A、Soil Erosion. B、Water Pollution. C、Nature for Water. D、Water Challenges of the 21 st Century. C

On March 22, we observe World Water Day. It is an opportunity to shine a light on the importance of clean water, and take action to counter water-related crises arising around the world. Without water, life is not possible. And yet, around 2 billion people now live in areas of severe scarcity. Some 1.8 billion people depend on sources of drinking water that are contaminated with faecal waste, putting them at risk of contracting a number of deadly diseases such as cholera and dysentery. If current trends of consumption and pollution continue, by 2050 that number will increase to 3 billion people.
    While increased waste water treatment is needed, green infrastructure solutions based on nature can produce low-cost options for restoring water quality and quantity. Right now, unsustainable land and water usage practices are contributing to the problems of pollution and scarcity. As forested land is degraded and natural wetlands lost, drier areas become drier still and are rendered unsuitable for agriculture, while areas that are subject to heavy precipitation such as monsoon rains, suffer more frequent and intense flooding.
    Soil erosion is also a problem. Every year, 25 to 40 billion tons of topsoil are carried off by erosion, significantly reducing the soil’s ability to regulate and retain water, carbon and nutrients. The runoff, containing large amounts of nitrogen and phosphorous, is also a major contributor to water pollution. These are some of the reasons why this year’s World Water Day’s theme is “Nature for Water”, exploring how we can use nature to overcome the water challenges of the 21st century.
    This includes restoring forests, grasslands and natural wetlands; reconnecting rivers to floodplains; creating buffers of vegetation along water courses; all are examples of nature-based solutions that help maintain water availability and quality. We can protect soil from erosion by utilizing conservation agriculture and planting native trees and shrubs along water courses.
    We can help filter and purify waste water and enhance biodiversity. Protecting wetlands, which naturally filter and hold water, and reducing areas of hard surfaces and turf will also decrease runoff and water pollution. When we degrade our ecosystems, we make it more difficult to provide our population with the water we need to survive and thrive. On this World Water Day, we explore how nature-based solutions may help to solve many of these challenges.
    Question 22. How many people live in the places where there are severe water shortages?
    Question 23. What leads to the problems of water scarcity?
    Question 24. What’s the theme of this year’s World Water Day?
    Question 25. What does the speaker say is a nature-based solution that helps maintain water availability and quality?