Characteristics of dissolved N 2 O concentrations and flux in the agricultural watershed of Jurong Reservoir

Transcription

1 Characteristics of dissolved N 2 O concentrations and flux in the agricultural watershed of Jurong Reservoir Reporter: BIAN Hang

2 Outline 1 Introduction 2 Experimental method 3 Results and Discussion 4 Conclusions 2

3 Outline 1 Introduction 2 Experimental method 3 Results and Discussion 4 Conclusions 3

4 1 Introduction Nitrous oxide (N 2 O) is the third most important greenhouse gas and grows annually by.2 percent as a result of anthropogenic perturbation in antural nitrogen (N) cycle (Khalil et al., 22). Agriculture is the major source of N 2 O (Kroeze et al.,1999), while little attention is given to agriculture watershed. (Beaulieu et al., 28). This report studies N 2 O concentration and flux in the Jurong Reservoir watershed, which has obviously spatial and temporal changes.

5 Outline 1 Introduction 2 Experimental method 3 Results and Discussion 4 Conclusions 5

6 2 Experimental method 2.1 Site description and sample collection Fig.1 Location and sampling map of the Jurong Reservoir watershed.

7 2 Experimental method 2.2 Sample analyses K ] [ N2O] g /[ N2O L [ N O] W [ N2O] 1 ( k 2 g ) F k [ N [( X V 9 L 2O] L (1 X ) V P EX L V g / V L ( eq) C W C /18) 1 ] k / k6 ( / 6) S C n n=2/3 :for U 1 < 3.7m/s n=.5 :for U 1 3.7m/s k 6 = U 1.7 1

8 Outline 1 Introduction 2 Experimental method 3 Results and Discussion 4 Conclusions 8

9 (a) N 2 O 浓度 (nmol L -1 ) (b) 时间 Fig.2 The N 2 O concentration in River 1 for two years.

10 4 秋冬春夏 (a) N 2 O 浓度 (nmol L -1 ) 水库河流池塘 (b) 秋冬春夏 水库 河流 池塘 水体类型 Fig.3Temporal variation of dissolved N 2 O concentration in different water spaces.

11 6 n=138 N 2 O 浓度 (nmol L -1 ) n=21 n=2 河流 池塘 水库 n=14 n=12 n=12 河流 池塘 水库 水体类型 Fig.4 The dissolved N 2 O concentration in different water space.

12 3 NH 4 + -N 浓度 (mg L -1 ) NO 2 - -N 浓度 (mg L -1 ) (a) (c) 水库 河流池塘 日期 ( 年 - 月 ) NO 3 - -N 浓度 (mg L -1 ) DIN 浓度 (mg L -1 ) (b) (d) 日期 ( 年 - 月 ) NH 4+ -N NO 3- -N NO 2- -N DIN 河流.46 **.61 **.42 **.63 ** 水库 池塘.78 ** **.76 ** 总水体.45 **.6 **.45 **.64 ** Fig.5NH 4+ -N, NO 3- -N, NO 2- -N, and DIN concentrations in different water space in 216 Table 1 Correlation analysis between N 2 O concentration and Inorganic salt in 216

13 NH 4 + -N 浓度 (mg L -1 ) (a) 水库 河流池塘 NO 3 - -N 浓度 (mg L -1 ) 4 (b) Fig.6NH 4+ -N, NO 3- -N, NO 2- -N, and DIN concentrations in different water space in 217 NO 2 - -N 浓度 (mg L -1 ).4.2 (c) 日期 ( 年 - 月 ) DIN(mg L -1 ) 浓度 (d) 日期 ( 年 - 月 ) Table 2 Correlation analysis between N 2 O concentration and Inorganic salt in 217 NH 4+ -N NO 3- -N NO 2- -N DIN River.53 **.68 **.66 **.74 ** Reservoir Pond * Total.46 **.62 **.51 **.68 **

14 Fig.7 The relationship between N 2 O concentration and (a)t (b)do (c)ph(d)orp.

15 Table.3The level of dissolved N 2 O concentration in other rivers ponds,and reservoirs 水体类型 研究区域 时间 N 2 O 浓度 (nmol L -1 ) 参考文献 Upper Thurne( 英国 ) Outram et al., 212 句容水库流域 ( 中国 ) 21.9~ Xia et al., 213 河流 池塘 水库 脱甲河小流域 ( 中国 ) 214.4~ ~138 张羽等, 216 句容水库流域 215.1~ ~7.83 本研究 句容水库流域 21.9~ Xia et al.213 句容水库流域 215.1~ ~32.36 本研究 句容水库流域 21.9~ Xia et al.213 句容水库流域 215.1~ ~51.52 本研究

16 12 1 (a) N 2 O 通量 ( g m -2 h -1 ) (b) 时间 Fig.8 The N 2 O flux in River 1 for two years

17 8 6 (a) 秋冬春夏 N 2 O 通量 ( g m -2 h -1 ) 水库河流池塘 (b) 秋冬春夏 5 水库 河流 池塘 水体类型 Fig.9Temporal variation of dissolved N 2 O flux in different water spaces.

18 1 8 n= n=17 n=18 N 2 O 通量 ( g m -2 h -1 ) 河流池塘水库 n= n=14 n=12 河流 池塘 水库 水体类型 Fig.1 The dissolved N 2 O flux in different water space.

19 N 2 O 通量 ( g m -2 h -1 ) N 2 O 通量 ( g m -2 h -1 ) (a) y=3.52x r=.419,p= T 1 5 (c) r=-.8,p=.93 y=-49.37x ph (b) r=-.241,p=.1 y=-6.88x DO(mg L -1 ) 15 (d) 1 5 r=-.293,p=.1 y=-.466x ORP(mV) N 2 O 通量 ( g m -2 h -1 ) N 2 O 通量 ( g m -2 h -1 ) (a) r=.533,p=. y=5.469x T 25 r=-.52,p=.599 (c) 2 y=-.694x ph 1 5 (b) r=-.83,p=.554 y=-1.754x DO(mg L -1 ) 2 (d) r=-.579,p=. y=-.89x ORP(mV) Fig.11 The relationship between N 2 O flux and (a)t (b)do (c)ph(d)orp.

20 Table.4The level of dissolved N 2 O flux in other rivers ponds,and reservoirs 水体类型 河流 池塘 研究区域 时间 N 2 O 浓度 (µg m -2 h -1 ) 参考文献 乌江流域 刘小龙等,215 句容水库流域 ( 中国 ) 21.9~ ±21.8 Xia et al., 213 脱甲河小流域 ( 中国 ) 214.4~ ±56.41 张羽等, 216 句容水库流域 215.1~ ±38.35 本研究 句容水库流域 21.9~ ±16.3 Xia et al.213 句容水库流域 215.1~ ±2.21 本研究 水库 句容水库流域 21.9~ ±1. Xia et al.213 句容水库流域 215.1~ ±12.48 本研究

21 Outline 1 Introduction 2 Experimental method 3 Results and Discussion 4 Conclusions 21

22 4 Conclusions In Jurong Reservior watershed, the maximum of N 2 O flux appeared in the summer and the peak of N 2 O concentration occurred in the summer and winter. For three types of water bodies, N 2 O flux and N 2 O was maximum in river, higher than that in ponds and reservior. The N 2 O flux decreased gradually from upstream to downstream in River 1. N 2 O concentration in rivers presented obviously postive correlation with ORP and DO, while is negative with ph.n 2 O flux had the obviously postive correlation with T W and negative correlation with DO and ORP.

23 Thank you for your attention! 23