Water quality assessments for urban water environment
Worldwide demand for freshwater resources is continuously increasing to satisfy the need for increasing population and growing economies. Further, both biophysical and social patterns and processes are interacting in ways that increase pressure on water and lead to water scarcity. About one-third of the world’s river basins attend their maximum capacity for exploitation, and more than half of the world’s population is directly/indirectly affected by water scarcity. In addition, rapid urbanization in developing countries of Asia, Africa, and South America is one of the prime causes for water quality deterioration in urban waterbodies and, hence, increasing health risk for urban dwellers. One of the main causes for this water scarcity is direct discharge of approximately 85% of all wastewater into water bodies without being properly treated and nonstructured/weak governance policies. It is predicted that with continuous rapid economic growth and urbanization, more than 3.5 billion people will live in cities by the year 2050, which will lead to massive increase in the need for land, food, and water. However, existing sanitation systems and land use management frameworks are inadequate, meaning that without transformational changes, these cities will fall well short in meeting the growing demands for resources. In addition, global changes (urbanization and climate change) will further aggravate the challenges for different entities involved in water planning and management. Based on the aforementioned background information, this Special Issue strives to highlight the gaps, opportunities, and challenges, lessons learned from past experiences for estimating current status and future predictions of water resources in the context of urban spaces/cities, as well as up to what extent scientific innovations have contributed significantly to resolve these issues, and, finally, what the way forward is for the better science-policy we need to create to achieve global goals, e.g., SDGs at local level in a timely manner.