A distributed model of water balance in the Motueka catchment, New Zealand

A distributed water balance model is used to simulate the soil moisture regime of the Motueka catchment. The model is a major simplification of the Distributed HydrologyeVegetationeSoil Model (DHVSM) with modifications suitable for the study area. The model was applied at 25-m resolution with a 1-day time-step for 10 years. The simulated hydrograph showed good correspondence with the observed hydrograph and there was good agreement of simulated and measured mean annual discharges (57.3 m3 sÀ1 as compared with 58.7 m3 sÀ1 ). Five different land cover scenarios were used to predict the effects of vegetation change on the hydrological regime: (1) current land cover; (2) prehistoric land cover; (3) maximum pine planting; (4) pine trees on easy slopes; and (5) pine trees on steep slopes. The pine scenarios all reduced the mean annual flow by about 2 m3 sÀ1 , while the prehistoric scenario reduced the mean annual flow by about 6 m3 sÀ1 . The pine scenarios (3, 4, and 5) reduced the ...

• Type: Journal
• Year: 2007
• Where: ENVSOFT
• Authors: Robbie M. Andrew, John R. Dymond
• Keywords: ENVSOFT 2007, Mean Annual flow, Model, Scenario