# **4. Next steps**

There are a number of natural extensions to this work including: (i) defining explicit fragilities of different WWTP components to better define a risk of damage to both shaking and ground deformation, as well as to flood depths, (ii) a further completed wastewater network in both WWTP assets and representations of outlet structures and possible conveyance infrastructure densities in upstream catchments, (iii) a more complete understanding of the spatial variability in earthquake/flood design standards to clarify the most appropriate return periods to use. For earthquake specifically, we need to adopt more localized PGA and VS30 models derived specifically for China, and PGV (peak ground velocity) maps for specific events to enable probabilities of liquefaction to be presented as opposed to susceptibility.

# **References**

- CRED and EM‐DAT (2019) _The OFDA/CRED ‐ International Disaster Database_ . Available at: www.emdat.be (Accessed: 11 March 2019).

- CRED and UNISDR (2018) _Economic Losses, Poverty & Disasters 1998‐2017_ . Available at:

- https://www.unisdr.org/files/61119_credeconomiclosses.pdf.

- Hu, X. _et al._ (2015) ‘The spatial exposure of the Chinese infrastructure system to flooding and drought hazards’, _Natural Hazards_ . doi: 10.1007/s11069‐015‐2012‐3.

- Hu, X. _et al._ (2017) ‘The Spatial Exposure of China’s Infrastructure System to Flooding Risks in the Context of Climate Change’, in _The Fifth Green Growth Knowledge Platform (GGKP) Annual Conference_ . Washington, D.C.: Green Growth Knowledge Platform. Available at:

http://www.greengrowthknowledge.org/resource/spatial‐exposure‐china’s‐infrastructure‐system‐ flooding‐risks‐context‐climate‐change.

IPCC (2014) _IPCC AR5_ . doi: 10.1017/CBO9781107415324.004.

Libralato, G., Ghirardini, A. V. and Avezzù, F. (2012) ‘To centralise or to decentralise : An overview of the

- most recent trends in wastewater treatment management’, _Journal of Environmental Management_ . Elsevier Ltd, 94(1), pp. 61–68. doi: 10.1016/j.jenvman.2011.07.010.

- Lin, A. _et al._ (2018) ‘National‐scale infrastructure network exposure to liquefaction using geospatial

- techniques’, in _International Conference on GIS and Geoinformation Zoning for Disaster Mitigation_ . Auckland, New Zealand.

Ministry of the Environment (2013) ‘Statistics on national urban sewage treatment facilities in China (全国 投运城镇污水处理设施清单)’, pp. 1–204. Available at: http://www.mep.gov.cn/gkml/hbb/bgg/201305/W020130508476747765965.pdf.

Mumbengegwi, D., Li, T. and Muhoza, J. P. (2018) ‘An Overview of Sewage Treatment Rates in Chinese Cities’, _International Journal of Waste Resources_ , 8(2). doi: 10.4172/2252‐5211.1000333.

Shearer, P. M. and Stark, P. B. (2012) ‘Global risk of big earthquakes has not recently increased’, _PNAS_ , 109(3), pp. 717–721. doi: 10.1073/pnas.1118525109.

Stocker, T. . _et al._ (2013) _Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change_ . Cambridge, United Kingdom.

UNISDR (2015) _GAR Risk Data Platform_ , _UNISDR Global Assessment Report_ . Available at: https://risk.preventionweb.net/capraviewer/main.jsp?countrycode=g15 (Accessed: 11 March 2019).

Yamazaki, D. _et al._ (2011) ‘A physically based description of floodplain inundation dynamics in a global river routing model’, _Water Resources Research_ , 47(4), pp. 1–21. doi: 10.1029/2010WR009726.

21