Water Crisis of Lake Taihu, China

Guangwei ZhuTaihu Laboratory for Lake Ecosystem Research (TLLER)

Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (NIGLAS)

2015-10-21

FEW Workshop: Food, Energy, and Water Nexus in Sustainable Cities

ACKNOWLEDGEMENTS

Contract No. 2015DFG91980

Contract No. 2012ZX07101-010

Taihu Laboratory for Lake Ecosystem Research(TLLER)

中国科学院南京地理与湖泊研究所太湖湖泊生态系统研究站

Main campus is 110km west of Shanghai Hongqiao airport

Taihu Laboratory for Lake Ecosystem Research(TLLER)

中国科学院南京地理与湖泊研究所太湖湖泊生态系统研究站

Taihu Laboratory for Lake Ecosystem Research(TLLER)

中国科学院南京地理与湖泊研究所太湖湖泊生态系统研究站

Lake in China and where is Lake Taihu?

Ma et al., Geophysical Research Letters, 2010.

Taihu

2009 data

2693 lakes(> 1 km2)

81414.6 km2

(smaller than Superior)

243 disappearedIn recent 40 years13% shrink by size

Lakes in China and the location of Taihu

Catchment of Taihu, megacity of Changjiang Delta

Population density: >1200

Water surface: 2338 km2

Average depth: 2 m

Maximal depth: 3 m

A big plate!

Catchment: 36500 km2

Wuxi

SuzhouShanghai

Jiaxing

Hangzhou

Huzhou

Changzhou

Zhenjiang

Taihu is Water source of Wuxi, Suzhou and Shanghai

Water intakes for water plants in Taihu.

Cyanobacterial blooms in Taihu

1950’s 1970’s 1980 1987

1994 2000 2006

History of blooms in Taihu

Major player: Microcystis spp.

Microcystis spp. in Taihu

Microcystis aeruginosa Microcystis wesenbergii Microcystis flos-aquae

Photos by Gregory Boyer, at May 28 2012

Supporting actor: Anabaena spp.

Photos by Gregory Boyer, at May 28 2012

Microcystis and Anabaena are Toxic produced species

Su et al., Toxins, 2015

Microcystin

Water crisis caused by black patch in Taihu

Water crisis happened at Wuxi during May 29 – 3 Jun 2007, for the block of intake at Gonghu blocked by black patch.

The cause 1: Extreme serious bloom, black patch

Serious bloom start 8 April, a month earlier than normal.

The cause 2: Extreme warmer spring

Spring Water temperature

Spring Air temperature

Qin et al, 2010

The cause 3: Suitable wind direction

3. Actions after water crisis of 2007

Catchment:

In lake: Bloom collection Sediment dredging Ecological engineering

Fertilization control Ecological restoration

Water hyacinth

The total investigation is over 100 billions RMB

What we done: Monitor and forecast the bloom

Based on Remote sensing image interpret bloom

Chlorophyll a Temperature Suspended solid Transparency

Data sources: HJ – CCD MODIS MERIS GOCI

Interpret model: APPLE model or 3 wavelengths model: 660-690 nm; 710-730nm; > 730nm

And high frequency sensors buoy system monitor

水环境自动监测站点分类

EMB01 EMB02 EMB03

EMB08 EMB10 EMB11 EMB12 EMB13 EMB14

EMB4 EMB5 EMB6 EMB7

Hydrodynamical bloom simulation model

3D model

Model result

Field data

Model calcultion Model calibration

Model development and calibration

Stereo

-mo

nito

ring

system in

L

ake Taihu

Chlorophyll a and DO model

Chl-a DO

3-days forecast report to local goverment

Possible reaction of local managers

Water plants: Change the

intake site, or use

Yangtze river as source,

prepare the active carbon

addition.

Tourism agency: Change

the travel lines.

Monitoring agency: Pay

more attention to High

possible zone.

Bloom emergency action

organization: adjust the

collection power invest.

Other solution: reservoirs

Reservoir Qiandaohu:Surface area of 571 km2, and volume of 18 billion m3, 4 times of TaihuInvested 1 billion to protect water quality in recent 5 years.Will supply Hangzhou, one of the big cities in Changjiang Delta soon.

Take home messages

Taihu, located in the center of megacity Changjiang Delta region,

is seriously over-burden to supply the cities around it, largely

affect the sustainable development of these cities.

Environmental sensors and information technology, include high-

frequency buoy and models, has been used to prevent drink

water pollution event in Taihu.

The ability of environmental technology to is limited. The over

burden water issue is a social and economic issue, too. To solve

the problem, more social and economic solutions should be

involve in.

Thank you for your attention!

Guangwei Zhu, professorExecutive vice director of TLLEREmail: gwzhu@niglas.ac.cn