Session: For more information: www.hydropower.org/congress
General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resource Regulation of Downstream Flows in China Li Yuanyuan General Institute of Water Resources and Hydropower Planning and Design, MWR May, 2015
Outline Issues & rational General approach Regulation framework
Issues & rational Present situation Hydropower stations provide clean energy and multiple functions including runoff regulation, water service & disaster mitigation, water resources utilization, flood control, improve navigation etc.. 500 KW Hydropower stations in China (except Taiwan) Scale Amount Installed capacity (MW) total 46758 333000 large-scale 142 207000 middle-scale 477 52000 small-scale 21571 68000 <500 KW 24568 6000
Issues & rational Issues of rivers (i) Significant reduced instream flow (ii) significant influence of natural runoff pattern (iii) changed significantly habitat downstream 200 % water use efficiency in basins (regions) of Change of month-flow at downstream of The northern China Three Gorges 150 100 50 0
Issues & rational Rationales How to balanced demand between human and nature? How to exploit water and hydropower resource sustainable? How to regulate eco-hydrological process properly?
Outline Issues & rational General approach Regulation framework
General approach River basin process Mines River basin Component Soil Water Energy Biota Water cycle Load cycle River basin cycle Energy cycle Ecological cycle Hydro-Ecological Process Biotical Process Landscape Process Hydro-Soil Process Hydro-Power Process Hydro-Salt Process Ecological Process
General approach Concepts & Framework Water Energy Sand & Soil River Ecosystem Services Disaster Mitigation Water services Stability Continuity Diversity Sustainability Reliability Efficiency Variability Instream & offstream Balance Different function Balance Balance human & nature Hydro process Balance Hydro Load Matrix Balance Landscape Process Hydrological Process Health river basin process Energy Process Ecological Process
General approach The development of water resources can not exceed the amount of available water resources. The available water usually accounted for 1/3 of total water resources, should be the upper limit of development. The flood which is difficult to use and control The available water The minimum acceptable environmental flow 1 2 3 4 5 6 7 8 9 10 11 12 The component of surface water
General approach hydropower development should be consider the Environmental Flow Process which maintains the health of river ecosystem. The different environmental flow processes demands the development limitation and dispatching of hydropower station. The downstream water use addup environmental flow The function requirement environmental flow The minimum acceptable environmental flow 1 2 3 4 5 6 7 8 9 10 11 12 The component of surface water
General approach Hence, the development of hydropower should be: consider the constraints The available water resources The environmental flow process optimize the efficiency The efficiency for hydropower The efficiency for water use Balancing natural and artificial state Balancing water use efficiency Optimizing the target Optimizing the process
Outline Issues & rational General approach Regulation framework
Regulation framework The framework of regulation of downstream flow includes FOUR LEVEL REGULATION Policy and basin regulation River reaches regulation Planning and design regulation Operational regulation
Regulation framework Level one: river basin balance and function balance Balance society, economy, and environment needs Balance different demands of river basin Society Economy Environment Regulation of downstream flows Flood control Hydropower Navigation Water supply.
Regulation framework Level two: river reaches regulation hydropower function zoning: four type hydropower function zoning: prohibited zone, restricted zone, reserved zone, and development zone Yangtze River basin reserved zone development zone prohibited zone development zone restricted zone Reserved zone
Regulation framework Level three: planning & design regulation Environmental flow stipulated by National and Sector Standards Environmental flow/total surface water (%) Major rives Large rivers Small rivers Inland rivers The current development degree of river High Medium Low Basic Well Basic Well Basic Well North 10~20 40~50 15~25 45~55 25 60 South 20~30 65~80 25~35 70~80 35 80 North 10~15 40~50 10~25 40~55 25 55 South 15~30 60~70 20~35 65~75 35 75 North 5~10 40~45 10~20 40~50 20 50 South 15~25 50~60 20~30 55~65 30 65 NW 40~50 45~55 55 Tibet 80 80 According to the Specification for Calculation of Environmental Flow in Rivers and Lakes (SL/Z 712-2014)
Regulation framework Level four: operation level, comprehensive considering the different demands of river functions, such as environmental flows demand, the downstream water supply demand, the navigation demand, and so on, to maximum the hydropower outputs. downstream water supply demand navigation demand environmental flows demand Maximum hydropower output
Regulation framework Case study: The Three Gorges Dam downstream flow regulation Consumption control the upstream water utilization 74% of total surface water should be discharged to downstream. Including environmental flow and water demands of downstream 2030 planned total discharge should exceed 85% Basic environmental flow required 34% of surface water should be discharge for basic environmental use 24% of in flood season and 61% in non flood seasons runoff Process of total downstream flows 78% of flood season runoff and 61% of non flood season runoff should be discharge (8083 and 2500m 3 /s)
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