A local, collaborative, natural capital-approach to enhance the value of nature in Manchester

Metric 1 – Access to natural space

There are several methods for this, but we calculate the percentage of residential houses that are 600m from accessible natural green space of >1ha in size or 600m from accessible blue space or 600m from a rural public right of way and an extra point if there is >1ha of natural space per 1000 people. 

Metric 2 – Air quality

Mean concentration of PM_2.5. This could be adjusted to use emissions data in combination with modelled air quality and/or to look at an array of different pollutants. This pollutant was selected as it has the highest correlation with health impacts, but the evidence relating to other pollutants is growing all the time and they may need to be considered. It is also worth noting that air quality (as measured by emissions) is not really an ecosystem service – natural assets in an urban landscape act to clean air, but the final air quality is the net integrated effect of two opposing factors.

Metric 3 – Local climate regulation

There are a number of methods for looking at average surface temperature, but we use Landsat imagery at present. The key challenge is obtaining the best, most appropriate satellite image for the assessment and Manchester Metropolitan University, among several others, have been undertaking research into this that will inform the refinement of this metric.

Metric 4 – Noise pollution/tranquillity

The source of outdoor noise machinery or transport systems, but can also include loud music, lawn care maintenance, construction or people yelling (sports games). High noise levels can damage cardiovascular health in humans and can interfere with predator-prey interactions, reproduction and navigation in wildlife. Children are especially vulnerable to noise, and the physical and psychological health effects that noise has on children may be permanent.

Metric 5 – Flood risk from rivers and sea

Number of properties that are situated in 1 in 100-year flood zones (rivers and sea). We use the number of properties in a management unit as the indicator, as density does not give a clear indication of the magnitude of the problem in any one unit – this, of course, is open for discussion, but we reasoned that every property at risk is another household or business suffering the negative consequences of living at risk of flooding or actually being flooded.

Metric 6 – Flood risk from surface water

Number of properties that are situated in 1 in 100-year flood zones (surface water). We use the number of properties in a management unit as the indicator, as density does not give a clear indication of the magnitude of the problem in any one unit – this, of course, is open for discussion, but we reasoned that every property at risk is another household or business suffering the negative consequences of living at risk of flooding or actually being flooded.

Metric 7 – Aesthetic value of the landscape (Nature photo hotspots)

It is an increasingly common approach to use tagged social media or online posts (in this case the number of nature-tagged geo-located photos on Flickr) as an indicator of landscape quality.

Metric 8 – Cultural activity facilities

This metric is designed to assess the provision of cultural spaces/resources within a landscape and we use a variety of data sources to map features where cultural activities can be undertaken. These include features such as the number of allotments per 1000 people, area/number of playing fields per 1000 people, and the number of outdoor sports clubs per 1000 people.

Metric 9 – Water quality

This is assessed using the number of urban-caused ‘Reasons for Not Achieving Good Status’ recorded in the Environment Agency WFD assessments as an indicator for the level of complexity in and magnitude of ecological/water quality degradation. This indicator is being improved for the EnRoute assessment – especially as the Manchester WFD data is not very robust.

Metric 10 – Priority habitats for wildlife

As a simple indicator of wildlife habitat provision and biodiversity in an urban landscape we assess the percentage area of priority habitats in each ward. The key analysis stage in this is to obtain/create an inventory of natural habitats in the urban landscape, which we are still working to do using data from a variety of sources. Building on this, we are now developing new approaches to assessing provision of habitats and the performance of the ecological network (connectivity and patch size).

Metric 11 – Surface water flood damage cost

This is calculated using the published National Flood Risk Assessment (NaFRA) methodology created and previously used by the Environment Agency. Due to data availability restrictions, we have created a simplified version of this assessment (approached by the EA) and we have adapted it to calculate the average estimated cost of flood damages from surface water flooding (rather than the fluvial and coastal flood risk assessment data it was designed for). We believe that this is a more relevant indicator for urban ESS (including GI and water management).

Metric 12 – Property value

We have explored numerous ways to assess this indicator. It is a controversial metric as there are many interpretations of it and it has a great deal of social impacts/causes of the variation in the scores. It is included in our assessment purely as an economic indicator on the basis that house prices/values and business outputs are positively correlated (albeit with huge additional factors involved) with environmental quality in an urban landscape. To assess this indicator, we assess the mean price paid for a terraced house in 2014 and 2015. This indicator may be replaced in the final assessment – especially if the stakeholders consulted regard it as being too controversial.