Multitemporal Analysis of Soil Sealing and Land Use Changes Linked to Urban Expansion of Salamanca (Spain) Using Landsat Images and Soil Carbon Management as a Mitigating Tool for Climate Change

Marco Criado,Leticia Merchán,Antonio Martínez-Graña,Fernando Santos-Francés,Yolanda Sánchez

doi:10.3390/rs12071131

Abstract

The lack of urban sustainability is a widespread deficiency in urban agglomerations. To achieve adequate land use, we present a methodology that allows for: 1) the identification of the impacts caused by urban expansion since 1956 to the present in Salamanca (Spain); and 2) the promotion of a more sustainable future in urban development. A multi-temporal assessment of land use was made by remote sensing, while sustainability criteria were analyzed using the multicriteria analysis (MCA) with Geographical Information Systems (GIS). In addition, we established recommendations for soil carbon management in semi-arid ecosystem soils that contribute to climate change mitigation. The results show an increase of the urbanized area from 3.8% to 22.3% in the studied period, identifying up to 15% of buildings in zones with some type of restriction. In 71% of the cases, urbanization caused the sealing of productive agricultural soils (2519 Ha), almost 20% of which were of the highest quality. In last few decades, an excessive increase of built-up areas in comparison to population dynamics was identified, which causes unnecessary soil sealing that affects the food production and the capacity to mitigate climate change by managing the carbon cycle in the soil.

Highlights

The progressive increase of population and its agglomeration in cities [1], which by 2050 is estimated at 68% [2] and by the end of the twenty-first century at 90% [3], is one of the important current challenges for humanity
Unmeasured and unplanned urbanization causes multiple negative impacts on society and economy and in the environment
The water extension, belonging exclusively to the Tormes River, is relatively similar, we detect extension decreases over time, which may be due to the riverbank forest’s improvement, which covers more and more riverbed areas

Summary

Introduction

The progressive increase of population and its agglomeration in cities [1], which by 2050 is estimated at 68% [2] and by the end of the twenty-first century at 90% [3], is one of the important current challenges for humanity. The impact of urban agglomerations on climate change is evident due these agglomerations being the largest greenhouse gases emitting and resource consuming group, which may compromise economic development, food security and/or social justice [17,18,19]. Cities have generally spread without planning or restriction criteria, linked to economic development that originated in disorganized cities as a result of a massive unplanned experiment in landscape change [20]. Society demanded more respectful and responsible practices with the environment, which caused the acceptance of sustainable development being the only development model that guarantees social welfare, which requires adequate and sustainable urban development [21,22,23]

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