Modelling Impacts of Land Cover Change on Critical Water Resources in the Motueka River Catchment, New Zealand

Abstract

After the SWAT (Soil and Water Assessment Tool) model was calibrated and validated to historic flow records for the current land use conditions, two additional land cover scenarios (a prehistoric land cover and a potential maximum plantation pine cover) were used to evaluate the impacts of land cover change on total water yields, groundwater flow, and quick flow in the Motueka River catchment, New Zealand. Low-flow characteristics and their potential impacts on availability for water abstraction and for support of in-stream habitat values were focused on. The results showed that the annual total water yields, quick flow and baseflow decreased moderately in the two scenarios when compared with the current actual land use. The annual water balance for the pine potential land cover scenario did not differ substantially from the prehistoric scenario for the catchment as whole. However, there were more notable differences among individual tributary catchments, which could be attributed to the relative area of land cover altered and location of those catchments. Simulated low flows for the prehistoric and potential pine land cover scenarios were both significantly lower than the low flows for the current land use. In summary, under the current land use conditions, both annual water yield and low flow are higher than was the case before human intervention in the area or in a maximum commercial reforestation scenario.

Effects of Watershed Vegetation on Tributary Water Yields During the Wet Season in the Heishui Valley, China

“…Our results provided further evidence for correlations between forest coverage and water yields that have been found in many different watersheds (Bosch and Hewlett 1982;Bruijnzeel 1996;Andreassian 2004;Sun et al 2006). Recently, Cao et al (2009) used model simulation for the Motueka River catchment in New Zealand and found water yields from the current actual land use to be higher than those from both prehistoric land use and maximum pine plantation scenarios. This finding was established in assuming some ideal changes in vegetation coverage.…”

“…This finding was established in assuming some ideal changes in vegetation coverage. In our study, however, we quantified the linear correlations and exact water yields corresponding to actual differences in vegetation coverage resulting from human activities in 12 sub-watersheds, and this quantitative aspect further validated the results of model simulation (Saghafian et al 2008;Cao et al 2009;Carlon Allende et al 2009) and strengthened our understanding of land use effects on water yield. The effect of alpine shrub-meadow on water yield in our study mirrored that of subalpine forest.…”

The effects of human activities, climatic conditions and land-use factors on water resources development in huai river basin northeast china

“…[21][22][23][24][25][26][27][28] Investigated the effects of best management practices implementation on pesticide fluxes contaminating surface water by means of SWAT method. Again, 29 applied SWAT to examine the effects of land cover change on groundwater flow, entire water yields, and quick flow in the Motueka River catchment/section. Later, 30 studied the SWAT method for the Xixian watershed hydrological modelling and compared outcomes to the XAJ method and 31 evaluated the impact of tile drainage systems on composition of stream flow in in a Tile-Drained lowland section/catchment with application of the SWAT.…”

“…[21][22][23][24][25][26][27][28] assess the effects of implementing of superlative management practices on pesticide fluxes arriving on surface water by means of SWAT. Again, 29 appraised the influences of land-cover conversion on total water yields, groundwater flow, and fast flow in the Motueka River catchment using SWAT scheme. 30 estimated the SWAT for hydrological modelling in the Xixian watershed and compared results with the XAJ model.…”

Opportunities for restoring indigenous forest in New Zealand

“…Identification of opportunities for protection and restoration of indigenous forest thus requires an analysis of the trade-offs between any environmental benefits and agricultural production. While land-use planning for multiple economic and environmental benefits has enjoyed popular debate over many decades in New Zealand (Norton 1998; Parliamentary Commissioner for the Environment 2002; Cao et al 2009), very few tools have been produced to quantify tradeoffs between landscape-scale properties. The rise of an 'ecosystem services' approach now provides a framework within which properties can be quantified and assessed against one another (e.g.…”