Oliver John Marr

Biodiversity is highly dependent on the presence of open, natural space. However, urbanisation has led to the rapid decline of such areas.  Thisis exacerbated bygrey solutions that attempt to mitigate the increasingflood risk posed by climate breakdown.  As such, alternative methods of promotingbiodiversity must be employed. One such method involves increasing theconnectivity betweenexisting patches of natural habitat, thereby creating networks of green space within the urbanmatrix. 

This dissertation examinestheextent to which green infrastructure(GI)such as Sustainable Drainage Systems (SuDS) can contribute to these networks. To better understand the role ofSuDSinfunctional habitatconnectivitybetween natural spaces in an urban environmentand to identify howSuDSdesignand planning mightbe leveraged to enhance this,the studyuses data from Sentinel 2B, SuDS master plans, and Geographic Imaging Software(GIS)to model theconnectivity of several areas around London,including Sutton and Ebbsfleet. 

The modelcombinesthe SuDSmasterplans with pre-existing greenspace and usesa graph theory approach to assesstheinfluence ofdifferentSuDS elements onhabitatconnectivity. 

Thefollowing studyaddresseschallenges and opportunities that exist for biodiversity within anurban context,anduses the findingsto suggeststrategies for urban connectivity at a macro, systemslevel (e.g., the integration ofecological corridors and steppingstones into urban infrastructure) and ata micro, local level (e.g., the physical design of the structures that form these components).

The dissertation highlights that functional habitat connectivity can be increasedmostsignificantlywith acombination of SuDS elementssuch as green roofs, swales, retention ponds, rain gardens, and street trees, andbyfocussing on structure and vegetation heterogeneity inSuDS design. The studydemonstrates thatof all SuDSelements,green roofshave the greatest potential to increase connectivity, particularly in areas with limited space. In areas with pre-existing natural space, it was seen that retention pondsplay a valuable role in connectivity and that care should be taken when converting natural landto retentionpondsthat this value is not reduced or lostdue toa reduction in structure and vegetation heterogeneity. Ultimately,this researchdemonstratesthat urban planning centred around green solutions can significantly enhancefunctional habitat connectivitywithin the urban matrix.