A multiple-class distance-decaying approach for mapping temperature reduction ecosystem services provided by urban vegetation in Santiago de Chile

Abstract

Mapping ecosystem services is a challenging task, particularly for regulating services presenting spatial mismatches between the areas providing the services and those benefiting from them, such as the temperature reduction ecosystem service (TRES) provided by urban vegetation. The challenge for mapping TRES arises because vegetation not only reduces temperatures at the immediate location, but also in distance-decaying rates in surrounding areas. Furthermore, different functional types of vegetation have differential cooling capabilities, making difficult to assess the accumulated level of TRES provided by vegetated areas if these are heterogeneous in terms of vegetation cover and functional types. To help overcoming these challenges, this work presents a GIS-based methodological approach for mapping TRES that takes explicit consideration of the differential cooling capabilities of vegetation functional types and the distance-decaying spatial transference of services from vegetated to surrounding areas. This approach is applied to the city of Santiago, comparing the mapping results with two other potential alternative mapping methods. The mapping approach presented in this work consistently outperformed the alternative methods. This approach could be easily applied to other urban areas and adapted to be used for mapping other regulating services, such as air and noise pollution mitigation provided by urban vegetation.

Mapping ecosystem services is a challenging task, particularly for regulating services presenting spatial mismatches between the areas providing the services and those benefiting from them, such as the temperature reduction ecosystem service (TRES) provided by urban vegetation. The challenge for mapping TRES arises because vegetation not only reduces temperatures at the immediate location, but also in distance-decaying rates in surrounding areas. Furthermore, different functional types of vegetation have differential cooling capabilities, making difficult to assess the accumulated level of TRES provided by vegetated areas if these are heterogeneous in terms of vegetation cover and functional types. To help overcoming these challenges, this work presents a GIS-based methodological approach for mapping TRES that takes explicit consideration of the differential cooling capabilities of vegetation functional types and the distance-decaying spatial transference of services from vegetated to surrounding areas. This approach is applied to the city of Santiago, comparing the mapping results with two other potential alternative mapping methods. The mapping approach presented in this work consistently outperformed the alternative methods. This approach could be easily applied to other urban areas and adapted to be used for mapping other regulating services, such as air and noise pollution mitigation provided by urban vegetation.