Application of Multivariate Statistical Analysis in Evaluation of Surface River Water Quality of a Tropical River

Table 3

Mean difference of in situ and ex situ water quality parameters between the main river of the Batang Baram and its tributaries.

Parameter		Mean difference	value
In situ	Temperature, °C	−0.7	0.050
	pH	−0.2	0.001
	Conductivity, µS/cm	−16.2	0.000
	DOsat, %	−0.2	0.915
	DO, mg/L	+0.2	0.000
	Turbidity, NTU	+132.0	0.000
	Transparency, m	−0.4	0.000
Ex situ	Chl a, mg/m^3	−2.6	0.048
	TSS, mg/L	+120.7	0.000
	BOD5, mg/L	+0.5	0.026
	COD, mg/L	−8.3	0.474
	TP, mg/L	+0.4	0.002
	TAN, mg/L	+0.1	0.497
	-N, mg/L	−0.006	0.006
	-N, mg/L	+0.007	0.169
	Org-N, mg/L	+0.3	0.093
	H2S, mg/L	+0.1	0.000

Positive value of mean difference indicates parameter studied was higher in the main river of Batang Baram whereas negative value indicates parameter studied was higher in the tributary. The significant difference at value ≤ 0.05 was indicated in bold.