摘要
The imbalance of land-surface water budget was discovered in past studies, but there have been few further investigations on the relevant causes. To probe into the problem, annual variations of precipitation and land-surface evapotranspiration were analyzed by using the historical observation data from a compre- hensive land-surface observation base of LOPEX （Loess Plateau Experiment）. A remarkable imbalance in the land-surface water budget was found, and the total annual imbalance reached 20.6%. Then, the impact factors related to additional water budget components and observational methods were studied. The total annual imbalance could be reduced to 3.8% by using a combination of compensated land-surface water bud- get components and the surface evapotranspiration values obtained from the large-scale weighing lysimeter rather than from the eddy correlation method.
The imbalance of land-surface water budget was discovered in past studies, but there have been few further investigations on the relevant causes. To probe into the problem, annual variations of precipitation and land-surface evapotranspiration were analyzed by using the historical observation data from a compre- hensive land-surface observation base of LOPEX （Loess Plateau Experiment）. A remarkable imbalance in the land-surface water budget was found, and the total annual imbalance reached 20.6%. Then, the impact factors related to additional water budget components and observational methods were studied. The total annual imbalance could be reduced to 3.8% by using a combination of compensated land-surface water bud- get components and the surface evapotranspiration values obtained from the large-scale weighing lysimeter rather than from the eddy correlation method.
基金
Supported by the National Natural Science Foundation of China(40830957and41075009)
the China Meteorological Adminstration Special Public Welfare Research Fund(GYHY200806021)
