Qiong Wu Xinghui Xia* Xiaohan Li Xinli Mou

Impacts of Climatic Variations on Urban Lake Water Quality: A Sensitivity Analysis for Twelve Urban Lakes with Different Trophic States

State Key Laboratory of Water Environment Simulation,

School of Environment, Beijing Normal University, Beijing 100875, China

*Corresponding author. Tel.: +86 10 58805314; fax: + 86 10 58805314.

Email address:

Supporting Information (pp.17)

Tables

Table S1 General characteristic of the studied urban lakes

Table S2 The classification standard of lake water quality and water function in China Table S3 Correlations between trophic state index and the level of the lake water quality (Wang et al. 2002)

Table S4 Trophic Level Index of twelve urban lakes of Beijing city from 2009 to 2011

Table S5a Results of ordinary least square (OLS) regression analysis for (a) DO (mg L-1), (b) COD (mg L-1), (c) TP (mg L-1), and (d) chlorophyll a (mg m-3) in urban lakes with highly eutrophication in Beijing from 2009 to 2011. D-W test indicated the data were not auto-correlative. F1 represents temperature and precipitation, F2 represents wind speed and sunshine duration.

Table S5b Results of generalized least square (GLS) regression analysis for (a) DO (mg L-1), (b) COD (mg L-1), (c) TP (mg L-1), and (d) chlorophyll a (mg m-3) in urban lakes with highly eutrophication in Beijing from 2009 to 2011. D-W test indicated the data were auto-correlative F1 represents temperature and precipitation, F2 represents wind speed and sunshine duration. SE represents standard errors, χ2 represents the Wald Chi-Square.

Table S6 Correlation between DO saturation and climatic factors, DOS indicates DO saturation, TC, KM, HH, QH, FH, BH, YYT, LY, LT, TRT, LH, QN represents Lake Tuacheng, Kunming, Houhai, Qianhai, Fuhai, Beihai, Yuyuantan, Liuyin, Longtan, Taoranting, Lianhua, and Qingnian. COD, BOD, and Chla represent the values in the corresponding lakes.

Table S7 Correlation between water quality parameters and climatic factors for lakes with mesotrophication/light eutrophication

Figures

Fig. S1 Monthly variations of (a) precipitation, (b) mean air temperature, (c) wind speed, and (d) sunshine duration during the period 2009-2011 in Beijing city

Fig. S2 Correlation between air temperature and water temperature in (a) Lake Tuancheng, (b) Lake Kunming, (c) Lake Qianhai, (d) Lake Houhai, (e) Lake Liuyin (f) Lake Fuhai, (g) Lake Lianhua, (h) Lake Beihai, (i) Lake Qingnian, (j) Lake Yuyuantan, (k) Lake Taoranting, and (l) Lake Longtan of Beijing city

Fig. S3 Variations of TP and temperature in (a) Lake Tuancheng, (b) Lake Kunming, (c) Lake Qianhai, and (d) Lake Houhai in the state of mesotrophication/light eutrophication

Fig. S4 Variations of chemical oxygen demand (COD) and precipitation in (a) Lake Beihai, (b) Lake Taoranting, (c) Lake Lianhua, (d) Lake Qingnian of highly eutrophication from 2009 to 2011

Fig. S5 Change trend of (a) precipitation, (b) mean air temperature, (c) sunshine duration, (d) wind speed, and (e) day of heavy rainfall in Beijing during the last 50 years (1962-2011)

The calculation of the improved Carlson’s trophic level index (TLI)

TLI(= TLI(j) (1)

where TLI(∑) is integrated trophic level index; Wj is correlative weighted score for trophic level index of j.

Wj= rij2/ (2)

where rij is relative coefficient, TLI (j) is trophic level index of j, j represents chlorophyll a (Chla), TP, TN, CODMn, and SD, respectively, which is expressed as the following formula.

TLI (Chla)=10(2.5+1.086lnChla) (3)

TLI (TP)=10(9.436+1.624lnTP) (4)

TLI (TN)=10(5.453+1.694lnTN) (5)

TLI (COD)=10(0.109+2.66lnCOD) (6)

TLI (SD)=10( 5.118-1.94lnSD) (7)

Table S1 General characteristic of the studied urban lakes

Lake name / Area(km2) / Depth(m) / Water Source / Longitude / Latitude
Tuancheng / 0.03 / 1.5 / Miyun Reservoir / E116°15′44.45″ / N39°59′23.4″
Kunming / 1.94 / 1.9 / Miyun and Guanting Reservoir / E116°15′58.0″ / N39°59′32.06″
Yuyuantan / 0.44 / 2.0 / Miyun and Guanting Reservoir / E116°18′41.63″ / N39°54′56.1″
Houhai / 0.21 / 1.5 / Miyun and Guanting Reservoir / E116°22′47.25″ / N39°56′27.93″
Qianhai / 0.13 / 1.5 / Miyun and Guanting Reservoir / E116°23′13.33″ / N39°56′5.21″
Beihai / 0.39 / 1.5 / Miyun and Guanting Reservoir / E116°22′56.75″ / N39°55′37.36″
Fuhai / 0.7 / 1.5 / Qinghe Water Reclamation Plant / E116°17′54.12″ / N40°0′31.98″
Taoranting / 0.17 / 1.5 / No.6 Water Reclamation Plant / E116°22′40.2″ / N39°52′24.06″
Longtan / 0.35 / 1.5 / No.6 Water Reclamation Plant / E116°26′9.81″ / N39°52′33.64″
Qingnian / 0.05 / 1.6 / Wujiacun Water Reclamation Plant / E116°23′54.6″ / N39°57′13.92″
Lianhua / 0.15 / 1.6 / Wujiacun Water Reclamation Plant / E116°18′36.48″ / N39°53′27.11″
Liuyin / 0.07 / 1.0 / Wujiacun Water Reclamation Plant / E116°23′53.40″ / N39°57′35.88″

Table S2 The classification standard of lake water quality and water function in China

Water classification / Water function / TN (mg/L) / TP (mg/L) / COD (mg/L) / BOD (mg/L)
Class I / Applicable to water source and state reserve / 0.2 / 0.01 / 15 / 3
Class II / Applicable to centralized source of drinking water, hydrobiology habitat and etc. / 0.5 / 0.025 / 15 / 3
Class III / Applicable to centralized source of drinking water, aquaculture and etc. / 1.0 / 0.05 / 20 / 4
Class IV / Applicable to industry and recreation / 1.5 / 0.1 / 30 / 6
Class V / Applicable to agriculture and landscape / 2.0 / 0.2 / 40 / 10

Table S3 Correlations between trophic state index and the level of the lake water quality (Wang et al. 2002)

Trophic state / Trophic state index / Water quality
Oligotrophic / 0<TLI≤30 / Excellence
Mesotrophic / 30<TLI≤50 / Good
Eutrophic / 50<TLI≤60 / Polluted
Supereutrophic / 60<TLI≤70 / Superpolluted
Hypereutrophic / 70<TLI≤100 / Hyperpolluted

Table S4 Trophic Level Index of twelve urban lakes of Beijing city from 2009 to 2011

Lake name / 2009 / 2010 / 2011
TLI / Eutrophic state / TLI / Eutrophic state / TLI / Eutrophic state
Tuancheng / 35.5 / mesotrophic / 36.8 / mesotrophic / 47.1 / mesotrophic
Kunming / 47.2 / mesotrophic / 49.9 / mesotrophic / 47.6 / mesotrophic
Qianhai / 51.7 / eutrophic / 52.1 / eutrophic / 51.3 / eutrophic
Houhai / 50.9 / eutrophic / 53.7 / eutrophic / 54.4 / eutrophic
Fuhai / 59.1 / eutrophic / 50.0 / mesotrophic / 57.0 / eutrophic
Beihai / 57.5 / eutrophic / 60.1 / supereutrophic / 53.5 / eutrophic
Qingnian / 59.6 / eutrophic / 56.3 / eutrophic / 59.4 / eutrophic
Yuyuantan / 53.7 / eutrophic / 61.5 / supereutrophic / 69.6 / supereutrophic
Longtan / 61.8 / supereutrophic / 65.4 / supereutrophic / 66.0 / supereutrophic
Taoranting / 61.7 / supereutrophic / 61.2 / supereutrophic / 65.5 / supereutrophic
Liuyin / 67.6 / supereutrophic / 66.8 / supereutrophic / 70.8 / hypereutrophic
Lianhua / 72.3 / hypereutrophic / 74.3 / hypereutrophic / 69.7 / supereutrophic

Lake / Variables / Standardised regression (β) coefficient / Lake / Variables / Standardised regression (β) coefficient
Beihai / (b) COD
(P<0.001, R2adj= 0.319, DW=1.78)
F1
(c) TP
(P<0.001, R2adj=0.479, DW=1.56)
F1
(d) Chlorophyll a
(P<0.001, R2adj= 0.493, DW=1.66 )
F1
F2 / 0.582
0.703
0.662
-0.290 / Fuhai / (a) DO
(P<0.001, R2adj= 0.337, DW=1.62)
F1
(b) COD
(P<0.001, R2adj= 0.294, DW=1.66)
F1
(c) TP
No significant variables
(d) Chlorophyll a
(P<0.001, R2adj= 0.366, DW=1.58)
F1
F2 / -0.598
0.320
0.488
-0.381
Lake / Variables / Standardised regression (β) coefficient / Lake / Variables / Standardised regression (β) coefficient
Taoranting / (a) DO
(P<0.001, R2adj= 0.585, DW= 1.78)
F1
(b) COD
(P<0.001, R2adj=0.374, DW=1.71)
F1
(c) TP
(P<0.001, R2adj=0.257, DW=1.85)
F1 / -0.773
0.626
0.528 / Longtan / (a) DO
(P<0.001, R2adj= 0.329, DW=1.53)
F1
(b) COD
(P<0.001, R2adj=0.111, DW=1.52)
F1
(c) TP
(P<0.001, R2adj=0.392, DW=1.64)
F1
(d) Chlorophyll a
(P<0.001, R2adj= 0.632, DW=2.06)
F1
F2 / -0.619
0.373
0.642
s
0.730
-0.275
Lake / Variables / Standardised regression (β) coefficient / Lake / Variables / Standardised regression (β) coefficient
Qingnian / (b) COD (no significant variables)
(c) TP (no significant variables)
(d) Chlorophyll a
(P<0.001, R2adj= 0.189, DW=2.3)
F1 / 0.464 / Liuyin / (b) COD (no significant variables)
(c) TP (no significant variables)
(d) Chlorophyll a
(P<0.001, R2adj= 0.372, DW=1.75)
F2
F1 / -0.506
0.364
Lake / Variables / Standardised regression (β) coefficient / Lake / Variables / Standardised regression (β) coefficient
Yuyuantan / (c) TP
(P<0.001, R2adj= 0.247, DW=1.99)
F1
(d) Chlorophyll a
(P<0.001, R2adj= 0.170, DW=1.3)
F1 / 0.524
0.447 / Lianhua / (a) DO (no significant variables)
(c) TP
(P<0.001, R2adj= 0.147, DW=2.00)
F1
(d) Chlorophyll a
(no significant variables) / 0.384

Table S5b Results of generalized least square (GLS) regression analysis for (a) DO (mg L-1), (b) COD (mg L-1), (c) TP (mg L-1), and (d) chlorophyll a (mg m-3) in urban lakes with highly eutrophication in Beijing from 2009 to 2011. D-W test indicated the data were auto-correlative. F1 represents temperature and precipitation, F2 represents wind speed and sunshine duration. SE represents standard errors, χ2 represents the Wald Chi-Square.

DO Beihai / Estimate / SE / χ2 / p / DO-Qingnian / Estimate / SE / χ2 / p
(Intercept) / 10.011 / 0.2239 / 1999.869 / .000 / (Intercept) / 8.293 / 0.3497 / 562.247 / .000
F1 / -1.574 / 0.2270 / 48.084 / .000 / ZF1 / -.846 / 0.3761 / 5.057 / .025
F2 / .251 / 0.2270 / 1.218 / .270 / ZF2 / .406 / 0.3291 / 1.518 / .218
Chla-Taoranting / Estimate / SE / χ2 / p / DO-Fuhai / Estimate / SE / χ2 / p
(Intercept) / 42.134 / 5.4575 / 59.605 / .000 / (Intercept) / 9.496 / 0.2801 / 1149.076 / .000
ZF1 / 26.628 / 5.4607 / 23.778 / .000 / ZF1 / -1.257 / 0.2948 / 18.184 / .000
ZF2 / -14.398 / 5.7134 / 6.350 / .012 / ZF2 / .123 / 0.2765 / .197 / .657
DO-Yuyuantan / Estimate / SE / χ2 / p / COD-Yuyuantan / Estimate / SE / χ2 / p
(Intercept) / 8.671 / 0.5798 / 223.686 / .000 / (Intercept) / 24.686 / 1.4376 / 294.888 / .000
ZF1 / -.199 / 0.6412 / .097 / .756 / ZF1 / 5.693 / 1.5898 / 12.823 / .000
ZF2 / 1.255 / .5032 / 6.221 / .013 / ZF2 / -2.221 / 1.2478 / 3.168 / .075
DO-Liuyin / Estimate / SE / χ2 / p / COD-Lianhua / Estimate / SE / χ2 / p
(Intercept) / 8.233 / 0.4495 / 335.392 / .000 / (Intercept) / 70.526 / 3.5544 / 393.703 / .000
ZF1 / -1.368 / 0.4834 / 8.012 / .005 / ZF1 / 11.710 / 3.7543 / 9.729 / .002
ZF2 / .962 / 0.4230 / 5.174 / .023 / ZF2 / 5.546 / 3.4363 / 2.604 / .107

Parameters / DOS-TC / DOS-KM / DOS-HH / DOS-QH / SDO-FH / DOS-BH / DOS-YYT / DOS-LY / DOS-LT / DOS-TRT / DOS-LH / SDOqn
Temperature / 0.201 / 0.350* / -0.083 / -0.054 / 0.376* / 0.470 / 0.413* / 0.125 / 0.459 / 0.637 / 0.384* / 0.418
Sunshine / -0.029 / 0.096 / 0.249 / 0.174 / 0.085 / 0.228 / 0.227 / 0.337* / 0.439 / 0.092 / -0.224 / 0.241
meanwind / 0.016 / 0.022 / 0.458 / 0.418 / -0.095 / 0.106 / 0.306 / 0.435 / 0.264 / -0.090 / -0.340* / 0.153
Windspeed / -0.172 / -0.140 / 0.454 / 0.378* / -0.067 / -0.029 / 0.061 / 0.323* / -0.098 / 0.077 / -0.399* / 0.060
Precipitation / 0.025 / 0.011 / -0.183 / 0.007 / 0.211 / 0.232 / 0.113 / 0.222 / 0.263 / 0.341* / 0.209 / 0.315*
COD / 0.298* / 0.249 / -0.100 / 0.237 / 0.554** / 0.112 / -0.211 / 0.498** / 0.274 / 0.270 / 0.218 / 0.474
BOD / -0.159 / -0.088 / 0.085 / -0.047 / 0.165 / 0.130 / -0.103 / -0.226 / -0.119 / 0.330* / 0.152 / 0.130
Chla / 0.380* / 0.168 / 0.230 / 0.318* / 0.051 / 0.294* / -0.380* / -0.203 / 0.076 / 0.328* / 0.331* / 0.380*

*Correlation is significant at the 0.05 level

** Correlation is significant at the 0.01 level

Table S7 Correlation between water quality parameters and climatic factors for lakes with mesotrophication/light eutrophication

Lake Tuancheng / DO / TN / TP / Chla / COD / BOD / Lake Kunming / DO / TN / TP / Chla / COD / BOD
Water temperature / -.477** / -.183 / -.183 / .013 / .057 / -.195 / Water temperature / -.038 / -.277 / .032 / .538** / .117 / -.702**
Precipitation / -.480** / -.044 / -.189 / -.022 / -.112 / -.133 / Precipitation / .010 / .052 / -.078 / -.053 / .-.024 / -.096
Wind speed / .196 / -.144 / .082 / .024 / -.209 / .157 / Wind speed / .118 / .151 / .097 / -.433* / -.190 / .327*
Sunshine duration / .001 / .030 / .485** / .351* / -.250 / .049 / Sunshine duration / -.166 / .296 / .270 / -.055 / -.087 / .194
Lake Qianhai / DO / TN / TP / Chla / COD / BOD / Lake Houhai / DO / TN / TP / Chla / COD / BOD
Water temperature / -.748** / -.164 / .232 / -.393** / .019 / .027 / Water temperature / -.735** / -.043 / .310* / .056 / .114 / .082
Precipitation / -.440** / -.117 / .188 / -.296* / .176 / .048 / Precipitation / -.511** / -.054 / .134 / -.080 / .188 / .065
Wind speed / .440** / .099 / .313* / .284* / .217 / .071 / Wind speed / .476** / .000 / .100 / .051 / -.134 / .025
Sunshine duration / .010 / .100 / .394** / .010 / .082 / .054 / Sunshine duration / .053 / .051 / .486** / .161 / -.102 / .072

*Correlation is significant at the 0.05 level