1.26 16.91 14.98 6.21 0 0 23.84 0 38.06
20* 15.69 1.75 0.71 3.39 -0.76 47.72 33.71 2.73 0 0 3.61 0 12.24
21* 17.15 1.43 0.57 1.42 -0.43 58.08 24.08 0 0 7.06 0 1.08 8.95
22* 20.23 1.58 0.58 2.24 -0.58 55.1 31.12 0.07 0 0 4.22 0 8.48
23* 19.36 1.59 0.75 2.63 -0.59 52.14 30.78 0 0 4.7 4.11 0 8.27
24* 22.01 1.59 0.63 3.99 -0.59 55.06 32.43 0 0 2.12 0.39 0 10
25 11.44 1.90 0.54 2.66 -0.90 41.62 22.6 15.37 0 0 5.57 0 14.83
26 12.91 1.68 0.36 3.19 -0.68 48.83 17.6 15.45 0 0 4.32 0 13.8
27 11.83 1.81 0.36 5.49 -0.81 45.75 16.49 21.79 0 0 2.46 0 13.63
28 13.68 1.11 0.39 1.70 -0.11 65.12 6.71 0 0 10.43 0 8.72 9.02
29 17.29 1.26 0.37 1.27 -0.26 64.08 17 0 0 7.08 1.24 0 10.6
30* 17.99 1.55 0.52 5.32 -0.55 56.25 29.25 1.27 0 0 2.09 0 11.14
31 13.66 1.51 0.47 1.33 -0.51 54.67 25.99 1.91 0 0 4.47 0 9.95
32 3.039 0.92 0.34 2.86 0.08 47.17 0 0 4.17 9.49 0 8.3 30.88
33 5.438 0.88 0.28 3.32 0.12 54.88 0 0 7.11 3.33 0 14.49 20.19
34 6.266 0.93 0.41 1.85 0.06 55.31 0 0 4.17 11.42 0 13.32 15.78
35 5.223 0.66 0.31 1.70 0.33 44.39 0 0 20.5 0 0 22.17 12.93
36 6.425 2.17 1.36 2.43 -1.17 29.86 35.01 0 0 5.8 4.4 0 24.92
37 14.64 1.32 0.61 1.24 -0.32 54.35 17.58 0 0 12.53 0 3.28 12.26
38 7.666 1.64 0.54 8.64 -0.64 42.49 23.26 3.68 0 0 3.17 0 27.41
39 8.371 1.36 0.39 3.49 -0.36 50.98 18.02 0 0 1.91 4.99 0 24.1
40 12.91 1.78 0.49 1.99 -5.91 45.81 22.69 13.26 0 0 6.09 0 12.15
41* 7.631 2.00 0.66 1.59 -1.00 38.34 25.51 13.31 0 0 8.8 0 14.04
42 13.81 1.74 0.57 1.99 -0.74 47.24 27.34 8.16 0 0 5.76 0 11.5
43 12.38 1.49 0.48 1.77 -0.49 53.24 25.84 0.67 0 0 7.3 0 12.95
44 10.50 1.08 0.62 2.09 -0.08 55.45 4.71 0 0 12.87 0 16.99 9.98
45 10.40 1.09 0.81 1.66 -0.09 61.94 5.74 0 0 12.14 0 13.67 6.52
46 12.78 1.13 0.38 1.41 -0.13 66.07 8.9 0 0 10.35 0 6.25 8.43
47 17.97 0.95 0.39 4.42 0.04 67.42 0 0 0 3.31 0 24.36 2.21
48 14.45 1.39 0.72 1.22 -0.39 53.41 21.73 0 0 11.16 0 5.99 7.71
(*) shallow wells
17
5.4 Groundwater pollution
The use of large quantities of fertilizers like phosphate and nitrate in agriculural
activites and the lake of advanced drainage system are the main sources of groundwater
pollution in the study area. Deterioration groundwater quality has been resulted. The degree of
contamination was evaluated based on the results of chemical analyses of some minor and
trace elements such as PO4, NO3, Fe, Mn and Zn. The concentrations of these elements in the
collected groundwater samples were shown in Table (2). The concentration of phosphate in
the collected groundwater samples is more than the permissible limit (0.1 mg/l) (WHO,
1984a), it ranges from 17 mg/l (well No. 15) to 111 mg/l (well No. 10) of groundwater
samples representing shallow wells. The iso-phosphate contour map of shallow wells (Fig.
19) shows that the concentration of phosphate increases towards new reclaimed areas located
northeast Abu Sweir (Izbet Abazzah, Izbet El-Karamat and Izbet El-Arab). These areas
receive excess irrigation water rich in phosphate fertilizers. Groundwater samples
representing deep wells have phosphate content ranging from 3 mg/l (well No. 42) to 42 mg/l
(well No. 28). This reflects that, the concentration of phosphate decreases with depth. The iso-
phosphate contour map of deep wells (Fig. 20), shows that the concentration of phosphate
increases towards the middle and eastern parts, this due to deep percolation of excess
irrigation water rich in phosphate fertilizer.
The concentration of nitrate in the majority of collected groundwater samples is more
than the permissible limit (45 mg/l) (USEPA, 2000), the concentration of nitrate in the
groundwater samples representing shallow wells ranges from 8 mg/l (well No. 5) to 135 mg/l
(well No. 18). The nitrate distribution contour map of shallow wells (Fig. 21) shows local
high closure areas especially at the reclaimed areas that located northwest and northeast Abu
Sweir area; this is mainly attributed to the seepage of excess irrigation water rich in nitrate
fertilizers. Groundwater samples representing deep wells have nitrate ranging from 7 mg/l
(well No. 12) to 70 mg/l (well No. 29). The iso–nitrate contour map of the deep zone (Fig.
22), shows increasing in nitrate concentration towards the middle part. The increase of nitrate
and phosphate at such areas reflect impact of traditional irrigation system and deep
percolation of excess irrigation water rich in phosphate and nitrate. Based on the results of
phosphate and nitrate concentrations, groundwater of the Quaternary aquifer is highly
polluted with these elements and hence it is unsuitable for drinking purposes (USEPA, 2000)
In the concerned aquifer, the iron concentration is within the recommended limit (0.3
mg/l) (WHO, 1984a). It ranges between 0.01 mg/l and 0.3 with exception to well No 10,
which displays 0.53 mg/l (Table 2). The relatively low iron content in most the groundwater
samples is mainly attributed to the free nature of the aquifer in the study area. Concerning the
concentration of manganese in the area under consideration (Table 2), it is clear that the
groundwater samples are dominated by low concentration of manganese less than the
recommended limits (0.05 mg/l) ((USEPA, 2000) with exception of wells Nos. 35, 37 and 45,
they display values 0.95 mg/l, 0.26 mg/l and 0.12 mg/l respectively. Zink concentration
ranges from 0.1 mg/l to 0.50 mg/l. It is within the permissible limit in all groundwater
samples (5 mg/l) (WHO, 1984a), these elements cause no problems in groundwater of the
study area.
5.5 Suitability of groundwater for irrigation purposes:
The proposed approach by the United State Salinity Laboratory staff of agriculture
(USSLs, 1954) is used for determining the suitability of groundwater for irrigation purposes.
Distribution of the collected groundwater samples within the diagram (Table 3 and Fig. 23)
revealed that, groundwater of the Quaternary aquifer has a wide range from good to bad class.
The majority of samples show relatively high salinity and high sodium adsorption ratio, they
lie in C3-S2, C3-S3 and C4-S4 classes. So a proper irrigation system, adequate drainage
system and salt tolerant plants were recommended.
18
El Salhia El Gidida
ElQassasin Abu
Sweir
El Ismailiacanal
El Kassara canal
Cair
o -
El
Ism
ail
ia R
oad
waterlogging
0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canals Main roadsConture line (mg/l)30
El Salhia Canal
El Salhia El Gidida
ElQassasin Abu
Sweir
El Ismailiacanal
El Kassara canal
Cair
o -
El
Ism
ail
ia R
oad
waterlogging
0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canals Main roadsConture line (mg/l)30
El Salhia Canal
1
3
4
567
8
10 11
13
14
1516
1718
19
20
212223
24
30
41
El Salhia El Gidida
El Qassasin Abu
Sweir
El Ismailiacanal
El Kassara canal
Cair
o -
El
Ism
ail
ia R
oad
waterlogging
0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canals Main roadsConture line (mg/l)30
El Salhia Canal
Fig. (20) Iso – phosphate contour map of shallow wells of the Quaternary
aquifer in El Salhia El Gidida-Abu Sweir area (September 2006).
Fig. (21) Iso – phosphate contour map of deep wells of the Quaternary
aquifer in El Salhia El Gidida - Abu Sweir area (September
2006).
Fig. (21) Iso – nitrate contour map of shallow wells of the Quaternary
aquifer in El Salhia El Gidida - Abu Sweir area (September 2006).
19
2
912
2526
27
28
29
31
3233
3435
36
37
38
39
40
42
43
44
45
46
47
48
El Salhia El Gidida
El Qassasin Abu
Sweir
El Ismailiacanal
El Kassara canal
Cair
o -
El
Ism
ail
ia R
oad
waterlogging
0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canals Main roadsConture line (mg/l)30
El Salhia Canal
5. Aquifer Vulnerability Assessment
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
250100750
2250 10000
C1 (LOw) C2 (Medium) C3 (High) C4 (Very High)
S1
(L
ow
)S
2 (
Me
diu
m)
S3
(H
igh
)
S4
(V.H
)
So
diu
m A
ds
orp
tio
n R
ati
o
Conductivity Micromhos/cmx106 at 25°C
C1-S1
C1-S2
C1-S3
C1-S4
C2-S1
C2-S2
C2-S3
C2-S4
C3-S1
C3-S3
C3-S4
C4-S1
C4-S2
C4-S3
C4-S4
Good Water Class
Moderate Water Class
Intermediate Water Class
C3-S2
5000
Bad Water Class
47
1
2
3
45
6
7
89 10
11
12
1314
15
16
17
18
19
20
21
2223
24
25
2627
28
2930
31
32
33
34
35
36
37
3839
40
41
42
43
44
45
46
48
Fig. (23) Diagram for the classification of groundwater for irrigation
(According to U. S. Salinity Laboratory Staff, 1954).
Fig. (22) Iso – nitrate contour map of deep wells of the Quaternary aquifer
in El Salhia El Gidida-Abu Sweir area (September 2006).
21
5.Vulnerability Assessment
The concept of groundwater vulnerability can be defined as the possibility of
percolation and diffusion of contaminants from the ground surface into the groundwater
system. A specific vulnerability assessment is indicated if a particular contaminant is
identified posing a threat to groundwater quality allowing its individual behavior to be
included into groundwater vulnerability studies. In the concerned groundwater aquifer,
phosphate and nitrate are the most common identified contaminants in the groundwater
reflecting the excessive use of fertilizers in agriculural activities. The results of chemical
analyses of phosphate and nitrate as mentioned before in 48 water samples (Table 2) indicated
that 100% of the water samples reflecting high pollutant rizk of groundwater with phosphate
all over the study area. About 62% have concentration of NO3 more than the permissible
concentration (45 mg/l) especially at the middle and eastern part of the study area; this
indicates high pollutant risk of groundwater with phosphate and nitrate under such localities.
Both contaminant elements have severely differing the physical and chemical characteristics
of groundwater. The possibility of percolation and diffusion of such contaminants from the
ground surface into the groundwater system depends mainly up on the hydrogeological
characteristics of the aquifer. This concept is based on the assumption that the geological
setting can provide a certain degree of groundwater protection from natural and anthropogenic
sources, practically from contaminants available in the soil zone. The geological setting
includes a composite description of all the major geological and hydrological factors that
affect and control the groundwater movement into, through and out the area (Aller et al.,
1987). For assessing the inherent vulnerability of the Quaternary aquifer in the investigated
area, five hydrogeological and hydrochemical parameters were introduced (Zekster, 2000),
they include depth to groundwater (thickness of vadose zone), lithological composition of
vadose zone, infiltration recharge of the principle aquifer, residence time of groundwater and
transmissivity of principle aquifer. The model yields a cumulative rank assigned for such
parameters reflecting the vulnerability categories (Table 4).
In the study area, the vadose zone (depth to groundwater) ranges from 0.5 m to 34 m
(rank 3); lithology varies from sand, gravel and clay in the eastern part (rank 2) to sand and
sandstone in the western part (rank 4); infiltration rate is more than (300 mm/year i.e. rank 1)
and ranges between 14235 mm/year and 175200 mm/year (Gad, 1995); transmissivity values
are very high (> 2000 m2/day i.e. rank 1) and range from 19986 m
2/day in the east to 40600
m2/day in the west (Gad, 1995) and residence time of groundwater is less than < 200 years i.e.
rank 1. According to the specific and inherent vulnerability scheme introduced by Zekster
(2000), groundwater vulnerability scores were calculated and vulnerability categories map
was constructed (Fig.24). From this map it is clear to noticed that, the groundwater
vulnerability categories are ranges from high groundwater vulnerability (not protected areas)
including new reclaimed areas occupying in the middle and eastern part of the study area to
moderately vulnerability (poorly protected areas) in the other parts of the investigated area. In
general, the high groundwater vulnerability in the study area is mainly attributed to traditional
irrigation system, excessive usage of fertilizers and high percolation of excess irrigation
through vadoze zone.
21
Table (4) Parameters used in assessing the aquifer vulnerability according to Zekster (2000).
Vadose zone
thick. (m)
Rank
Vadose zone
lithology
Rank
Infiltration rate
(mm/year)
Rank
Transmissivity (m2/day)
Rank
Residence time of
groundwater (year)
Rank
Cumulative Rank
Vulnerability categories
<30
3
Sand,
gravel &
clay
2
< 15
5
< 500
4
< 200
1
< 10
Not protected
30 – 60
6
Sand &
sandstone
4
15 – 30
4
500 – 1000
3
200 - 250
2
10 – 20
Poorly
protected
60 – 150
9
sandstone
, shale &
limestone
6
30 – 90
3
1000 – 2000
2
500 - 1000
3
20 – 30
Conditionally
protected
> 150
12
Granile
&
volcanic
rocks
9
90 – 150
2
> 2000
1
> 1000
4
> 30
Protected
150 - 300
1
Poorly protected (Moderate vulnerability)
El Salhia canal
El Salhia El Giddida
El Qassasin Abu Sweir
El Ismailia canal0 2 4 6
Scale
31 50 32 00 32 10
3035
3040
Irrigation canalsMain roads
Legend:
Not protected (High vulnerability)
Fig. (24): Groundwater vulnerability categories map of the Quaternary aquifer in El
Salhia El Gidida-Abu Sweir area (based on the classification scheme of Zekster,
2000).
Summary and conclusion:
In the area of study, the Quaternary water bearing formations constitute the main source
of groundwater in the study area. It is mainly composed of sand and gravels intercalated with
clay and shale lenses. It rests directly on Pliocene clay and Miocene sandy limestone. The
thickness of Quaternary aquifer is strongly affected by normal faults with downthrown sides
towards the east and north. The Quaternary aquifer is hydraulically connected with the
underlain Miocene saline water aquifer through deep-seated normal faults. The groundwater
exists under free water condition. Semiconfined and confined conditions were developed
beside free water table condition toward east and northeast direction (East Abu Sweir area).
The absolute groundwater levels range from +9 (amsl) in the south close to Ismailia canal and
+8 amsl in the north close to El Salhia canal in the north while it ranges from +5 m to + 4 m
(amsl) in the middle and eastern parts of the study area. Water logging and water ponding
represent serious environmental problems under the new reclaimed areas that located
northeast Abu Swier (Izbet Abazzah, Izbet El-Karamat and Izbet El-Arab).
22
Hydrogeochemically, groundwater of the Quaternary aquifer has wide range from
fresh to brackish water. Water salinity ranges from 447.6 mg/l close to irrigation canals to
7043.4 mg/l in the middle part of the study area. It increases generally on going far away from
the canals, which indicates that they act as a recharge source for the Quaternary aquifer. The
occurrence of NaCl, Na2SO4, Na HCO3, Ca(HCO3)2, Mg(HCO3)2, MgSO4, CaSO4, and
MgCl2 salts in groundwater reveals its meteoric origin and geochemical processes as well as
the recharging from surface water canals and the upward leakage from the Miocene aquifer
for groundwater. The groundwater vulnerability ranges from high groundwater vulnerability
(not protected) including new reclaimed areas occupying in the middle and eastern part of the
study area to moderately vulnerability (poorly protected) in the other parts of the investigated
area.
According to the results of the present study, the following solutions can be taken into
account:
1- Good drainage system should be constructed in the areas suffering from water pond
and water logging (Iz El Arab and Iz Abaza) to protect the old and new reclaimed
cultivated lands from destruction.
2- Applying enforcement laws for completely stop the traditional irrigation system and
apply the modern irrigation systems (drip and shower) to save more water and prevent
excess irrigation water.
3- Public awareness is effective tool to protect groundwater as human activities for the
main threat of polluting groundwater, plant the low dependent water plants and plant
the salt tolerant crops in the areas suffering from high saline groundwater.
4- Geophysical exploration should be applied to locate the best sites for drilling knew
wells and determine suitable depths.
References
Aller, L., Bennet, T., Leher, J., Etty, R., and Hackett, G. (1987): "DRASTIC; a standardized
system for evaluation groundwater pollution potential using hydrogeological setting". EPA
600/2-87-035; 622.
Chebotarev, I. L. (1953): "Metamorphism of natural waters in the crust of weathering". Geochem
Acta, 8, pp. 23-48, 137-170 and 198-212, London, New York.
El-Dairy, M. D. (1980): "Hydrogeological studies on the eastern part of Nile Delta using isotope
techniques". M. Sc. Thesis, Fac. of Sci., Zagazig Unvi. 233p.
El-Fakharany, M. A. (2004): Impact of hydrogeological conditions and human activities on
groundwater quality of the Quaternary aquifer at Abu Zaabal area, SE Nile Delta, Egypt.
Proc. Of 6th conf. On Geochemistry, Alex. Univ., Pages 339-351.
El-Fayoumy, I. F. (1968): "Geology of groundwater supplies in the region east of the Nile Delta". Ph.
D. Thesis, Fac. of Sci., Cairo Unvi. 201p.
El-Shazly, E. M., Abdel Hady, M. A., El Shazly, M. M., El Ghawabby, M. A., El Kassas, I. A.,
Salman, A. B. and Morsi, M. A. (1975): "Geological and groundwater potential studies of
El Ismailya master plan study area". Remote Sensing Research Project, Academy of
scientific Research and Technology, Cairo, Egypt, 24p.
Gad, M.I. (1995): "Hydrogeological studies for groundwater reservoirs, East of the Tenth of
Ramadan city and vicinities". M.Sc. Thesis,. Fac. of Sc., Ain Shams Univ., Cairo, Egypt.
Hefny, K. (1980): "Groundwater in the Nile Valley". Ministry of Irrigation. Water Research Center.
Groundwater Research Inst. (in Arabic); 120p.
Korany, E. A., Shendi, E. H. and Abdel Tawab, S. (1993): Intergrated detection of the problem of
groundwater over flow in Abu Zaabal Basalt Quarries, Egypt. E.G.S. Proc. Of 11th
Ann.Meet. pp:161-180.
Moussa, B.M. (1990): "Petrologyand soil Genesis of the surface Quaternary deposits, East of the Nile
Delta, Egypt". Ph. D. Thesis, Fac. of Sci., Ain Shams Unvi. 391p.
Said, R. and Beheri, S. (1961): "Quantitative geomorphology of the area East of Cairo". Bull. Soc.
Geographic, Egypt, pp. 121-132.
23
Sallouma, M. K. M. (1983): "Hydrogeological and hydrogeochemical studies east of Nile Delta,
Egypt". Ph. D. Thesis, Fac. of Sci., Ain Shams Unvi. 166p.
Shata A. A. and El Fayoumy, I. F. (1970): "Remarks on the regional geological structure of the Nile
Delta". Symposium Hydrology of Delta, UNESCO, Vol. I., pp. 189 – 197.
Shata, A. A. (1965): "Geological structure of the Nile Delta". Journ. Of Engin. Cairo, (in Arabic), pp.
1-3.
Sukri, N.M. and El Ayouti, M.K. (1956): "The geology of Gebel Iwiebid, Gafra area, Cairo Suez
district". Bull Soc. Geographic, Egypt, pp. 67-71.
U.S. Environmental protection Agency (USEPA), (2000): Quality criteria for regulations and health
advisories. Washington, DC., Office of water 822-B00-001unnumbered.
U.S. Salinity Laboratory Staff (1954): "Diagnosis and improvement of saline and alkali soils". Dept.
of Agric., Handbook, Washington D. C., No. 60, 60p.
World Health Organization ( WHO), (1984 a): International standards for drinking water. 3 rd
edition , Vol.1. Geneva, Switzerland.
Zekster, I.S. (2000): "Groundwater and the environment". Lewis publishers London, New York
175p.