Institutional Challenges, Scientific Opportunities

Transcription

1 Managing Urban Climate Risks: Institutional Challenges, Scientific Opportunities Shiv Someshwar and Esther Conrad IRI/Earth Institute, Columbia University Mihir Bhatt All India Disaster Mitigation Institute, Ahmedabad Key Messages Urban institutions are primarily reactive to climate risks, lacking (anticipatory) risk framing, management Climate risks are complex, involving i climate and nonclimate drivers Emergent urban vulnerabilities are under-appreciated Climate information & forecasts, driven by decisionmakers needs, is critically required for risk management Effective climate risk management requires more than just climate information i Mumbai flood management Metro Manila water supply 1

2 Greater Mumbai, India Metro Manila, Philippines Sources: Greater Mumbai: Metro Manila: Metro Manila Greater Mumbai Date formally established Population (city) 5.9 million (1980) 9.9 million (2000) 11.2 million (2009) 8.24 million (1981) 11.9 million (2001) 13.9 million (2009) Population 19.9 million (2009) 21.3 million (2009) (greater metro area) Land Area (city) 617 km km 2 Elevation 60% of area below 4m 14m (average elevation) Number (percent) living in informal settlements/slums 2.54 million (30%) (2002) Percent of households with 85-93% 42% access to piped water Total annual rainfall 2060 mm 2170 mm Main rainy seasons June September October February 6.9 million (58%) (2001) June - October 2

3 Monsoon Flooding in Mumbai Flooding is an annual event (94% of rain falls in June October period) >40 neighborhoods experience chronic flooding 20+ rail sections, routinely, submerged Institutional mechanisms strongly respond to flooding Mumbai Municipal Area and Wards implement response programs State-managed disaster response funds disbursed to Mumbai Disaster Mgmt Committee Emergency Response in Mumbai Source: BrihanMumbai Corporation,

4 2005 Mumbai Floods 994mm rainfall within 24 hours (exceptional?) Mithi River overflow, key arterial highway flooded Suburbs under 15 feet of water >630 deaths 50,000 residential, 40,000 commercial buildings badly damaged Reactive management of flood risks, Mumbai Identified causes of floods: weather/climate AND urbanization Anomalous precipitation, context of narrow monsoon window Inadequate drainage (design 25mm/hr / pumping) Land use changes (built over holding ponds, hard surfacing) Slums encroached (permanently) into drain areas Climate change! Catalyzed (some) immediate action Rehabilitation of sewerage system & enhanced pumping Installation of weather radar system On key drivers, non-action / return to stasis Climate-smart land use planning? Drain encroachment removal? No to No urban sprawl? 4

5 Metro Manila s water supply Angat Reservoir: Supplies 97% of Manila s water Irrigates 30,000 ha rice/season Supplies hydropower to Luzon Helps control floods Angat Reservoir, Bulacan Province. Photo: PAGASA. 0 Reservoir management to address high seasonal variability (climatology) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC R a in fa ll ( m m ) NE Monsoon Basin Rainfall Monthly Inflow SW Monsoon NE Monsoon In flo w ( m c m )

6 El Niño impacts No irrigation Jun- Dec 1997, and all of 1998 No power generation in Oct-Dec 1997 and Jan-Sept 1998 Flooding due to spillage in Oct-Dec 1998 Philippine Water Code National Water Resources Board Technical Working Group Water supply (MWSS) Faces risk of paying fees to concessionaires if insufficient water available Informally, > 10% reduction unacceptable Risk is year-round Informal Institutional Dynamics Formal Institutional & Policy Structure Inter-Agency Committee for Water Crisis i Management Irrigation (NIA) Faces costs when water unavailable at particular times No regs for farmer compensation, despite Water Code NIA depends upon irrigation fees NWRB Board Resolutions Power (NPC) Angat water allocations Operates reservoir, but third priority for hydropower generation Privatization introducing conflicting priorities 6

7 Powerful urban institutions externalize costs Power of Metro Manila used to safeguard water resources Invoke water scarcity under Philippine Water Code > 10% reductions of urban water unacceptable Private concessionaires guaranteed supply Farmers not compensated despite Water Code 1968> water to Metro Manila has been stable (and increasing) Farmers experience highly variable and decreasing water share, loss of livelihoods Climate information for proactive NWRB response: Probabilistic forecasts, inflow, demand 7

8 Limits of coping: Angat & water competition in Metro Manila in a changing climate Population projections (millions) Projected population served (millions) Supply threshold New infrastructure required Planning infrastructure Powerful urban interests; Not well organized farming communities Infrastructure planning NOW: Best estimates of range of climate and demand conditions Toward anticipatory urban climate risk management Current approach is stove-pipe and piecemeal Climate not the only driver of urban risks Climate risks involve continuum of time scales (weather, seasonal, inter-annual, multi-decadal ) Different institutions for disaster response and routine Emergencies focus attention + garner resources Complexity Layered, multi-spatial, complex urban decision scales Policies need to contend intra+inter generational equity Toward anticipating climate risks Management using probability, and not certainty Framing of multiple drivers Focus on dynamic emergent risks (monitoring, evaluation) Risk spreading 8