Lu Zhang

Abstract: The partition of available energy into evapotranspiration affected by environmental and physiological factors is critical in understanding the water cycle and optimizing the water management in the field. Our study attempted to accurately quantify the environmental and physiological control on variability in evaporative fraction (EF) based on the Penman–Monteith model. The eddy covariance method was used to measure water flux over a canopy and then calculate the EF above a maize field in northwest China in 2007. Results indicate that the EF was lower in other growth stages than in the heading stage, so the EF value in the heading stage was taken as the standard value. The decreases in EF caused by canopy conductance and environmental factors were 0.176 and −0.026, accounting for 117% and −17% of the total difference in EF, respectively. Such results were mainly due to the following: (1) the variation of maize canopy conductance was greater than that of the environmental factors, such as air temperature, air humidity, wind speed and radiation; (2) the EF of the maize was more sensitive to variation in canopy conductance than the environmental factor. Our study revealed that crop physiological factor played an important role in determining the energy partition processes and reducing the sensible heat flux in the maize field. Copyright © 2012 John Wiley & Sons, Ltd.

TL;DR: In this article, the effects of a rainfall regime change on soil moisture and water balance in the Loess Plateau were explored, and the results showed that soil moisture tended to be more frequent at low levels with decreasing precipitation and the ratio of evapotranspiration under stress in response to rainfall also changed.

TL;DR: In this paper, an alternative approach, described in this paper, is to estimate the extractable soil moisture capacity from direct measurements of soil moisture content in the field, using a time series of water values, over the depth of the soil, shows the actual changes in water content.

TL;DR: In this article, the characteristics of riverbed infiltration and its spatial patterns were analyzed using geostatistical method and kriging method, and the results showed that the saturated permeability coefficient varied from 0.089 to 2.802m/d, indicating moderate degree of variability.