Gippel hydrology & rh nov_2010_b

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Gippel hydrology & rh nov_2010_b

  1. 1. River Health and HydrologicalAlteration 河流健康和水文因素Dr Chris GippelTraining Workshop Beijing2010 November 19
  2. 2. Contents• Role of hydrology as a river health indicator• Introduce the Taizi River basin• Apply a hydrological index• Develop a new method based on flow needs• Test the method in the Taizi River basin
  3. 3. Catchmentmanagement Physical policy Geology Hydrology Geomorphology Climate Land use Hydraulic habitat Economy Education Trade, etc Ecological river health Social river health Rivermanagement policy Water quality Ecological processes Chemical Biological
  4. 4. Main Issues 主要问题• Hydrology RESPONDS to catchment and disturbance• Hydrology DRIVES the ecology• Is it OK to mix response and driver variables?• YES• Hydrology is open to management action to improve health
  5. 5. Choices 选择• Indicators of 指标 : – Hydrological alteration – Hydrological stress – Hydrological disturbance – Hydrological deviation – …….• Ostensibly 表面上 : – “ecologically meaningful” “生态意义”• Warning 警告 – From a different area 从一个不同的区域 – Not linked to ecological assets of interest 没有联系到当地的生态环境
  6. 6. Objectives 目标• Assess hydrological health of Taizi River• Try an index of hydrological stress• Develop a new method sensitive to: – Local ecological assets – Local hydrology – Local flow-ecology knowledge – Closely linked to flow management options
  7. 7. Taizi River Basin Shenwo Reservoir 参窝水库 Finished 1972 7.91 × 108m3 Guanyinge Reservoir 观音阁水库 Finished 1995 Finished 1995 Tanghe Reservoir 21.68 × 108m3 汤河水库 Finished 1969 7.07 × 108m3Yingkou Flow data from 1950s
  8. 8. 2,000 Flow exceeded 5 percent of the time 2,500 Flow exceeded 5 percent of the time Benxi TangmazaiDaily discharge (m3 /s) Daily discharge (m3 /s) 2,000 1,500 1,500 1,000 1,000 500 500 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 350 Median and Interquartile range [exceeded 75 - 25 percent of time] 1,000 Median and Interquartile range [exceeded 75 - 25 percent of time] Daily discharge (m3 /s) Daily discharge (m3 /s) 300 800 250 200 600 150 400 100 200 50 0 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 3.5 Relative interquartile range [IQ range/median] 8.0 Relative interquartile range [IQ range/median] Relative IQ range Relative IQ range 3.0 7.0 2.5 6.0 5.0 2.0 4.0 1.5 3.0 1.0 2.0 0.5 1.0 0.0 0.0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  9. 9. Flow Stress Indicator• Mean annual flow• Seasonal difference• Seasonal timing• Low flow magnitude• High flow magnitude• Days of river drying up• Flow duration• Flow variability
  10. 10. Benxi (pre-Guanyinge V. post-Guanyinge) Liaoyang (pre-Tanghe/Shenwo V. post-Tanghe/Shenwo) 1.0 1.0 Hydrological change Index valueHydrological change Index value 0.9 0.99 0.9 0.980 0.8 0.85 0.8 0.87 0.7 0.75 0.7 0.77 0.73 0.6 0.683 0.67 0.6 0.59 0.60 0.60 0.59 0.5 0.5 0.55 0.53 0.4 0.47 0.4 0.3 0.35 0.3 0.2 0.2 0.23 0.1 0.18 0.1 0.10 0.13 0.00 0.0 0.0 Xiaolinzi (pre-Tanghe/Shenwo V. post-Tanghe/Shenwo) Liaoyang (pre-Tanghe/Shenwo V. post-Guanyinge) 1.0 1.0 Hydrological change Index value Hydrological change Index value 0.9 0.991 0.9 0.92 0.912 0.8 0.8 0.84 0.7 0.79 0.78 0.7 0.77 0.74 0.6 0.67 0.6 0.68 0.62 0.64 0.5 0.5 0.54 0.54 0.4 0.4 0.44 0.3 0.34 0.3 0.32 0.2 0.2 0.1 0.1 0.13 0.03 0.06 0.09 0.00 0.0 0.0 Xiaolinzi (pre-Tanghe/Shenwo V. post-Guanyinge) 1.0 Hydrological change Index value 0.9 0.937 0.90 Can measure differences in periods 0.8 0.86 0.7 0.6 0.5 0.66 0.58 0.65 Does not work on a single year 0.4 0.46 0.48 0.3 0.34 0.2 0.1 0.10 0.03 0.0
  11. 11. Rapid eco-hydraulic environmental flowsassessment• We need to know about the eco-hydraulics• What specific flows will satisfy the needs of the identified ecological assets?• Ecology responds to – Velocity – Depth hydraulics – Width – Shear stress
  12. 12. Flow components King et al (2008) Building Block Method
  13. 13. Baseflows Benxi 45 Median baseflow daily discharge (m3/s) 40 35 30 25 20 15 10 5 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Pre-Guanyinge Dam 3.7 3.8 4.0 8.7 20.8 17.3 23.5 38.6 26.0 15.1 11.1 5.6 Post-Guanyinge Dam 14.2 15.1 16.1 19.1 23.0 27.5 28.4 16.6 12.1 18.7 16.9 13.9
  14. 14. Baseflows Tangmazai Median baseflow daily discharge (m3/s) 70 60 50 40 30 20 10 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Pre-Tang/Shenwo 9.3 8.6 10.8 19.4 20.0 18.6 17.1 65.3 45.3 33.2 31.0 16.1 Post-Tang/Shenwo 10.3 10.0 13.1 11.3 16.1 59.3 35.1 32.7 25.6 18.0 17.1 11.6 Post-Guanyinge 12.6 13.3 12.8 13.6 42.8 18.8 25.8 26.6 23.5 17.7 16.4 13.6
  15. 15. Cease to flow Cumulative annual days of cease to f low Liaoyang Annual peak cease to f low spell duration 350Days of cease to flow 300 250 200 150 100 50 0 Tangehe Shenwo Guanyinge
  16. 16. Flow events Frequency Duration
  17. 17. Hydraulic information• No surveys• Need to find whatever is available• Gauging stations have useful information• Can derive as a function of discharge: – Velocity – Depth – Width – Shear stress• These variables are used to determine the discharge that will satisfy the hydraulically defined ecological and geomorphological objectives
  18. 18. Benxi 18/06/2001 24/05/1978 120Elevation (m ASL) 115 110 105 100 0 50 100 150 200 250 300 350 Chainage (m) 0 500 Benxi metres Weir
  19. 19. Liaoyang Liaoyang 8/11/2001 8/11/2001 19/07/1978 19/07/1978 35 35Elevation (m ASL)Elevation (m ASL) 30 30 25 25 20 20 15 15 -500 -500 0 0 500 500 1000 1000 1500 1500 2000 2000 2500 2500 3000 3000 3500 3500 4000 4000 Chainage (m) Chainage (m) Weir Liaoyang 0 2 km
  20. 20. Xiaolinzi 13/09/2001 2/05/1978 19Elevation (m ASL) 17 15 13 11 9 7 5 1000 800 600 400 200 0 -200 Chainage (m) 0 500 metres Xiaolinzi
  21. 21. Tangmazai 2/09/2001 3/06/1978 16 14Elevation (m ASL) 12 10 8 6 4 2 0 0 200 400 600 800 1000 1200 Chainage (m)
  22. 22. Geomorphological objectivesID Objective Flow Hydraulic Frequency/ Timing Reach component criteria Duration1a Maintain Bankfull/overba Morphologically Every 2 years Anytime All channel form nk defined levels1b Flush fine Low flow pulse Critical shear 1 – 2/year, Mar-May All sediment from stress to 0.5 – 1 day surface of bed mobilize silts and >30% of bed materiala1c Mobilize coarse High flow Critical shear Annual Anytime All bed sediments pulse/bankfull stress to mobilize >70% of bed material1d Maintain key in- High flow Morphologically Annual Anytime All channel pulse/bankfull defined level physical habitat forms
  23. 23. Fish objectivesID Objective3a Maintain sufficient water depth in pools for large bodied fish3b Maintain sufficient depth in riffles and in depositional habitats out of the main flow3c Localised movement of resident fish3d Maintenance of benthic habitats and hyporheic flushing3e Provide habitat during the high flow period, to induce spawning and to maintain transport of semi-buoyant eggs within the water column3f Stimulate spawning migration and maintain longitudinal connectivity3g Provide access to floodplain habitat
  24. 24. Invertebrate objectivesID Objective4a Maintain sufficient depth in riffles4b Maintenance of benthic habitats and hyporheic flushing4c Maintenance of half of the width of the bed wet for habitat4d Provide habitat during the high flow period, make some pool along the river full of water4e Provide access to floodplain habitat
  25. 25. Waterbird objectivesID Objective5a Maintenance of half of the width of the bed wet for habitat5b Provide habitat during the high flow period, make some pool along the river full of water, provide the habitat for the bird to nest
  26. 26. Preliminary result only 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968OverbankBankfullHigh flow pulseLow flow pulseHigh flowLow flow 1Low flow 2 Before Tangehe and Shenwo 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994OverbankBankfullHigh flow pulseLow flow pulseHigh flowLow flow 1Low flow 2 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 After Tangehe and ShenwoOverbankBankfullHigh flow pulseLow flow pulseHigh flowLow flow 1Low flow 2 After Guanyinge
  27. 27. Conclusion• It is possible to develop indicators sensitive to the local hydrology and ecology• Most of the data and knowledge are already there

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