HYDROGEOLOGY, HYDROGEOCHEMISTRY AND HYDROGEOLOGY, HYDROGEOCHEMISTRY AND ISOTOPE HYDROLOGY OF BORKENA BASINISOTOPE HYDROLOGY OF BORKENA BASIN
Sileshi MamoSileshi Mamo
Plot of 2H versus 18O, Borkena final
y = 7.54x + 13.72y = 8x + 10
-30
-20
-10
0
10
20
30
40
-5 -4 -3 -2 -1 0 1 2 3 4
18O (o/oo)
2H (
o/o
o)
cold spring
hot spring
borehole
river
dug well
rfch
rfkch
rfdse
rfwh
rfw
rfk
GMWL
LMWL
Linear(LMWL)Linear(GMWL)
LMWLGMWL
Plot of 18O versus elevation
y = -0.0003x - 0.6642
R2 = 0.0562
-2
-1.8
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
1000 1200 1400 1600 1800 2000 2200 2400 2600 2800
Elevation (m a.s.l)
18O
(o
/oo
)
570000 580000 590000 600000
1180000
1190000
1200000
1210000
1220000
1230000
1240000
82
83 84
85
87
8990
91
92
94
97
101
104
106
107
108
109
111
112113
114
115
117
119120123
0
0.3
1
2
3
4
5
6
7
8
9
10
0 10000 20000 30000 40000
Tritum m ap of Borkena basin
RECHARGE EVALUATION
1. Water balance method
R= P- AET- SR/O or Surplus- SR/O
2. Cl balance method
R= Clrain*Peff/Clgw, Peff=P-SR/O
3. Hydrograph separation method
Hydrograph separation of Borkena river at the swamp outlet
0
2.5
5
7.5
10
12.5
15
17.5
20
22.5
25
27.5
30
32.5
35
37.5
40
42.5
45
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Months
Me
an
mo
nth
ly f
low
(m
3/s
)