The environment and disaster management

The environment and disaster management

Alcira Kreimer and Mohan Munasinghe

The objective of this special issue is to explore the role of environmental degradation - and its relation to disaster vulnerability - on both natural and manmade habitats. Accordingly, this article begins with a brief overview of the problem, ie how extreme events and environmental degradation are related. It then goes on to review the main themes in the ensuing articles. The authors are Guest Editors of this special issue of Land Use Policy and can be contacted at the Environment Department, the World Bank. 1818 H Street, NW, Washington, DC 20433, USA. The authors acknowledge Tova Maria Solo’s contribution to the early drafts of this article.

The underlying causes of many natural disasters can often be traced, at least in part, to the same tampering with the natural environment that concerns natural scientists and ecologists. The impact of these disasters on the enviornment can be devastating. Many experts predict that desertification will continue to progress in many areas of the world. Desertification and drought arc both slow-onset events: distinguishing between the different effects of the natural disaster and the normal results of environmental degradation is often difficult in such circumstances. Damage and destruction due to quick-onset events such as floods, landslides, glacial lake outbursts, wind storms, tsunamis, volcanic eruptions and earthquakes may occur more often where there is a history of environmental tampering. Although environmental degradation will continue to cause natural disasters. the options to promote more efficient environmental management and sustainability are at our disposal. In most cases, quite modest investments in disaster reduction clearly provide more than commensurate benefits.’ The articles in this volume explore three main topics: 0 0 a

environmental and land degradation and climate change, and how these changes increase our vulnerability to disaster; the role of poverty in constraining the resilience of the natural and man-made environments to natural hazards; ways of reducing vulnerability by enhancing local capabilities to prevent and reduce losses due to catastrophic events.

The role of the World Bank In this issue,

‘Mary B. Anderson, Analyzing the Costs and Benefits of Natural Disaster Responses in the Context of Development, Environment Working Paper No 29, World Bank, Washington, DC, USA, 1990. “Alcira Kreimer, ‘Lessons on emergency recovery from past experience’, Land Use Policy, Vol 8, No 4, October 1991, pp 31 O-323.

0264-8377/91/040269-l

two articles discuss the above themes within the context of the work of the World Bank. The Bank has a long tradition of working with countries affected by natural disasters. Until recently, most of the Bank’s emergency recovery projects were concerned with the welfare of the disasters’ victims and focused on rebuilding infrastructure and productivity after the disasters. The retrospective review of Bank reconstruction projects in the article by Kreimer suggests that more preventive measures should be taken to protect future development efforts from falling victim to catastrophes and to reduce the negative effects of environmental degradation and subsequent extreme events.’ Limited attention has so far been paid to repairing the environmental effects of disasters or to preventing the environmental degradation that can augment and spark further natural disasters. The lack of a concep-

3 0 1991 Butterworth-Heinemann

Ltd

269

tual framework to link natural disasters and the environment is ;I widespread phenomenon due mostly to the division between disaster management (an issue of concern to agencies mostly concerned with relief and rehabilitation) and environmental policy (a topic addressed by environmental agencies). Only recently have major efforts begun to integrate disaster prevention and mitigation in emergency recovery projects. The World Bank is OIK of the few institutions which has recently started combining the concerns for both disasters and environmental degradation. In their article, Munasinghc. Menczcs and Preecc describe the Rio Flood Project for emergency recovery. prevention and mitigation in Brazil, which illustrates one of the Bank’s prominent efforts in this direction.3 The Rio Project is ;I significant step towards the development of ;I long-term prevention and mitigation strategy for confronting natural disasters. This effort is also an excellent example of developing support for long-term environmental policies by strengthening indigenous managerial and planning capabilities.

Environmental

and land degradation

Riebsame discusscs the new requirements for development planning posed by the threat of global warming.J According to him, this new planning approach should incorporate analysis of the sensitivity of resource systems to variations in climate and environmental change; to allow for adjustment to climate change: and for expansion of the repertoire of options. to avoid being pressured into premature action or paralyscd by uncertainty. In such a repertoire, Ricbsamc includes actions that are easily and cheaply implemented and reversed. and adjustments that expand rather than limit future options. He argues that the mitigation of current natural hazards should be link4 to concerns about climatic warming so that actions taken today hove both immediate and long-term benefits.

3Mohan Munastnghe, Braz Menezes and Martha Preece, ‘Rio reconstruction and flood prevention In Brazil’, Land Use PO/Icy, Vol 8, No 4, October 1991, pp 282287. “William E. Riebsame, ‘Climate hazards, climate change and development planninq’, Land Use Policy, Vol 8. No 4. Octobe;1 991, pp 288-296. ‘Sevril R. Sieoel and Peter Witham. ‘UN’DP coordination of disaster and development planning’, Land Use Policy, Vol 8, No 4, October 1991, pp 297-309. ‘John R. Clark, ‘Coastal zone management’, Land Use Policy, Vol 8, No 4, October 1991, pp 324-330.

270

Siegel and Witham discuss how many disaster-prone countries are now recognizing the need to formulate development policies that arc more responsive to disaster prevention and mitigation.’ In their CBSL' studies, they illustrate how Bangladesh, Colombia, Ethiopia and Jamaica are accomplishing this. They also discuss the special role of the United Nations system. especially the United Nations Development Programme (UNDP), in helping governments strengthen their capacity to build links between planning for disasters and planning for development. Clark describes how Bangladesh, St Lucia. the Philippines and other countries that are affected by serious storms and flooding can adopt preventive measures through specific mechanisms such as effective coastal management.” Clark examines how coastal management programmes can control the type, density and location of coastal settlements and can preserve natural landforms that take the brunt of storms and thus protect lives and structures. Erlhmciq

local qxxiry

forpr”~‘t~tltion

und tnitigatiorl

Cuny describes how most efforts designed to reduce the effects of floods have so far focused on structural measures such as the construction of

LAND USE POLICY

October

1991

dams or embankments (poiders, levees, etc).’ He highlights some of the posed by large-scale flood control projects. For example, embankments may foster unrealistic expectations that all flooding can be prevented and thereby stimulate movement onto flood plains and increase total risk. Alternative strategies are discussed for protecting flood plains, especially in rural areas. One strategy has been to encourage people living in rural areas and in some small communities to adapt to floods and capture their benefits for economic development. Traditional rural societies have developed many ways to adapt to floods and their consequences. These strategies can often be adopted or modified into a national ‘living with Roods’ strategy. According to Cuny, where this strategy has been applied it has been cost-effective, easy to implement and comp~~tibl~ with the envir(~nment. The finks between residents’ standards of living and reconstruction in an urban context are described by Pantclic.x She argues that reconstruction after a sudden-onset event like an earthquake should help improve the residents’ standard of living. Pantclic describes how social and cultural values and resources should be incorporated into reconstruction and development efforts after extreme events. dilemmas

Links between natural disasters and environmental degradation The direct and second~~ry impacts of disasters on the environment are described below. including the way that eilvironment~~l degra~~~~ti~~n subsequently increases vulnerability to further disasters. The ideal process to deal with the two-way linkage between disasters and environmental degradation is a circular and cumulative one. Sound environmental planning that accounts for natural hazard risk leads to an improved resilience and sustainability of natural and man-made environments through integral prevention. mitigation and preparedness measures. The standard reports that follow a natural disaster focus on the number of dead and wounded and on the value of property Iost and damaged. Although natural disasters can pose a signific~~nt threat to ecosystems and natural habitats, the envir~~nment~ll impact of a natural disaster rarely appears in the experts’ reports, news items or academic studies. Not only does environmental damage defy simple cost analysis, but it generally takes a back seat to the human suffering inflicted by a natural disaster. News that does emerge about the environmental impact of natural disasters tends to come from developed countries. In light of scarce resources, few developing countries can afford to turn their attention to natural habitats in the wake of a disaster. However, ignoring environmental damage leads to increased vulnerability to future disasters, since the after-effects of disasters include factors such as destruction of species and habitats, alteration of ecosystems and de~r~~~j~~ti(~nof the environInelit. ‘Frederick C. Cuny, ‘Living with floods: alternatives for riverine flood mitigation’, land Use Policy, Vol 8, No 4, October 1991, pp 331-342. ‘Jelena Pantelk?, ‘The link between reconstruction and development’, Land Use Policy, Vol 8, No 4, October 1991, pp 343-347.

LAND USE POLICY

October 1991

Hurricane Hugo, which hit the Carolinas (USA) and the Caribbean in 1989, is a recent example of a natural disaster that destroyed wildlife. important ecosystems and sensitive natural habitats. In Hugo’s aftermath most reports understandably focused on the hurricane’s damage to human life and property. But Hugo cut through more than 3 million

271

acres of South Carolina’s timberland, laying IO waste l50-year-old stands of loblolly and longleaf pine, oak, cypress and tupelo. The hurricane also affected biodivcrsity: ~ILI~O reduced the only growing population of woodpeckers in the USA by more than 60% and almost wiped out the endangered red wolf population. The waters dumped in the Santee-Cooper watershed drastically reduced the levels of oxygen in local rivers. which killed tens of thousands of fish and damaged breeding In Puerto Rico. Hugo damaged X0’%, of the tropical rninforest and damaged and destroyed many coral reefs - home to fish and ocean fauna.” The 1980 eruption of Mount St Helens in north-west LJSA destroyed stands of more than 250 plant and tree species. The lava covered ;I wide

grounds.

area, killing disaster,

the above-ground

officials

r-e-emerged.

reported

Five

years

after

that had been destroyed volcanic ty in

eruption

portions

that

of plants.“‘Thrce

90%

of the plant

the volcanic

Japan.

the area of impact has contributed

roots

in the soil.

which

eruption.

10%

after

the

species

had

of the species

no sign of life. As ;I

had still shown

of Mt Sakurajima,

years tree

and

result of the species divcrsi-

the Iowcrcd

to a monotonous

has accelerated

soil

distribution

of

erosion.

are particularly susccptiblc to wildfires - ;I form that may he set off by a ~lcano. lightning or The chance of a naturally ignited fire turning into disaster incrcasea with the forcst environment’s

Forest environments of quick-onset disaster human

an

carelessness.

uncontrollable

degradation.

The

forest

damage of flash fires

that

raged

19X2-83, This

single

272

When

-

;I disaster

wipes

of forests

~ normally

hurricane

can take years

million of

report4

in

out ;I natural attributed

and cyclone

to

-

The

has

contributed after

to the spread

clearings

began.

in

century.

the

reduced

may continue

and mussivc

destruction

also

caused

by

of

hut

been

of ‘monkey

1000 casts

J~I-css -

lrctivities.

of areas of the Kyazanur

clcarnnce

in

of this

the survivors

rapid

the

(Indonesia)

disaster?;

f’orcign

from

destroyed

known to spark epidemics animal host5 after deforestation.

human

viruses that outlive their traditional 198.3,

the

habitat,

its after-effects.

were

Kalimantan

natural

I’

by half.

to rccovcr

ha of forest

East

of the worst

little

or to spread

3.3

forests

rainforcsts

to suffer fire,

the

it one

event

tropical

environment Some

in

making

world’s

“Kerry Gruson, ‘Healing comes slowly to woods and streams where hurricane left death’, New York Times, 12 November 1989, p 32. ‘OUNEP News, Supplement 2, March/April 1986. “Erwin Adriawan and Sandra Monlaga, ‘The burntng of a tropical forest: fire in East Kalimantan. What caused this catasThe Ecologist, Vol 16, No 6, trophe?‘, 1986, pp 269-270. ‘?=I. Motha, T. Puterbaugh and R. Lundine, ‘An ill wind: El N~rio ralnfall anomalies and regional crop yield variability’, Mazingira, Vol 8, No 6, 1985, pp 13-l 8. 13UNEP News, op tit, Ref IO. “‘P. Baxter, M. Kapila, L. Kaptue and D. Mfonfu, ‘Medical aspects of large scale volcanic gas emissions’, in Proceedings Of Kagoshima lntemational Conference on Volcanoes, National Institute for Research Advancement, Tokyo and Kagoshlma, Japan, 1988. “Tamlo Yanagawa and Hiroyukt Minamizono, ‘Effect of volcanic gas on environmental air quality and its characteristics’, in Proceedings of Kagoshima lntemational Conference on Volcanoes, National Instltute for Research Advancement, Tokyo and Kagoshima, Japan, 1988.

fires.

Forest

disease’

of the viral

in Karnatako.

to humitns.

disease

Five

wcrc

In

India. months

reported.

and

5% deaths. I2 Volcanoes

and earthquakes

have

gases and particulate

ash.

rose

in Cameroon

from

Lake

Nios

1700 inhabitants

Clouds

of the towns

been

linked

to emissions

of toxic

of volcanic gases with carbon in August

of Nios,

Bubum

lC)Sh, asphyxiating

dioxide about

and C’hc. and destroying

the surrounding agriculture. Local geologists and foreign experts attributed this damage to gases released from ~ubmergecl craters. ‘j Previous recorded

incidents

the eruptions

-

and

ral

in Indonesia crops

involving

of voIc;~nocs Mount

releases ~ Hclka

in 1979. I-)

Volcanic

of carbon

dioxide

in 1947 and Eldfcll gases

damaged

include in 1073

agricultu-

Japan. even though no volcanic also contribute greatly to changing the turbidity of the atmosphere - ;I condition that reduces its transparency to radiation - thus contributing to the greenhouse effect. After the Mount St Helens eruption, huge amounts of large particles

explosion

on

- Sinila

massive in Iceland

occurred.”

Sakurajima.

Volcanocs

LAND

USE POLICY

October

1991

The environment

and disaster management

pumice were injected into the troposphere and stratosphere, which measurably (albeit temporarily) reduced the amount of solar radiation reaching the ground. El Chichon, which erupted two years later in Mexico, blasted great quantities of sulphurous gases into the stratosphere. The suspension of particles and the reduction in solar radiation were recorded in different sites around the world and residual effects were felt up to five years later.‘” Volcanic activity also has a significant impact on vegetational succession. In the case of Mount Sakurajima, the accumulation rate of volcanic sands and ashes is so high on the slope of the volcano and on the forest floor that the sands and ashes are neither sustained by the network of thin rootlets nor fixed by humus and fungal systems. According to Tagawa, the heap of small particles of sand absorbs and stores little water; rainwater flows down the slopes in the forest like water through wadis in the desert.” Rapid floods (associated with such disasters as hurricanes, tsunamis, volcanoes and earthquakes) can alter the oxygen and bacteria content of rivers and lakes, destroying fish and the breeding grounds of aquatic life. Research after the 1988 eruption of Lonquimay in Chile revealed that the high concentration of gases and suspended particles in the air caused not only many respiratory and other ailments in the human population, but they also affected the vegetation, which provoked mass dehydration in the fauna and an epidemic of osteofluorosis in the large population of grazing animals.‘x

of

Environmental

!“Norman J. Rosenberg, ‘Climate change: a primer’, Resources, Vol 87, spring 1987, P 9. ’ ‘Hide0 Tagawa, ‘Vegetational succession on Sakurajima Volcano’, In Proceedings of Kagoshima lnternafional Conference on Volcanoes, National Institute for Research Advancement, Tokyo and Kagoshima, Japan, 1988. “Gustave Fuentealba and Munllo T. Marisol, ‘Analisis de la vulnerabilidad ante desastres naturales usando coma un ejemplo la eruption en el complejo volcanic0 Lonqurmay’, Medio Ambiente y Urbanizacidn, Vol 30. No 90, March 1990. “David Pearce, The Major Consequences of Land and Water Mismanagement in Developing Countries, World Bank issues paper, Washington, DC, USA, 1985. “‘/bid.

LAND USE POLICY

October

1991

degradation and vulnerability

The patterns by which one natural disaster leads to another are well known. High windstorms are followed by floods and landslides, floods by drought, and drought by epidemics of pests. Such chains result partly from the tendency of natural disasters to debilitate the environment and increase its vulnerability to future disasters. Human activities also contribute to a weakening of the environment. When natural disasters cause widespread, rapid deforestation and erosion, they set the stage for future landslides, floods, droughts and epidemics. David Pearce’s explanation of the chain of environmental damage resulting from reduced tree cover, increased water runoff and soil erosion is that as tree cover is reduced, the soil loses wind shelter and water runoff increases, which in turn reduces soil fertility and hence land productivity.‘” Fuelwood also becomes scarce. Inhabitants try to adapt: women must walk increasing distances in search of remoter sources of fuelwood, the burning of dung and crop residues increases, and ultimately the cooking of one meal a day is abandoned, all of which affect health and food output negatively. In turn. reduced tree cover directly affects livestock fodder, especially in semi-arid environments and upland watersheds. Increased burning of dung and crop residues deprives the soil of chemical, physical and microbiological inputs and thus reduces soil fertility further. As water runoff increases, water sources are subject to increased salinity, which affects agricultural output and reduces potability. Sedimentation affects irrigation channels and reduces the water available for agriculture. It also affects rivers and estuaries by raising flood plain levels, which incurs costs to agriculture and increases risks of damage to property and life.‘” Pearce mentions other causes of degradation outside of extreme events, although the same cycle results whether deforestation springs

273

“P. Ltndsay and L.D. Pryor, Ecological Mismanagement in Natural Disasters, International Union for Conservation of Nature and Natural Resources, Gland, Switzerland, 1982. “Anders Wijkman and Lloyd TImberlake, Natural Disasters: Acts of God or Acts of Man?, International Institute for Environment and Development. Washington, DC, USA, 1984. 231bid. “‘Lindsay Hilsum, ‘Aggravating Ethtopia’s environmental disaster’, Panoscope, Vol 2, August 1987, p 9. 25Wijkman and Timberlake, op tit, Ref 22. ““bid. ‘7Precipitation patterns are remarkably similar in the Sudan, the Sahel and the tropics, but with different results. An intense rainy season followed by a stark dry season will bring floods to Sudan and the Sahel, but will mean simply a change from the dry to the wet season for the tropics. The absorptive capacities of tropical sotls makes the difference (ibid). “Eric P. Eckholm, The Other Energy Crisis: Firewood, Worldwatch Paper No 1, Worldwatch Institute, WashIngton, DC, USA, 1975. “‘Wijkman and Timberlake, op tit, Ref 22.

274

from human effort or from hurricanes, forest fires or volcanoes - and whether the increased water runoff results from tropical storms. tsunamis or flash floods. The fact that disasters might occur ‘naturally’ does not lessen their impact on environmental systems or mean that we should neglect to assess their effects and protect natural habitats from their ravages. Hurricanes and forest fires produce the same effects of reduced tree cover that Pearce cites, but on a massive scale. When measuring the after-effects of fires in Australia, Arizona and Tennessee. L.D. Pryor found that the devastation of forests led to increases of lOO--370% in sedimentation in the surrounding riverbeds.” Dead and uprooted trees no longer held down the topsoil. which washed away in normal rainfall. Not only did fires and hurricanes affect river and watershed ecosystems, but the rivers’ flow more than quadrupled and increased the danger of floods in the area.” That disasters cause water runoff can be seen in Bangladesh and Ethiopia, where the flood-drought cycle accelerates yearly. When describing the phenomenon in Bangladesh. Roy Ward said: ‘It may appear ironic that, in lands where the second greatest river system in the world flows, the floods are followed immediately by droughts.“’ In Ethiopia the very rains that overran riverbanks in 1986 washed away more topsoil than ever, exacerbating erosion and contributing to Ethiopia’s subscquent droughts and famines, in a vicious circle that ‘is pushing parts of Ethiopia closer and closer to irreversible environmental collapse’.” Finally, soil erosion can be accelerated by windstorms and floods. In the Caribbean the periodic ravages of hurricane winds and rains are known to carry off topsoil and thus to reduce the land’s absorptive capacity. A peculiar phenomenon follows: arable lands become parched, even when rain is ample, and agriculture suffers. Experts estimate that even with normal levels of precipitation. crop losses from such ‘pseudo-droughts’ between 1970 and 1975 amounted to $20 million in bananas alone.” Most disaster assessments calculate the cost of lost crops or plants. Few estimate the cost of damage to the soil. Tropical storms in particular can dm~~rge the environment in areas susceptible to erosion - especially deforested areas. When rainfall reaches 35 mm an hour, ;I splash effect actually uproots pieces of earth not simply dust - and begins ;I process called surface cracking.‘” Such erosion tends to increase where there is monocropping and deforestution. Indeed, droughts and floods have less to do with dramatic changes in) rainfall than with the ground’s capacity to absorb and retain water.‘7 Windstorms, tsunamis, earthquakes and forest fires all contribute to the drought-flood cycle by reducing tree cover. eroding soil and causing water I?unoff. But the main actors in the cycle are droughts and floods, which tend to cause the very degradation that intensifies their own effects. Lowered

resistut1c.e

to Iuizarr1.s

cu~iserl hJ tle[brestution

Deforestation and erosion are now considered a primary cause of catastrophic flooding. Eric Eckholm describes the relationship of dcforestation - particularly of watersheds - to increased flooding.‘” Studies by the Food and Agriculture Organization (FAO) and the United Nations Development Programme (UNDP) specifically link the increase in world flood disaster to the destruction of the tropical rainforests.“’ Authorities from China’s National Science Association

LAND USE POLICY

October

1991

The environment

30Edward Goldsmith and Nicholas Hildyard, eds, The Social and Environmental Effects of Large Dams: Vol 1, Wadebridge Ecolooical Centre, Camelford, Cornwall, UK, 1984. p 106. 3’13atliwale. ‘Preventable traaedv or lost Vol 9: November cause?‘, Panoscope, 1988, p 22. 3’William B. Magrath and John B. Doolette, Sfrafegic issues for Watershed Development in Asia, Environment Working Paper No 30, Policy, Planning and Research Staff, World Bank, Washington, DC, USA, 1990. 33Miles Litvinoff and World Wildlife Fund, The Earthscan Action Handbook, Earthscan, London, UK, 1990. 34Magrath and Doolette, op cif, Ref 32. ?an Burton, Robert W. Kates and G.F. White, The Environment as Hazards, Oxford University Press, New York, NY, USA, 1978, p 62. 36Francisco Brzovic, ‘Procesos relevantes de deterioro ambiental en el Peru’, CEPAL Working Paper, Santiago, Chile, unpubIshed, 1990.

LAND USE POLICY

October

1991

und disaster tnanugemerzl

blame the recent spate of floods in Sichuan province on progressive deforestation. Some 10 000 ha of Wuzeng forests in the early 195Os, for example, had been reduced to 56 ha by 197S.3” The Chittagong hill tracts of Bangladesh have suffered extensive deforestation,“’ but in Nepal, where much siltation originates, deforestation has caused landslides and floods. Limited fuelwood supplies in Nepal have been a key factor in the denuding of the Himalayas. Robbed of vegetative cover - which acts like a sponge to prevent flash floods the slopes wash away. The washaways have reduced rice production by 30% in the past decade.“’ Typhoons and hurricanes are not sparked by so far as we know, but trees serve as environmental degradation, important windbreaks and ground cover to absorb flash floods and maintain forests, particularly on shorelines. Reports from Manila indicate that typhoons Maring and Nitang left 1000 dead in Luzon from floods in September 1984; 90% of the victims were drowned as water swept over the Philippine island. According to Eurthscm. the typhoons’ force would have been weaker had there been trees to hold back some of the waters.33 Greater environmental degradation increases the proneness to natural hazard. According to Magrath and Doolette, in Asia it is estimated that forest cover is receding at around 1% per year and that degradation through overcutting and grazing is reducing productivity on much of the remaining stand.j“ Environmental degradation weakens resistance to certain disasters and exacerbates the effects of others - as when floods and landslides follow earthquakes and hurricanes. Environmental tampering - in the form of dams, levees, irrigation works and even flood protection - can increase the danger of floods in both rural and urban areas. In his studies of Sri Lanka, Hewapathirane concludes that ‘the risk enlarges in the face of heavy government expenditure for levees. channel improvements and upstream dams’.j’ Colombo grew into the flood plain as the constructed levees appeared to offer settlers protection from floods. However, the levees offer only temporary protection against the floods they were designed to curb. When the levees break, the losses will be tremendous. Moreover, the levees in some places prevent water from draining back to the confined streams and so caused prolonged flooding in theoretically protected areas.

Environmental

degradation and natural disasters

The Economic Council for Latin America and the Caribbean defines natural disasters as dramatic situations of degradation that correspond to rapid processes with great negative impact, both economic and social. The actions that spark these processes can be natural or man-made; the latter are generally accidenta1.j” Some of the many forms of environmental degradation directly linked to natural disasters - land degradation, erosion. the reduction of groundwater and its absorptive capacities, and the alteration of surface and subterranean pressures - are discussed below in the context of specific types of disaster. Others - such as the destruction of biodiversity and ecological systems-can certainly be connected to natural disasters, especially epidemics of pests. Earthquakes

Earthquakes

trigged

by hurnm uctivity

are generally

considered

to be acts

of God,

but some

275

tremors The

h:rve

been

tremors in

to man’s

Mead

of up to 5.0

t;rmpering

in Arizona

on the

with

the environment.

in 1035 produced

Richter

scale

in what

more

than 600

was called

‘the first

case of reservoir-induced seismicity’.” Dam-building zones - cg the Aswan Dam in Egypt.

recognized ties

connected

of Lake

creation

xtiviand

non-seismic

Akosombo

(Ghana)

associated the newly

with

and

reservoirs.

ence have connected emptying

of

onset of tremors

suddc~~

the

construct4

seismic

reservoirs

-

activity

perhaps

with

-

also

have

quakes

and

Subsequent

most

the

been

relatively

investig:rtion

filling

and

at Italy’s

dramatically

set off ;I landslide

near experi-

and

the construction,

shown

Dam in 1963, in which tremor\

Vaiont

(USSR)

dams

Bratsk

that killed

9000

pcoplc.3” area loads can also change in other

Surface lr)8S

earthquake

in Mexico,

location

in

between

the gradually

itself.

The

shifted own

an

unfilled

weight.

mental

Floods

places

degradation.

and

ing

of

may

of rivers, otherwise

(which for

that

overflows

37Goldsmith and Hildyard, op tit, Ref 30. 38/M. 39Wiikman and Timberlake, op tit, Ref 22 40Busrton et al, op tit, Ref 35. 4’Fave Henderson, ‘The Philiootnes: a country profile’, OFDMJS Agendy for International Development, cited in Philippine Country Study, Asian lnstltute of Technology, Bangkok, ThaIland, September 1990. 42John Williams, ‘Foreword’, in Earl Brabb and Betty L. Harrod, eds, Landslides: Extent and Economic Significance, Proceedinqs of the 28th International Geoloqical Congress: Symposium on Landslides, Washinaton. DC, USA. 17 Julv 1989. A. A. Balkem:, Rotterdam, the Netherlands, 1989.

276

As

the ultimate

capacity

to carry

Floods

environmental

wider

such

flood

a flood

of

Arno

the Vito

in C‘entral

in Florence

as

by

the

e\‘en b>

and

can combine plains.

Think-

a disaster

can take River

\evcral

watershed

dcl Cilento

Italy)

often

disasters

triggered

‘spark’

floods

but they

as ‘triggering’

in

1133

in

accounted

in great

date

to

in l%(,.“’ in

Sri

clearin g in the colonial effect

of improving

flow.

areas

occur

new

Lanka

back

its

and stream channels have filled with sediment, mot-c common. With the spread of plantation

stream

lowland may

floods recent

river

and forest

control,

and many

onto

on by Gianbatista floods

its

environmental

- all of which

that

triggered

creates

capacity, of soils,

mechanisms

deforestation

have become

agriculture

absorptive

processes

increasing

period.

generally

but

the disastrous

Events colonial

with

arc

precipitation

gradual

disasters. progressive

degradation

was commented

connection

floods

control

normal

of

environmental

be difficult, The

but

from

in environ-

tampering

may accompany

and rainfall

the reduced

of flood

long-term

centuries.

part

winds

included

is controversial.

history

long

tsunamis.

the construction to drive

a

is rareI>,

of as rapid-onset

thought

with

lake

C’ity was sinking

Mexico

environmental

ones

however.

rnxic,

and the quake capital over the years has

on that

pressure

whether

existing

High

hurricanes silting-up

of Mexico’s

measurably:

studies:

are generally in

expansion surface

was

connection

pressul-e

Changing

impact

No

increased

table

stresses or releases

occur

lake.

tremendous

the water

ways. The impact of the cxamplc, was exacerbated by the city’s

for

Channels

dropped

from

storm

period

silted.

follo\ving

British

LV;IS to reduce

channels

drainage

their

was impaired

out of cultivation.J” surges

and

from

other

negative

such 2s the destruction of mangroves, coral reefs of natural breakw;~tera: the siltation of river deltas,

factors.

and other forms bays and gulfs; and

shoreline

reclamation.4’

to Williams. the great variability of the speed and thercfore the perceived significance of slope stability and failure5 offer ;I major challenge in dealing effectively with landdidcs.” There ma); bc ;I dramatic collapse of mountains of rock or an impcrceptiblc distortion of large slope arcas. In the LISA. ;I surge of interest in ~nvironment~11 According

LAND

USE

POLICY

October

1991

The environment und disuster munugemetlt

concerns in the late 1960s and early 197Os, together with the passage of the National Policy Act by Congress in 1969 and similar laws by state governments, stimulated research on landslide recurrence and the mechanisms of slope stability and failure.‘” In some areas, the geology and climate contribute to the prevalence of landslides. For example, in the Caribbean the warm, wet climate influences the material involved in landslides and serves as the most common mechanism for their According to Tianchi, limited knowledge in China about initiation.j4 identifying and preventing landslides led to excavations on and reactivation of ancient landslides.‘5 For example, many landslides plagued the construction of the Baocheng railway (1954-57). Slow-onset

%allas Peck, ‘Foreword’, in Brabb and Harrod, op tit, Fief 42. @J. De Graff et al, ‘Landslides: their extent and significance in the Caribbean’, in Brabb and Harrod, op tit, Ref 42. 45Li Tianchi, ‘Landslides: extent and economic significance in China’, in Brabb and Harrod, op tit, Ref 42. 46Michael H. Glantz, The Politics of Natural Disasfer: fhe Case of the Sahel Drought, Praeger, New York, NY, USA, 1976; Michael H. Glantz, ‘Drought in Africa’, Scientific American, No 256, June 1987, pp 34-40; Michael H. Glantz and Richard W. Katz, ‘When is a drought a drought?‘, Nature, Vol267, 1977, ~~-192-193; and D. Wilhite et al, Plannina for Drouohf: Toward a Reduction of E&eta/ ~ulnerabilify, Westview Press, Boulder, CO, USA, 1987. 4’Wijkman and Timberlake, op cif, Ref 22. 48R. Lal, ‘Environmental impact of deforestation and arable landuse’, in Roberto Vanore and Society for International Deat the velopment, eds, Presentations Pane/ on Environmental Degradation and Rural Development Strategies, held on 2 July at the 18th World Conference of the Society for International Development (SID), AISI, Rome, Italy, 1985. 49Erick P. Eckholm and Lester Brown, Spreading Deserts: The Hand of Man, Worldwatch Paper No 13, Worldwatch Institute, Washington, DC, USA, 1977, p 17. “Wijkman and Timberlake. op cif, Ref 22. ” /bid.

LAND USE POLICY

October

1991

disasters:

drought

Earthquakes, landslides and volcanoes tend to attract more media attention, but recurrent flooding and drought destroy more lives and affect more people annually than all other forms of natural disasters combined. In the 1970s some 24.4 million people were affected by droughts and another 15.4 million by floods. The devastating effects of drought in Africa have been substantially documented.‘” Even in the Caribbean-where hurricanes, earthquakes and volcanoes are notorious - drought and erosion continue to cause the most damage and the greatest economic losses.“’ The soil deterioration that results from the erosion and compacting of topsoil, downhill water runoff (from deforestation) and the decreasing activity of soil fauna, threatens the ecosystem and greatly increases the risk of drought, floods and pest epidemics.“” Drought is classified as a natural disaster precisely because people tend to attribute it to the capriciousness of nature - ie the uncontrollable, unpredictable lack of rain - but the evidence has led experts to question this assumption. Drought-induced famine has occurred in North Africa together with desertification of the Sahel. yet no evidence exists to suggest that rainfall levels in the past 100 years have declined there, in the Sahara (to its south), or in the Middle East.J” The Caribbean pseudo-droughts in the midst of tropical rainfall reinforce the popular association of rainfall and drought. But the lack of groundwater _ not the lack of rainwater - appears to be the central cause of drought. Deforestation in Haiti has reduced the soil’s capacity to absorb water. Despite steady rainfall, waters run off the razed hillsides and offer little benefit to crops; the effect is that of a drought, despite normal rainfall. Even in flat areas, such as rice paddies in the Philippines, similar pseudo-droughts have been traced to deforestation through traditional slash-and-burn agriculture.5” According to Alan Grainger of Oxford University, ‘A drought may initiate a crisis, but it does not cause if.‘>’ Overgrazing and ovcrcultivation weaken the lands and ‘do not permit a sufficient margin when the dry season comes’. The inappropriate introduction of modern and mechanized agricultural methods, and sometimes simply overintensive cultivation, are often underlying causes of drought. Examples abound of the cycle of overcultivation. erosion and drought. The dust bowls in the US Midwest in the 1930s are attributed to drought, which in turned stemmed from the transformation of the prairies of the Great Plains into wheat farms. In the USSR the substitution of cereal crops for the natural ground cover of the Central Asian steppes in the 1950s led to desertification and drought in the

mid-1960s. Overgrazing. deforestation and overcultivation in the Sahel reduced the :rmount of topsoil and compacted what soil remained. causing the waters to run off rapidly before the soil could barely absorb them. Whether or not torrential runoffs arc considered floods. when waters slide over topsoil without penetrating it the effect is drought or pseudo-drought.5’ Observers in Nepal have noted ;I secondary degradation cycle produccd by deforestation. The lack of rrecs for firewood has led farmers to burn cow dung for cooking fuel, which has reduced the amount of fertilizer available and thus lowered the fertility of the hills and agricultural land. This has led to further erosion even in areas far removed from the forested arcas. Nepal’s National Planning Commission estimates that continuation of the present trend will create ;I ‘semi-desert type of ecology in the hilly region’.‘3 Increasing drought in India is also linked to environmental degradation, especially deforestation. On hart

slops. rainfall

is no longer

hclcl hack to soak into the land and replenish

off rapidly into ri\,ers and back to the SC;I. Paradoxically, India is one of the wcttect countries in the world, with an avcragr of I170 mm of rain/)ear and yet people stiII go without water.i’ thr

water

table.

Sometimes

vironmental

Insto:rd

it streams

supply to semi-arid lands causes cnherds grow more rapidly and destroy that helps maintain topsoil. The resulting new endangers cvcn more people and animals than

introducing

degradation

the local vegetation threat of drought

;i water

because

before .i

Degradation

=/bid. 53Eckholm, op tit, Ref 28. ‘India faces worsening 54Asia Ram, drought’, Panoscope, Vol 2, August 1987, p 14. 55DANIDA, Environmental Issues in Dry/and Agriculture, DANIDA, Department of International Develooment Coooeration. Copenhagen, Denmark, 1988. 56David Oaklev, Studv of Hazard Manauement in Maw&, UNDP with the UNDEO Co-ordinator and the Government of Mauritius, 1990. 571bid. 58Munasinghe et a/, op tit, Ref 3

278

of the urban environment

Urban settings are no less vulnerable and no less subject to environmental tampering than the natural environment. The problem is defining environmental degradation in an urban setting. In :I sense, the mere existence of a metropolitan area represents an irreversible degradation of a once natural environment, which inevitably increases vulnerability to disasters. The landslides in Mauritius illustrate how urban ecosystems, or a lack thereof. contribute to disasters. A UNDP study of hazard management in Mauritius refers to the way urbanization distorts natural drainage and can cause landslides.‘” Slopes in Mauritius have generally been stable for many generations, but the stability can be undermined by excessive rains alone. Slips are usually triggered by ;I leaking reservoir, blocked or leaking underground drains, or natural drainage (soil and subsoil) which has been seriously disturbed by the construction of roads and buildings.” In Mauritius, municipal infrastructure and drainage programmes had not kept up with urban growth. The Rio Prevention and Mitigntion Project described in this issue illustrates further how dcvclopmcnt and poverty contribute to urban vulnerability.‘” This is not to nay that 21city must live with the catastrophes it creates. Urbanization by itself does not make cities more vulnerable to disasters. In general, the catastrophes can be traced to poor planning, inappropriate design, faulty construction, inadequate maintenance and the effects of poverty - which x-c usually found together. Rapid urban growth can lead to inappropriate USC of watershed ;u-cx or primary deforestation.

dunes, Such

the effects was

the

of which

may

resemble

case in a mud avalnnchc

those

of erosion

in Viria

LAND USE POLICY

del

October

or Mar,

1991

Chile,

5QAlfredo Rodriguez, ‘Desastres urbanos, fenbmenos no-naturales’, Media Ambiente y Urbanizacidn, Vol 8, No 30, March 1990, p 14. V_/A!EP News, Supplement 6, November/ December 1987.

LAND USE POLICY

October

that buried more than 100 homes in 1984. Although the avaianthe occurred during the normal rainy season, there were many ‘UnnatUral’ causes which together led to floods and further damage and disasters. All the high areas of the watershed had been developed residentially, and the natural vegetative and forest cover that would normally have retained the rainwaters had been destroyed. The dunes were paved over, which increased the volume of stormwater runoff, and the cross-highway drainage was inadequate, which precipitated an avalanche of mud and slush that covered the residential area in the lower parts of the watershed.“’ In the literature on urban disasters, problems of poor or absent planning are depicted as triggering serious environmental degradation. But more common and disturbing are references to urban infrastructure that, through poor or non-existent maintenance, have become agents of degradation. Clogged drains, for example, can be worse than no drains at all in a flood situation. Silted-up drains or riverbeds worsen the impact of floods on precarious soils. Inadequate environmental policies can exacerbate floods in urban areas. The pollution from accumulated garbage and human waste can turn a flood into an open and overflowing sewer. The outbreaks of typhoid and gastrointestinal infections are a secondary effect of a disaster which was directly sparked by earlier degradation of the urban environment. Outbreaks of diarrhoea and dysentery, for example, followed the Bangladesh floods of 1987, and left more than 700 dead and 600 000 hospitalized.h” Developing countries are particularly susceptible to problems of rapid urbanization. Most recent urban settlers are poor and unable to afford properly serviced homesites, which compounds the danger for them and their fellow citizens. Unplanned squatter neighbourhoods - which account for an estimated 70% of the urban development in developing countries - are generally formed without the approval or guidance of planning authorities. Settlers’ survival depends on their establishing squatters’ rights, through construction and occupati~~n, as soon as possible. Under pressure to build fast, squatters represent a great threat to the natural environment of cities. To begin with, they tend to settle on precarious sites where degradation has already begun. They apply slash-and-burn techniques, destroying whatever vegetation covers the original terrain. Rapid construction compacts soils that are usually already depleted. Because of a lack of public infrastructure, squatters rarely have water to spare for plants, so vegetative cover is further reduced. At the same time, where no drainage is provided, uncontrolled or unchannelled waste water causes further soil erosion and deforestation. Squatter settlements through~)llt the world are commonly characterized as arid. Indeed, after a squatter settlement is established, restoring fertility to the surr(~unding ground becomes difficult. Unseated or improperly leached septic tanks can saturate already precarious soils, so that their absorptive capacity is drastically reduced, waste waters puddle, and flooding and landslides become common. The 1987 mudslides in Venezuela were attributed to heavy rains and flooding, and caused the deaths of at least 150 people living along the highway between Caracas and the central airport. Landslides are common in the informal neighbourhoods of Caracas’s poor, as deforestation combined

1991

with

no drainage

causes

erosion,

making

otherwise

firm

land

unstable

and susceptible 500 squatter

to washout.“’

Municipal

are destroyed

shanties

authorities

Disasters and global environmental According ozone floods

to UNEP,

layer for

In northern longer

the greenhouse

can bc expected the next SO years. latitudes

subtropical

might

rise.

leading

to severe

of all human

beings

live within

sea level

of

habitation

patterns,

even

important

cities

half

;I meter

cilusing

flooding

to conit‘

summc’rx

even drier

over

low-level

60 kilometers

cc~uld therefore

many people

and ports

and wetter. become

of the

of droughts

and

would

he

than they are

as the oceans warmccl up :und expxnded,

ones even wetter

sea levels one-third

some

and the destruction

the likelihood

he shortt‘r

regions

now and tropical would

that

changes

effect

to increase

would

winters

and drier

report

each year in landslides.

under

I:mcls.

of ;t coastline.

h:lvc

profound

Ntxrly

A rise in effects

to move :~nd many of the world’s threat

of

on most

flood.“-

Mauritius, an island country visited regularly by destructive cyclones. is watching changing weather patterns closely. The official Committee for Cyclones and Other Natural Disasters has already noted increased high-wave phenomena in the South Indian Ocean and has concluded that global climatic changes and rising seas will aggravate (in frequency and force) existing risks such as sea storms. Rising sea levels COLIIC~also increase the risk of salt intruding in island aquifers, which in turn would increase the risk of drought and landslides, destroy or damage coral reefs (which

offer

natural

patterns. which would Apparently changes visits

of El Nitio,

protection

cause more in

periodic

global

to shorelines), flooding

weather

sprin, cr currents

and change

rainfall

and heavier conditions

silt deposits. also provoke the

that

the mid-Pacific

warm

Ocean. A study hy the US Office of Nnv:~l Research (NOAA). the National Science Foundation and NASA - under the code name TOGA (Tropical Ocean Global Atmosphere) - show> El Nirio as being somehow associated with floods and heavy rains in the US north-eastern and Gulf states. as well as in Bolivia, Ecuador and Peru. Siniultaneously. droughts cripple Australia, Indonesia. Sri Lanka. southern Africa, southern India and the Philippines. Landslides and mudslides OCCLII more often in Ecuador and Peru when .!?‘INitio pastes hy. In 1983, El Nitio was associated with both droughts and unseasonably heavy rains and storms in the Americas. The effect was seen immediately in the starvation of almost the entire adult sea-bird population of Christmas Island, including endangered species such as blue-faced boobies, petrels and sheerwaters. Investigation of El Nirio’s 19S3 visit establishcd beyond ;I doubt that 1;1/ Nirio is not the result of random unconnected events. Analysts hope that understanding and analysing its patterns could help to predict wcathcr changes and cvcn disasters.“’

Conclusions Environmental degradation can incrrass the risk of natural disasters in both man-made and natural environments. Global environmental

I31Ibid. “*UNEP News, op tit, Ref 60. 63Motha el al, op tit, Ref 12.

280

changes appear to he linked to events that trigger and worsen the impact of natural disasters. Urban and natural environments arc affected by similar patterns of events. Environmental changes provoke or contrihutc to natural disasters. which in turn destroy natural environments and increase their vulnerability to disaster. C;ILISC and effect may cross

LAND USE POLICY

October

1991

The environment and disusler manugrmen~

borders. Deforestation in one country can cause sedimentation and floods in another, producing erosion and drought in a third. Even quick-onset disasters often involve long-term environmental degradation. Information about the obvious links between natural disasters and environmental degradation is limited. In particular, little methodical data exists about the environmental damage natural disasters produce although there is a great deal of data about the costs of damage to persons and property. More important, there have been few systematic attempts to restore imbalances or to reverse harmful environmental processes that can result from or even produce disasters. Despite widespread interest in damage to the environment, the interaction of natural disasters and the environment has hardly been explored, although natural disasters may cause as much environmental degradation as human activities or slow-moving global changes. Disaster prevention and repair could prove to be a critical approach to defending the natural environment, and conservation could prove to be the basis for preventing and mitigating natural disasters. Sound environmental planning that accounts for natural hazards may promote increased resilience to extreme events and stability of the socioeconomic base. The articles in this special issue of Lmd Use Policy attempt to analyse disaster prevention and environmental protection, to further such an approach.

LAND USE POLICY

October 1991

281