Abstract:Mapping ecosystem services (ES) increases the awareness of natural capital value, leading to building sustainability into decision-making processes. Recently, many techniques to assess the value of ES delivered by different scenarios of land use/land cover (LULC) are available, thus becoming important practices in mapping to support the land use planning process. The spatial analysis of the biophysical ES distribution allows a better comprehension of the environmental and social implications of planning, especially when ES concerns the management of risk (e.g., erosion, pollution). This paper investigates the nutrient retention model of InVEST software through its spatial distribution and its quantitative value. The model was analyzed by testing its response to changes in input parameters: (1) the digital terrain elevation model (DEM); and (2) different LULC attribute configurations. The paper increases the level of attention to specific ES models that use water runoff as a proxy of nutrient delivery. It shows that the spatial distribution of biophysical values is highly influenced by many factors, among which the characteristics of the DEM and its interaction with LULC are included. The results seem to confirm that the biophysical value of ES is still affected by a high degree of uncertainty and encourage an expert field campaign as the only solution to use ES mapping for a regulative land use framework.

The integration of ecosystem service mapping in decision-making is crucial to place effective urban design and sustainable planning solutions. Nonetheless, often ecosystem service maps are the product of different data inputs that influences the final modeling output thus affecting final decisions, especially when a finer and site-specific assessment is required to design practical and effective solutions. In this work, the city of Turin (Northwest Italy) was selected as a test site for an empirical experiment of ecosystem service mapping using the software Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST): two habitat quality models of the city were compared in a Geographic Information System environment, the first using the “traditional” sensitivity employed during the LIFE SAM4CP European research while the second using the natural difference vegetation index to re-assign the sensitivity scores. Results demonstrate that the integration of site-specific information in the habitat quality input model generates a different result, which is capable of differentiating all those dense built-up areas of the dense settlement system that provide ecosystem supporting functions at the city-level. These differences were analyzed to define new green hotspots in the compact city while furnishing a new perspective for sustainable city planning.

Climate change impacts urban areas with greater frequency and exposes continental cities located on floodplains to extreme cloudbursts events. This scenario requires developing specific flooding vulnerability mitigation strategies that improve local knowledge of flood-prone areas at the urban scale and supersede the traditional hazard approach based on the classification of riverine buffers. Moreover, decision-makers need to adopt performance-based strategies for contrasting climate changes and increasing the resilience of the system. This research develops the recent Flooding Risk Mitigation model of InVEST (Integrated Evaluation of Ecosystem Services and Trade-off), where cloudburst vulnerability results from the soil’s hydrological conductivity. It is based on the assumption that during cloudburst events, all saturated soils have the potential for flooding, regardless of the distance to rivers or channels, causing damage and, in the worst cases, victims. The model’s output gives the run-off retention index evaluated in the catchment area of Turin (Italy) and its neighborhoods. We evaluated the outcome to gain specific insight into potential land use adaptation strategies. The index is the first experimental biophysical assessment developed in this area, and it could prove useful in the revision process of the general town plan underway.

Ecosystem Service assessment requires better integration of the information that supports land use decisions. Nevertheless, the interpretation of maps and their utilisation to address sustainability during the land use planning process remains critical, especially at a local scale. In this study, a Geographic Information System-Based approach is presented to transform an Ecosystem Service biophysical multipart analysis into a composite parcel-scale indicator, mainly using Esri ArcGIS (version 10.5) functions, and particularly: (i) the Weighted Overlay, (ii) Hotspot Analysis and (iii) Aggregation of Polygons. This methodology has been used experimentally in three municipalities of the metropolitan city of Turin (Italy) during the LIFE SAM4CP project. The study aims to demonstrate how the operationalisation of Ecosystem Service assessment in planning aided Local Administrations in defining land use planning priorities, such as the identification of land take control strategies and the definition of Urban Growth Boundaries.

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