Our goal is to better understand land changes in rural and urban landscapes of temperate and tropical regions. We conduct research both on the causes of land-use change and on their impacts on soils, ecosystems, vectors of diseases, and sustainable development. This work is conducted at local, regional and global scales.
We detect and measure land-cover changes using time series of remote sensing data, and field collected data, that we analyse using geographic information systems. We focus on both slow, fine scale land-cover conversions and fast, broad scale land-cover modifications.
Based on several case studies worldwide, we develop an integrated, spatial approach to human-environment interactions in land systems, by linking land-cover change and socio-economic data. This leads to a better understanding of the causes of processes such as tropical deforestation, dryland degradation, land use conflicts around natural reserves, and forest transition.
Land-use change has affected natural patterns and rates of geomorphic and hydrological processes. Quantitative data on human impact on historical and modern erosion rates are obtained using in-situ produced cosmogenic nuclides, such as 10-Be, 26-Al. This allows estimating natural, erosion rate benchmarks against which short-term increases or decreases in erosion rates due to land use can be quantified.
Changing agricultural practices, such as the replacement of traditional systems or intensive use of marginal land can lead to a rapid degradation of soil and water resources, with off-site effects such as flooding. We monitor changes in soil organic carbon (SOC) content to quantify soil-atmosphere CO2 fluxes. Erosion and sedimentation of soil and associated organic matter within the landscape are quantified as sources or sinks of CO2. To control for the spatial variability in SOC within landscapes, we estimate change in SOC over time using fractionation techniques, new analytical techniques for rapid assessment of SOC contents, and new integrative modelling approaches.
The (re-)emergence of vector-borne and zoonotic diseases is caused by multiple factors, including ecosystem changes. We predict disease risk based on integrated, landscape-level models of the interactions between land use, human behaviour, ecosystem changes, vector/host ecology, and pathogens. We study tropical diseases (malaria and dengue), emerging diseases in temperate regions (Lyme disease, Puumala hantavirus, tick-borne encephalitis, leishmaniasis), and animal diseases (foot-and-mouth disease around parks in Africa, cowpox).
We also investigate spatial interactions taking place in European cities. European cities are paradoxical places, where, although high levels of GDP are found, unemployment rates are high and environmental pressures important. Cities must manage opposing forces relating to a logic of economic growth and to sustainable development and find solutions to these multifaceted problems. Socio-economic imbalances are expressed spatially in the urban territory. Although intercorrelation is found between explanatory factors, these development dynamics are analysed by looking at housing, employment, poverty, mobility and planning.
All our research projects contribute to an identification of conditions for a transition toward a sustainable use of land resources.
