Response characteristics of soil moisture to rainfall for a single grass
vegetation in the urban area A case of regional grassland in Yangzhou
City
Abstract
A regional grassland with Bermudagrass in Yangzhou City of China was
adopted as the study location. Based on the analysis of the different
rainfall events and soil water content data in the same periods, the
response characteristics of infiltration to rainfall were revealed in a
certain degree. The surface resistance parameters (rs) are calibrated
according to the soil water content at the depths of a range for 0-30 cm
and of the root layer (0-10 cm). Penman-Monteith (P-M) equation was
adopted to estimated the hourly evapotranspiration (ET) over the
Bermudagrass lawn of the soil layers for the depths of 0-30 cm (ET30)
and 0-10 cm (ET10), respectively. Applicability of HYDRUS-1D model for
simulating soil water content at different depths was validated. The
results indicated that the infiltration depth generally varies with the
rainfall event grade, and on the whole, the infiltration depth increases
with the improvement of amount of rainfall; the response time for the
soil water content in root layer is much shorter with the less soil
water content in the topsoil (0-5.5 cm); the increase rate of soil water
content raised with increasing of rainfall intensity in the state of
unsaturation; ET10 accounts for about 78% of ET30, which demonstrates
the water consumed by ET is mainly provided by the soil water in the
root layer. the rationality of the results of different rainfall events
and infiltration depth achieved by the analysis of the observed data
were verified via numerical simulation using Hydrus-1D.