Slide 3 of 7
Water flows through the landscape. The condition of the land surface affects the flow and quality of water. Land surface condition can be characterized at any location by the type of land use, soils, climate and terrain conditions prevailing there. The effects on water resources can be measured by the water yield (mean annual flow), flooding (peak discharges and water surface elevations), groundwater (recharge and pumping), pollution (constituent concentrations and loads), and sediment (rate of erosion, sediment transport and deposition).
The connection between land and water resources can thus be viewed on two axes, for land and water characteristics respectively. Land and water characteristics are connected. Land characteristics tend to be relatively fixed in time, and spatially extensive. Water characteristics vary much more in time but tend to be spatially concentrated, such as at points of measurement of streamflow or water quality. Water characteristics are related to the character of the surrounding land surface by relationships expressed as equations e.g. runoff = precipitation * runoff coefficient, where the runoff coefficient is a function of land use.