The Water Cycle & Wildfire Risk
"Water - is taught by Thirst!"
~ Emily Dickinson.
Water covers approximately 70% of the Earth's surface.
About 98% of our water is in the oceans, leaving about 2% which is fresh.
After taking into consideration the ice-caps and glaciers, this leaves only around 0.4% that is left in lakes, rivers and aquifers.
Many of us take our water for granted.Photo - A stream in the Blue Mountains rainforest - courtesy of AirNinja - at airninja.com
We shouldn't, because without it, not one of us would survive.
Water is one of nature's masterpieces.
Yes, I realize that it sounds like a cliche, writing about that 'wet stuff' that pours from our taps -- but consider -- how would your life be without it?
To truly appreciate and experience this wonder, try this;
** Paddle about in a slow moving creek - feel the water flowing between your toes - listen - as it chuckles across the pebbles in a shady glade.
Or - if you are lucky enough to live near a waterfall like the one in this photo above - sit close-by - hear it - listen as it tumbles down across the moss-covered rocks - feel the cooling mist on your skin.
Stop - Relax -- and enjoy the tranquility.
For those in the mountains;
** Stand on a hill or ridgeline, blanketed by fog - cold vapour tendrils reaching out - chilling moisture upon your cheeks.
And for those of us living in the coldest regions, it is easy to 'experience' water in its solid form - where it creates evocative images of ice-crystals, glaciers and vast, beautiful snowscapes.
Photo - Snow Scene - courtesy of Trip Advisor - at tripadvisor.com
All of these images display the wonder of water - in all of its forms;
- liquid - gaseous - solid.
Water slakes our thirst - cools our bodies - and - saves our lives."Water is life’s mater and matrix, mother and medium.
There is no life without water."
Our Sun is the driver of the water cycle. When water is heated it turns to steam or vapour and when it’s cooled it turns back into a liquid, or, into snow or ice.
Water is in a constantly moving cycle between each of these forms. There are 5 main parts of this water cycle are;1. Evaporation
The graphic below illustrates how this process works.
The Water Cycle - courtesy of the Science Education Research Center - Carleton College - Minnesota USA - http://serc.carleton.edu/1310
The volume measurements refer to global average annual data - each specific region will depend upon its own unique weather variables.
As you can see from this image - there are 3 "pathways"
for moisture to enter the Vapour Transport system;1. Evaporation from the Oceans & Seas.
2. Evapotranspiration from vegetation, creeks and rivers.
3. Evaporation from inland lakes and seas.
For many years, it was considered that rainfall over the land came from moisture-laden ocean air.
However, recent studies by Nick Nuttall, from the UN Environment Programme, have concluded that;"Contrary to conventional wisdom, an estimated 62 percent of precipitation occurs over land as a result of evapotranspiration from lakes and wetlands and dense vegetation, particularly forests, which pump ground water into the sky."
"The moisture then condenses and falls as rain."
"Only about 38 percent of the precipitation is generated over oceans and seas."
Nuttall also makes a direct link between drought and deforestation. "Trees actually do two processes. They drill water into the ground.
They funnel water into underground aquifers where it is stored to supply rivers during drought."
Source: UN website for Humanitarian Aid
So, what happens across those large tracts of land without forests, rivers, lakes or vegetation?
With no evapo-transpiration, is there any effect on rainfall in these areas?
It must decrease - and - commonsense tells us that as rainfall decreases, there is less water flowing from the streams into the lakes - and - less water to grow and sustain vegetation.
Of course, nature will adapt to the drier conditions, but after continuous cycles of lower and lower rainfall events, nature will have little option but to create a desert or wilderness.
We are already seeing this type of event in our Australian climate - and it is already affecting our landscape.
Massive deforestation, combined with other factors, have contributed to our increasingly drier climate - today we are experiencing our worst long-term drought on record.
This graphic below clearly shows the links between evapo-transpiration & rainfall.
"We forget that the water cycle
Water is the Key to our personal and community survival.
And before we can protect ourselves & our families, we need to protect our environment - because - each single element supports the other - and they are all intertwined.
and the life cycle are one."
~ Jacques Cousteau
And without water - we cannot stop wildfires.
So - just as military commanders prepare their ground before battle - so too must we prepare the ground on which we plan to fight -- only our enemy is wildfire
- and one thing is for sure -- wildfires never
The Fire Triangle