Ecological exergy as an indicator of land-use impacts on functional guilds in river ecosystems

Systematic processes of land use/land cover change to identify relevant driving forces: implications on water quality

Land use and land cover (LULC) are driving forces that potentially exert pressures on water bodies, which are most commonly quantified by simply obtained aggregated data. However, this is insufficient to detect the drivers that arise from the landscape change itself. To achieve this objective one must distinguish between random and systematic transitions and identify the transitions that show strong signals of change, since these will make it possible to identify the transitions that have evolved due to population growth, industrial expansion and/or changes in land management policies. Our goal is to describe a method to characterize driving forces both from LULC and dominant LULC changes, recognizing that the presence of certain LULC classes as well as the processes of transition to other uses are both sources of stress with potential effects on the condition of water bodies. This paper first quantifies the driving forces from LULC and also from processes of LULC change for three nested regions within the Mondego river basin in 1990, 2000 and 2006. It then discusses the implications for the environmental water body condition and management policies. The fingerprint left on the landscape by some of the dominant changes found, such as urbanization and industrial expansion, is, as expected, low due to their proportion in the geographic regions under study, yet their magnitude of change and consistency reveal strong signals of change regarding the pressures acting in the system. Assessing dominant LULC changes is vital for a comprehensive study of driving forces with potential impacts on water condition.