This is a special edition of AQUA, where all contributing authors are part of the new board of Associate Editors. The new board has been put in place to mark a change in direction for AQUA. The new scope of the journal focuses on the evolution of water supply which, while under pressures of climate change, population growth and aging infrastructure, needs to be developed by integrating infrastructure, ecosystems and society to be part of the creation of a sustainable future. To achieve this AQUA needs to delve deeper into the understanding of topics like water sustainability, water infrastructure, water technologies and water management and governance.

Therefore, we are proud to introduce this special issue which is a collection of exciting research results that have the potential to increase water sustainability thinking with you the reader while at the same time introducing some of the members of the new board of Associate Editors. It also meets the need for good research papers to build a strong scientific journal with new and sound inspiration and information. We are also happy to see fresh ideas, case stories and review papers – all of them with an eye to a future of sustainable water practices.

The contribution of Biniam Ashagre et al. (Ashagre et al. 2020) is a paper called ‘Automaton and real-time control of urban water and wastewater systems: a review of the move towards sustainability’. The review posits that there is a large untapped potential in thinking of control and automation to move towards sustainability. The potential is currently overlooked as objectives focus primarily on cost-benefit and water quality for compliance. Water and wastewater management is an important key in securing a sustainable development. Hence, moving forward a framework involving social, economic and environmental factors ought to be put in place and addressed explicitly in control and automation systems. Regulatory bodies play an important role to promote sustainable thinking so they ought to create an overarching sustainability framework with indicators of sustainability clearly defined.

Qi Wang et al. (Wang et al. 2020) in their paper ‘Impact of problem formulations, pipe selection methods and optimization algorithms on the rehabilitation of large-scale water distribution systems’ take on an important aspect of asset management within the drinking water pipeline system. They ask: how to make a strategic plan to maintain an entire water distribution system? The Exeter distribution system was used as a case for demonstrating an approach based on (1) problem formulation, (2) the pipe selection method for identifying critical components of WDSs, and (3) the multi-objective evolutionary algorithms (MOEAs). One interesting result is that applying more aspects into the problem definition than the usual few seem to provide solutions that are better and more sustainable.

Wenhai Chu is co-author on a paper with Rong Xiao et al. (Xiao et al. 2020) named ‘The effectiveness of household water treatment and safe storage in improving drinking water quality: a disinfection by-products (DBPs) perspective’. Household Water Treatment and Safe Storage (HWTS) is an important though interim component in ensuring safe drinking water in households where safely managed drinking water services are still lacking. This is the case for 2 billion people, i.e. one in four people in the world(!). In low- and middle-income countries 40% use some kind of household water treatment. The paper looks into the problem of DBP formation and how DBP could be managed in a HWTS setting.

Monica Rivas Cassado and Paul Leinster (Cassado & Leinster 2020) write about the potential of Unmanned Aerial Vehicles (UAVs) for flood management in their paper ‘Towards more effective strategies to reduce property level flood risk’. The problem addressed is that it is difficult to monitor flooding events in a standardised way. This problem can be solved by the use of drones (UAVs). By taking a systems thinking approach underpinned by statistical theory and based on five pillars including standardised data collection, standardised processing, standardised technological integration, standardised use of outcomes and standardised policy and governance it is possible to achieve better informed flood management decisions leading to increased risk mitigation.

Gemma Carr et al. (Carr et al. 2020) in their paper ‘People and water: Understanding integrated systems needs integrated approaches’ states what we often forget that water systems involve water and people – interacting together. Through three case stories from Jordan, Burkino Faso and Dresden the modelling of interaction between water systems and people is illustrated. This highlights how changes in water systems cause change in people's response and this again causes changes in water systems. The paper makes a strong call for collaboration across different research fields especially a call for building a bridge between the social and natural sciences of water. The lack of the inclusion of social science in water is a blind spot in our current approach that we need to improve upon.

As cities grow due to increasing urbanization the problem of the threat of pollution emissions of upstream cities on the drinking water safety of downstream cities cannot be eliminated by the self-purification ability of rivers. This calls for safe distances between cities and therefore limitations to city sprawls. This topic is taken up in the paper Xin Dong co-authors with Ning Jia et al. (Jia et al. 2020) called ‘Research on the safe distance between cities based on the distributed CA model and BP neural network water quality model’ by using neural network methods. A case area is explored where the two cities Wuhu and Ma'anshan lay adjacently along the Yangtze River. The expansion of both cities means shrinking of the distance between them from 11 km in 2010 to 5 km in 2020. This shrinkage means an increased water quality risk for downstream city Ma'anshan. The paper posits that distance is better than reducing point source emissions in the upstream city.

Ashok Sharma and Jake Kyle Day (Day & Sharma 2020) in their paper ‘Infrastructure design for stormwater harvesting systems for urban park irrigation: Brimbank Park, Melbourne case study’ describe the process of planning a system for re-use of storm water. Stormwater harvesting for residential and non-residential reuse is a method to reduce freshwater demand to address climate change, population growth and urbanization challenges. By laying out the planning methodology as well as analyzing and publishing the economic implications the paper nudges water professionals to look for ways to re-use storm water. The options are many: irrigation of public spaces and playing fields, garden watering, toilet flushing; laundry supply; hot water supply; firefighting and environmental applications (e.g. groundwater recharge).

Together with a group of PhD students and Bin Pan, Huan-Feng Duan (Duan et al. 2020) has prepared a paper called ‘State-of-the-art review on the transient flow modelling and utilization for urban water supply system (UWSS) management’. Older parts of water distribution systems are often made ineffective by pipe anomalies such as leakage, blockage, ill-junction, corrosion, biofilm, deformation, cavitation, air-pocket, detachment which may lead to reduction of flow capacity, increase of energy loss and deterioration of water quality. The paper reviews the literature from 226 publications of the modelling of the important problem in this context of water hammer as well as the use of transient-based methods for the detection of pipe defects. This provide an important input to e.g. asset management (detection) as well as to design of future systems.

We hope you will enjoy and be inspired by this special issue.

REFERENCES

REFERENCES
Ashagre
B. B.
Fu
G.
Butler
D.
2020
Automation and real-time control of urban wastewater systems: a review of the move towards sustainability
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
751
768
.
Carr
G.
Barendrecht
M. H.
Debevec
L.
Kuil
L.
Blöschl
G.
2020
People and water: understanding integrated systems needs integrated approaches
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
819
832
.
Casado
M. R.
Leinster
P.
2020
Towards more effective strategies to reduce property level flood risk: standardising the use of Unmanned Aerial Vehicles
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
807
818
.
Day
J. K.
Sharma
A. K.
2020
Stormwater harvesting infrastructure systems design for urban park irrigation: Brimbank Park, Melbourne case study
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
844
857
.
Duan
H.-F.
Pan
B.
Wang
M.
Chen
L.
Zheng
F.
Zhang
Y.
2020
State-of-the-art review on the transient flow modeling and utilization for urban water supply system (UWSS) management
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
858
893
.
Jia
N.
Dong
X.
Liu
Y.
2020
Modeling water quality to determine a safe distance between cities: a case study in China
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
833
843
.
Wang
Q.
Huang
W.
Yang
X.
Wang
L.
Wang
Z.
Wang
Y.
2020
Impact of problem formulations, pipe selection methods, and optimization algorithms on the rehabilitation of water distribution systems
.
Journal of Water Supply: Research and Technology—AQUA
69
(
8
),
769
784
.