Introduction to Week 2

Welcome back. And welcome to week two of our course exploring global water security for people and ecosystems. Last week, we took you into the water cycle as a basis for a large part of the course. We also introduced the concept of water security and the different ways that it’s defined. This week, we turn to the most important issues currently affecting water security. We start by considering trends in water quality and the contrasting factors that affect it in rural and in urban locations.

We’ll show you how, in regions such as Western Europe, we’ve increasingly controlled some of the worst problems of the past, such as insanitary discharges, only to be confronted by the degradation of our rural rivers by sediment, by nutrients, and by chemicals such as agricultural pesticides. But these patterns differ around the world. In economically poorer regions, sewage and wastewater released to rivers is still a major concern. That’s linked also to the second topic, where we’ll exemplify how waterborne pathogen diseases and other kinds of widespread infections reach people and animals through contact with contaminated water. These are some of the largest causes of illness and even death across the world.

We’ll also hear how species that are being transported around the world by people can become a significant issue in freshwater management when those species become invasive. Our third session focuses on the ways that extreme events can affect water security. Problems can arise from either too much water– in other words, flooding– or too little water when there are droughts. These kinds of events can seriously affect the well-being of people. Ecosystems are also affected when extremes go off the natural scale, but also by some of the measures intended to manage the effects of extremes on people. One of the key questions throughout this course is just how much water do we use?

We address this question in the fourth session of the week through the concept of the water footprint. As individuals, we not only use water directly, but water is embedded in the clothes that we wear or the food that we eat. Indeed, agriculture is the major user of water across the world. Water was even used in the production of the device that you’re using to watch me now. Where these products are produced may be many kilometres from where we live, which means that our use of resources affects the water security of others in distant lands. The week’s final session moves to the concept of water ethics.

This important issue asks us to consider who or what we are seeking to secure water for when we talk of water security and how we make decisions about what uses or users should have the greatest priority. All of these are challenging issues to focus our minds on in the coming week.