Final answer:
Countries manage water resources in transition zones through conservation methods like rainwater harvesting and water re-use, as well as using technologies like desalination and water recycling for agriculture. Modern pollution-control technology plays a key role, and strategies for sustainable water management are focused on both local and global scales.
Step-by-step explanation:
Countries in the transition zone manage water resources through various methods that address the unique challenges posed by their respective environments. In areas such as Delhi, India, where a decrease in rainfall is predicted, strategies include rainwater harvesting, water re-use, and increased irrigation efficiency. These practices focus on conservation of water and utilizing every possible source effectively. Cities near oceans, like Los Angeles, may turn to desalination to convert seawater into potable water.
Others, like Israel, have advanced water recycling systems, using treated sewage, also known as gray water, for agricultural purposes. This highlights the importance of modern pollution-control technologies and their potential to provide clean water in less affluent regions. Furthermore, water engineers work on broader water management strategies that involve ensuring the supply of clean water, water treatment and distribution, and agricultural irrigation, which can include techniques like drip irrigation to minimize loss.
However, challenges such as decreasing water tables due to heavy industrial irrigation remind us that some current practices, such as the heavy use of underground aquifers, are not sustainable in the long run. The global nature of water use also means that countries are interconnected through virtual water trade—where water-intensive products are traded internationally, effectively exporting water resources.