Geoscience Reference
In-Depth Information
Water and Landscapes
Water and land use are almost always treated separately in academic research, plan-
ning and government. Yet the two are inextricably interrelated. Environmental
geographers have explored the interrelationship between land and water in detail.
Their fi ndings, as explored in this section, have signifi cant implications for applied
water management. In conceptual terms, this work's importance stems from its
ability to demonstrate the mutual causality between human societies and landscapes:
how human activities shape landscapes and waterscapes; and, simultaneously, how
the water cycle shapes human societies.
One obvious way in which water and landscapes are interrelated is through the
infl uence of land use and land cover on the hydrological cycle, which has long been
the focus of study by geographers (see, e.g., Clifford, 2002; Brazier, 2004; Dollar,
2004; Holden et al., 2004, and the classic works by Chorley, 1969, Pereira, 1973,
and White et al, 1972). Given the rapid rate of change in land use in many regions,
this is one of the most pressing issues in water management. Indeed, the central
problem of hydrology has frequently been characterised as an attempt to refi ne and
solve the 'water balance' equation, which necessarily implies analysis of both land
and water use. However, a central diffi culty faced by physical geographers in gen-
eralising their results about the impact of land use is the fact that the majority of
studies are fi eld-based, hampering efforts to extrapolate from 'a series of mainly
small-scale, short-term empirical studies of land-use effects . . . to a generalised body
of scientifi c results operable in river basin management' (Newson, 1997: 96). Indeed,
this problem characterises work in the environmental sciences more generally.
Recent advances in hydrology have developed conceptual frameworks upon which
such generalisations might soundly rest (see, e.g., Eagleson 2002, Eaton et al., 2004;
Rodriguez-Iturbe and Porporato, 2004).
Given this fi eld-based emphasis, it is not surprising that geographers have made
important contributions to the study of the impacts of human land use on the
hydrological cycle. For example, geomorphological and hydrological research on
rivers has examined the role of riparian vegetation as a control on bank stability
(Bennett and Simon, 2004) or as a buffer for material entering the channel from
the hillslope (Burt and Pinay, 2005), and the effect of channel morphology and
instream vegetation growth on river dynamics, such as sediment transport (Clarke,
2002; Nistor and Church, 2005). The empirical studies by geographers in this area
complement theoretical work done in eco-hydrology on the relationship between
soils, climate and vegetation (see, e.g., Budyko, 1974).
The implications of this work for the relationship between water and landscapes
are particularly important for applied water management (e.g., Bonell and
Bruijnzeel, 2005, Pereira 1989). For example, geographers have documented the
impacts of dam construction, with its concomitant changes in fl uvial fl ow regime,
sediment transport, channel morphology and river ecosystems, as well as the impli-
cations of logging on stream temperature and water yields (Graf, 2001; Moore
et al., 2005; Robinson and Dupeyrat, 2005). As the work of hydrologists has
demonstrated, this implies that debates over restoring the physical integrity of
rivers necessarily imply choices about how to intervene in landscapes which are
already actively managed and shaped by human hands (see, for example, Graf,
2001; Downs and Gregory, 2004; McDonald et al., 2004; Hillman and Brierly,
