People in the Mountains - Mountain Geography: Physical and Human Dimensions - page 521

the frequency and magnitude of avalanche events. In every case, risk increases. On
the other hand, prohibiting building in dangerous places, forgoing skiing in dangerous
conditions and places, managing forests so as to retain their snow-stabilizing qualities,
and introducing other preventive and mitigative structures, controls, guidelines, and
laws may reduce risk. These principles apply in any environment, and mountain envir-
onments provide some telling examples of both successes and failures in reducing risks
from hazards. They offer examples of disproportionate victimization of women, children,
and older and poor people, as is fairly common in many disasters, but they also show
that all people may be affected (Carey 2010), and that the affluent may be substantially
affected in material terms. However, access to resources, power, and influence may give
the latter greater resiliency and ability to recover from disaster than poorer people. In
sum, understanding and reducing risk in mountain environments is a highly complex
topic with physical, engineering, social, economic, and other components (Brundl et al.
2009).
The elements that produce hazards are essentially those discussed earlier as key
components of the relationship between people and environment: geological conditions,
weather and climate, hydrology, topography, and vegetation, among other things. We
use these as the framework for discussing risks in the mountain environment. However,
both components of risk—hazard and vulnerability—are dynamic, varying in response to
environmental and social-ecological changes. Climate warming (hazard), for example,
may produce both glacial recession and, in some mountain areas such as the Himalaya
and central Andes, an elevated hazard of glacial lake outburst floods (e.g., Carey 2010).
In many cases, however, changes leading to increased risk have resulted from popula-
tion and settlement growth (social-ecological change) in locations exposed to hazardous
processes (Gardner 2002).
Earthquake Hazard
Frequently occurring earthquake disasters remind us that seismic activity, a part of
the mountain building process, is also part of everyday life for many mountain people.
Among earthquake disasters, those that have occurred in mountain areas and their mar-
gins have been some of the most devastating (Hewitt 1997a), the 2005 and 2008 Kash-
mir and Sichuan (Wenchuan) earthquakes being recent examples. Reasons for this in-
clude the extreme ground shaking and the propensity for earthquakes to generate im-
mediate and delayed hazard cascades of landslides, debris flows, and landslide dam out-
burst floods which amplify the disaster impact spatially and temporally. The relation-
ship between mountain areas and high earthquake frequency arises from the locational
proximity between mountains and the edges of the Earth's crustal plates (e.g., the west-
ern Cordillera of the Americas and the Himalaya and Tibetan Plateau). Hewitt (1997a)
demonstrated that some of the most disastrous earthquakes have affected not only the
main mountain ranges but also mountain front ranges and margins. Thus, very high risk
situations are found in the mountain regions of the Mediterranean, the Cordilleras of
the Americas, the mountains of the Middle East, and the extended mountain systems of
central, southern, and eastern Asia.
Two recent mountain earthquake disasters—Kashmir, Pakistan/India (8 October
2005) and Wenchuan/Sichuan, China (12 May 2008)—illustrate many of the elements