Study and Evaluation of Environmental flows in the Yellow River Delta Wetland Xingong WANG Yellow River Water Resources Protection Institute 12/10/2010
Outline 1. Background 2. Methodology 3. Research results 4. Practice of EFs 5. Conclusion
Neimenggu Qinghai Shan xi Shaan Shandong xi Sichuan Henan Yellow River in China is flowing through nine provinces, with a total length of 5,464km, basin area 795,000km 2, finally empties itself into the Bohai Ocean.
呼和浩特 银川 榆林 太原 西宁 延安 兰州 西安 洛阳 The main area is Loess Plateau, Main Water- Soil Loss Area is 454,000km 2. Every year, average 400 million tons of sediment deposit on the lower reach of Yellow River which results in rising of river bed with a speed of 10cm.
呼和浩特 56% of the water resource 银川 Hekouzheng 西宁 L a n z h o u 西安 Sanmenxia 郑州 90% of the total sediment 56% of the total water resource comes from the sector, the Source to Lanzhou. 90% of the total sediment comes from the sector, Hekouzheng to Sanmenxia.
The main environmental problems 1. More water Flooding (In the past) 2. Less water Dry up 3. Dirty Water Pollution 4. Turbid Water High sediment 5. Changed Water (Regime) Unsuitable to Aquatic Organism
More Water
Sediments come into Yellow River and result in riverbed increasing. The downstream riverbed is 4-7 meters higher than the ground outside bank on average, the maximum is 13 meters higher. Flood control is the huge and main task for YRCC. The riverbed of Yellow River is 13m higher than Kaifeng. Kaifeng Tower Yellow River bank 13m
Days 250 200 Less Water 150 100 50 0 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 Year From 1972 to 1999, Yellow River dried up downstream for 21 years, amounting to 1050 days.
Dirty Water 10 8 tons 45 40 35 30 25 20 15 10 5 0 43 21 1980s 2007 Wastewater into Yellow River
Changed Water 已建 在建工程 规划工程 积石峡苏只尼娜公伯峡拉西瓦龙羊峡 柴家峡三盛公龙口万家寨盐锅峡乌金峡海渤湾黑山峡天桥青铜峡碛口河口沙坡头兰州大峡小峡古贤八盘峡李家峡大河家刘家峡甘泽坡山坪郑州寺沟峡潼关直岗拉卡西霞院黄丰康扬桃花峪小浪底三门峡 The present and planning hydraulic engineering of the YR
The National Nature Reserve in the Yellow River
Yellow River Delta Nature Reserve Yellow River YR Delta NR
Migration routes in Eurasia Yellow River Delta The nature reserve is an important staging, wintering and breeding site for birds in north-east Asia and around Pacific migration route.
The newest land of China
Estuary ecosystem deteriorated
MoU China Netherlands on Water Management: focus on Yellow River YRD Environmental Flow Study implemented by YRCC, leading a consortium of Chinese and Netherlands experts Contract signed between Royal Netherlands Embassy and YRCC, in the presence of Prince Willem Alexander of the Netherlands on 17 October 2005 ZhengZhou
1. Background 2. Methodology Outline 3. Research results 4. Practice of EFs 5. Conclusion
SEBS evapotranspiration modelling YRD EFS Study Methodology ETc per month spreadsheet calculation water balance + salinity management strategies Micro-method feed back water demand of wetland units (m 3 /month) MODFLOW: spatial distribution of groundwater levels SOBEK 1D-2D: supplies water flow to meet water demands spatial distribution of inundation duration per year spatial distribution of groundwater levels LEDESS: ecotope and ha bitat assessment Macro-method spatial distribution of ecotopes; suitability for indicator species ecological evaluation
Methodology 4 key questions How many areas to be restored (Integrated method) How much water (EFs) do they needed (ET+ physiologic demands ) How to evaluate the restoration results (SOBEK+MODFLOW+LEDESS) How to implement environmental flows (Integrated water resources management and regulation)
Restoration area: 236km 2 Integrated method Objective: Fresh water reed wetlands (1992 level) Scenario A, B, C
Scenarios Design Scenario Current0 Scenario A Scenario B Scenario C Restoration area 3333ha 23600ha 23600ha 23600ha Discharge month Water quantity (10 8 m 3 ) 3-10 3-10 3-10 3-10 0 2.78 3.49 4.17
Assessment standard Landscape Ecological Decision & Evaluation Support System (LEDESS) Freshwater wetland area Indicator species numbers Swan Sauder s gull Red Crown crane
Outline 1. Background 2. Methodology 3. Research Results 4. Practice of EFs 5. Conclusion
Hydrological results of water supplying No water supplying 2.78 10 8 m 3 3.49 10 8 m 3 4.17 108 m 3
Ar ea(ha) Wetland Restoration landscape modeling results 25000 20000 15000 10000 Cur r ent Scenar i o D Scenar i o E Scenar i o F 5000 0 Reed meadow Reed mar sh Tot al r eed Pond Tamar i sk Seabl i t e Sal i na
The number changing of indicator species Red Crown Crane 12000 10000 Good Habitat(ha) Optimal Habitat(ha) 8000 6000 4000 2000 0 Scenario 0 Scenario A Scenario B Scenario C
The number changing of indicator species Sauder s gull 50000 40000 Good Habitat(ha) Optimal Habitat(ha) 30000 20000 10000 0 Scenario 0 Scenario A Scenario B Scenario C
The number changing of indicator species Swan 10000 8000 Good Habitat(ha) Optimal Habitat(ha) 6000 4000 2000 0 Scenario 0 Scenario A Scenario B Scenario C
All scenarios can notably increase reed area through replenishment fresh water to the wetland., the landscape pattern changed a lot. Former reed meadow wetland evolved to reed marshes after 5 years, which are extensively distributed in the demonstration area. As for YRD, large area ponds formed by scenario B and C have important ecological values in sustaining wetland water balance. Besides, ponds are optimal habitats for most swimming fowl like Red Crown Crane, Sauders gull and swans. But it is not the more water quantities we discharged, the better outcomes we can get for reed wetlands restoration.
Stakeholders meeting 2008, Dong ying, Shangdong, China
Outline 1. Background 2. Methodology 3. Research Results 4. Practice of EFs 5. Conclusion
Integrated management and regulation of water resources- Guarantee enough water to flow into Delta Remote monitoring system of sluice gate
Recharging water to important wetlands Restored wetlands
Create man-made flooding to flush sediment -more than 0.6 billion tons of sediment that were accumulated reservoir and riverbed downstream were flushed into the sea, improved degraded river ecosystem, etc.
Outline 1. Background 2. Methodology 3. Research Results 4. Practice of EFs 5. Conclusions
Big rivers restoration should be consider at a basin s and macroscopic perspective. Landscape ecology approaches are good ways to solve complex problems in river ecosystem management and restoration. Environmental flows, as one of essential elements of sustainable water resources management, is playing an important role on keeping rivers healthy life. Optimizing big Reservoirs operating mode and implement ecological regulation is a basic method to restore the Yellow River ecosystem.
Thank you for your attention