risks in the built environment in a changing world bob scholes csir natural resources and...

16
Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Upload: rudolf-porter

Post on 24-Dec-2015

214 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Risks in the built environment in a changing world

Bob ScholesCSIR Natural Resources and Environment

5Feb 2013 SAIA workshop

Page 2: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Question 1: What aspects of the built environment present risks that could be collaboratively addressed?

• Coastal Flooding due to sea level rise and storms• Inland flooding due to increased storm intensity• Fires, especially megafires due to climate change• Drought, particularly in western southern Africa

Page 3: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Sea level rise

Cazenave & Llovel 2010 Contemporary Sea Level Rise. Ann Rev Marine Sci 2, 145-173

Rahmstorf 2007 Science 316:368

IPCC AR4

Tide gaugesChurch et al 2004

Satellites

Historicalsources

Page 4: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Sea level rise, plus changes in storm intensity, combined with tidal dynamics and increased coastal development.

CSIR has developed a wave climate model for the entire coastline. Detailed analyses for specific locations require high-resolution bathymetry and altimetry

Sea level rise will effect even South Africa

Predicted SA runup elevations on exposed coastsSpring tide (MHWS) & 1-in10yr wave height (Hs)

5

6

7

8

9

Location (East to West)

Ru

nu

p e

lev

ati

on

(m

MS

L)

2% runup mild slope 2% runup steep slope2% runup steep slope +10% wave height 2% runup steep slope +0.5m SLR2% runup steep slope +10% wave +0.5m SLR

Page 5: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

© CSIR 2007 www.csir.co.za

A general increase in the frequency of extreme

rainfall events, especially the highveld

Projected change in

extreme rain events over South Africa

(>20 mm in 24 hours over an area of 50 km x 50 km)

Slide: Francois Engelbrecht, CSIR

Page 6: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Question 2: Practical steps, by whom… coastal flooding

Body Topic Action

Surveyor General, SA Navy, private firms

Near coast high resolution altimetry and bathymetry

Survey areas of infrastructure

CSIR Surge mapping Apply models to map impact areas

Local authorities Building permits Do not give permits in at risk areas

Insurance industry Insurance premiums Structure premiums to reflect changing risk

Coastal management Coastal protection Dune, beach and estuary management

Page 7: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Question 2: Practical steps … inland floodingBody Topic Action

CSIR Downscaled climate Models with 8 km resolution for 21st century

Hydrologists: universitis and consultancies

Flood return statistics New tables and maps for 20 and 100 yr floods

DWA Catchment management Restoration, flood control structures, management of flows

National Disaster Management, DWA and SAWS

Real-time warning Models and observaion system with alerts

Planning authorities Reduction in exposure Control development in flood zone

Page 8: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Question 2 cont: Practical steps…fireBody Topic Action

CSIR Advanced Fire Information System

Realtime warning

SAWS Fire danger index 24 and 48 hour forecasts

Working on Fire Fire avoidance Fuel reduction, firebreaks

National Disaster Management

Rapid intervention Response teams for megafires

Planning authorities Reduction in exposure Control buiding in fire-prone areas

Fire Protection associations Avoidance and response Firebreaks, local response teams

Page 9: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Question 2 cont: Practical steps…drought

Body Topic Action

CSIR, UCT-CESAG Downscaled aridity projections

Drought probability maps for future climates

ARC, SANSA, SAWS Early warning, affected area verification

Greenness and wetness anomalies

DAFF, Provincial authorities, Farmers organisations

Non-financial insurance avoids damage rather than compensating for it

Forage and livestock bankingRapid offtake schemes

Insurance industry Financial insurance for farmers taking appropriate adaptation steps

Re-assess risks as they change through the century

Page 10: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

End of brief presentation

[email protected]

Page 11: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Human vs Natural Causes

Page 12: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

Evidence of a changing world

Page 13: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

2071-2100 vs 1961-1990

Southern Africa is projected to warm at a

higher rate than the global average

Page 14: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

CCAM ensemble-average projected change in the Annual frequency of very hot days

(>35C, 2071-2100 vs 1961-1990)

Page 15: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

..but rainfall futures remain

uncertain for our region

Ensemble average

Page 16: Risks in the built environment in a changing world Bob Scholes CSIR Natural Resources and Environment 5Feb 2013 SAIA workshop

AgricultureClimate change effects are negative overall

Blignaut et alDube & Scholes 2011

Scholes livestock: substantial decrease in production

Rising temperatures arethe key driver, even once rain and CO2 are factored in

But,1. Large yield gap in Africa

(5x)2. Substantial potential for

crop area expansion in in sub-humid Africa (2x)