Table 7.
Descriptive statistics: mean and standard deviation (in bracket) of the physicochemical characteristics for 19 monitoring stations in Lake Hawassa Watershed for evaluation of WA WQI for drinking, irrigation, aquatic life and recreational purposes.
| Parameters | S1/S2/S3/S4/S5 | MS1 | MS2 | MS3 | MS4 | MS5 | MS6 | MS7 | MS8 | MS9 | MS10 | MS11 | MS12 | MS13 | MS14 | MS15 | MS16 | MS17 | MS18 | MS19 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Turbidity | 5 ac 50 d | 11.7 (3.7) |
27.3 (18.3) |
34.8 (8.7) |
20.5 (14.2) |
21.7 (10.1) |
12.2 (0.2) |
7.4 (2.5) |
7.4 (0.4) |
5.7 (1.3) |
6.1 (0.5) |
7.2 (0.1) |
6 (0.8) |
7.8 (1.7) |
7.3 (3.4) |
14 (1.7) |
8.8 (0.2) |
7.6 (0.1) |
46.5 (5.9) |
4.2 (0.6) |
| TDS | 1000, 2000 ab | 84.3 (6.9) |
83 (24) |
79 (11.7) |
1704 (183) |
2129 (312) | 224 (132) |
391 (4) |
484 (48.6) |
417 (37) |
458 (21) |
464 (2.1) |
464 (4.7) |
412 (0.8) |
247 (157) |
1491 (199) |
476 (9.2) |
475 (5.1) |
518 (61) |
776 (409) |
| EC | 1500, 3000 ab | 169 (14) |
166 (48) |
158 (23) |
3768 (81) |
4257 (623) |
446 (266) |
776 (16) |
835 (23) |
822 (104) |
932 (33) |
924 (62) |
928 (10) |
799 (11) |
491 (316) |
2984 (399) |
882 (75) |
908 (38) |
1084 (69) |
1614 (6.3) |
| pH | 6.5–9 abcd | 7.6 (0.8) |
8.1 (0.8) |
8 (0.4) |
7.6 (0.7) |
9.1 (0.5) |
7.5 (0.03) |
8.9 (0.1) |
9 (0.1) |
8.7 (0.001) |
8.7 (0.2) |
8.7 (0.1) |
8.6 (0.04) |
8.5 (0.1) |
7.4 (0.1) |
8.1 (0.2) |
8.5 (0.2) |
8.6 (0.02) |
8.6 (0.2) |
8.3 (0.1) |
| NH4-N | 2.33 (3.23) |
1.07 (1.24) |
1.0 (1.26) |
6.18 (4.1) |
5.09 (1.56) |
0.28 (0.29) |
1.87 (2.18) |
7.35 (3.52) |
0.83 (0.67) |
0.13 (0.003) |
4.1 (0.6) |
1.72 (0.53) |
0.66 (0.72) |
1.85 (0.93) |
16.81 (14.55) |
3.56 (0.01) |
3.1 (0.01) |
0.65 (0.18) |
0.12 (0.09) |
|
| NH3 | 1.5, 1.37 b | 0.14 (0.2) |
0.19 (0.27) |
0.1 (0.13) |
0.43 (0.36) |
8.9 (6.31) |
0.01 (0.01) |
1.23 (1.52) |
4.47 (1.29) |
0.29 (0.22) |
0.04 (0.01) |
1.34 (0.48) |
0.46 (0.14) |
0.14 (0.14) |
0.41 (0.15) |
2.25 (2.36) |
0.75 (0.22) |
0.95 (0.07) |
0.23 (0.14) |
0.02 (0.01) |
| NO2− | 3 a | 0.03 (0.01) |
0.08 (0.08) |
0.08 (0.01) |
0.02 (0.01) |
0.13 (0.01) |
0.06 (0.01) |
0.03 (0.01) |
0.03 (0.002) |
0.14 (0.15) |
0.03 (0.03) |
0.02 (0.01) |
0.02 (0.02) |
0.04 (0.04) |
0.02 (0.001) |
0.03 (0.02) |
0.02 (0.01) |
0.08 (0.02) |
0.04 (0.02) |
0.08 (0.004) |
| NO3− | 45, 1 ac | 2.9 (0.02) |
1.6 (0.04) |
3.1 (0.5) |
12.2 (0.1) |
2.3 (0.8) |
3.0 (2.3) |
3.6 (0.7) |
3.7 (0.7) |
11.2 (3.3) |
3.1 (0.8) |
17.4 (6.8) |
4.2 (0.4) |
19.4 (7.8) |
4.5 (1.6) |
11.5 (6) |
4 (0.4) |
4.4 (0.02) |
4.2 (0.02) |
3.8 (0.5) |
| SRP | 5 b | 5.3 (1.9) |
14.3 (4.7) |
4.5 (4.8) |
20.2 (1.8) |
76.8 (47) |
4.1 (2.3) |
2.3 (0.2) |
3.2 (1.1) |
2.3 (0.8) |
2.5 (0.04) |
1.8 (0.2) |
2 (0.3) |
2.9 (0.2) |
3.6 (0.2) |
28 (9.8) |
3.5 (0.5) |
2.7 (0.1) |
6.9 (1) |
8 (2.1) |
| DO | 5 cd | 5.4 (1.8) |
4.8 (1.8) |
5.1 (1) |
1.8 (0.4) |
0.9 (0.04) |
4.8 (1.2) |
4.9 (0.7) |
5.2 (0.1) |
4.1 (0.02) |
4.5 (0.3) |
3.4 (0.1) |
4.6 (0.04) |
3.6 (0.6) |
3.1 (0.5) |
1.5 (0.04) |
4.5 (0.2) |
4.3 (0.3) |
4.5 (0.4) |
4.4 (0.41) |
| BOD | 5 acd | 10.9 (4.1) |
14.2 (13.4) |
41 (40) |
48 (21.6) |
218 (131) |
4.6 (0.9) |
8.1 (3.1) |
9.2 (0.4) |
11.9 (2.9) |
40.2 (44.7) |
7.4 (2.3) |
10.9 (1.0) |
35.6 (16.5) |
16.1 (5.8) |
56.4 (9.9) |
19.3 (4.6) |
45 (4.2) |
56.4 (1.3) |
104 (30.6) |
| COD | 20 a | 129 (58) |
101 (9) |
186 (181) |
215 (69) |
589 (393) |
35 (12.4) |
178 (87.1) |
136 (1.4) |
52.4 (10.5) |
193 (189) |
90 (7.8) |
55.4 (13.2) |
171 (119) |
140 (8.8) |
252 (53.7) |
64.4 (15.7) |
150 14.1) |
188 (4.2) |
416 (5.7) |
| Mg2+ | 200 a | 10 (4.2) |
16.9 (10) |
84 (98) |
12.2 (1.1) |
5 (3) |
4.3 (2) |
5.4 (0.5) |
4.1 (0.2) |
14.1 (1.9) |
5 (0.4) |
5.2 (0.3) |
7.5 (3.7) |
11.2 (3.3) |
5.7 (0.9) |
10.6 (44) |
2.9 (0.4) |
12.3 (2.5) |
14.7 (1.9) |
14.4 (5.5) |
| Ca2+ | 100 a | 32.8 (18) |
17.4 (12) |
19 (20) |
43.8 (9.3) |
26.4 (16) |
22.5 (5.4) |
21.5 (7.4) |
22 (3.2) |
19.5 (3.7) |
25 (9.3) |
23.8 (4.1) |
28.8 (4.1) |
35 (8.3) |
20.5 (5.2) |
35.7 (2.8) |
7.8 (1.4) |
32.6 (1.7) |
32.4 (2.3) |
46.9 (9.7) |
| Na+ | 200 a | 28.4 (5.8) |
22.6 (5.1) |
22 (5.3) |
429 (101) |
895 (259) |
83 (41) |
204 (26) |
217 (54) |
189 (4.6) |
217 (10.1) |
199.4 (8.1) |
218.2 (9.6) |
249 (45) |
110 (58) |
316 (148) |
182 (21) |
143 (22) |
232 (17) |
261 (58) |
| K+ | 20 a | 6 (0.9) |
7.3 (1.1) |
5.7 (1.5) |
18 (2.5) |
18.2 (1.6) |
7.9 (2.2) |
19.2 (1.3) |
21.1 (1.5) |
20.4 (0.5) |
19.6 (0.6) |
19.1 (2.2) |
23.9 (0.8) |
18.5 (0.7) |
12.1 (6.5) |
94.6 (70.6) |
15.8 (3.2) |
15.7 (3.2) |
17.8 (1.8) |
21.7 (1.2) |
| Temperature | 15–20 ac | 17.4 (2.5) |
16.6 (1.56) |
17.2 (1.2) |
33.6 (0.37) |
30 (1.4) |
23.2 (1.94) |
22.6 (0.26) |
22.3 (0.68) |
22.2 (0.79) |
20.6 (0.91) |
22.6 (0.83) |
21.6 (1.5) |
23.2 (1.1) |
20 (1.06) |
25.4 (2.12) |
22.1 (0.93) |
23.1 (1.6) |
23.8 (1.05) |
21.36 (0.16) |
| SAR | 26 b | 0.25 (0.1) |
0.3 (0.03) |
0.14 (0.04) |
10.9 (0.05) |
0.93 (0.37) |
0.4 (0.12) |
0.97 (0.2) |
1.1 (0.02) |
0.85 (0.03) |
0.95 (0.15) |
0.93 (0.16) |
1.02 (0.06) |
0.7 (0.07) |
0.62 (0.37) |
3.62 (2.81) |
1.22 (0.12) |
0.59 (0.09) |
0.65 (0.04) |
0.7 (0.14) |
| KR | 1 b | 0.13 (0.08) |
0.14 (0.01) |
0.05 (0.03) |
0.24 (0.01) |
0.6 (0.4) |
0.23 (0.08) |
0.57 (0.19) |
0.64 (0.02) |
0.4 (0.02) |
0.53 (0.12) |
0.52 (0.12) |
0.5 (0.04) |
0.3 (0.07) |
0.37 (0.23) |
1.6 (1.3) |
1.08 (0.02) |
0.26 (0.02) |
0.27 (0.002) |
0.28 (0.1) |
| MAR | 50 b | 34.9 (3.5) |
60.2 (30.5) |
70.2 (39.7) |
32 (6.7) |
24 (0.25) |
24.4 (13.2) |
30.3 (5.5) |
23.8 (3.6) |
54.7 (8.1) |
26 (8.7) |
26.9 (4.53) |
30 (13.3) |
34.5 (1.3) |
32.2 (8.8) |
32.6 (10.9) |
38.6 (1.26) |
38.4 (3.67) |
42.9 (1.42) |
33.3 (4.1) |
| SSP | 50 b | 30.8 (14.9) |
28.1 (1.96) |
12.9 (8.5) |
78.3 (1.97) |
92.6 (5.8) |
60.9 (12.8) |
79.2 (6.2) |
81.7 (1.8) |
72.7 (0.06) |
79.4 (5) |
78.5 (2.8) |
76.2 (0.3) |
73 (1.9) |
66.7 (14.7) |
82.1 (0.34) |
89.4 (0.33) |
62 (1.24) |
70.3 (0.42) |
68.5 (1.8) |
All units are in mg/L except turbidity, EC, temperature, SAR, KR, MAR, SSP and pH which were expressed in NTU, µS/cm, °C, meq/L, % and non-dimensional, respectively. (a) Labels drinking use, (b) irrigation water use, (c) express water use for aquatic life and (d) designates recreational water use. S1 labels Standard values taken from World Health organization (WHO), S2 labels Standard values taken from Environmental protection Agency (EPA) of US or Ethiopia, S3 labels Standard values taken from Canadian Council of Ministries of the Environment (CCME), S4 labels Standard values taken from Food for Agricultural organization (FAO) and S5 labels standard values taken from Health Canada (HC).