Hazards Planning and Risk Management Lecture No. 26 DROUGHTS Fall 2017 Pic source: Internet US – Pakistan Center for Advanced Studies in Water

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

Reading Material NDMA website: Drought Mitigation Action Plan Matrix http://www.ndma.gov.pk/plans/Directive_2015.pdf Pakistan Met Dept. website: http://www.pakmet.com.pk/ Other material mentioned throughout the presentation Drought bulletin of PMD (at pmd website).

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

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

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

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

TYPES OF DROUGHTS

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 http://www.pakmet.com.pk/journal/historyworstdrought2001report.htm

Hydrological Reduction in water resources (stream flows, reservoir levels, ground water, underground aquifers etc) below a specified level for a given period of time http://www.pakmet.com.pk/journal/historyworstdrought2001report.htm

Agricultural Emerges due to the impact of Meteorological and Hydrological droughts on a particular area of human activity If the moisture availability falls below the optimum amount during the growth cycle, the crop growth will be impaired and yields reduced http://www.pakmet.com.pk/journal/historyworstdrought2001report.htm

http://www.pakmet.com.pk/journal/historyworstdrought2001report.htm

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:http://www.pakmet.com.pk/journal/historyworstdrought2001report.htm 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.

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

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

Hazard Monitoring Drought monitoring and assessment rely mainly on rainfall data Satellite Remote Sensing Soil Moisture and Ocean Salinity Satellite. drought root zone soil moisture index (0 dry – 1 wet) Source: http://www.cesbio.ups-tlse.fr/SMOS_blog/?page_id=2589

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.

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 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)?????

PMD Report Pakistan frequently experiences several droughts. El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. PMD Report Pakistan frequently experiences several droughts. 11 out of 21 drought years were El Nino years El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. The El Nino phase of the Southern Oscillations (ENSO) has direct impact on drought in Pakistan as it poses mainly negative impact on summer monsoon

Source: PMD?

Drought Bulletin of PMD

Source: Pakistan Weather Portal - https://pakistanweatherportal

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

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

Impacts on population in drought hit areas About 2.21 million people and 23.51 million livestock population affected due to severe drought conditions only during 1999-2000 in Pakistan (PDMA) Since 2013, Tharparkar has been affected by a drought‐like situation impacting livelihoods, nutrition and health conditions (reliefweb) www.ndma.gov.pk/publications/DRM%20-%20Manual%20(NIDM).pdf http://reliefweb.int/disaster/dr-2014-000035-pak Pic source: Internet

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

Other socioeconomic impacts Crop failure due to low rainfall and loss of livestock can greatly reduce the impoverished communities’ purchasing power. The loss of livestock to drought was about 40% in Balochistan and 60 % in Sindh only during 1999-2000 Government has to face billion rupees losses due to drought and water shortage http://reliefweb.int/disaster/dr-2014-000035-pak NDMA

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. https://www.nap.edu/read/6425/chapter/8

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

Applications of Satellite and Ground based Measurements For delineating drought prone areas For developing a continuous drought monitoring system For designing future strategies for water resource management

Drought Detection using Satellite Remote Sensing Satellite RS can also provide continuous mapping of temporal changes in drought indicators vegetation cover, soil moisture content, land surface temperature (LST)

Remote Sensing Data relevant to Drought Study

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

Discussion/Comment/Question