1. Monitoring and estimation of land-based nutrients loads in the yellow sea region: Methodology and case study National Marine Environmental Monitoring Center Zhifeng Zhang, Lijun Wang 2010.2.25

2. Content Background Research Contents Materials and Methods Results and discussion Conclusion Advice on total loading control of nutrients

3. Background Research background  Yalu River is one of the most important rivers in Yellow Sea Region, and Yalu River estuary is one of the high- eutrophication-level areas defined by the “UNDP/GEF YSLME”.  to facilitate protection and sustainable use of marine and coastal resources, mitigate environmental problems, and improve the biological diversity of marine ecosystem in the Yellow Sea, YSLME conducted demonstration activities on some of the key management actions.  This demonstration actives was conducted to estimate the land-based nutrients loads from the Yalu river, and to recognize the major sources.

4. Background Physical geography of the Yalu River  Bounder river of China and DPRK  is 795 km long, covers a watershed area of about 63,700 km 2

5. Major cities:  Changbai, Linjiang, Kuandian, Dandong in China Major tributaries:  Ai River, Pushi River in China River flow and climate condition  The flood season is usually from June to August, discharging about 60% of the annualflux, and the ice period is usually from December to next April.  annual temperature and humidity in Dandong were 8.9 ℃ and 69%.  the annual precipitation was about 925.6 mm.

6. Background The society and economics  Dandong Land area: about 15,000 square hectares Population: 2.42 million Pillar industries: automobile, cotton spinning, paper making and aquaculture food supplies: corn, rice and soya economic crops: oil plants, tobaccos, medicinal plants, trawberry, and chestnut.  Other cities such as Changbai, Linjiang and Kuandian are agriculture-dominant area

7. Background Environment quality status  Wastewater discharge 69 enterprises are discharging wastewater over 100 tons per day in 2005 the water quality of Yalu River improved significantly compared to 1990s.  pesticide and fertilizer use and soil erosion pesticide and fertilizer used in the whole watershed were about 1,325 and 174,500 tons in 2005 the area of soil erosion was about 3908.6 km 2 in Dandong, which is about 27% of the total area  Marine environment status harmful algal blooms (HABs) occurred frequently over the past decades in Yalu River estuary

8. 1996~2002 2003~20091996~2009 The largest HABs reported there was to be nearly 1,100 square kilometers, which occurred from 24th Aug to 14th Sep 2001

9. Research Contents Collection of historical data and statistical information Monitoring of discharging sources of nutrients into the Yalu River estuary Establishment of calculation model for the total loading of nutrients from various sources Seasonal field surveys and validation of the calculation model Identification of the major nutrient sources for the Yalu River estuary To propose management actions for local government agencies for the total loading control of nutrients

10. Materials and Methods Historical data collection  Flux of the Yalu River from 2003~2009  Monitoring data of the pollutants concentration of the Yalu River from 2003~2009  Monitoring data of the sewage and industrial effluent, from 2003~2008  Monitoring data of the marine and estuary water  Statistics information of mariculture in Yalu River estuary  Land use types of the Yalu River watershed  Other related data from scientific research projects carried out in this area

11. Field surveys China North Korea Dandong 8 sampling sites were in the downstream of Yalu River, with the sample salinity from 0 to 20 9 monitoring stations were in Yalu River estuary with the sample salinity from 20 to 28 One 24h-continuously monitoring station was at A4 station, water samples were collected per two-hours;

12. China North Korea Sampling SiteDDO nameSampling SiteDDO name D1Bamen No.10D8Qiantanggou D2Wenhua SquareD9Longtai river D3Huayuan riverD10Zaoergou D4WudaogouD11Yilong river D5SidaogouD12Dayang river D6Langtou No.2D13Shangcha river D7Langtou No.1D14Shaba river 14 DDOs sampling sites

14. Materials and Methods Pollutant load calculation method

15.  Riverine loads calculation method L R  Annual loading of nutrients from Yalu River; K i  Monitoring interval for batch j; C j  Concentration of nutrients in water samples for batch j; Q i  River water flux for time i in batch j; n  Number of data for river water flux; j  Monitoring frequency of the year.

16.  DDOs loads calculation method L D  Annual loading of nutrients from waste water DDOs; Q i  Wastewater flux during sampling day of batch i; C i  Concentration of nutrients in water samples for batch i; n  4, number of sampling batches per year; T  Discharge time per year for DDOs

17.  land-based non-point sources load domestic sewage farmland surface runoff soil erosion, and livestock farming sewage The catchment cells need to be divided in the whole river watershed, then the load from each catchment cells is calculated firstly.

18. the Yalu River watershed was divided into 36 catchment cells, according the topographic map of the watershed in China side.

19.  Domestic sewage production estimation (discharge coefficient method ) L 1  Domestic sewage pollutant production [kg/yr]; i  Calculated catchment cell number, the total amount of cells is n; f 1,f 2  Rural and urban domestic sewage production coefficient [kg/(person·yr)]; Q 1i, Q 2i  The rural and urban population in the calculated cell i (person); λ 1, λ 2  Collection and pretreatment ratio of rural and urban domestic sewage in calculated cell i China Environment Protection Standard

20.  Livestock- farming sewage production estimation (discharge coefficient method ) L 2  Livestock farming sewage production [kg/yr]; i  Calculated catchment cell number, the total amount of cells is n; f 3 ~f 7  The discharge coefficients of cattle, sheep, pig, poultry and rabbit respectively [kg/(individual·yr)]; Q 3 ~Q 7  Amounts of cattle, sheep, pig, poultry and rabbit respectively in calculated cell i. Hong Huasheng et al

21.  Chemical fertilizer pollutant production estimation (discharge coefficient method ) L 3  Chemical fertilizer pollutant production [kg/yr]; i  Calculated catchment cell number, the total amount of cells is n; f 8, f 9  Nitrogenous fertilizer and phosphorus fertilizer loss ratio (%), the empirical value is 5%, T ni, T pi  the amount of N and P element in the fertilizer (kg).

22.  Soil erosion pollutant production estimation (USLE model ) L 4  Soil erosion pollutant production [kg/yr]; A i  Soil loss in calculated cell i; i  Calculated catchment cell number, the total amount of cells is n; Q ai  the average concentration of absorption fractions of pollutants in calculated cell i; η  The accumulation coefficient of soil-absorbed fractions from non-point sources;

23.  Estimation of nutrient loads from mariculture (law of conservation of mass, OSPAR) L M  P or N discharged to water body (ton/yr); I  weight of feed used (ton/yr); C i  P or N content in feed (%); G  Prawn production (ton/yr); C f  P or N content in grown prawn (%).

24. Data collected from Li Chunhou et al

25. Results and discussion Nutrient loads from Yalu River  River flow The flow rate of the Yalu River presented a seasonal character, and the flood season started in June to August, with an average flow rate of 856.6 m 3.s -1, and in the dry season the average was 589.8 m 3.s -1. The annual average flow rate from 2003 to 2009 was 501~983 m 3.s -1, with an average flow rate of 682 m 3.s -1. The maximum flow rate was 1736 m 3.s -1, occurred in July 2005, and the minimum flow rate was 361 m 3.s -1, occurred in May 2009.

26. Month average flow rate of the Yalu River Annual average flow rate of the Yalu River

27.  Water quality of Yalu River The concentration of NH 3 -N in the Yalu River showed decreasing from 2003~2009, The annual average was 0.12~0.41 mg/L, with maximum value in 2003 and minimum value in 2009. There was no obvious trend for TN and TP, partially due to the very low concentration and insufficient data series.

28. concentration of TP of Yalu River concentration of NH 3 -N of Yalu River concentration of TN of Yalu River

29. Pollutant loads from Yalu River  Daily loads the daily load of NH 3 -N, TN and TP from 2003 to 2009 was 0.3~23.5 tons/d, 0.23~4.79 tons/d and 49.8~116.5 tons/d respectively.

30.  Annual loads The annual loads of TN, TP and NH 3 -N were calculated based on the daily loads. The annual loads of TN were 22,531~37,340 tons from 2003~2009, with an average of 24,610 tons; the annual loads of TP were 114~672 tons, with an average of 395 tons; and for NH 3 -N, the annual loads were 3,372~6,268 tons with an average of 4,794 tons.

31. Nutrient loads from DDOs  Types of DDOs I - wastewater discharged directly to Yalu River (14 DDOs ) II - wastewater discharged directly to the sea (7 DDOs )

32.  The annual loads of pollutants to the Yalu River increasing Decreasing So, even with the upgrade of the wastewater treatment capacities, the increasing use of the water and wastewater discharge may cause the load of pollutant in high level

33. Station No.DDOsTPTN D8Qiantanggou0.0371.25 D9Longtaigou0.0901.18 D10Zaoergou0.0610.40 D11Yilong river0.0340.40 D12Dayang river0.3063.77 D13Shuangcha river0.0480.46 D14Shaba river0.0330.58 Subtotal0.6108.05  Annual load of the pollutants from type II DDOs to Yellow Sea

34. Nutrient loads from non-point sources ProvinceCity TN/tonproportion/% sewagelivestockfertilizersoil erosionsubtotalsewagelivestockfertilizersoil erosion Jilin Tonghua city84.58213.0778.23966.781342.666.3015.875.8372.00 Tonghua county165.12394.93153.36487.961201.3713.7432.8712.7740.62 Ji’an188.45455.19179.51936.161759.3110.7125.8710.2053.21 Liuhe31.6270.5129.126.30137.5522.9951.2621.174.58 Baishan87.81337.4624.971099.361549.605.6721.781.6170.94 Fusong44.45166.3110.39564.81785.965.6621.161.3271.86 Liaoning Dandong35.4744.2723.38275.70378.829.3611.696.1772.78 Fengcheng280.19366.60193.63981.371821.7915.3820.1210.6353.87 Donggang13.2616.5511.4412.5453.7924.6530.7721.2723.32 Kuandian428.27534.59295.861425.052683.7715.9619.9211.0253.10 Hengren160.03438.9775.79749.121423.9111.2430.835.3252.61 Benxi22.4461.569.3625.51118.8718.8851.797.8721.46 Xinbin46.7984.8824.3817.51173.5626.9648.9114.0510.09 Total1588.473184.881109.437548.1913430.9611.8323.718.2656.20

35. ProvinceCity TP/tonproportion/% sewagelivestockfertilizersoil erosionsubtotalsewagelivestockfertilizersoil erosion Jilin Tonghua city6.345.369.16102.37123.235.144.357.4383.07 Tonghua county11.749.9420.7651.6694.1012.4810.5622.0654.90 Ji’an13.4011.3420.0499.12143.909.317.8813.9368.88 Liuhe2.251.894.930.679.7423.1119.4150.646.84 Baishan6.2411.211.57116.40135.424.618.281.1685.95 Fusong3.164.050.7959.8067.804.665.971.1788.20 Liaoning Dandong2.521.611.4929.1934.817.244.624.2883.86 Fengcheng21.8413.319.66112.55157.3613.888.466.1471.52 Donggang0.940.600.441.333.3128.4118.1413.3040.15 Kuandian30.4519.4017.29150.89218.0313.978.907.9369.21 Hengren11.3817.486.7179.32114.899.9115.215.8469.04 Benxi1.602.000.942.707.2422.1027.6212.9837.29 Xinbin3.332.743.591.8811.5428.8523.7431.1016.31 Total115.20100.9497.38807.891121.4110.279.008.6872.04

36. Nutrient loads from mariculture load of TN and TP were calculated to be 321.9t and 130.1t

37. Annual loads of nutrients for Yalu River estuary in 2008  the total loads of nutrients in Yalu River estuary were mainly consisted of three fractions: nutrient loads from Yalu River, directly from DDOs, and from mariculture. The annual total loads of N and P in the Yalu River estuary was 37,669.7t and 3370t respectively  Yalu River is the major source of nutrients discharged into Yalu River estuary, contributing to total N and P loads with proportion of 99.1% and 96.1%

38. Contribution of DDOs to the nutrient loads of Yalu River DDOs contributed about 13.3%~52.0% of TP and 16.5%~57.7% of NH3-N to the total loads of Yalu River from 2003~2009

39. Contribution of non-point sources to nutrient loads of Yalu River Monitoring and assessment results showed that the non-point sources were the first-order pollution sources for Yalu River estuary, which contributed to 35.6% TN and 33.2% TP of the total loads. If the whole watershed is considered, contribution of non-point sources will be much higher.

40. Conclusion According to the monitoring and assessment results, Yalu River was the major nutrient source of the estuary, annually discharging 37,669.7t N and 3,370t P to the sea in 2008, with a proportion of 99.1% and 96.1% of the total loads of N and P. Annual nutrient loads from DDOs directly to the sea were 8.05t N and 0.61t P respectively, and the annual loads from mariculture were 321.9t N and 130.1t P, respectively. As far as Yalu River – the major nutrient source – was concerned, 14 DDOs along the river contributed 13.3%~52.0% of TP and 16.5%~57.7% of TN to the whole nutrient loads of the river from 2003 to 2008. Non-point sources in the watershed were even more important contributor to Yalu River, more than thirty percent of TP of the total loads were from non-point sources in the watershed of China.

41. Problems…….  However, this work was an original research for the load calculation of N and P in the northern Yellow Sea. The lack of the historical data, especially TN in the study area was a big problem for the assessment of TN load trends.  Nutrient loads from non-point sources were calculated mainly based on empirical parameters and models, which should be verified by on-site monitoring results.

42. Advice on total loading control of nutrients The local marine environmental monitoring agency should frequently check the eutrophication status of Yalu River estuary, especially after the implementation of Society and Economy Developing Strategy for Coastal Areas of Liaoning Province, which was approved by the State Department of China early this year. Promote wastewater treatment capacity of Dandong City and other cities along Yalu River, and to introduce domestic sewage settlement ponds in rural areas. Establish cooperation between crop farming and live-stock farming all through the watershed by collecting livestock excretions as organic fertilizers for crop farms. Promote public awareness education to urban and rural residents, especially the necessity on reduction of nutrient loads from domestic sewage.

43. Acknowledgement Thanks to the YSLME for the research funding. Thanks to Chen Shumei, Zong Humin, Zhao Yunying for samples analysis, and Jiang Yuewen, Xu Mingguo, for the sampling and field determination. Thanks to the members in Dandong marine environmental monitoring center for their assistance during the field surveys and historical data collection.

44. Thanks !