In December 1999,days of heavy rain on steepslopes north of Caracas,Venezuela triggeredmassive mud and debris flows, killing tens ofthousands. Partly in response to this disaster,a multidisciplinary team of urban planners andEarth scientists from Columbia University re-cently developed a framework plan for buildingdisaster resilience into the Venezuelan capitalregion. After assessing the complex intersectionof urban geography with severe seismic andhydrologic hazards, substantial recommenda-tions were made to local and regional authoritieson future hazards mitigation.

Areas found most at risk in the Caracas regioninclude the transportation and utility infrastruc-ture and the friable building stock of squattersettlements.Recognizing realistic economic andsocio-political constraints on implementingchange,a prioritized list of goals and activitieswas constructed,and recommendations madealong various time scales. Immediate disaster-avoidance goals (to be completed within 1 to 5years) include strengthening critical infrastructure

nodes,housing stock,and emergency services.More intermediate goals (5 to 10 years) focuson upgrading fragile housing units,creatingdetailed hazard maps across the city, andincorporating disaster education into culturalactivities.Recommended activities for the longterm (beyond 10 years) include creating a fullyredundant transportation and water deliverynetwork, establishing legitimate land title forsquatters, and re-locating critical facilities currently in high-risk areas.

These recommendations were presented togovernment officials in Caracas, the AndeanParliament, representatives from Venezuelanacademic institutions, the United Nations Deve-lopment Programme, and the Venezuelan RedCross.

This article presents a pedagogic approach todeveloping urban planning and design principlesthat are sensitive to hazard and risk issues.

Studio Implementation

At Columbia University in New York, the Gra-duate School of Architecture, Planning and

Preservation offers a studio in urban planningand design.This provides degree candidates theopportunity to work in a collaborative settingto solve problems for a particular urban client,usually a civil municipality.In January 2001,sucha studio was organized to also include facultyand Ph.D. students from Columbia’s Lamont-Doherty Earth Observatory and Department ofEarth and Environmental Sciences.The purposewas primarily to perform an academic experi-ment attempting to incorporate knowledge aboutnatural hazards and mitigation into the urbanplanning and design process. Participantsworked with the realistic goal of providing thecitizens of Caracas with a solid planning docu-ment that could be used as a starting point asthey build disaster resilience into their city.

The final 125-page report is available at http://www.arch.columbia.edu/Studio/Spring2001/Caracas/.

The Caracas Urban and Environmental Context

NNaattuurraall hhaazzaarrddss.. Located on the intersectionof the South American and Caribbean Plates,northern Venezuela faces extreme seismologicalhazards. Perez et al.[2001] report a 2 cm/yr rateof plate motion at the offshore boundary; halfof which is accommodated by the San Sebastianfault,which likely comes ashore under the SimonBolivar International Airport in Vargas State[Audemard et al.,2000].The fault zone is diffuse,containing the Tacagua-El Ávila and La Victoriafault systems that surround the city to the northand south. Major earthquakes have destroyed

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Integrating Complexity of Social Systems in Natural HazardsPlanning:An Example fromCaracas,VenezuelaPAGES 55–56

and P. semisulcatus to nursery grounds in the Gulf ofCarpentaria, northern Australia: implications forassessing stock-recruitment relationships.Mar.Ecol.Prog.Ser., 178, 55–68, 1999.

Harris, G. H. and C. J. Crossland, Introduction to thePort Phillip Bay Environmental Study,Mar.Freshwat.Res., 50(6), iii-iv, 1999.

Holloway, P. E.,A regional model of the semidiurnalinternal tide on the Australian North West Shelf, J.Geophys.Res., 106, 19625–19638, 2001.

Murray,A. G. and J. S. Parslow, Modelling of nutrientimpacts in Port Phillip Bay – a semi-enclosedmarine Australian ecosystem, Mar.Freshwat.Res.,50, 597–611, 1999.

Nuttle,W. K., Ecosystem managers can learn frompast successes, Eos,Trans.,AGU,81, 278, 2000.

Punt,A.E.,A.D.M.Smith,and G.Cui,Review ofprogress in the introduction of management strategyevaluation (MSE) approaches in Australia’s SouthEast Fishery,Mar.Freshwat.Res.,52,719–726,2001.

Schiller,A.,J.S.Godfrey,P.C.McIntosh,G.Meyers,and R.Fiedler, Interannual dynamics and thermodynamicsof the Indo-Pacific Oceans, J. Phys.Oceanogr.,987–1012, 2000.

Author Information

Scott Condie, Chris Fandry, David McDonald,John Parslow, and Keith Sainsbury, CSIRO MarineResearch, Hobart,Tasmania

For additional information, contact Scott Condie,CSIRO Marine Research, GPO Box 1538, Hobart,Tasmania 7001,Australia;E-mail: scott.condie@csiro.au,or visit http://www.marine.csiro.au/nwsjems/index.html.

Fig.3.Probability that water from the region around the Monte Bellow and Barrow Islands(marked by cross-hatching) will reach other areas within a 21-day period.The distribution isbased on a single month of particle outputs from the hydrodynamic model (January 1999).The image is taken from Web-based graphical-user-interface,which allows the user to select thesource region of interest (e.g.,a proposed marine reserve or an oil platform), the period of interest(specific months and years or seasonal composites),and the dispersion time (e.g., larval lifetimeor time for chemical biodegradation).

Eos,Vol. 84, No. 6, 11 February 2003

Caracas three times in the last 400 years.The lastlarge earthquake (Mw=6.5) came in 1967,killingan estimated 300 people and destroying fourmodern structures built for earthquake resistance[Papageorgiou and Kim, 1990].

The natural hazards faced by northern Vene-zuela are not limited to earthquakes.The positionof the northern coast near 10°N ensures fre-quent heavy rainfall events with strong erosionpotential. In December 1999, a month of rainon the north central coast of Venezuela—including over 900 mm of rain in a 72-hourperiod between 15 and 17 December—triggeredlandslides, mudflows, and debris flows on thenorth face of the El Ávila range that killed anestimated 25,000–250,000 residents of thecoastal state of Vargas.(Estimates of this numbervary by one order of magnitude within theVenezuelan government and non-governmentalorganizations.) The heavy rains also causedfatalities in the Caracas basin.

High slope angles along El Ávila (some upto 80%) allow for immediate acceleration ofsurface fluids.The December 1999 event sawevidence of hyper-concentrated flows, alluvialfan re-activation, and some evidence of prior,larger flows [Salcedo, 2000, 2001].The Vargascoast is lined with extensive alluvial fans,nineof which re-activated during the December 1999event [Larsen et al., 2001].The Caracas basincontains at least three alluvial fans with clearsigns of Earth movement in the past 100 years.In an article in Eos,Larsen et al. [2001] presentan excellent overview of El Ávila geology andmud flow processes during the December 1999disaster.

Although rainfall data is sparse, historicalrecords compiled by Salcedo [2000] show thateither the Caracas or Vargas area has been se-verely affected by debris flows roughly every25 years since recorded history.Previous empir-ical work by local geologists illustrates that anyrainfall exceeding 100 mm in 24 hours willcause damaging mud and debris flows; anyrainfall exceeding 300 mm in 72 hours is con-sidered catastrophic.An analysis of 25 years ofregional rainfall data produced during theColumbia studio extrapolates a frequency ofrecurrence of 100 mm/24 hours to once every5 to 10 years; the probability of 300 mm/24 hoursis once in 25 years.

BBuuiilltt eennvviirroonnmmeenntt.. Since the last major earth-quake in 1967, the population of Caracas has doubled to 5 million people,with a populationdensity of 12,000 persons/km2 and growth of3.1% per year.Eighty-six percent of the Venezuelanpopulation is urban,making it the seventh mosturbanized country in the world.

The valley floor is well developed,with high-rise buildings and densely packed apartmentblocks scattered unevenly throughout the city.These buildings are generally concentrated inthe deepest part of the basin (where shakingis expected to be highest during an earthquake).Barrios,or informal squatter settlements,domi-nate the landscape on the low-lying, ruggedmountains to the east and west of the city center,where rainfall-induced debris flows are expectedto be greatest.To the south exists a mixture ofurbanazacions (similar to suburbs) and barrios.The individual building blocks of the barrios,

known as ranchos, are constructed of un-rein-forced masonry, making them particularly vul-nerable to earthquakes.The ranchos are highlyvisible from every point in the city as they carpetthe hills,creating a starkly contrasting landscapeof a dual urban fabric (Figure 2).

While the formal city averages 6,000 persons/km2,similar to the world average urban density,the barrios approach 25,000 persons/km2.

Vargas State is isolated physically from theCaracas basin by El Ávila (Figure 1).However,Vargas is inextricably linked to Caracas.It servesas Caracas’ economic connection to the restof the Caribbean, and acts as the social “reliefvalve” for the city, by offering weekend recre-

ation for residents. Although separated geographi-cally,Vargas and Caracas are economically andculturally intertwined.

Collision of the Built Environment and Natural Hazards

Centuries ago,Caracas was purposefully builtaway from the coast and through steep terrainto deter sea-borne attacks on the city.However,this removal creates major transportation andutility infrastructure problems which are exacer-bated by natural hazards. Caracas is linked tothe world through its airport and seaport,bothof which are located across El Ávila on the Vargas

Fig.1.Regional elevation map of Caracas,Venezuela and Vargas State.Stars indicate major mud flowand alluvial fan re-activation during the December 1999 catastrophe.Dashed line denotes approximatepath of the single road and water link between Caracas and Vargas.Caracas relies upon this link fortransportation of people and goods;Vargas relies on this link for fresh water.A major bridge alongthe highway is being compressed by an active landslide. (Basemap credit: F.Urbani,UniversidadCentral de Venezuela.)

Fig.2.Map of the Petare barrio of Caracas,Venezuela, illustrating dual nature of city.On left is theopen spacing of the planned,“formal” city.On right is the densely packed squatter barrios of the“informal” city.This diversity in housing quality and density creates large challenges in planningfor natural hazards mitigation. A vast majority of informal housing stock on the right is constructedof un-reinforced masonry.

Eos,Vol. 84, No. 6, 11 February 2003

coast (Figure 1).The only road between Caracasand the airport and seaport is a single highwaythat travels through steep,landslide-prone valleyscrossing secondary faults of the active SanSebastian fault.

Uncontrolled building and lack of enforcementof building and zoning codes in this hazardousenvironment have led to human disasters andpotential problems of great magnitude.

A lack of building code and enforcement allowed Vargas residents to build on active (butquiescent for the previous 50 years) alluvial fans,which re-activated during December 1999.Al-though various groups are working to repairand rebuild Vargas State with new housing builtin safe locations,a general lack of planning andenforcement are allowing squatters to return tothe alluvial fans and stream beds where most ofthe December 1999 destruction was concen-trated.

Results of the Studio

The main threats to the future health of theCaracas urban landscape were identified (Fig-ure 3) during a one-week field reconnaissancein Caracas and Vargas State in January andFebruary 2001,and during further collaborativeinvestigation from February to May 2001.On-sitevisits included meetings with local academicand professional geologists, hydrologists, engi-neers,urban planners,sociologists,disaster-reliefworkers,and political officials,as well as touringareas affected by the disaster. With the goal ofmaking hazards-related recommendations in thecontext of the current socio-political and eco-nomic situation, we attempted to determineboth the natural and social magnitude of theproblem. It was a surprising revelation duringthe visit to learn that neither Caracas nor Vene-zuela currently has any urban planning projectsor studies that incorporate or discuss naturalhazards and disasters. It became readily appa-rent that our project could help to fill thoselarge planning,policy,and administrative gaps.

Critical areas classified as at highest risk inCaracas include the utility infrastructure (water,sewage, and power), the emergency responsesystem (medical,police,and fire),and the high-way system (both within and the one connectingthe city to Vargas).

For example,more than 95% of the water sup-ply to the Caracas basin comes from three linesoriginating from southern reservoirs in the TuyValley,with all lines crossing seismic faults.Lessthan a one-day supply of water is stored withinthe city,and the state of Vargas receives all of itswater from one line along the vulnerable Cara-cas-Vargas highway.The water system is thereforeconsidered extremely fragile,and it is likely thatfirefighting and medical operations will be se-verely hampered in the event of a major earth-quake.

The only direct road link between Caracas andits airport and seaport crosses a bridge threat-ened by an active landslide into its northernabutment.While the current slip rate has re-cently slowed from 2 cm/month to 1 cm/year,local engineers have estimated that the bridgecan tolerate less than 23 cm of further slip [Sal-cedo and Ortas,1992;Salcedo,pers.comm.,2002].

Losing the bridge would mean losing Caracas’commerce and transport link to the world.

This threatened bridge is emblematic of theregional road system,which is neither redundantnor strengthened. Illustrating the unstable con-fluence of hazards and politics, in the past cen-tury, the typical tenure of the Venezuelan tran-sportation minister has been six months. Manychanges recommended by the studio requirecontinuity and stability within the government;mitigation projects are difficult to achieve withoutconsistent leadership.

Intermediate-term recommendations includeestablishing constitutional and legal legitimacyfor disaster management; fostering internationalexchange among scientists, professionals, andtechnicians; and starting public outreach pro-grams in schools and communities.Creating aredundant utility infrastructure, developing ahazards-based zoning code,and enforcing no-build zones in highly hazardous areas for thereservation of open space are also importantgoals.

A strong lesson of the field reconnaissancewas the general ignorance of the public to naturaldisasters.We recommended educating barrioresidents about safer building techniques,recognizing that unregulated building willcontinue into the future.Hazards intersect withpopulation realities in Caracas: half of thepopulation live in unplanned,unzoned,andunofficial squatter settlements, built of non-reinforced masonry.

Long-term recommendations include the re-alization of open spaces and resilient structures.Open spaces are considered critical dual-usefacilities: they have obvious cultural value andhistorical context for daily activities; and duringnatural disasters, they provide important gath-ering and distribution locations for critical ser-vices. Establishing legitimate land-title for ran-chos built on a squatter basis and the creationof a working real estate market are crucial pro-perty issues that will contribute to disaster miti-gation through planned building and location.

Finally,a clearly organized hazards and disastermanagement system that incorporates govern-ment officials, the military, the scientific com-munity,non-governmental organizations (NGOs),and the public is critical to effectively respondto inevitable disasters.

Before any changes are to begin,one very im-portant activity must be undertaken: our plan-ning exercise must be duplicated on a granderand more detailed scale by those with intimateknowledge of local issues.The obstacles to im-plementing these goals by Venezuelans parallelour obstacles in researching this project: lack ofobservational data, lack of clear channels ingovernment, and an overwhelming array ofissues to be tackled.

Future of Caracas and Other Regions

While the recommendations summarized herewere well received by local government andNGOs,they represent only the first of many stepsrequired to construct a viable multi-hazards miti-gation plan for Caracas.Data collection,assimi-lation, and integration leading to quantitativerisk assessments are high-priority needs. Effec-tive risk reduction strategies and appropriatemitigation policies can be designed only oncerisks are assessed. Given our interactions withVenezuelans currently engaged in hazards-re-lated research throughout government, aca-demic, and private institutions,we remain con-fident that natural hazards mitigation will returnto its high priority once the current politicalcrisis is resolved.

Since this project was undertaken, a similarinternational hazards studio has been repeatedfor seismic hazards in Istanbul,Turkey, andanother will soon examine flooding and publichealth issues in Ghana.

Comparatively, the Caracas studio was impor-tant in providing an original first-step plan to a region currently lacking in any adaptive,integrated planning to ameliorate such animmediate risk.

Fig.3. An example of a studio-produced hazard map of urbanized Caracas.The map is a compilation ofurban facilities research and natural hazards research,and is the type of presentation provided to localgovernment officials.This map relied upon existing estimates of ground-shaking period from FUNVISISand estimated flooding extent,based on local topography,produced during the Columbia studio.

The U.S. Immigration and Naturalization Service (INS) has delayed the date by whichuniversities and colleges who enroll non-U.S.citizens holding non-immigrant visas mustdecide whether or not they are going to par-ticipate in the INS’ new Student and ExchangeVisitor Information System (SEVIS). The newdeadline is 15 February.

The initial deadline was 30 January. However,it has been delayed “to accommodate schoolsand visitors centers that are new users”of theInternet-based SEVIS system, according to astatement released by the INS.

SEVIS-participating schools will be requiredto enter certain information about such stu-dents in this new data base.The information

will be provided by students on SEVIS Form I-20, which will be distributed to them by theschools in which they are enrolled. For currentlyenrolled students, schools are required to havethe requisite data entered in SEVIS no later than15 August 2003.

In addition,a prospective student not alreadyin the United States will be required to completeForm I-20 at the time he or she applies for a visaat a U.S. embassy or consulate. The INS willformally notify the university at which the studenthas been accepted; if the student fails to register,the school is required to report this to the INS.

Schools are also required to update SEVISwith any change of a student’s status, such asa change in home or work address, programextensions, changes in program of study, etc.

Also, students in the U.S. who are citizens ofcertain countries are now required to register

directly with the INS so that various personaldata, such as home address and school regis-tration,can be entered in another new database, the National Security Entry-Exit RegisterSystem (NSEERS).

All citizens of Iran, Iraq, Libya, Sudan, andSyria were required to report to their localINS offices for this purpose by 16 December2002. Male citizens of Afghanistan,Algeria,Bahrain,Eritrea,Lebanon,Morocco,North Korea,Oman,Qatar,Somalia,Tunisia,the United ArabEmirates,and Yemen were required to report by10 January 2003. Male citizens of Pakistan andSaudi Arabia have until 21 February to register.

Individuals registered in NSEERS will alsobe required to periodically verify their loca-tion and activities with the INS—for example,whether they are still attending school—and toconfirm their departure dates when they leavethe United States.

—EMILY CRUM,AGU Staff Writer; AND JUDY JACOBS,Assistant Managing Editor, Eos

Eos,Vol. 84, No. 6, 11 February 2003

Acknowledgments

Interaction with and assistance from IREU,FUNVISIS, and numerous other Venezuelanacademic and government groups was greatlyappreciated. Financial support for this projectcame from the Graduate School of Architecture,Planning and Preservation, the Lamont-DohertyEarth Observatory, and the Columbia EarthInstitute through the Center for Hazards andRisk Research. Lamont-Doherty ContributionNumber 6410.

References

Audemard, F.A., M. Machette, J. Cox, R. L. Dart and K.M. Haller, Map and Database of Quaternary Faults

in Venezuela and its Offshore Regions, UnitedStates Geological Survey Open File Report 00-018,USGS, Reston,Va., 2000.

Larsen, M.C.,Wieczorek, G. F., Eaton, L. S., Morgan, B.A.,Torres-Sierra, H.,Venezuelan debris flow andflash flood disaster of 1999 studied, Eos Trans.,AGU,82, 572–573, 2001.

Papageorgiou,A.S. and J. Kim, Study of the propaga-tion and amplification of seismic waves in Cara-cas Valley with reference to the 29 July 1967earthquake: SH waves, Bull. Seism.Soc.of Amer.,81, 6, 2214–2233, 1991.

Salcedo, D. and J. Ortas, Investigation of the slide atthe southern abutment hill of Viaduct No. 1, Cara-cas-La Guaira highway,Venezuela, Proc.of Sixth Int.Symposium,Landslides, 189–198, 1992.

Salcedo,D.,Aspectos socio-económicos y socio-ambi-entales de los flujos catastróficos de Diciembre

1999 en el Estado Vargas y el Area metropolitanade Caracas,Proc.of III Panamerican Symposium onLandslides,Cartagena,Colombia, 291-317, 2001.

Salcedo,D.,The December 1999 catastrophic debrisflows at Vargas State and Caracas,Venezuela,char-acteristics and lessons learned,Proc.XVI SeminarioSociedad,Venezolana de Geotecnia, 28–175,2000.

Author Information

Kevin Vranes and Kristina R. Czuchlewski, Lamont-Doherty Earth Observatory, Columbia University,New York

Windy, cold, remote, hostile, barren, extreme.These are just some of the words that come

to mind when describing Antarctica.Antarctica is the highest,coldest,and windiest

continent on Earth.Less than 3% of Antarcticais free of ice,and the continent contains someof the most spectacular mountain ranges inthe world.The most extensive are in the AntarcticPeninsula, 1700 km in length, and the Transan-tarctic Mountains,which are more than 3000 kmlong.The highest mountain,Vinson Massif inthe Ellsworth Mountains, peaks at 4897 m.

For the explorers of 100 years ago,Antarcticawas the ultimate survival contest. For today’sscientists, it remains a place of intellectualchallenge that is of key importance to ourunderstanding of how the world works. Scien-tific research in Antarctica is coordinated bythe Scientific Committee on Antarctic Research(SCAR), an interdisciplinary committee of theInternational Council for Science (ICSU).SCARinitiates, promotes, and coordinates scientificresearch in Antarctica and provides scientificadvice to the Antarctic Treaty System.

Recently, an organizational restructuring ofSCAR resulted in three large scientific groupsbeing formed to examine the areas of geo-sci-ence, life science,and physical science.TheGeoscience Standing Scientific Group (GSSG)is charged with sharing information on disci-plinary scientific research being conducted bynational Antarctic programs,identifying researchareas or fields where current research is lacking,and promoting geoscientific research activitieswithin SCAR, and to the broader geosciencecommunity.

The GSSG coordinates the research beingconducted in such disciplines as geology,geo-physics, geodesy, geographic information, per-mafrost, climate change and evolution, neo-tectonics, geochronological evolution, andsubglacial lake exploration.The group is alsothe provider of a number of key data basesand products that are assisting not only scientistswith their research, but logistics personnel aswell.The Antarctic Digital Database, a digitalvector topographic representation of the con-tinent, is the group’s flagship product. Othervery important data sets available online includea gazetteer of Antarctic place names, a map

catalogue for all Antarctic maps known to SCAR,an Antarctic Seismic Data Library, details onpermanent geoscientific observatories, and ageodetic control data base.

If you are interested in learning more aboutAntarctic geoscience research and GSSG activi-ties, see www.geoscience.scar.org.

Links for additional information about Ant-arctica: SCAR Web site: www.scar.org;AntarcticTreaty Consultative Meeting: www.25atcm.gov.pl; ICSU Web site: www.icsu.org;Antarctic DigitalDatabase: www.nerc-bas.ac.uk/public/magic/add_main.html; Composite Gazetteer ofAntarctica: www.pnra.it/SCAR_GAZE; SCARMap Catalogue:www-aadc.aad.gov.au/mapping/scarmaps.asp; Antarctic Seismic Data LibrarySystem: walrus.wr.usgs.gov/sdls/; SCAR Geological Map Catalogue:www.nerc-bas.ac.uk/geosci/geomapcat/geomapcat.html.

—GLENN JOHNSTONE, Scientific Committee onAntarctic Research, Geoscience Standing ScientificGroup, Belconnen,Australia

Learning More about Antarctic Geoscience

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