Estimating soil water retention function from its particle-size distribution

particle-size distribution;pedotransfer function;soil water;van Genuchten model;water retention function;630

농업생명과학대학 농생명공학부 ;

University:서울대학교 대학원

关键词: particle-size distribution;    pedotransfer function;    soil water;    van Genuchten model;    water retention function;    630;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/125807/1/000000012710.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

103 datasets for calibration and 46 datasets for validation).iiVerification was conducted additionally with data from previous studies (Ariana silty clay loam and Yolo loam) and experimentally obtained data (Bancheon silty clay, Upyeong silty clay, Chusan clay loam). From calibration dataset, PSD and SWRC were fitted independently and Pearson product moment correlation coefficients (R2) of each model were shown 0.987 and 0.965, respectively, which means estimation was appropriate based on the van Genuchten model. Shape-related parameters, m, for cumulative PSD and SWRC were shown nonlinear relationship each other. In contrast, any relationship between inflection points of each cumulative PSD and SWRC could not be found. Alternatively, particle-size and reciprocal of matric head were partial linearly related at the point of 43 % of each normalized cumulative distribution. Root mean square of residuals (RMSR) of predicted SWRC were 0.091 to entire verification dataset, which was highest in sandy clay (RMSR=0.241) and lowest in silty clay loam (RMSR=0.016). Estimated water contents were relatively smaller than actual contents, because the inflection point was predicted higher than ideal value. Although particle-size and reciprocal of matric head were asymmetrically related in each soil, the relationship was shown very different among the soil survey data. Further researches need to be conducted to solve under-estimation by verifying the relationship between particle- and pore-size that could cover overall soil.