HR: 10:50h
AN: H32A-02    [Abstracts]
TI: The World's Biggest Water Filter: The Vadose Zone
AU: * Clothier, B E
EM: bclothier@hortresearch.co.nz
AF: HortResearch, Tennent Drive, Palmerston North, New Zealand
AB: Soil is the fragile yet productive skin of our planet. The soil of the vadose zone occupies a critical position between the atmosphere and the subterranean realm. The vadose zone lies astride the main thoroughfare along which water and solutes enter our ground and surface waters. The soil of the vadose zone is the world's biggest filter. Water and chemical fluxes though the heterogeneous porous medium of the unsaturated soil of the vadose zone, in the active presence of plants, are necessary for the healthy functioning of soil as the productive base for sustainable agriculture. As well, these fluxes are critical determinants of the quantity and quality of our underground and surface reserves of water. Our understanding of transport and fate processes in the vadose zone has been enhanced thanks to two developments. New measurement devices and remote monitoring techniques are providing better observations, at the local scale, of the state and fluxes of water and solute into, and through, the vadose zone. Here I outline some of the new observations that are improving the acuity of our vision of rootzone processes. In tandem, better theoretical understanding and new modelling techniques are being developed to extend and extrapolate these still-meager observations to realize improved understanding of vadose zone processes at larger spatial and temporal scales. Water is now known as "blue gold". "Blue gold" will be this century's most urgent environmental issue. We need to use our scientific understanding of the functioning world's largest water filter - the vadose zone - to protect the quantity and quality of our reserves of "blue gold".
UR: http://www.hortresearch.co.nz
DE: 1818 Evapotranspiration
DE: 1829 Groundwater hydrology
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 1899 General or miscellaneous
SC: Hydrology [H]
MN: 2005 Joint Assembly