The effects of urban growth on
downstream water resources
Mike Hutchins (CEH Wallingford)
Steven Loiselle (Earthwatch Institute)
Steven Loiselle
Community monitoring / citizen science
Lack of field
data for monitoring, earth
observation, model
validation
Active and knowledgeable
communities supporting
improved environmental
management and policies
Why?...
Citizen/Community Science and modelling/monitoring
https://freshwaterwatch.thewaterhub.org
A network of citizen scientists acquiring water quality data in a consistent manner across the globe …
Supporting modelling and management programmes of leading scientists and agencies in 30 locations…
Obtaining robust and consistent water quality and ecological dataExternal and automated quality control
Wat
er c
olou
r
low density
(<14500 org/ml)high density
(>14500 org/ml)
Castilla et al. "Quantification of phytoplankton bloom dynamics by citizen scientists in urban and peri-urban
environments." Environmental monitoring and assessment 187.11 (2015).
Citizen scientist data in catchment scale monitoringHigh phytoplankton densities identified and reported
https://freshwaterwatch.thewaterhub.org/totally-thames-water-blitz
Site specific nitrate concentrations Thames Blitz 16/9/2015
(n= 645)
Citizen scientist data in catchment scale monitoringThames Water Blitz - 645 measurements on 16 September 2015
Challenges of scaleWater BlitzBasin averaged phosphate concentrations
Thames Blitz 16/9/2015 Streams and rivers (n= 620, units = mg/L)
Citizen scientist data in catchment scale monitoringThames Water Blitz - 645 measurements on 16 September 2015
Continuous learning and engagement…creating a virtual community
93% Committed to
personal action
89% Improved
understanding
of water issues
92% Excellent
research
experience
…for the scientist and agency ?
…for the participants?
Hours
CSL sampling
Hours
training
CSLs
Is it worthwhile?...
• Previous modelling work shows that there will be an increase in the number of days per year having undesirable water quality
• Eutrophication is likely to become more prevalent and severe
• This assumes no change in population, which is estimated to increase by 16% to 2035
• We are refining these estimates to consider future urbanisation (in POLLCURB project)
How will water quality change by 2050?
• POLLCURB investigates how water pollution
relates to change in urban areas, in particular
brought about by population growth.
• By measuring land cover, river flow and quality
in urbanising case studies (Bracknell/Swindon),
• and thereby by developing better models of how
change in land cover affects water resources….
• Leads to…. a better understanding of
how urban areas affect our water
resources so we can better plan future
urban developments so they have less
unwanted impacts on these resources
A NERC Changing Water Cycle project…
CEH-led: collaborators…
www.pollcurb.ceh.ac.uk
Increase in urban cover since 1960
Satellite imagery
(5 images since
1975)
Aerial
photography
Topographic
mapping (OS)
Derivation of indices of the percentage of impervious surface cover.
Since 1960, increasing frequency/intensity of storm flows, especially in summer. Without 17 new balancing ponds and flood storage areas changes would have been 20% more severe in Bracknell.
Impact of winter 2013-14 storms in Swindon
Ray at Water Eaton (84 km2)
0
20
40
60
80
100
Pry Great Western
Way
Rodbourne Hayden Wick Water Eaton
Sub-catchments (% urban cover)
1. Transient low DO in sub-catchments a response to pollutant first flushes2. Chronic low DO (and high ammonium) only seen at Water Eaton, not elsewhere 3. Summer DO sags are at least as severe as the winter 2013-14 storms4. Winter DO in 2014-15 at Water Eaton was roughly 2 mg/L higher than winter 2013-14
STW
Sources
In-situ sediment
Runoff: roads and paved areas
Trading estates (poor waste control/storage)
Misconnections in separate storm/foul sewer systems
Sewage and household waste
Contaminated land runoff
Mechanisms Timing
Overflows:• Combined sewers• Storm tanks at sewage treatment works deliver untreated sewage
During/following heavy rainfall
First flushes of accumulated pollutants via surface sewers
Rainfall following dry spells
Treated effluents at sewage treatment works
Continuous: especially important at low flow
Leaky infrastructure Continuous
Diagnosing urban pollution: complex system
Modelling activities for 2050s predictions
QUESTOR model (daily time-step)
CEH weekly water quality (2009 - )Upstream QUESTOR boundary
Tidal limit
Major urban areas outside London
LONDON
20 km
9
65
4
3
2
1
8
7
Cellular automata
land use change
Rainfall-runoffUrban water
management
River channel
water flow/quality
Meta-model
River Thames
water resources
Future climate
Future
urbanisation
upscaling
Local-scale
testing
Basin-scale
application
• A 6-month Follow-on Fund Pathfinder award for a scoping study (End: March 2016)
• 3 workpackages: objectives:
– WP1: enable us to define a business model
– WP2: define sensor technologies and a river monitoring network appropriate for professional scientists, community scientists and stakeholders
– WP3: identify model interface most appropriate for end-users to provide timely information on water quality
• Also a fully-costed proposal for a demonstration study
But the models can also be used for short-term forecasting
A
CEH weekly water quality (2009 - )Upstream QUESTOR boundary
Tidal limit
Major urban areas outside London
LONDON
20 km
9
65
4
3
2
1
8
7
10
WP2: networks to support forecasting between Sites 5-8
• Caversham (5) and Windsor (8) have continuous EA water quality and flow monitoring
• How much better can we forecast if we establish additional monitoring and modelling of the main Thames and its tributary basins (A, B, C)?
• The Cut at Bracknell (C) is a POLLCURB case study
• Catchment based approach (CABA). We are exploring links to EA catchment partnerships in A (Loddon - via University of Reading) and B (South Chilterns - via FWR)
A
B
C
Spectrum
of sensors
Low cost, mobile, ideal for surveys (e.g. depth, temp, cond)
High cost, fixed, ideal for continuous monitoring using e.g. optical sensors
WP3: conceptual design of internet service platform
1. Sensors
2. MobileApplications
3. Data store
4. Analytics and visualisation
For the platform we have
some expertise in CEH. We
are looking for partners with
IT expertise to fully cover
the 4-stage process in the
pilot study funding proposal
Challenges for analytics and visualisation
- Costly to setup the model to run online
- Successfully cater for a variety of information providers and information receivers
Integrate diverse data
from different domains
Maps and charts of (i) data and (ii)
forecast output
“Real time” QUESTOR
model applications
Water quality forecasting is needed!
1. By regulators (e.g. Environment Agency asked for information in June about the likely fate of this year’s algal bloom, a problem ideally suited to our proposed system)
2. By recreational groups (e.g. anglers)
3. We want to investigate the views and potential benefits to the water industry (e.g. protection of water supply intakes?)
1. To act as end-users of the forecasting system
2. To act as advisors in formulating the business model
3. To be facilitators for establishing local networks inclusive of community participation
We are looking for partners for a full proposal
Thank You