Table 3.

Seasonal Mann–Kendal trend analyses in Soyang reservoir during 1992–2013.

Parameters	Tau Correlation	S	Z	p-value	Empirical Model	Trend Analysis
WT	−0.158	−411	−3.517	0.0416	WT = 12.07 − 0.5000E-01 × T	−
pH	0.238	620	5.304	0.0092	pH = 6.958 + 0.1667E-01 × T	+
DO	−0.036	−94	−0.793	0.5107	DO = 9.372 − 0.6250E-02 × T	−
BOD	−0.139	−362	−3.104	0.2543	BOD = 1.246 − 0.8333E-02 × T	−
COD	0.287	748	6.400	0.0048	COD = 1.913 + 0.2500E-01 × T	+
TSS	−0.046	−121	−1.023	0.6476	TSS = 2.680 − 0.2000E-01 × T	−
EC	0.344	897	7.642	0.0026	EC = 58.33 + 0.6667 × T	+
TN	0.167	436	3.702	0.1673	TN = 1.411 + 0.1131E-01 × T	+
TP	−0.058	−152	−1.289	0.5190	TP = 15.82 − 0.7143E-01 × T	−
Chl-a	−0.131	−342	−2.906	0.1361	Chl-a = 3.200 − 0.5000E-01 × T	−

Note: S = Statistic, Z = Standardized variable, T = Time (minutes), WT = Water temperature (°C), DO = Dissolved oxygen (mg/L); BOD = Biological oxygen demand (mg/L); COD = Chemical oxygen demand (mg/L); TSS = Total suspended solids (mg/L); EC = Electrical conductivity (mS/cm); TN = Total nitrogen (mg/LTP = Total phosphorus (µg/L); Chl-a = Chlorophyll-a (µg/L).