Download Understanding the impacts of multiple pressures with MARS

Understanding the impacts of multiple
pressures with MARS experiments, catchment
models and pan-European analyses
Stefan Schmutz & Laurence Carvalho
What we will cover
Introduction – concepts
Literature review
Lakes
River Basins (incl. transitional waters)
Synthesising understanding for tools/apps
How do pressures interact?
Dominant?
Additive?
Synergistic?
Antagonistic?
Concepts in ecology
Concepts in ecology
Concepts in ecology
Two gradients of pressure
Review of the Literature
Evidence item (EI) - effect of combined
pressures described in a quantitative way
Nõges et al. 2016. Science Total Environment: 540:43-52
Pressure groups
Nõges et al. 2016. Science Total Environment: 540:43-52
Types of pressure interaction
Types of interactions are seldom specified
Nõges et al. 2016. Science Total Environment: 540:43-52
Response of BQEs (all water categories)
Number of pressures
Fish response better explained
by multiple pressures
Number of pressures
Benthic flora sensitive to
one dominant pressure
Nõges et al. 2016. Science Total Environment: 540:43-52
Common questions being studied in MARS
What is the response of BQEs (and related services) to: 1. Extreme temperature and nutrient stress? What are the consequences for water supply and recreation?
2. Extreme rainfall (drought) and nutrient stress? What are the implications for abstraction & eFlows?
3. Extreme rainfall (floods) and nutrient stress? What are the consequences for water supply?
4. Changes in morphology & nutrient stress? What are the consequences for flood management?
Temperature & nutrients in lakes
+
Temperature & Nutrients in lakes
Knowledge from experiments, time-series
and pan-European studies
Does climate change act
synergistically with
eutrophication to exacerbate
problems of algal blooms?
What are the consequences for
water supply and recreation?
Lake mesocosm experiment
Control (P)
+ Phosphorus
Heated
Control (Temp)
• Nutrient reductions need to continue
to be the focus of management
• Warming increases risk at lower
nutrient conditions
Jess Richardson, NERC
Cyanobacteria abundance
Lake time series
• Significant effects of
nutrients
• No significant effect
of temperature
extremes
• Significant
interaction
Year
Carvalho and 15 others (4 external)
% lakes exceeding health threshold
European Lake Data
20 µg L-­‐1 TP 10% exceed low risk
50 µg L-­‐1 TP 40% exceed low risk
80 µg L-­‐1 TP 50% exceed low risk
Data from 1300 lakes
used to establish
management targets to
reduce risks to water
supply and recreation
services
Carvalho et al. 2013. Journal of Applied Ecology, 50: 315-323
Had
Pro
Ref
Had
Worst
probability (%)
(e)
Had
Best
Ref
Had
0
Ref
Application to Lake Vansjø (Bayesian Model)
Best
ef
Ref
Had
Climate scenario
0
Ref
Management scenario
Best
Worst
80
60
60
40
40
20
20
0
0
-
Had
Worst
Ref
Had
Climate scenario
Had
Ref
Ref
Management scenario
Cyanobacteria most sensitive
to management scenarios
Had
Best
Ref
Ref
Had
Climate R
Climate scenario
Worst Ref
R
Management scenario
Manageme
Phytop
100
80
Ref
Had
(f)
Cyanobacteria
100
Ref
Poor-­Bad
Moderate
High-­Good
Ref
Had
Worst
Ref
Climate R
Manageme
(g)
ity (%)
ef
0
20
100
80
Jannicke Moe, NIVA
60
La
Drought & Nutrients
+
Extreme rainfall (drought) & nutrients: concepts
Before
Water level fluctuations
After
+
=
Eutrophication
Extreme rainfall (drought) and nutrient stress
Case-study: Lake Beyşehir
• Largest freshwater lake in Turkey
(650 km2)
• Pressure of water abstraction for
irrigation & drinking water
• Climate change adds additional
pressure
• Model simulation of scenarios to
derive optimum water use & nutrients
*
*
Extreme rainfall (drought) and nutrients
Future water levels of Lake Beyşehir
Climate scenarios: 2 GCMs
Land use & abstraction scenarios
Default : Current land use & abstraction
LC1 : Sugarbeet farming increase LC2 : Forest to shrubland
LC3 : Agricultural land to shrubland
LC4 : Shrubland to agricultural area
OUT10 : 10% increase in abstraction
OUT20 : 20% increase in abstraction
• Minor effect of land use change on
water levels
• Abstraction pressure dominant
• MPI model suggests lake may dry out
by 2040
How can we synthesise this understanding
for useful RBM tools?
Synthesis will:
- identify indicators (species, metrics)
that are sensitive or tolerant to
multiple pressures to aid diagnosis
- identify water-body types that are
sensitive or tolerant to multiple
pressures to aid risk and resilience
management