Multiscale landscape analyses: The Megalopolis of Mexico as a case study

Abstract

This paper investigates land cover, land use and vegetation changes at macro-regional, regional, local, and site spatial resolutions in the Megalopolis of Mexico City and how these affect groundwater recharge potential. Our research was framed within a transdisciplinary-holistic scope to unpack the complex social, geographic, and environmental processes often hidden when using single discipline, one-scale, one-stakeholder perspectives. Land cover/use data from the 1970s and 2018 were used as the primary input to analyze changes using remote sensing and geographical information systems. At the (macro)regional scale, land-use changes, especially human settlements, increased from about four to almost 40 % between 1970 and 2018, with a significant incursion into rural landscapes. At the local scale, analyses revealed a considerable decline in predominantly cold-humid vegetation types and conversion of agricultural fields into peri-urban landscapes. At pedon scale, hydrological balance analyses were calculated and then extrapolated to the region on behalf of soil maps information to assess groundwater recharge potentials, revealing the importance of soils as the core landscape component for water infiltration. Furthermore, social perception of changes was investigated among local stakeholders using semi-structured interviews with four communities. Nested multi-scale analyses revealed different disrupting processes hidden at one scale and evident at another. Outcomes are discussed considering their relevance for addressing transdisciplinary and theoretically applied frameworks.