Toward a spatially explicit analysis of land vulnerability to degradation: a country-level approach supporting policy strategies.

Vulnerability to land degradation in Mediterranean Europe increased substantially in the last decades because of the latent interplay of climate and land-use change, progressive soil deterioration, and rising human pressure. The present study provides a quantitative evaluation of the intrinsic change over time in the level of vulnerability to land degradation over a representative Mediterranean area (Italy) using a normative indicator, the percentage of land classified as 'critical' in total area. This indicator derives from a spatially explicit elaboration of the ESA (Environmental Sensitive Area) Index (ESAI), a standard methodology of land classification considering different levels of vulnerability to degradation at a particularly refined spatial scale (1 km2). This indicator was calculated over a relatively long time interval (1960-2010) and aggregated at the geographical scale of administrative regions in Italy, a relevant domain in the implementation of the National Action Plan (NAP) to combat desertification and the adoption of individual Regional Action Plans (RAP). A significant - but spatially heterogeneous - increase in 'critical' land was observed in Italy, leading to distinctive dynamics in northern/central regions and southern regions. Climate aridity and anthropogenic pressure leveraged the sudden vulnerability in some marginal land of Northern Italy - a region classified as unexposed to desertification risk - paralleling the levels observed in some districts of Southern Italy, an 'affected' region to desertification risk. These results suggest a re-thinking of mitigation policies proposed in the Italian NAP and a redesign of the RAPs toward place-specific adaptation measures, especially in the 'less exposed' Northern Italian region.

Investigating metropolitan change through mathematical morphology and a dynamic factor analysis of structural and functional land-use indicators.

We presented an operational rationale grounded on complex system thinking to quantify structural and functional landscape transformations along three stages representative of post-war metropolitan development in Rome, Italy (urbanisation with population/settlement densification, 1949-1974; suburbanisation with medium-density settlement expansion, 1974-1999; counter-urbanisation with settlement sprawl, 1999-2016). A mathematical morphology approach assessing the geometric form of land patches and a multi-way factor analysis (MFA) of landscape metrics were used to investigate the joint evolution of urban form and land-use functions over time. The empirical results of the MFA delineated the multivariate relationship between nine land-use classes (with distinctive socioeconomic functions) and seven morphological types (reflecting different landscape structures) according to four observation times (1949, 1974, 1999, 2016). Taken as an intrinsic attribute of complex landscape systems experiencing intense transformations, an estimation of the 'rapidity-of-change' in the form-functions relationship at a given development stage was derived from MFA outcomes separately for urbanisation, suburbanisation, and counter-urbanisation. A simplified form-functions relationship, reflecting the spatial polarisation in compact settlements and rural (low-density) landscapes, was observed with compact urbanisation. By stimulating urban sprawl into fringe farmland, suburbanisation resulted in patchy and heterogeneous rural landscapes. Counter-urbanization was associated with the fragmentation of built-up settlements leading to a chaotic mosaic of land structures that mixes urban and rural traits. Rapidity-of-change in form-function relationships was greater during suburbanisation than urbanisation and counter-urbanisation. It reflects the intrinsic pressure of economic growth in contemporary cities.

Urbanisation-driven land degradation and socioeconomic challenges in peri-urban areas: Insights from Southern Europe.

Climate change and landscape transformation have led to rapid expansion of peri-urban areas globally, representing new 'laboratories' for the study of human-nature relationships aiming at land degradation management. This paper contributes to the debate on human-driven land degradation processes by highlighting how natural and socioeconomic forces trigger soil depletion and environmental degradation in peri-urban areas. The aim was to classify and synthesise the interactions of urbanisation-driven factors with direct or indirect, on-site or off-site, and short-term or century-scale impacts on land degradation, focussing on Southern Europe as a paradigmatic case to address this issue. Assuming complex and multifaceted interactions among influencing factors, a relevant contribution to land degradation was shown to derive from socioeconomic drivers, the most important of which were population growth and urban sprawl. Viewing peri-urban areas as socio-environmental systems adapting to intense socioeconomic transformations, these factors were identified as forming complex environmental 'syndromes' driven by urbanisation. Based on this classification, we suggested three key measures to support future land management in Southern European peri-urban areas.

Unraveling Latent Aspects of Urban Expansion: Desertification Risk Reveals More.

Urban expansion results in socioeconomic transformations with relevant impacts for peri-urban soils, leading to environmental concerns about land degradation and increased desertification risk in ecologically fragile districts. Spatial planning can help achieve sustainable land-use patterns and identify alternative locations for settlements and infrastructure. However, it is sometimes unable to comprehend and manage complex processes in metropolitan developments, fueling unregulated and mainly dispersed urban expansion on land with less stringent building constraints. Using the Mediterranean cities of Barcelona and Rome as examples of intense urbanization and ecological fragility, the present study investigated whether land use planning in these cities is (directly or indirectly) oriented towards conservation of soil quality and mitigation of desertification risk. Empirical results obtained using composite, geo-referenced indices of soil quality (SQI) and sensitivity to land desertification (SDI), integrated with high-resolution land zoning maps, indicated that land devoted to natural and semi-natural uses has lower soil quality in both contexts. The highest values of SDI, indicating high sensitivity to desertification, were observed in fringe areas with medium-high population density and settlement expansion. These findings reveal processes of land take involving buildable soils, sometimes of high quality, and surrounding landscapes in both cities. Overall, the results in this study can help inform land use planers and policymakers for conservation of high-quality soils, especially under weak (or partial) regulatory constraints.