Water is essential to survival and yet extreme, less predictable weather conditions are affecting its availability in many regions. In our blog series about Highly Cited Researchers™ and the UN Sustainable Development Goals (SDGs), we turn our attention to SDG 6: Clean Water and Sanitation. We analyze the emerging trends for this SDG and discuss how some of the top researchers are tackling the water crisis and its challenges related to climate change and wastewater treatment.
There are huge economic and geographic divides regarding access to safe drinking water, sanitation and hygiene. According to the United Nations, two billion people lacked access to safe drinking water in their homes and 3.6 billion lacked safely managed sanitation in 2020. A further 2.3 billion people lacked basic hygiene services.
While significant developments have been made to improve sustainable water and sanitation services over recent years, climate change is presenting new and global challenges that are exacerbating the water crisis. An example of this came in August, when researchers warned that Europe is facing its worst drought in 500 years.
The number of droughts and the severity of their impact are on an upward trajectory, according to a recent report by the UN Convention to Combat Desertification. This report warns that unless action is taken, an estimated 700 million people may be displaced by drought by 2030, and an estimated one in four children will live in areas with extreme water shortages by 2040.
What is SDG 6: Clean Water and Sanitation?
- By 2030, achieve universal and equitable access to safe and affordable drinking water for all
- By 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations
- By 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity and substantially reduce the number of people suffering from water scarcity.
Highly Cited Researchers tackle the water crisis
Many of the 2021 recipients of our Highly Cited Researchers program have explored the water crisis from a variety of angles. Our analysis of papers related to SDG6: Clean Water and Sanitation produced a list of nearly 400 Highly Cited Researchers working in this area, and 1,800 Highly Cited Papers™ published on this topic. Using the Web of Science™, we created a tree map to demonstrate the primary citation clusters represented in these Highly Cited Papers.
Source: Web of Science
Researchers from Mainland China play a central role in the number of Highly Cited Papers published in relation to this SDG. 668 articles (37% of the total) have at least one Chinese author. This finding is not surprising. With a population of 1.4 billion, Mainland China faces extreme water challenges: it contains only 7% of the world’s freshwater, while having 21% of the global population. Published articles with at least one author from the United States have the second-highest volume of papers related to SDG 6, followed by Australia, another country experiencing serious water issues from droughts and floods.
Source: Web of Science and InCites Benchmarking & Analytics™
Water scarcity and severe droughts
Many areas of the globe are facing severe droughts. In the US, Lake Mead and Lake Powell, major reservoirs in the West, are shrinking at an increasing rate. Several European rivers are running dry, and Mainland China’s rivers and lakes are likewise receding. The Horn of Africa continues to struggle with drought and ensuing famine.
Yoshihide Wada, a Highly Cited Researcher in Geosciences from the International Institute for Applied Systems Analysis (IIASA) in Austria, has published 11 Highly Cited Papers on global water scarcity using global models to understand predict water supplies. His 2020 paper on the effect of climate change’s on global water availability is also deemed a Hot Paper, with 180 citations to date.
Wada has not only studied the effects of climate change on water supplies, but also human impacts like dams and irrigation. His Highly Cited papers have collectively been cited over 3,000 times to date, and one is even cited by a patent.
Wada’s research on global hydrological models helps researchers and policymakers to understand the present and future state of water supplies across geographies. The global perspective he and his coauthors employ highlights the intricate connectivity of our water supply across the planet. These models can inform the critical decisions policymakers and politicians are now making on how to manage water in a rapidly changing environment.
Integration of green and gray infrastructure for water management
Two Highly Cited Researchers, close in name but not location, collaborated on a 2013 Highly Cited Paper about China’s water policies and their socioeconomic, environmental and ecological impacts.
“One issue we imply in this paper is that we need to integrate gray infrastructure with green infrastructure – a network of natural or seminatural features such as wetlands, healthy soils and forest ecosystems, as well as snowpack – to supply clean drinking water, regulate flooding, control erosion, and store water for hydropower and irrigation.”
Junguo Liu, from North China University of Water Resources and Electric Power, and Jianguo Liu, from Michigan State University, are recognized in our cross-field category of Highly Cited Researchers. Their 2013 paper has been cited 220 times.
Dr. Junguo Liu commented, “We highlight a paradigm shift of water conservancy development towards maximizing economic and natural capitals, prioritizing investment to preserve natural ecosystems and to restore degraded ecosystems, and managing all types of water including surface water, groundwater and soil water. We are very proud that the Chinese government has made many policies that are closely relevant to the recommendations in our review paper. One issue we imply in this paper is that we need to integrate gray infrastructure with green infrastructure – a network of natural or seminatural features such as wetlands, healthy soils and forest ecosystems, as well as snowpack – to supply clean drinking water, regulate flooding, control erosion, and store water for hydropower and irrigation.”
Generating excess energy with wastewater treatment technology
Two Highly Cited Researchers from Zhijang Normal University in China, Hongjun Lin and Jianrong Chen, published a review of anaerobic membrane bioreactor (AnMBR) technology that has been cited over 400 times to date. This technology is used for wastewater treatment and is considered a sustainable alternative for sewage treatment because it can generate energy that exceeds the energy required for the process. Lin and Chen analyze AnMBR technology and its application in their review of the research to date. They are both recognized in the cross-field category of Highly Cited Researchers.
Tackling pharmaceuticals in wastewater
Wastewater treatment processes also take a leading role in the Highly Cited Papers for SDG 6. One of our Highly Cited Researchers, Dionysios Dionysiou, has the distinction of making the list in two categories: Engineering and Environment & Ecology. Dionysiou, affiliated with University of Cincinnati, has published no less than 16 Highly Cited Papers in recent years. In addition to several high impact reviews of wastewater treatment, his recent work on filtering pharmaceuticals (and specifically, antibiotics) in wastewater is gaining attention.
Recently, the public has become more aware of the issue of pharmaceuticals entering our drinking supplies and the lack of oversight. On the topic of antibiotics in wastewater and their impact on the environment and health, two Highly Cited Researchers have produced a total of 13 Highly Cited Papers, some of them in collaboration. Highly Cited Researchers Despo Fatta-Kassinos of University of Cyprus and Celia M. Manaia of Universidade Catolica Portuguesa are researching how antibiotics are released into the environment via urban wastewater plants, and the impact on antibiotic resistant bacteria.
“Antibiotic resistance is one of the numerous types of contaminants that threaten the quality of our water resources. However, unlike chemical (e.g. pharmaceuticals and personal care products) or physical (e.g. microplastics) contaminants, antibiotic resistance, acquired by bacteria, is capable of self-replication.”
In 2013, they coauthored a review article with Luigi Rizzo of University of Salerno amongst other researchers, Urban wastewater treatment plants as hotspots for antibiotic resistant bacteria and genes spread into the environment, which has been cited over 1,300 times to date. A more recent review from Fatta-Kassinos, Rizzo, and others in 2019 summarizes and compares the state-of-the-art technologies for treating urban wastewater according to their efficiency, economic attributes, technical limitations and other aspects.
Dr. Fatta-Kassinos explained, “Wastewater treatment has contributed substantially to the progress in health and environmental protection. However, as the classes, number and volume of chemicals used have risen, water pollution levels have increased, and conventional treatment has become less efficient. Our research has shown that even advanced wastewater such as advanced oxidation processes, filtration and adsorption processes have limitations, including demand for additional chemicals, generation of transformation products from parent compounds, which may be more toxic and to continue to be bioactive, and incomplete or, for some contaminants, no removal from the wastewater.
Considering the limitations of wastewater treatment and all current challenges in relation to wastewater treatment and reuse, in addition to the need for the optimization of wastewater treatment there is an urgent need for input prevention at the source and for the development of chemicals that degrade completely and rapidly in the aquatic environments.”
Dr. Manaia added, “Antibiotic resistance is one of the numerous types of contaminants that threaten the quality of our water resources. However, unlike chemical (e.g. pharmaceuticals and personal care products) or physical (e.g. microplastics) contaminants, antibiotic resistance, acquired by bacteria, is capable of self-replication. Increasingly, water quality is doubly endangered by scarcity and pollution, which, like a boomerang, impacts human health and wellbeing. Ironically, this is a consequence of the human “progress”, which urgently needs to be reassessed. The positive point is that we can all play a role in this change!”
Going forward: the benefits of an interdisciplinary approach
It is notable that many of the Highly Cited Researchers working on topics related to SDG 6 are recognized in the Cross-Field category. This reflects the interdisciplinary nature of the work these prominent researchers are doing. Tackling the world’s water crisis requires the latest thinking across fields to creatively keep up with our planet’s growing population and the increasing impacts of global climate change. Teams across the world are attempting to understand local problems, and in the process are furthering access to adequate supplies of clean, accessible water globally. From nanoscale filtration methods to global hydrological models, Highly Cited Researchers and their peers across disciplines are playing an important role in solving the vast array of water challenges associated with this Sustainable Development Goal.
We hope to see even more highly cited research on SDG 6, and all of the SDGs, in the future.
Stay up to date
We discussed the SDG Publishers Compact in the first post in our series and then celebrated the Highly Cited Researchers in SDG 1: No Poverty and SDG 2: Zero Hunger. We then covered SDG 3: Good Health and Well-Being and SDG 4: Quality Education, and then jumped ahead to cover SDG 16: Peace, Justice and Strong Institutions before looking at SDG 5: Gender equality.
Alongside this, we also looked at Ukrainian research contributions to the UN Sustainable Development Goals, here, and published an Institute for Scientific Information Global Research Report on sustainability concerns within ocean science and an Insights paper about climate change collaboration.
In our next post, we will identify Highly Cited Researchers who are working to address SDG 7: Affordable and Clean Energy.
At Clarivate™, sustainability is at the heart of everything we do, and this includes support of human rights, diversity and inclusion, and social justice. Read more about our commitment to driving sustainability worldwide, and see highlights from our 2021 Clarivate Sustainability Report.