Wycombe District Canopy Cover Assessment

This study estimated tree canopy cover in Wycombe District using the Bluesky National Tree Map dataset.

Estimates of canopy cover for each ward, as well as the district total were calculated. The study also looked at statistics from the Office for National Statistics (ONS) and reviewed other available sources of geographical data on human health, wellbeing and other societal factors (such as crime rates, house prices, social deprivation and life expectancy). Tree canopy cover estimates were then compared with these social data to determine if there was any correlation.

Canopy cover was compared with various quality of life indicators for Wycombe District. These were shown for the smallest geographical level that data is produced at, in this case Middle layer Super Output Areas (MSOA) and Lower layer Super Output Areas (LSOA). Output Areas are built from clusters of adjacent unit postcodes. They were designed to have similar population sizes and to be as socially homogenous as possible, based on tenure of household and dwelling type. Generally speaking, quality of life appeared to be significantly higher in areas with greater tree cover in comparison to areas with more limited tree cover.

As life expectancy continues to increase, it is important to measure what proportion of these additional years of life are being spent in favourable states of health, or in poor health and dependency. Comparisons of data suggested that both men and women living in areas with more than 25% tree cover had significantly higher average healthy life expectancies than those living in areas with less than 25% tree cover. More ‘treed’ areas of Wycombe District also had fewer hospital admissions.

In terms of educational achievement, the percentage of students achieving five A* to C grades in their GCSEs (including English and Maths) was also notably higher in areas with more than 25% tree cover at 68.4%, as compared to just 66.3% in areas with less than 25%.

Much of the data concerning deprivation was also collected in line with the Index of Multiple Deprivation (IMD). The IMD combines information from seven domains to produce an overall relative measure of deprivation. The domains were combined using the following weights: income deprivation (22.5%), employment deprivation (22.5%), education, skills and training deprivation (13.5%), health deprivation and disability (13.5%), crime (9.3%), barriers to housing and services (9.3%), and living environment deprivation (9.3%).

As one of the most heavily-weighted and significant indicators of deprivation, the Employment Deprivation domain measures the proportion of the working-age population in an area involuntarily excluded from the labour market, including those who would like to work but are unable to do so due to unemployment, sickness, disability, or caring responsibilities. In areas with more than 25% tree cover, the proportion of people deprived of employment in these terms was calculated to be 5.4%, compared to a considerably higher 6.9% in areas with less than 25%.

Even more disparate averages were calculated between areas in the domain of education, skills and training deprivation. This domain measures the lack of attainment and skills in the local population, factoring in two sub-domains; one relating to children and young people, and one relating to adult skills. In areas with less than 25% tree cover, average scores for this deprivation indicator were calculated at a sizeable 16.3. Areas with more than 25% tree cover in comparison averaged a score of just 9.9 for the same measure of deprivation.

Crime statistics as a measure of the risk of personal and material victimisation at the local level, were also accounted for in the comparative analysis. Wycombe District in general performs well in this regard, though once again a disparity was observed between areas of differing canopy cover. In areas with less than 25% tree cover, an average crime score of -0.35 was calculated, compared to a notably lowered figure of -0.51 in areas with more than 25% tree cover.

In sum, the average Index of Multiple Deprivation score calculated across areas with a less than 25% tree cover totaled 11.8, in comparison to a markedly lower score of 7.9 across areas with more than 25% tree cover.

This preliminary study presented basic data on the canopy cover found in Wycombe District, and within its smaller geographic boundaries. It also established a baseline which can be used to monitor future progress or in further research. For instance, the data could be used to further study the relationships between tree cover and house prices, social deprivation or flooding (where data exists). These relationships are often very useful in making the case for retaining or increasing canopy cover.