ABSTRACT
There are two components to global environmental change (Turner et al.y 1990). Systemic changes operate at the global scale, affecting large areas at the same time: global warming is the classic example. Cumulative change describes the net effect of local-scale changes occurring in different areas, perhaps for different local reasons: deforestation is a good example. This chapter focuses on the cumulative change component of global environmental change, looking in detail at how changes in the catchment affect hydrological behaviour at the catchment scale. Chapter 7 explores the effects of systemic changes - largely changes in the inputs to the catchment - whilst Chapter 8 examines the effect of changes in the catchment on the global environmental system beyond the catchment.
