Estimation of water consumption for ecosystems based on Vegetation Interfaces Processes Model: A case study of the Aksu River Basin, Northwest China.

Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) - Normalized Difference Vegetation Index (NDVI), the Vegetation Interfaces Processes (VIP) model simulated the spatio-temporal patterns of actual evapotranspiration (ET) and the water consumption of different ecosystems in the Aksu River Basin, Northwest China between 2000 and 2015. The results revealed that: (1) the applicability of the VIP model was confirmed, with good agreement (R2=0.79, P<0.05) between the VIP-ET and water balance model (WB)-ET in the Aksu River Basin; (2)arable land showed the highest annual actual ET per unit pixel (362.4mm/pixel), followed by forest (159.6mm/pixel), and grass land (142.8mm/pixel); (3) water consumption for arable, forest, and grass land were determined as 19.45×108, 1.94×108, and 28×108m3/a, respectively; and (4) there was a significant trend (P<0.05) of increasing water consumption of 0.379×108m3/a in the artificial ecosystem, but there was no significant trend in the time series of the natural ecosystem. Overall, the study demonstrated that the VIP model is able to supply important information for water resource management at the catchment-scale.