Table 4.15 ■ Summary of Present Valueof <strong>Climate</strong> Change Costs<strong>in</strong> HCMC (USD)Regular Flood<strong>in</strong>g Extreme Flood<strong>in</strong>g TotalL<strong>and</strong> (l<strong>in</strong>ear) 22,658,038,001 6,850,465,427 29,508,503,427L<strong>and</strong>6,156,082,749 423,561,165 6,579,643,914(quadratic)GDP 49,492,036,285 489,388,337 49,981,424,623Source: ADB (2010). Some differences due to exchange rate variations.1 USD=16302.25to market prices for l<strong>and</strong>) undervalue l<strong>and</strong> <strong>in</strong> thecity. On this basis alone, had market prices for l<strong>and</strong>values been used <strong>in</strong>stead of adm<strong>in</strong>istratively determ<strong>in</strong>edl<strong>and</strong> prices (which were effectively used), theestimated cost of climate change us<strong>in</strong>g l<strong>and</strong> valueswould have been higher than presented earlier.Second, GDP per capita figures at the district levelwere unavailable. This may overestimate the GDPloss across the city as rural districts <strong>in</strong> the southsuch as Can Gio <strong>and</strong> Nha Be are responsible forvery little GDP production, <strong>and</strong> yet which may bemore vulnerable to climate change. Further detailed<strong>in</strong>vestigations <strong>and</strong> data collection would be requiredto ref<strong>in</strong>e these figures.Box 4.4 ■ Rough Estimate ofViability of Proposed Flood ControlMeasuresHCMC has already proposed to build a system of flood defensesthat will significantly alter the pattern of flood<strong>in</strong>g <strong>and</strong> the hydrologyof the city. This project has an estimated capital cost of $750million <strong>and</strong> is expected to be completed by 2025. The effects of theproposed flood control measures on regular flood<strong>in</strong>g would seemto be significant <strong>in</strong> reduc<strong>in</strong>g the population exposed to flood<strong>in</strong>g <strong>in</strong>2050 from an estimated 10.2 million to 6.7 million, a reduction of 35percent. Based on the GDP method of estimation, the project wouldproportionately decrease damage costs by 35 percent, mak<strong>in</strong>g thisan economically viable project. However, further economic analysesof this project needs to be carefully undertaken.Source: ADB (2010).Analysis of Adaptation <strong>in</strong>HCMCUnlike the Bangkok <strong>and</strong> Manila studies, the HCMCstudy did not undertake a detailed cost benefitanalysis to prioritize <strong>adaptation</strong> options. Whileit did provide an estimate of the viability of thegovernment’s flood protection project (Box 4.4), thema<strong>in</strong> focus was to identify <strong>in</strong>stitutional m<strong>and</strong>ateswith respect to urban plann<strong>in</strong>g, flood protection,<strong>and</strong> <strong>adaptation</strong> <strong>and</strong> propose a range of <strong>adaptation</strong>options that need to be undertaken <strong>in</strong> coord<strong>in</strong>ationwith different sectors.Broadly, <strong>adaptation</strong> measures <strong>in</strong> the context ofmanag<strong>in</strong>g floods can be categorized as those that<strong>in</strong>volve (a) protection aga<strong>in</strong>st predicted climatechange, (b) accommodation to improve resilience,(c) retreat to reduce exposure, <strong>and</strong> (d) improvedmanagement (see Annex C). 58 For <strong>in</strong>stance, <strong>in</strong>frastructuralmeasures such as construction of floodembankments, polders, sea walls, <strong>and</strong> pumpeddra<strong>in</strong>age are common eng<strong>in</strong>eer<strong>in</strong>g solutions <strong>and</strong>are be<strong>in</strong>g implemented <strong>in</strong> all three cities discussed<strong>in</strong> this report. “Accommodation” measures thatseek to m<strong>in</strong>imize vulnerability <strong>in</strong>clude measuressuch as rais<strong>in</strong>g houses on stilts, adjust<strong>in</strong>g cropp<strong>in</strong>gpatterns, <strong>and</strong> revis<strong>in</strong>g build<strong>in</strong>g codes for hous<strong>in</strong>g<strong>and</strong> <strong>in</strong>dustry. In some cases, where the <strong>risks</strong> of lossof life or assets is severe, “retreat” as a plann<strong>in</strong>g optioncan reduce exposure to extreme events. Used<strong>in</strong> conjunction with restor<strong>in</strong>g natural ecosystemsthat provide flood protection benefits, it can be auseful plann<strong>in</strong>g tool. F<strong>in</strong>ally, flood<strong>in</strong>g needs to beconsidered <strong>in</strong> the context of overall water bas<strong>in</strong>management <strong>and</strong> the <strong>in</strong>stitutional capacity to managethe resource.Develop<strong>in</strong>g sector specific <strong>adaptation</strong>options with focus on the poorIn the HCMC study, a comb<strong>in</strong>ation of these measuresis proposed. Specifically, the study argues fordevelopment of sector specific <strong>adaptation</strong> optionswith a focus on the poor. For <strong>in</strong>stance, <strong>in</strong> terms58Drawn from IPCC, AR4, chapter 6, Coastal systems <strong>and</strong>low-ly<strong>in</strong>g areas, Figure 6.11 Evolution of planned <strong>coastal</strong><strong>adaptation</strong> measures, pg. 342, 2007.72 | <strong>Climate</strong> Risks <strong>and</strong> Adaptation <strong>in</strong> <strong>Asian</strong> Coastal Megacities: A Synthesis Report
of reduc<strong>in</strong>g vulnerability of the poor, the studyrecommends livelihood protection <strong>and</strong> livelihooddiversification schemes, improved early warn<strong>in</strong>gsystems, improved build<strong>in</strong>g construction requirements,l<strong>and</strong> use plann<strong>in</strong>g <strong>and</strong> use of open spacefor flood management, zon<strong>in</strong>g controls to ensurethat low <strong>in</strong>come hous<strong>in</strong>g is located outside offlood prone zones. HCMC already has a plannedprogram of resettlement away from rivers <strong>and</strong>dra<strong>in</strong>s <strong>and</strong> this may require expansion to <strong>in</strong>cludevulnerable areas (Can Gio <strong>and</strong> Nha Be districts)identified by the HCMC analysis. Priority <strong>adaptation</strong>actions <strong>in</strong> the transport sector <strong>in</strong>clude review<strong>and</strong> revision of design st<strong>and</strong>ards for roads, bridges,<strong>and</strong> embankments so they are consistent with expectedflood<strong>in</strong>g <strong>and</strong> climate conditions. Further,<strong>in</strong> light of the f<strong>in</strong>d<strong>in</strong>gs of the study, new transport<strong>in</strong>frastructure needs to be reassessed. Given thatmost <strong>in</strong>dustrial zones <strong>and</strong> clusters <strong>in</strong> HCMC willbe at direct risk of flood<strong>in</strong>g with or without theproposed flood control plan, a number of <strong>adaptation</strong>measures—such as locat<strong>in</strong>g <strong>in</strong>dustrial zonesoutside of vulnerable areas <strong>and</strong> retrofitt<strong>in</strong>g exist<strong>in</strong>g<strong>in</strong>frastructure—are proposed.Comb<strong>in</strong><strong>in</strong>g <strong>in</strong>frastructure based solutionswith eco-system based <strong>adaptation</strong> measuresAn important recommendation of the HCMC studyis to comb<strong>in</strong>e <strong>in</strong>frastructure-based solutions withthe use of ecosystem-based <strong>adaptation</strong> measures,which provide a buffer aga<strong>in</strong>st climate <strong>risks</strong>. Themangrove forests to the south of HCMC providesignificant protection aga<strong>in</strong>st storm surges, but areunder severe pressure due to l<strong>and</strong> use change <strong>and</strong>encroachment. Natural systems of the Dong NaiRiver bas<strong>in</strong> provide a range of ecosystem servicessuch as regulation of hydrological flows, freshwaterstorage, erosion control, <strong>and</strong> water purification.These too are under threat due to l<strong>and</strong> use change<strong>and</strong> urban development. Adaptation approachessuggested by the study <strong>in</strong>clude reforestation ofthe Dong Nai River bas<strong>in</strong> watershed, restorationof wetl<strong>and</strong>s, rehabilitation of canals <strong>and</strong> rivers,strengthen<strong>in</strong>g zon<strong>in</strong>g regulations to protect ecosystemresilience, <strong>and</strong> plant<strong>in</strong>g of buffer zones alongdykes <strong>and</strong> riverbanks, <strong>in</strong>clud<strong>in</strong>g dykes proposedby the planned flood control system.Strengthen<strong>in</strong>g <strong>in</strong>stitutional capacity toadapt to climate related <strong>risks</strong>The HCMC study argues that comprehensive <strong>adaptation</strong>plann<strong>in</strong>g is needed to provide the overallframework <strong>and</strong> direction for <strong>adaptation</strong> at the citylevel, <strong>in</strong> l<strong>in</strong>e with national level goals <strong>and</strong> targets.A key <strong>in</strong>stitutional recommendation aris<strong>in</strong>g fromthe study is the development of an HCMC <strong>Climate</strong>Change Adaptation Plan. The HCMC Peoples Committee(PC), the study argues, can take a proactiveleadership role <strong>in</strong> this context <strong>and</strong> <strong>in</strong> driv<strong>in</strong>g climatechange <strong>adaptation</strong> <strong>in</strong> the city. Further, there are severalkey agencies that shape overall l<strong>and</strong> use, spatialzon<strong>in</strong>g, environmental quality, <strong>and</strong> natural disasterresponse management <strong>in</strong> the city, each of whichcan pursue a range of actions with<strong>in</strong> their sectoraldoma<strong>in</strong> (Table 4.16). S<strong>in</strong>ce one sector or area’s planhas implications on activities carried out by othersectors, coord<strong>in</strong>ation between different <strong>adaptation</strong>plans <strong>and</strong> plann<strong>in</strong>g processes is critical.ConclusionGiven the magnitude of climate change costs, <strong>adaptation</strong>to climate change clearly needs to be a seriousconsideration. As discussed, <strong>adaptation</strong> <strong>in</strong>vestmentsare already under way <strong>in</strong> all three cities. Eachof the cities will be better protected aga<strong>in</strong>st climatechange with the flood control measures that areeither already planned or are slowly be<strong>in</strong>g implemented.However, additional policy, <strong>in</strong>stitutional,<strong>and</strong> ecosystem-based measures also need to be put<strong>in</strong> place <strong>and</strong> prioritized by the city governments.The analysis undertaken <strong>in</strong> the three casestudies needs to be viewed as an <strong>in</strong>itial attempt atestimat<strong>in</strong>g the impacts <strong>and</strong> damage costs relatedto climate change. As discussed <strong>in</strong> chapter 2, thereare a number of uncerta<strong>in</strong>ties associated with eachlevel of analysis. The climate downscal<strong>in</strong>g <strong>and</strong> thehydrological models provide results that are by nomeans certa<strong>in</strong>. The economic analysis overlays alarge number of assumptions related to prices, GDP,population distribution, growth, the structure ofcities <strong>and</strong> so on, over <strong>and</strong> above these uncerta<strong>in</strong>ties.Therefore, they should be viewed as a prelim<strong>in</strong>aryattempt to be followed by improved studies.Assess<strong>in</strong>g Damage Costs <strong>and</strong> Prioritiz<strong>in</strong>g Adaptation Options | 73