Good Morning good people visiting zoomradar.com today. My last blog entry was on Heatwaves and how deadly they can be and become. Well today I am going to write about something similar to heatwaves, they kind of go hand in hand, and that’s drought. The title of my last blog was heatwaves and drought, however I did not detail my writings on drought ;last time but I am now.
I am going to touch on Drought Defined, Importance of Drought, Predicting and Causes of Drought, Consequences of Drought, and Drought preparation and Mitigation.
1. DEFINITION OF DROUGHT
There are many definitions of Drought that cover a large spectrum of different sciences that define what Drought really is, so let’s take a look.
A. Meteorological – Below Average Precipitation or a below departure from normal precipitation over a long term period.
B. Agriculture – Soil moisture is clearly not sufficient enough for crops and produce to grow
C. Hydrological – Surface and sub-surface waters are below normal this includes: aquifers for irrigation of crops, Wells for consumption of water, and Groundwater table, Streams, Rivers, and Reservoirs.
D. Sociological – Water Shortages that affect Communties – Panic can set in due to lack of water and also migration. If people have the means to move they pick up and go. This can lead to Famine where long term drought affects the health of communities.
The National Weather Service defines drought as a period of abnormal dry weather sufficiently prolonged for the lack of water to cause serious hydrologic imbalances in the affected area.
This image is a photo of a farmer in Texas during drought conditions the last 4 years(prior to the copious amounts of rain this spring). image brought to you by texasdroughtproject.org
2. IMPORTANCE OF DROUGHT
Worldwide drought cause more DEATHS than any other world disaster. Drought coupled with heatwaves are the #1 Natural Disaster worldwide. The average annual cost and losses from floods and hurricanes in the United States combined is less than the average annual costs and losses from drought in the United States.On average drought costs the United States 6-8 BILLION in losses and other expenses alone. Drought has caused mass migration in the United States that has shaped the demographics. During the 1930’s the DUST BOWL ERA over 2.5 Million people fled the great plains for the West Coast and California to escape the fury of the Dust Storms because drought had gotten so bad there. Drought not only affects humans, it affects animals and plants which can suffer massive die-offs during drought conditions. Drought is very relative to location because every place on Earth has a slightly different ecosystem therefore drought affects each place differently.
Drought can be measured by: Temperature, Lack of Precipitation and Soil Moisture Data. One way Meteorologists keep up with heat and drought is called the PALMER DROUGHT SEVERITY INDEX OR PDSI.
This is an updated Palmer Drought Severity Index as of today. As you can see Texas has come out of its 4 year drought with a deluge of rain this past spring, while South Florida, California, the intermountain West and the Pacific Northwest are suffering in Heat and Drought. California is most severe because this drought has been ongoing for 5 years and water shortages are beginning to show up and wildfire season seems to have started early as well. I believe we can add Alaska to this list as well.
3. CAUSES OF DROUGHT
A. Drought – Drought is a function of Scale. Drought is regionally dependent, if really severe it can be nationally where all citizens are affected in some way – financially, economically or socially.
B. Variable Causes
- Large Scale Atmospheric Processes – where High Pressure in all levels of the Atmosphere Dominates.
- Teleconnections – During El Ninos and La Ninas drought seems to intensify and become more widespread due to warming of an El Nino and drying of a LA Nina.
- High Pressure – High Pressure is in control so adiabiatic warming is in full strength, which is warming due to sinking and compressing of air molecules. This is akin to pumping air into a bike tire. If you feel the air pump it’s going to be hot because you were compressing air into the tire. So High pressure cell does not support rising air, cloud development or any precipitation.
Here is a water cycle depiction from the USGS. If any one of these processes is interrupted drought can occur or most likely will occur. Most importantly if evaporation is high without condensation drought is MOST likely. My next graph will show this.
This next graph showing the importance of the evaporation/condensation cycle shows how temperature/ shortwave radiation from the Sun, Wind speed – the faster the wind the drier the soil, and Relative Humidity plays a role in drought. The lower the Relative Humidity the higher chance of drought due to lack of precipitation, also low RHs can initiate Wildfires. www.theresilientearth.com
4. CONSEQUENCES OF DROUGHT –
A. Famine – Famine causes lower economically underdeveloped countries to suffer immense losses in life, money, and resources. Famine can also put a strain on developed countries by costing Millions and Billions in losses, Food Shortages, Water Shortages, and if really severe drought occurs, Anarchy can break out.
B. Crop Losses – As mentioned above food shortages can put a strain on society by higher food prices for everyone thus hitting everyone in their wallets. For example, in 1988 2/3rds of the nation gripped in drought and heatwaves cost the American Farmers 4.7 BILLION dollars. The cost was felt by all consumers in the United States.
C. Water Rationing – In 2007-2008 Atlanta Georgia was facing water shortages due to the severe lowering of Lake Lanier the main watershed for North Georgia. I heard water rationing was occurring there.
pixshark.com
5. DROUGHT PREPARATION AND MITIGATION
A. What Mitigates a Drought
- Research on Teleconnections – This is a good predictor of droughts because if we analog forecast we can clearly see that drought is most prevalent during or after El Nino years. Or ENSO is EL Nino. In 1988 the heat waves were so severe and drought was so prevalent, that when we look back a very strong El Nino was occurring in 1987-1988. In 1997-1998 we had a repeat performance of drought and heat and what coincided? Yes a Super Nino of 1997-1998. We are currently headed in a Super Nino for 2015-2016 and we see California and the West suffering as well as the southeast with heat and drought.
- Preparation – we need to be prepared or at least acknowledge climate variability and how that affects/effects all of us. We can safely say that if El Nino with a moderate to Super intensity occurs we expect some heat and drought affecting us here in the United States and in some places in the World too. Look at Europe in Great Britain, France, Belgium, Spain, Portugal, and Germany are suffering severe heat and drought as I write. So El Nino and to a lesser degree La Nina can bring on drought conditions.
Well that’s it for now. I hope I entertained you with my blog writing. So until next time, Stay safe, be well, and I will see you soon. ADIOS, AU REVOIR, BYE