Economic drivers of land use and groundwater use by irrigators, Waimea Plains Nelson, New Zealand

摘要

Economics provides an important driver of land use change between the four main economic activities of groundwater irrigators (dairy, apples, horticulture-other and market gardening) using the Lower Confined Aquifer, Waimea Plains, Nelson. Over the period between 2003-4 and 2007-8, most irrigated land moved to higher value uses. In particular, dairy land use, with the lowest average revenue per hectare, was largely replaced by horticulture-other and market gardening with average revenues per hectare three to seven times greater than dairy. A causal link between economics and groundwater use is established as dairy generally uses more water per hectare than horticulture-other and market gardening, and as apple orchards responded to low apple prices in 2004-5 by either closing or removing blocks of low-producing trees. Average groundwater use efficiency increased over time from $4.9/m~3 to $16.7/m~3 because of changes in land use, land use practices and product price.