*Article* **The Role of Water Supply Development in the Earth System**

### **Slobodan P. Simonovic \* and Patrick A. Breach**

Department of Civil and Environmental Engineering, The University of Western Ontario, London, ON N6A 3K7, Canada; pbreach@uwo.ca

**\*** Correspondence: simonovic@uwo.ca

Received: 23 October 2020; Accepted: 24 November 2020; Published: 29 November 2020

**Abstract:** The ANEMI model is an integrated assessment model of global change that emphasizes the role of water resources. Securing water resources for the future is a key issue of global change and ties into global systems of population growth, climate change carbon cycle, hydrologic cycle, economy, energy production, land use and pollution generation. The focus of the presented work is on the development of global water supplies necessary to keep pace with a growing population and global economy. With the structure of the ANEMI model, a series of experiments are conducted in order to assess: (i) the current role of water supply in the global Earth system; (ii) the level of water stress that can be expected in the future; and (iii) what are the potential effects of water quality on global surface water supply and the distribution of water supply types. The results of model simulations show that surface water resources were sufficient to meet the water demand and water quality is not shown to be a significant factor for the development of surface water supplies. Due to globally aggregated scale, these impacts are averaged and likely understated.

**Keywords:** global change; integrated assessment modelling; system dynamics simulation; water resources management; water supply; climate change; earth system; feedback
