1. Hazards Planning and Risk Management
Lecture No. 28
DROUGHTS
Fall 2016
Pic source: Internet
US – Pakistan Center for Advanced Studies in Water

2. Learning Objective Droughts What are they? When do they occur?
Why do they occur?
Consequences of their occurrence?
How they can be managed? 2 2

3. Reading Material NDMA website: Drought Mitigation Action Plan Matrix
Pakistan Met Dept. website:
Other material mentioned throughout the presentation

4. Drought
Deficiency in water supply for an extended period of time (months or years)
Drought is a weather related natural disaster but can be observed in almost all climatic systems
Although drought may occur in both high as well as low rainfall areas but it is one of the consequences of long term reduction in precipitation
Moisture deficit

5. Drought
Temporary anomaly caused by a certain climatic condition occurring at a specific location for a specific duration
Can be aggravated by human activities
May influence a wide range of area
Moisture deficit

6. Slow onset hazard
Unlike others, drought is a slow onset hazard developing over months or even years
Due to its slow evolving pace it can be detected comparatively easily

7. Some argue that it should not be termed as an event rather they suggest it to be considered as a process, which can be understood and forecasted quite well before time

8. TYPES OF DROUGHTS

9. Meteorological
Reduction in rainfall over a region for a specified period (day, month, season, and year) below a specified amount
Involves only the precipitation statistics

10. Hydrological
Reduction in water resources (stream flows, reservoir levels, ground water, underground aquifers etc) below a specified level for a given period of time

11. Agricultural
Emerges due to the impact of Meteorological and Hydrological droughts on a particular area of human activity
If the moisture availability in particular falls below the optimum amount during the growth cycle, the crop growth will be impaired and yields reduced

13. Causes Weather related Low or no rainfall Elevated Temperatures
However conditions that initiate drought in one region of the globe may go unnoticed in another
Source:
For example a few consecutive months without precipitation over Cholistan, Thar and Nokkundi deserts constitute a drought whereas over other regions like the plains of Punjab where surface water making part of the perennial flows and ground water are available, may not suffer from drought under similar conditions.

14. Indicators Reduced soil moisture Decline in vegetative cover
Elevated surface temperature
The decline in the vegetation cover is directly linked with water unavailability

15. Hazard Analysis Identification of Hazard information about the
frequency
onset of drought
its extent
intensity
duration
and impacts

16. Hazard Monitoring
Drought monitoring and assessment rely mainly on rainfall data
Satellite Remote Sensing

17. Elements at Risk
Various environmental factors and activities in drought areas may be adversely affected:
Agriculture
Vegetation
Human life
Wildlife
Natural ecosystem
crop yield and production are very sensitive to drought especially during harvest and few weeks before harvest.

18. Droughts in Pakistan
Pakistan predominantly consists of arid and semi arid regions with a diversified climate
In arid rangelands of Pakistan with low rainfall (200 – 250 mm)- Thar, Cholistan, Dera Ghazi Khan, Tharparkar, Kohistan, and western Balochistan
Monsoon rainfall (erratic and scattered)
Also faces direct impact of solar radiation because of less cloud coverage causes an increase in rate of evapotranspiration
2 to 3 drought years in every 10 years in these areas
Except Balochistan, the above areas are within the range of monsoon rainfall (erratic and scattered)?????

19. Source: PMD?

20. Source: Pakistan Weather Portal - https://pakistanweatherportal

21. Full map source: http://reliefweb. int/sites/reliefweb

22. THARPARKAR DROUGHT SINDH - SITUATION REPORT: http://www. ndma. gov

23. Impacts on population in drought hit areas
About 2.21 million people and million livestock population affected due to severe drought conditions only during (PDMA)
Since 2013, Tharparkar has been affected by a drought‐like situation impacting livelihoods, nutrition and health conditions (reliefweb)
Pic source: Internet

24. Reduced agricultural produce leading to
shortage of food
Adverse impact on economy that largely depends on crop yield and production

25. Other socioeconomic impacts
Crop failure due to low rainfall and loss of livestock can greatly reduced the impoverished communities’ purchasing power.
The loss of livestock to drought was about 40% in Balochistan and 60 % in Sindh only during
Government has to face billion rupees losses due to drought and water shortage
NDMA

26. Impact of Drought on Environment
Unlike floods, droughts generally damage ecological systems and yield few offsetting benefits. In fact, the most subtle and enduring impacts of droughts occur in the environment. The cumulative stress on wetlands, wildlife, forests, ground water, and soils cannot be measured accurately, and many effects occur slowly and over a period of years, making them extremely difficult to quantify. The problems generated by droughts begin with changes in the quantity and quality of water available in the hydrologic system.

27. Continue..
Drought damages both plant and animal species by depriving them of food and water, increasing their susceptibility to disease, and increasing their vulnerability to predation. As with floods, droughts produce a loss of biodiversity, and often increase erosion of dried soils when rain eventually comes. Droughts also degrade water quality, shifting salt concentration, pH levels and dissolved oxygen, while increasing water temperatures. Even air quality is diminished because of increased dust and pollutants. Droughts also lead to more wildfires, while adversely changing salinity levels in coastal estuaries and reducing the flushing of pollutants.
Reading 12

28. Identification of Drought Vulnerable Areas
Regular monitoring of
vegetation status
Soil Moisture content
Land Surface Temperature
Other data including
climate,
soil type,
hydrology and
socioeconomic condition of people

29. Discussion/Comment/Question