Presentation on theme: "Water Quality and Ecological Restoration Bomchul Kim Department of Environmental Science Kangwon National University."— Presentation transcript:
Water Quality and Ecological Restoration Bomchul Kim Department of Environmental Science Kangwon National University
Contents 1.Water quality issues in Korea 2.Turbidity in streams and reservoirs 3.Water quality survey project in Haean 4.Control measures to improve water quality
Change of water quality issues in Korea Before 1970s –No pollution problems –No concern about environmental conservation In 1980s –High BOD from sewage –Fish farms installed in many reservoirs In 1990s –Sewage treatment systems established –Active operations of fish farms within reservoirs –Eutrophication problems emerged –Algal toxins were reported
Current issues in 2000s 1.Turbidity and siltation – major ecological hazard 2.TMDL of BOD and TP for water quality management Phosphorus removal from sewage 3.Biological assessment – new paradigm 4.Automatic monitoring – high frequency monitoring
Turbid water of the Soyang River on flood days that flows into Lake Soyang (July 15, 2006) Increased rainstorm intensity - Due to global warming ?
Two hot spots of turbid water discharge Haean Jawoon Lake Soyang
Soil disturbance in Haean (2007. Mar.8)
Making flatter fields for better cultivation – a cause of erosion in Haean Original slope Made flatter Made steeper
Tilling in Haean basin and the turbidity in Lake Soyang Turbidity
Movement of turbid interflow in Lake Soyang (result of simulation by CE-QUAL-W2, 1996)
Turbidity increase in Lake Soyang
Turbidity problem in reservoirs Turbid water lasts 3 months after summer monsoon in the Han River. Reservoirs are filled with turbid water after monsoon. Large dams prolongs the duration of turbid water in downstream. Destroys aquatic ecosystems. SAV is reduced. Fisheries is reduced.
Water blooms in Lake Soyang after turbid storm runoff cyanobacteria
increasing trend Phosphorus loading into Lake Soyang
Bongsan Daeki Land use vs. water quality Comparison of clean streams and turbid streams - case study of two couple sites (in 2006)
A turbid stream (Jawoon) and a clean stream (Kyebang) In 2007
A turbid stream (Daeki) and a clean stream (Bongsan) Result : change and reduction of fish and benthos community
Water quality survey project in the Haean basin Purpose : to evaluate effectiveness of soil erosion control and diffuse pollution control –To assess water quality improvement in subbasins w/wo erosion control measures –To assess efficiencies of each erosion control method –To quantify specific export of nonpoint source pollution Period : six years from 2009
Site of investigation Wolsan Seonghwang Kunjigol Naedong Doonjunggol Chungryounggolan
Land use in subbasins (km 2 ) WatershedTotalPaddyUplandForestetc. Naedong Doonjunggol Kunjigol Seonghwang Chunryounggolan Wolsan Mandae
Water level measurement Water level scales were installed. Two automatic water level meter (sonic distance meter type) and two automatic water samplers will be installed in next year. Str. NaedongStr. DoonjunggolStr. Kunjigol Str. SeonhwangStr. ChungryunggolStr. Wolsan Str. Mande
Effect of suspended sediment on fish References Minimum (mg·L -1 ) Moderate (mg·L -1 ) Serious (mg·L -1 ) <2525~80>80EIFAC, 1964 <2526~80>80 Alabaster, 1972, NAS and NAE, 1973, Alabaster and Lloyd, 1980 <2526~100>100 Newport and Moyer, 1974 <3030~85>83Wilber, 1969, 1983 <10 --Hill, ~100>100DFO, 1983 <1010~100>100 Mills et al >25 (<10 d/yr), >80 (< 5 d/yr) >25 (11~30 d/yr), >80 (5~10 d/yr) >25 (> 31 d/yr), >80 (> 11 d/yr) No fish is living in the Haean basin
WatershedLand useBODTNTPReference EPA, USA Mixed agricultural-1, Reckhow et al.(1980) forested urban USA and Europe forest-100~6300.7~88 Loehr et al.(1989) Rural cropland-2,100~7,9606~290 Wisconsin, USA agricultural Clesceri et al.(1986) forest Eastern, USA. forest-3005~10 Rast and Lee (1978) agricultural Mandaeagricultural - forest 2,3871, ,9896, Jawoonagricultural -forest 1,0873, The amounts of TP exported from these two basins were considerably high, compared to other many studies Table 3. The export loadings(kg yr -1 km -2 ) in each watershed.
Control measures of turbid water Sociological strategy Environmental management Agricultural practice
Struggling to control erosion in Haean
sometimes …… in vain
To protect steep slope
Food vs. Water Disturbed land poor water quality Conserved ecosystem good water quality Can we choose only one? The goal of Korea. ;even with intensive agriculture good water quality Is it possible?