| dc.description.abstract | Wetland ecosystems in Murang’a County are diminishing due to increased catchment land use practices. Part
of wetlands have been converted into farmlands where various agricultural activities are carried out while
some parts have been converted into settlement points. Agricultural practices carried out along wetland
ecosystems involve the use of excessive agrochemical s during crop production which later contribute to
wetland pollution through nutrients and heavy metals inflows. This study aimed at assessing the effects of
catchment land use on water quality parameters in Maragua and Mathioya river basins in Murang’a County.
Wat er samples were collected using the Grab technique, packed in plastic containers, kept in cool boxes, and
transported to the research laboratory for analysis. Salinity, turbidity, total dissolved solids (TDS), electrical
conductivity (EC) and P H were analy zed across the sampling levels using hand held portable pH meter
Salinity mean concentration across the three sampling levels was 116.28 ± 14.31 mg/L; 107.08±13.32 mg/L for
TDS; 0.16±0.02 mS/cm for electrical conductivity (EC), turbidity: 160.38 ± 8.53 NTU and a P H mean of
6.26±0.09.
TDS values differed across sampling levels: Down
Stream (mean = 135.43 ± 1.46 mg/L, rang e: 132.60 to
139.30 mg/L), Mid S tream (mean = 138.63 ± 6.60 mg/L, range: 122.70 to 150.60 mg/L), and Up Stream
(mean = 47.18 ± 10.43 mg/ range: 26.70 to 65.40 mg/L). EC showed significant variation across sampling
levels: Down Stream (mean = 0.20 ± 0.00 mS/cm, r ange: 0.19 to 0.20 mS/cm), Mid S tream (mean = 0.21 ±
0.01 mS/cm, range: 0.19 to 0.23 mS/cm), and Up Stream (mean = 0.07 ± 0.02 mS/ cm, range: 0.04 to 0.10
mS/cm). The pH levels varied across the different sampling levels: Down Stream (mean = 6.47 ± 0.03, range:
6.40 to 6.51), Mid stream (mean = 6.31 ± 0.10, range: 6.01 to 6.45), and Up Stream (mean = 6.00 ± 0.22,
range: 5.50 to 6.48). Salinity levels varied significantly: Down Stream (mean = 146.05 ± 1.81 mg/L, range:
141.40 to 150.20 mg/L), Mid S tream (mean = 150.93 ± 6.15 mg/L, range: 135.00 to 161.60 mg/L), and Up
Stream (mean = 51.88 ± 11.52 mg/L, range: 28.90 to 71.70 mg/L) and Tu rbidity levels also varied: Down
Stream (mean = 170.50 ± 15.40 NTU, range: 128.30 to 1 94.60 NTU), Mid S tream (mean = 173.53 ± 8.13
NTU, range: 158.40 to 190.90 NTU), and Up Stream (mean = 137.10 ± 15.00 NTU, range: 108.20 to 177.50
NTU).
P
ost hoc analysis showed a significant difference in pH between Down Stream and Up Stream (mean
difference = 0.465, p = .043). Significant differences noted in EC between Down Stream and Up Stream
(mean difference = 0.130, p < .001), and Mid Stream and Up Stream (mean diffe rence = 0.139, p < .001).
However, no significant difference was observed between Dow n Stream and Mid S tream. For TDS, s ignificant
differences were observed between Down Stream and Up Stream (mean difference = 88.250, p < .001), and
Mid Stream and Up Strea m (mean difference = 91.450, p < .001). No significant difference was observed
between Down Stream and Mid stream. Significant differences in salinity were found between Down Streamand Up
Stream (mean difference = 94.175, p < .001), and Mid Stream and Up Stream (mean difference =
99.050, p < .001). No significant difference was found between Down Stream and Mid stream. Variation in the
analyzed water parameters across the sampling levels show ed that the wetlands have been polluted and the
potential sources of pollution are agricultural run offs and anthropogenic activities | en_US |
