A2 GEOGRAPHY REVISIONHAZARDOUS ENVIRONMENTS

9.4 SUSTAINABLE MANAGEMENT OF HAZARDOUS ENVIRONMENTS

KEYTERMSANDDEFINITIONSBioengineering is the use of vegetation in engineering, e.g. the selection of plant species for the recolonisation of areas following landslides. Geo-materials refer to the use of naturally occurring materials such as vegetation in engineering. Geostructures are structures constructed from geo-materials such as bamboo bundles (fachines), coir rolls and straw wattles. Hazard assessment is the process of determining when and where hazards have occurred in the past, their frequency and magnitude and their likely impacts. Risk assessment is the process of establishing that a hazardous event of a particular magnitude will occur within a given period and estimating its impact, taking into account the location of buildings, facilities and emergency systems. Seismometer is an instrument used for measuring earthquakes.

TOPICSUMMARYWith careful analysis and planning, together with appropriate stabilisation techniques, the impacts of mass wasting can be reduced or eliminated. Maps showing areas that could be affected by mass wasting processes are important tools for land-use planners. Geo-materials can be used for erosion and sediment control. Bio-engineering can also be used. It is difficult to stop an earthquake from happening, thus prevention normally involves minimising the prospect of death, injury or damage by minimising building in high-risk areas, and using aseismic designs.

TOPICSUMMARYEarthquake predictions focus on small-scale ground surface changes, small-scale uplift or subsidence, ground tilt, changes in rock stress, microearthquake activity (clusters of small quakes), anomalies in the Earth’s magnetic field, changes in radon gas concentration and changes in electrical resistivity of rocks. ‘The sustainable livelihoods approach for volcano-related opportunities’ outlines ways in which people can have a sustainable livelihood in some volcanic areas. Sustainable livelihoods can be defined as creating and maintaining means of individual and community living that are flexible, safe, and healthy from one generation to the next.

ADDITIONALWORK1. Describe ways in which it is possible to limit mass movements. 2. Describe ways in which buildings can be made ‘life safe’.3. Outline the concept (idea) of the sustainable livelihoods approach for

volcano-related opportunities.4. To what extent can natural hazards be managed?5. Examine the ways in which mass wasting can be reduced.6. To what extent is it possible to minimise the impact of earthquakes?7. Outline the methods which scientists use to predict volcanic eruptions

and earthquakes. Comment on how effective these are.

SUGGESTEDWEBSITEShttp://sisgeo.files.wordpress.com/2007/09/hazardousenvironments_intro.ppt for a useful PowerPoint overview of this chapter. www.fema.gov/hazard/landslide/index.shtm for useful links on how to prepare for a landslide.www.fema.gov/areyouready/hurricanes.shtm for useful links on how to prepare for a hurricane.www.unops.org/english/whatwedo/UNOPSinaction/ Pages/Monitoring-Volcanic-Risk.aspx for management of Mount Nyiragongo by UNOPS (United Nations Office for Project Service).http://192.171.140.40/bgs/home.html for the British Geological Society.