Rainfall Predictions Possible With Cell Phone Technology

Knowing how much rain falls on a location is key to determining if any unfilled thirst remains unfilled at that particular location. Unfortunately, however, knowing actual rainfall amounts has always been a very difficult task.
Typical Precipitation Map

Source - climatecentral.org

Resolution of data that makeup such a map is, at best, around 50 miles and is possibly as high as 100-200 miles. This data is gathered from rain gauges installed every 50, 100 or larger distances apart.
We are, however, very well aware that rainfall amounts are not usually similar or identical over a 50 mile or a 100 mile or a 200 mile square of area.
Using rainfall data from this map can lead to incorrect conclusions: thirst experienced by some farms can be overlooked, or, some farms that don't experience thirst can be targeted for additional water supply. In either case, resources expended to deliver water (safe for irrigation) will end up being misspent.
Radar Maps

Source - weathercentral.com

Doppler radar have better resolution that do rainfall data maps.
However, the installed base of Doppler radar sites are predominantly around major cities and population centers. Doppler radar, thus, provides us with high resolution rainfall maps in and around cities.
Farms or other remote agricultural locations have few of these radars and thus assessing their thirst is a problematic task
Towers (for mobile phones) may hold the answer!

For cell phones to work, microwave transmissions are relayed between individual towers. 
These microwave signals, between towers, are transmitted at a known constant strength that allows for signal decay over distance and for known weather conditions that might reasonably be anticipated. For a particular weather condition, the rate at which this signal falls off (or deteriorates) can be predicted for any set of towers.
When liquid water is in the air (i.e. it is raining), however, the signal between towers drops (is weaker) because a part of the signal is reflected off raindrops and does not make it to the next tower.
Depending upon terrain, towers can be just 1-2 miles apart.
The Netherlands Experiment

Source - lonelyplanet.com

Netherlands, the country, has just 32 rain gauges, but about 8,000 mobile phone towers.
An algorithm has been developed that measures differences between normal (no rain) signal strength and signal strength when it rains.
An experiment was run, in September 2011, to see how well signal monitoring could measure actual rainfall amounts.
This test, conducted with data from just 2400 cell towers, mapped rainfall amounts very close to the measurements from a combination of radar and rain gauges.
Thirst in the Developing and Underdeveloped worlds As cell phones, and the towers that enable them, have become commonplace all over the developing and underdeveloped world, its a simpler step to use cell phone signals to measure and predict rainfall amounts in real time. The traditional alternative, involving radar and rain gauges, may not be necessary any more.

This post was inspired by an article in The New Scientist magazine

A Common Remedy for Differing Freshwater Consumption?

The most commonly quoted global statistic is that 70% of the world's freshwater is used in agriculture, 22% to make the industrial (i.e. non-agricultural) goods we cannot do without, and 8% for residential and personal use by people. What this statistic is missing is that this global breakdown is not the situation in any country
How Freshwater is Actually Used

Source - Scientific American.com

From the accompanying chart it does indeed appear that the global segmentation of 70%-22%-8% for agriculture-industry-residential is quite correct but the segmentation of individual countries is quite different. 
The only point of agreement might be that, generally speaking, the major users of freshwater do consume the most in the agricultural industry and the least in peoples' home.
Some conclusions:
- China and India, the countries with the largest numbers of people, do use the most water as could be expected. The US is the third larger user of freshwater in the world
- Nigeria, the last country in the top 10 list, seems to consume nearly all its freshwater to grow food, with tiny amounts spent on personal and industrial needs.
"Virtual Water" Exporters and Importers
Virtual water is defined as the amount of water consumed to create a product that is exported or imported. The exporter if the product is labelled an exported of virtual water while the importer of the product is known as an importer of virtual water. Some interesting conclusions:
- The US, an extremely large consumer of freshwater measured in terms of "per capita consumption" is also a large exporter of virtual water through all the food stuff it exports
- Japan, a consumer of small amounts of freshwater, is the largest importer of virtual water.
Resolving the Freshwater Crisis
Recognizing the different ways individual countries consume their water, implies that a different remedy may be required for each countries' specific situation. This conclusion must, however, be balanced against the "time" it will take to develop and deploy all the many necessary solutions.
Would it not be ideal if we could all pool our resources to develop a solution applicable to everyone?
Making this point again using different words:
- What is the equivalent of the "cell phone" for the freshwater industry?
or,
- What, in the freshwater industry can lead to the same result as the cell phone did in the personal communications industry, namely, hook the 60%+ people who had no hope of getting a land-line connection in their lifetime, but got connected using wireless technology embedded in the mobile handset!