Long Term Trends and Dynamics of Dissolved Organic Carbon (DOC) in a Subtropical Reservoir Basin
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Area
2.2. Sampling and Data Analysis
2.3. Data Analysis
3. Results and Discussion
3.1. Long-Term Trends of Climate, DOC and Chemistry Parameters in Fei-Tsui Reservoir
3.2. Long-Term Trends of DOC and Water Chemistry in Tributaries of Fei-Tsui Reservoir
3.3. Effect of Re-Oligotrophication in the Fei-Tsui Reservoir
3.4. Effects of Hydrological and Meteorological Factors
3.5. Effect of Declining Atmospheric Acid Deposition
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Station | Tributary | Catchment Area (ha) | Percentage of Land Use (%) | ||||
---|---|---|---|---|---|---|---|
Agriculture | Forest | Residential | Water | Others | |||
S2 | Huo-Shao-Zhang | 1138 | 4.00 | 91.54 | 0.06 | 3.22 | 1.16 |
S4 | Hou-Keng-Tsz | 2068 | 4.82 | 90.93 | 0.03 | 3.26 | 0.96 |
S10 | Jin-Gua | 2418 | 7.55 | 89.49 | 0.81 | 0.44 | 1.70 |
S12 | Dai-Yu | 7864 | 3.44 | 93.79 | 0.69 | 0.85 | 1.24 |
S13 | Bei-Shih | 13658 | 9.65 | 77.89 | 1.88 | 6.58 | 4.00 |
- | Total | 30051 | 6.6 | 85.9 | 1.1 | 3.7 | 2.6 |
Site | Parameter | Mean/Std. Dev | Monthly Trend (mg L−1 Month−1) | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Year | January | February | March | April | May | June | July | August | September | October | November | December | |||
Reservoir | Rainfall (mm) | 4018 ± 821 | −58.92 | 0.40 | 1.70 | −0.47 | −4.18 | 12.76 | 2.22 | 3.24 | 19.7 | −19.65 | 6.95 | 9.23 | −2.19 |
Air Temp. (°C) | 24.1 ± 1.2 | −0.006 | −0.002 | −0.028 | −0.139 | −0.214 ** | −0.081 | −0.005 | 0.152 * | 0.139 | 0.089 | −0.027 | 0.122 | −0.001 | |
Water Temp. (°C) | 24.1 ± 0.5 | −0.007 | −0.084 | −0.007 | −0.063 | −0.076 | −0.124 | −0.066 | 0.073 | 0.048 | 0.115 | −0.012 | 0.009 | −0.090 | |
DOC (mg/L) | 0.87 ± 0.2 | 0.004 | −0.011 + | −0.003 | 0.000 | 0.001 | 0.012 | 0.000 | 0.03 * | −0.003 + | 0.014 | 0.009 | −0.006 + | −0.003 | |
TSI | 42.4 ± 4.0 | −0.556 *** | −0.778 *** | −0.723 *** | −0.477 ** | −0.801 *** | −0.644 ** | −0.586 ** | −0.334 | −0.463 ** | −0.308 ** | −0.437 * | −0.528 * | −0.695 ** | |
SO4 (mg/L) | 8.21 ± 1.7 | −0.082 *** | - | −0.105 * | - | - | −0.127 * | - | - | −0.198 *** | - | - | −0.035 | - | |
NO3 (mg/L) | 0.49 ± 0.1 | −0.017 *** | - | −0.008 * | - | - | −0.012 * | - | - | −0.024 *** | - | - | −0.014 ** | - | |
pH | 7.50 ± 0.3 | 0.029 * | 0.002 | 0.012 | 0.024 | 0.022 | 0.029 | 0.065 * | 0.045 | 0.076 * | 0.060 * | 0.011 | 0.004 | 0.005 | |
T-Alk (mg/L) | 18.21 ± 1.8 | −0.080 | - | −0.130 | - | - | −0.045 | - | - | −0.295 | - | - | 0.103 | - | |
Cl (mg/L) | 4.55 ± 0.3 | −0.018 | - | −0.014 | - | - | −0.009 | - | - | −0.048 | - | - | 0.009 | - | |
DON (mg/L) | 0.16 ± 0.04 | −0.006 *** | - | −0.003 | - | - | −0.007 ** | - | - | −0.009 *** | - | - | −0.005 ** | - | |
Ca (mg/L) | 6.01 ± 1.0 | −0.036 | - | −0.007 | - | - | −0.083 * | - | - | −0.169 | - | - | 0.044 | - | |
Mg (mg/L) | 2.87 ± 0.4 | −0.036 | - | 0.023 | - | - | −0.080 * | - | - | −0.112 | - | - | 0.029 | - | |
ACI | 1.04 ± 0.1 | 0.012 ** | - | 0.021 ** | - | - | 0.008 | - | - | 0.019 * | - | - | 0.019 * | - | |
Bei-Shih | DOC | 0.80 ± 0.3 | −0.002 | −0.009 | −0.001 | −0.011 | −0.001 | 0.005 | 0.009 | 0.013 | −0.035 | 0.011 | −0.007 | 0.000 | −0.013 |
SO4 | 9.02 ± 3.7 | −0.451 *** | - | −0.329 ** | - | - | −0.379 *** | - | - | −0.460 ** | - | - | −0.244 * | - | |
pH | 7.41 ± 0.3 | 0.025 | 0.004 | 0.008 | 0.000 | 0.013 | −0.020 | 0.067 * | 0.032 | 0.024 | 0.015 | 0.037 * | 0.029 | 0.025 | |
Dai-Yu | DOC | 0.79 ± 0.3 | −0.003 | 0.000 | −0.001 | −0.015 | 0.007 | −0.030 * | 0.014 | 0.000 | −0.032 | 0.008 | −0.020 | −0.017 | −0.007 |
SO4 | 10.31 ± 2.9 | −0.359 *** | - | −0.243 * | - | - | −0.613 ** | - | - | −0.338 * | - | - | −0.212 * | - | |
pH | 7.62 ± 0.3 | 0.030 | 0.019 | −0.015 | 0.024 | 0.043 | 0.010 | 0.072 | 0.025 | 0.029 | 0.060 | 0.039 | 0.000 | 0.031 | |
Jin-Gua | DOC | 0.81 ± 0.3 | −0.013 | −0.007 | −0.006 | −0.025 * | −0.007 | −0.018 | 0.003 | −0.005 | −0.051 | −0.023 | −0.039 ** | −0.012 | −0.017 |
SO4 | 9.77 ± 1.9 | −0.267 *** | - | −0.072 | - | - | −0.270 * | - | −0.368 ** | - | - | −0.306 * | - | ||
pH | 7.53 ± 0.2 | 0.008 | −0.012 | −0.025 | −0.014 | 0.000 | −0.018 | 0.040 | 0.013 | 0.032 | 0.030 | 0.048 | −0.009 | 0.020 | |
Hou-Keng-Tsz | DOC | 0.89 ± 0.3 | −0.002 | - | −0.002 | - | - | 0.000 | - | - | −0.020 | - | - | −0.004 | - |
SO4 | 8.01 ± 1.5 | −0.100 ** | - | −0.084 | - | - | −0.130 *** | - | - | −0.144 ** | - | - | −0.044 | - | |
pH | 7.53 ± 0.3 | 0.008 | - | 0.010 | - | - | 0.000 | - | - | 0.048 | - | - | 0.000 | - | |
Huo-Shao-Zhang | DOC | 0.91 ± 0.3 | 0.002 | - | −0.007 | - | - | 0.001 | - | - | −0.002 | - | - | 0.004 | - |
SO4 | 8.06 ± 1.5 | −0.093 *** | - | −0.104 ** | - | - | −0.123 *** | - | - | −0.136 ** | - | - | −0.026 | - | |
pH | 7.51 ± 0.3 | 0.012 | - | 0.000 | - | - | 0.000 | - | - | 0.059 | - | - | 0.000 | - |
Parameter | Yearly Trend (mg L−1 yr−1) | |||||
---|---|---|---|---|---|---|
Surface Water | Bei-Shih | Dai-Yu | Jin-Gua | Hou-Keng-Tsz | Huo-Shao-Zhang | |
DOC | 0.004 | −0.002 | −0.003 | −0.013 | −0.022 | 0.002 |
DON | −0.006 *** | −0.009 ** | −0.003 | −0.007 ** | −0.005 *** | −0.006 *** |
COD | −0.044 | 0.132 | 0.018 | −0.077 | −0.025 | −0.002 |
SO4 | −0.082 *** | −0.225 | −0.359 *** | −0.267 *** | −0.100 ** | −0.093 *** |
NO3 | −0.017 *** | −0.005 | −0.005 | −0.010 * | −0.014 *** | −0.015 *** |
Cl | −0.018 | 0.050 | 0.001 | −0.039 | −0.007 | 0.005 |
pH | 0.029 * | 0.050 | 0.030 | 0.008 | 0.008 | 0.012 |
T-Alk | −0.080 | 0.030 | −0.601 ** | −0.594 ** | −0.077 | −0.116 |
Ca | −0.036 | -0.550 ** | −0.427 *** | −0.192 * | −0.211 ** | −0.029 |
Mg | −0.036 | −0.108 * | −0.056 | −0.049 | −0.029 | −0.024 |
∑Cation | −0.045 | −0.422 *** | −0.459 *** | −0.222 * | −0.181 ** | −0.039 |
∑Anion | −0.094 *** | −0.448 *** | −0.353 *** | −0.271 *** | −0.090 *** | −0.100 *** |
ACI | 0.012 ** | 0.013 * | 0.000 | 0.009 | −0.006 | 0.013 * |
Parameter | Sites | Air Temperature | Water Temperature | Runoff |
---|---|---|---|---|
DOC concentration (mg/L) | Bei-Shih | 0.115 | 0.375 | −0.554 |
Dai-Yu | 0.050 | 0.503 | −0.696 * | |
Jin-Gua | 0.068 | 0.320 | −0.607 * | |
Hou-Keng-Tsz | 0.382 | 0.252 | −0.846 | |
Huo-Shao-Zhang | 0.605 | 0.973 | −0.063 |
Parameter | DOC | SO4 | Cl | COD | pH | T-Alk | NO3 | Ca | DON |
---|---|---|---|---|---|---|---|---|---|
SO4 | 0.599 ** | ||||||||
Cl | −0.241 | −0.122 | |||||||
COD | 0.003 | −0.027 | −0.146 | ||||||
pH | −0.020 | −0.147 | 0.184 | −0.011 | |||||
T-Alk | 0.265 | 0.395 * | 0.079 | −0.122 | 0.380 * | ||||
NO3 | 0.335 | 0.384 * | 0.355 | 0.024 | −0.212 | 0.518 ** | |||
Ca | 0.529 ** | 0.756 ** | −0.164 | −0.137 | 0.032 | 0.431 * | −0.476 * | ||
DON | 0.205 | 0.145 | 0.046 | 0.310 | −0.090 | −0.208 | 0.239 | 0.126 | |
Mg | 0.235 | 0.436 * | 0.131 | 0.007 | −0.041 | 0.296 | 0.172 | 0.372 | 0.318 |
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Chow, M.F.; Lai, C.-C.; Kuo, H.-Y.; Lin, C.-H.; Chen, T.-Y.; Shiah, F.-K. Long Term Trends and Dynamics of Dissolved Organic Carbon (DOC) in a Subtropical Reservoir Basin. Water 2017, 9, 545. https://doi.org/10.3390/w9070545
Chow MF, Lai C-C, Kuo H-Y, Lin C-H, Chen T-Y, Shiah F-K. Long Term Trends and Dynamics of Dissolved Organic Carbon (DOC) in a Subtropical Reservoir Basin. Water. 2017; 9(7):545. https://doi.org/10.3390/w9070545
Chicago/Turabian StyleChow, Ming Fai, Chao-Chen Lai, Hsiang-Yi Kuo, Chih-Hsien Lin, Tzong-Yueh Chen, and Fuh-Kwo Shiah. 2017. "Long Term Trends and Dynamics of Dissolved Organic Carbon (DOC) in a Subtropical Reservoir Basin" Water 9, no. 7: 545. https://doi.org/10.3390/w9070545