@article{oai:mie-u.repo.nii.ac.jp:00005742,
 author = {加治佐, 隆光 and Kajisa, Takamitsu},
 journal = {三重大学生物資源学部紀要 = The bulletin of the Faculty of Bioresources, Mie University},
 month = {Mar},
 note = {application/pdf, The relationship of the Antecedent Precipitation index (Hereafter, abbreviated as API) to soil suction, outlet discharge and height of a sorgo are discussed. As API is the sum of weighted data of daily precipitation, this value is obtained for every field on every day. The relation between API and soil suction was determined. The following experimental equation based on least squares method was derived. 
 pF=a・log (API)＋b     (A)
a: constant parameter which is minus, b: constant parameter. 
The effect of heat on this equation is not known and Eq. (A) should be used under almost the same thermal conditions for obtaining hydrological data using API. 
Based on Eq. (A), APIdry was defined for pF 1.5 and APIwet was defined for pF 3.5 in this paper. For better vegetaЫe quality, small APIdry and big APIwet are essential.
 Eq. (B) was derived for obtaining the mean value of API for confirming long‐term regional condition of wetness.
API≒c･R     (B)
API: mean value for bong term API (mm), R: mean value of daily precipitation (mm/day). As the sum value of daily precipitation is shown in a meteological report, R is easily obtained. c:constant parameter which was 5.45 in this study. 
Eqs. (A) and (B) are quite practical for irrigation, drainage and oulet discharge analysis.},
 pages = {35--41},
 title = {先行降雨指数と畑地内サクションの関係},
 volume = {8},
 year = {1992}
}