What renders a water system vulnerable to climate change?
Vulnerability to the impact of climate change differs from one water system to the next. A “resilient” water system is not or slightly vulnerable, as opposed to a “highly vulnerable” system. A wide range of variations can be distinguished between resilient and highly vulnerable. How do you know how vulnerable a water system is? This depends on various characteristics of the water system. This is explained on this page.
Do you know how vulnerable a water system is to the impact of climate change, and what characteristics are to blame? Only then will you know whether you need to counteract negative effects on water quality and will you be able to identify efficient water quality measures.
Characteristics of a water system categorised in six indicators
A characteristic of a water system may be, e.g., that it heats up quickly because of its shallow depth. Another characteristic can involve poor through-flow of the water in the system. Both characteristics render the system prone to the growth of blue-green algae or duckweed. Many different characteristics can affect the water quality. To gain proper insight into such effects, researchers have subdivided the characteristics into six indicators: nutriment content, through-flow, water temperature, oxygen content, salt content, and pollution.
Indicators depend on control variables
The indicators depend on various factors: the so-called control variables. Ergo, the water quality in a water system depends on these six indicators, which in turn are affected by various underlying control variables. The six indicators are listed below. Click on each one for more information on the indicator and on the underlying control variables. Indicators may be based on more control variables than presented here, as eco systems involve complex interactions between a wide range of biological and physicochemical factors. We have selected these control variables to provide a clear overview for use in actual practice.
- Nutriment content (in Dutch)
- Through-flow (in Dutch)
- Water temperature (in Dutch)
- Oxygen content (in Dutch)
- Salt content (in Dutch)
- Pollution (in Dutch)
Rather than clicking via the above indicators, you can also view the Urban Water Quality, Climate and Adaptation knowledge document (in Dutch). This interactive document offers a visual overview that easily directs you to the information you require, based on your own question or problem.
Climate change affects control variables
As a result of climate change, the weather is becoming warmer, drier, and wetter. This impacts the quality of urban water. On hot days, surface water heats up, potentially leading to an increase in the growth of blue-green algae or to fish mortality. Severe downpours may cause sewer overflow, as a result of which polluted water will end up in surface water. And prolonged periods of drought may require the intake of lesser quality water in order to keep up water levels. This may also compromise water quality. Thus, climate change can have a range of impacts on the control variables, which in turn affect urban water quality.
Do you want to know more about the effects of heat, drought, and waterlogging on water quality? In the interactive Urban Water Quality, Climate and Adaptation knowledge document (in Dutch), click the section on “climate change”. Do you want to know how climate change can impact a specific control variable? Then click through to the page relating to that control variable. The top centre symbols show how heat, drought, and/or waterlogging will impact the control variable.
