A GIS based approach to modelling the effects of land-use change on soil erosion in New Zealand |
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| Authors: | H.J.E. Rodda M.J. Stroud U. Shankar B.S. Thorrold |
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| Affiliation: | Risk Management Solutions, 10 Eastcheap, London EC3M 1AJ, UK;New Zealand National Institute of Water and Atmospheric Research Ltd, PO BOX 11–115, Hamilton, New Zealand;New Zealand National Institute of Water and Atmospheric Research Ltd, PO BOX 8026, Christchurch, New Zealand;AgResearch, Private Bag 3123, Hamilton, New Zealand |
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| Abstract: | Abstract. The problem of soil erosion is particularly evident in New Zealand, given the combination of coarse-textured soils, steep relief, high rainfall, and intensification of agriculture. A study was undertaken to assess the effects of land use change on soil erosion and sediment transport for the Ngongotaha catchment in New Zealand's North Island, using a GIS based decision support and modelling system. Model simulations considered the effect of increased catchment area under deer farming and forestry on the amount of sediment delivered to the catchment outlet, averaged over a period of six years. The simulations predicted that sediment loss from land under deer farming was considerably greater than from land under other livestock or forestry. Further model simulations testing best management practices demonstrated that sediment yield could be halved if deer farming was restricted to slopes under 20%. |
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| Keywords: | Erosion sediment yield catchment hydrology models geographical information systems land use New Zealand |
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