Table 1.

Average dissolved organic C (DOC), NO3−, and δ18O concentrations and their linear relationships in Groups A to D.

StationStream partDOCn (DOC)NO3n (NO3)Missing pairwiserr2Significance (2-tailed)δ18O
mg L−1mg L−1%
Group A, subsurface runoff dominated
W1MS4.79 ± 1.591661.82 ± 1.5917614.15−0.280.080.000**−8.19 ± 0.36
W2MS5.81 ± 3.011812.38 ± 2.191897.32−0.640.410.000**−8.23 ± 0.29
W8T6.38 ± 3.541423.55 ± 2.4214429.27−0.750.570.000**−8.25 ± 0.20
W9T5.85 ± 3.131782.50 ± 2.1717212.20−0.730.530.000**−8.26 ± 0.19
All5.69 ± 2.946672.51 ± 2.1868115.73−0.580.330.000**−8.24 ± 0.27
Group B, intermediate type
W4MS3.03 ± 1.291835.20 ± 1.751907.32−0.670.450.000**−8.36 ± 0.16
W5T2.06 ± 0.741753.89 ± 1.781887.80−0.590.350.000**−8.34 ± 0.13
W6MS2.97 ± 1.221834.99 ± 1.741888.29−0.670.440.000**−8.35 ± 0.15
W10MS3.35 ± 1.401864.72 ± 1.701886.83−0.710.500.000**−8.34 ± 0.16
W11MS2.75 ± 1.191865.01 ± 1.551877.32−0.610.370.000**−8.37 ± 0.14
W14OUT2.59 ± 1.091855.56 ± 1.661876.83−0.580.340.000**−8.36 ± 0.14
All2.80 ± 1.2410984.89 ± 1.7711287.40−0.530.290.000**−8.35 ± 0.15
Group C, groundwater dominated
W3T0.99 ± 0.421878.85 ± 1.181846.83−0.470.220.000**−8.45 ± 0.11
W12T1.09 ± 0.421658.78 ± 1.3916915.12−0.080.010.288−8.50 ± 0.10
W13T1.47 ± 0.601219.80 ± 1.6012338.54−0.540.300.000**−8.41 ± 0.19
W15REF0.82 ± 0.361827.18 ± 1.291817.80−0.290.090.000**−8.40 ± 0.12
W16REF1.96 ± 0.851865.61 ± 2.051906.83−0.670.440.000**−8.35 ± 0.11
All1.26 ± 0.708417.89 ± 2.1284715.02−0.510.260.000**−8.42 ± 0.13
Group D, groundwater–leakage water dominated
GW1Lower0.53 ± 0.2514510.86 ± 1.215722.93−0.350.120.000**−8.54 ± 0.11
GW3Lower0.70 ± 0.351367.91 ± 1.3814329.76−0.100.010.231−8.42 ± 0.11
GW8Central0.55 ± 0.28908.01 ± 1.269550.73−0.160.030.140−8.44 ± 0.13
GW9Central1.91 ± 0.831656.56 ± 0.8616316.10−0.220.050.007**−8.40 ± 0.12
All1.00 ± 0.805368.36 ± 2.0455829.88−0.530.280.000**−8.43 ± 0.12
Group E, direct filtration dominated
GW2Lower4.16 ± 2.951585.68 ± 1.9717414.63−0.040.000.622−8.37 ± 0.44
  • ** Significant correlations of DOC and NO3 at 1% using linear regression analysis.

  • MS, main stream; T, tributary; OUT, outlet; REF, reference stream; Lower, lower stream part; Central, central stream part.

  • Means ± standard deviations.