Bishop p. 111 – 116
- Drought is an extended period of dry weather leading to conditions of extreme dryness.
- It is a characteristic of moisture deficiency, when lower than normal rainfal occurs for an extended period of time.
- Because the ecosystem and/or human system is adapted to a certain amount of rainfall, the deficit will have a negative impact.
- Impact will vary depending on evapotranspiration, runoff and infiltration.
- “For a drought to develop the lack of rainfall must be enough to cause the soil and groundwater stores to decline” (Bishop, 111)
- There is a difference between drought, aridity and desertification (see Bishop table 6.5, p. 112)
- Mainly in semi-arid areas
- Large human influence
Thake your notes on this shared google doc: IB12 -Hazards -Droughts
Define flash floods:
1. Use this link to define, in your own words, the following terms:
- Meteorological drought
- Hydrological drought
- Agricultural drought
- Socio-economic drought
2. Find a map of the global distribution of droughts and their severity, and write a short description of the spacial distribution of droughts.
3. Explain the difference with your answer in Q2 and the global distribution of drought mortality
3. Explain the four physical reasons why droughts are more prominent in certain areas:
- Cold ocean currents
- Rain-shadow effect
- the main features of the Palmer Drought Indices and evaluate its efficiency in comparing droughts
- The method of measuring rainfall
5 describe the following characteristics of droughts:
- Speed of onset
- Areal extent
- Spatial dispersion
6. Case study: California / American South West drought of 2012
- Santa Barabra County, California
- Santa Ynez River
- Lake Cachuma
- Gibraltar Reservoir
- Jameson Lake
Complete the case study questions on the doc:
Make sure these areas are covered:
- Will El Nino end the drought?
- Prevention / management strategy (reduce use by 25%)
- Land use planning
- Economic impact
- Measuring the drought
- Social impacts
- Environmental impacts