By Amir Dakkak

Driving down the streets of Dubai, one cannot ignore the large puddles of water that cover the side of the streets and sidewalks. These puddles, which are the result of attempted irrigation of green patches and plants, are a big waste. As a result, a very important question comes to mind: Does the UAE have that much water to spare? The answer is no. The UAE is one of the top 10 most water scarce countries in the world, and has one of the highest per capita water usage globally. With 550 liters per person per day, a UAE resident consumes more than double the global national average of 250 liters per person per day.  Water in the UAE is in very short supply.

Why do people use this wasteful method? Simple: it's the cheapest and fastest way to irrigate the plants, or it may seem so. Although the up front costs are cheaper, there's a large hidden cost of water that underlies the use of conventional irrigation methods. There are a number of problems concerning spray irrigation but the most important is its inefficiency. When using spray irrigation (sprinkler systems) in a country as arid as the UAE, 60% of the water evaporates before it is absorbed by the plants. As a result, only 40% of the water intended for irrigation is used, which itself is not evenly distributed. This lack of uneven distribution coupled with the decrease in the amount of water used is detrimental to the plants' health.

However, as awareness about water scarcity increases, more efficient methods are being used. Drip irrigation is one of the methods being used as an alternative to spray irrigation. Drip irrigation consists of perforated tubes placed along the floor, or buried near the roots of plants, which deposit water directly to the plant roots. The result is not only a drastic decrease in the amount of water evaporated, but also uses 25% less water than spray irrigation systems. 

A second method being used in the UAE is an irrigation system consisting of a gravel and pipes 60cm below the surface. Before anything is planted, the plot is excavated and lined with a water-proof tarp followed by layers of gravel and dirt placed around a half pipe. The pipe is drilled at strategic areas in order to let water flow through but sand and soil stay out. This method only requires 2.5 litres of water in order to maintain a plot which usually requires 10 to 12 litres. (To learn more Click here.)

Some are quite simple and you can take action immediately:
1. Adjust sprinklers so only the grass and plants are watered and not the streets and side walks. 
2. Water during cooler times of the day such as in the morning or evening to avoid large amounts of evaporation. 
3. Coordinate irrigation with seasonal rains.
4. Grow more drought tolerant plants.

Other solutions could be more complicated such as transitioning to more efficient methods of irrigation (see above). Of course the government has a role to play in incentivizing the adoption of environmentally friendly behaviors. The government of the UAE can:
1. subsidize the installation of more complex irrigation systems (e.g. drip irrigation).
2. Provide preferential loan and credit conditions for farmers that abide by environmentally friendly laws or standards. 
3. Launch different campaigns across the the UAE that aim at educating farmers and residents about environmentally conscious water consumption.  

With water scarcity continuing to reach all time low's, there isn't enough water to be equally distributed between the people of the UAE let alone water to waste. The time to act is now.

References: Gulf news, Government of Dubai.

By Amir Dakkak
 
"Water scarcity affects one in three people on every continent of the globe."-World Health Organization

What exactly does that mean? What is meant by "Water Scarcity"? How is it measured? There are many different definitions of water scarcity; the simplest one being: the unavailability of adequate amounts of water for human and environmental use. This can be measured using different methods. 

The first and most commonly used method of measuring water scarcity is by using the "water stress index". This is the simplest of all the other methods. The water stress index defines water scarcity in terms of the water available for a population in a certain region; measuring scarcity as the amount of renewable freshwater that is available per person per year. This method is easy and simple to use, but its simplicity causes some faults. The water stress index does not account for:

• The regional differences in water availability.
• Wether the water sources are accessible to humans. For example, the freshwater that is said to be available might be heavily contaminated, therefore unusable. 
• Man made water sources such as desalination.
• The different amounts of water used depending on the different countries or regions.

The second method of measuring water scarcity is by using the "criticality ratio". This method accounts for the fact that different countries use different amounts of water and instead defines water scarcity by comparing the country's water demand to the amount of water available; measuring scarcity as the proportion of total annual water withdrawals relative to total available water resources. Although this method avoids the simplistic assumption that all countries have the same demand for water, it still does not account for:

• Man made water sources.
• It ignores water reuse and recycle.
• It doesn’t consider a country's capacity to adapt to lower water availability through changing behaviour or new technology.

The third method, which was developed by the International Water Management Institute (IWMI), attempts to adress the problems listed above. It includes each country's technological ability and water infrastructure into a country's water sources, recycled water by limiting water use to consumptive purposes rather than total withdrawal, and measures a country's adaptive capacity by assessing its potential for infrastructure development and efficiency improvements. 
Although this method accounts for all the faults that were previously mentioned, it fails to account for the ability of people within the country to adapt to low water resources by importing food from other countries or by using water saving techniques and devices. Also, its complexity means that it requires large amounts of time, resources, and data to estimate. 

The fourth method is called the "water poverty index". This method attempts to take into account economic resources, such as income and wealth, by measuring:

• The level of access to water
• Water quality, quantity, and variability
• Water used for food, domestic, and productive processes
• Capacity for water management
• Environmental aspects

It's complexity however, makes it more suited for water scarcity analysis at a local scale rather than a national one.

It's very difficult to say one method is better than the other. However, the use of the "criticality ratio" seems to be the most effective method, for it compares the demand for water with its natural availability. It allows policy makers to initiate programs (e.g. desalination) to relieve some of the projected demand for water, and motivates them to lower their demand and consumption of water. 

There isn't one definition for water scarcity, and different measurement techniques capture different aspects of the pressures of water scarcity. But all measurement techniques lead to one conclusion: current water levels cannot sustain the continuous increase in water demand unless something changes, now.


References: Global Water Forum: Understanding Water Scarcity, FAO Water: Water Scarcity.