Economic Evaluation

Improving urban water environments is of great significance due to the close links between human and ecosystem health, biodiversity, fishing, recreation, tourism, cultural and religious activities. Evaluating multiple economic benefits is critical for justifying public funding, particularly in developing countries where activities aimed at improving the environment compete with other priorities such as poverty alleviation, basic education or health care.

WUI conducts an integrated economic evaluation of water quality, flood damage and health loss associated with urban flood.

1. Water Quality

Clean water environment has important amenity values contributing to the quality of urban life. The majority of urban water benefits represent non-consumptive use values, which include benefits derived from pleasant view, clean air, as well as recreational activities and aesthetics. The damages, pollution of urban watercourses, rivers, canals, and wetlands cause negative externalities e.g. the loss of non-priced benefits. Therefore, in urban planning, amenity values should be systematically assessed and measured accordingly, i.e. in monetary terms. WUI researchers will study whether and how clean urban water benefits are capitalized in economic benefits. Empirical study will use the contingent valuation/choice experiment techniques to examine benefits of clean urban environment associated with willingness to pay (WTP) or willingness to accept compensation (WTA). The study will be designed to measure the use- and non-use values of clean urban water environment. The results of the study will be used in assessing benefit and costs analysis of current and future water-related management issues and various urban planning decisions.

2. Flood Damage

Flood damage assessment can induce to increase policy-makers’ awareness and can be useful to develop effective strategies for flood risk prevention and reduction. In this context, WUI researchers will set up and establish models to estimate the cost of direct and indirect urban flood damage. A spatial analysis approach is used to determine direct damage in particular. This comprehensive method combined flood characteristics based on the results from flood inundation model, exposure components and economic data in Geographic Information Systems (GIS). As a result, flood depth-damage function which represents damage to a specific asset is developed and this could be used as a guide for future flood events. Moreover, in order to assess indirect impact, field survey with local people and specialists is conducted for data collection as well as validation. Flood damage loss showed in maps will be used for the policy recommendations to local stakeholders to prioritize their flood mitigation strategies.

3. Health Loss

To assess the economic damages caused by urban flooding, it is important to include health loss due to infectious diseases spread via flood water i.e. cholera, diarrhoea, and hepatitis. Although several outbreaks following urban floodings have been reported, economic damage by such infectious diseases has not been well investigated and often neglected in many post-flood investigations because of lack of scientific framework to estimate such damages. The WUI researchers are evaluating health loss caused by waterborne infectious diseases based on the health risk maps of infectious gastroenteritis spread via flood water. Using hypothetical scenarios including human activities during flooding events and population increase in the future, number of disease cases are estimated in current and future scenarios, and it was converted to disability-adjusted life years (DALYs), an indicator suggested by World Health Organization, to estimate economic loss caused by health loss. The estimated economic loss would raise awareness of stakeholders to mitigate health-related effects by urban flooding.