After reading this page:
- you've learned what the health indicator is.
- you've learned how the health indicator is calculated.
- you've learned how to adjust your project in order to make the health indicator functional.
What is the Health indicator?
The Health indicator calculates the effect of the green space on the health of the citizens living in a specific neighborhood and the value of the health effect that green in the selected neighborhoods has on nearby residences. The metric used is the amount of particulate matter which can be caught by the green present in the project area. The net effect is measured in terms of DALY, disability-adjusted life years, which are an expression of (extended) health-span for people.
This indicator is a simplified version of a RIVM calculation model and was created for a pilot with the RIVM. The indicators in this pilot are co-created with the RIVM, according to their (calculation) methods. They however are not validated as being indicators which calculate according to 'RIVM standards' or something along those lines, since they were for the pilot. For more information about this pilot and demo project, see this blog (in Dutch): http://www.tygron.com/nl/2018/12/07/de-economische-waarde-van-natuurlijk-kapitaal/
This indicator is useful for projects where for example:
- one of the goals is to create a better neighborhood/environment for citizens
- livability is measured in the project
This Excel indicator can be downloaded from the Tygron Index. Read on to find out more about the indicator's calculation method and how to set it up in your project.
The indicator panel shows the following information:
- The name of the neighborhood
- The effect of green in that neighborhood in the current situation
- The effect of green in that neighborhood in the future (planned) situation
- The value of green in that neighborhood in the current situation
- The value of green in that neighborhood in the future (planned) situation
- The averages for the effect of green and value of green in the current and planned situation
- The effect of green (in DALY) for the whole project area
- The goal (this is calculated by assuming the effect of green in Daly for the whole project area in the current situation is 50%. Double this amount is then 100%)
The calculations used in this indicator are based on the RIVM calculations on urban green and health effects.
Health effect due to green
For any given location, the amount of green is counted nearby, in a radius of 1km, and in a radius of 3km. The total effect of the green on that location is the cumulative effect of all the green which affect that location.
HealthEffectGreen = HealthEffectGreen_1km + HealthEffectGreen_3km HealthEffectGreen_1km = Green_1km x GREEN_HEALTH_EFFECT_1KM HealthEffectGreen_3km = Green_3km x GREEN_HEALTH_EFFECT_3KM
Where the variables are:
- HealthEffectGreen: is the effect of green on the health of residents in a selected area.
- HealthEffectGreen_1km: is the effect of green on the health of residents in a selected area with a buffer of 1km.
- HealthEffectGreen_3km: is the effect of green on the health of residents in a selected area with a buffer of 3km.
- Green_1km: amount of green per resident in a buffer of 1km
- Green_3km: amount of green per resident in a buffer of 3km
- GREEN_HEALTH_EFFECT_1KM: global variable that indicates the green effect for 1km
- GREEN_HEALTH_EFFECT_3KM: global variable that indicates the green effect for 3km
Monetary value of green due to effects
For any given location, the amount of residents are counted nearby, in a radius of 1km, and in a radius of 3km. The value of the green in that location is based on the amount of residents it affects.
MonetaryValueGreenNearbyResidents = MONETARY_VALUE_DALY x HealthEffectNearbyResidents HealthEffectNearbyResidents = HealthEffectNearbyResidents_1km + HealthEffectNearbyResidents_3km HealthEffectNearbyResidents_1km = ( GreenCoreArea x Population_1km x GREEN_HEALTH_EFFECT_1KM ) / AreaSize_1km HealthEffectNearbyResidents_3km = ( GreenCoreArea x Population_3km x GREEN_HEALTH_EFFECT_3KM ) / AreaSize_3km
Where the variables are:
- MonetaryValueGreenNearbyResidents : is the monetary value of the health effect that green has on nearby residents in the selected areas
- MONETARY_VALUE_DALY: is a global variable that indicates the disability-adjusted life year's monetary value
- HealthEffectNearbyResidents: is the health effect that green in selected areas has on nearby residents
- HealthEffectNearbyResidents_1km: is the green health effect on nearby residents in a buffer of 1km of the selected area
- HealthEffectNearbyResidents_3km: is the green health effect on nearby residents in a buffer of 3km of the selected area
- GreenCoreArea: is the green effect in the core area
- Population_1km: is the number of residents in a buffer of 1km
- Population_3km: is the number of residents in a buffer of 3km
- AreaSize_1km: is the size of the area (m²) in a buffer of 1km
- AreaSize_3km: is the size of the area (m²) in a buffer of 3km
- GREEN_HEALTH_EFFECT_1KM: is a global variable that indicates the effect of green in a radius of 1km
- GREEN_HEALTH_EFFECT_3KM: is a global variable that indicates the effect of green in a radius of 3km
The score is based on the amount of DALY( disability-adjusted life years) realized in the project area due to present green spaces. The additional life years are also assumed to have a monetary value due to avoided healthcare costs. The effect of green on the health of the citizens in the project area is visible as the score of the indicator. For each neighborhood the effect of green on the health of the citizens in that neighborhood is determined and an average of all results is calculated for the final score.
A set of areas need to be loaded based on the neighborhoods in the project area.
The project area should be prepared with a number of additional areas. For each neighborhood, two additional areas should be generated based on the polygon of the neighborhood. One area should be the neighborhood's polygon buffered with an additional 1km, and the other should be the neighborhood's polygon buffered with an additional 3km.
The areas should have a CELL_ID attribute, the value of which is the ID of the neighborhood the area is based on. The 1km buffer areas should have a BUFFER1KM attribute. The 3km buffer areas should have a BUFFER3KM attribute. These attributes are necessary for the indicator to recognize which buffer area is of what size, and which buffer area relates to which neighborhood.
Add the Global
The indicator works with several global variables. The following global variables need to be added manually to the project:
- RESIDENTS_PER_HOUSE: This global variable indicates the number of residents in a house per selected project area. The recommended value for this variable is 3 residents per house.
- GREEN_HEALTH_EFFECT_1KM: This global variable indicates the effect that green (public green space, park, garden, public square, etc..) has on the health of citizens in a radius of 1km, in terms of DALY. The recommended value for this variable is 0.000246.
- GREEN_HEALTH_EFFECT_3KM: This global variable indicates the effect that green (public green space, park, garden, public square, etc..) has on the health of citizens in a radius of 3km, in terms of DALY. The recommended value for this variable is 0.000078.
- MONETARY_VALUE_DALY: This global variable indicates the monetary value of a disability-adjusted life year. The recommended value for this variable is 87000. (2007).
- INDICATOR_START_VALUE: This global variable indicates the start value that should be attributed to the initial situation. The recommended value for this variable is 0.5. With this initial value, the target is to double the amount of particulate matter caught by green in the project area.
Note that this is only an example of the values that can be entered for each of the global variables. These values can be modified according to the needs of the project.
- Click on the add button in the bottom left corner. A new global named VARIABLE will be added to the left panel.
- Select the global VARIABLE.
- In the right panel, change VARIABLE to the name of the new global, for example RESIDENTS_PER_HOUSE.
- Change the start value to 0.1.
- Click on the tab Indicators and the button Indicators and choose for Reset to Start values (faster) to update your project.
- Remme, R. (RIVM), De Nijs, T. (RIVM), & Paulin, M. (RIVM), (2018). Natural Capital Model Technical documentation of the quantification, mapping and monetary valuation of urban ecosystem services.
- Hoeymans N (RIVM), Gommer AM (RIVM), Poos MJJC (RIVM) (2007). Sterfte, ziekte en ziektelast voor 56 geselecteerde aandoeningen. In: Volksgezondheid Toekomst Verkenning, Nationaal Kompas Volksgezondheid. Bilthoven: RIVM, on-line geraadpleegd via http://www.rivm.nl/
- Maas J, 2008. Vitamin G: Green environments, healthy environments, Proefschrift ter verkrijging van de graad van docoraat Universiteit Utrecht, Utrecht, 2008
- Stassen, K., Torfs R., Maris U., Dijkmans R., (2007). DALYs versus monetary valuation for Environmental Health Priority Setting based on Data of Air Pollution and Noise in Flanders (Belgium), Vito,2007