手法を比較

	Penman-Monteith方程式	植生による降雨分配：キャノピー遮断モデリング	土壌水分特性曲線
分野	農学	農学	農学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1948-1965	1971–1979 (foundational models; continuous development since)	1956-1980
提唱者	Howard Latimer Penman, John Monteith	Multiple contributors (Rutter et al. 1971; Gash 1979 for principal analytical frameworks)	Willard Robert Gardner, Rollin H. Brooks, Arthur T. Corey
種類	Mechanistic evapotranspiration model	Process-based hydrological model	Empirical soil water retention model
原典	Penman, H. L. (1948). Natural evaporation from open water, bare soil and grass. Proceedings of the Royal Society A, 193(1032), 120-145.	Rutter, A. J., Kershaw, K. A., Robins, P. C., & Morton, A. J. (1971). A predictive model of rainfall interception in forests. Agricultural Meteorology, 9, 367–384.	Gardner, W. R. (1956). Representation of soil aggregate-size distribution by a logarithmic-normal distribution. Soil Science Society of America Journal, 20(2), 151-153.
別名	PM Equation, FAO-56 PM, Evapotranspiration Model	interception loss modeling, canopy rainfall partitioning, forest interception modeling, throughfall-stemflow modeling	Water Retention Curve, pF Curve, Characteristic Curve, SWRC
関連	3	0	3
概要	The Penman-Monteith equation is a mechanistic model for estimating evapotranspiration (ET), the combined loss of water from soil and plant canopies to the atmosphere. First proposed by Penman (1948) for bare soil and water surfaces, then extended by Monteith (1965) to incorporate plant resistance to water vapor diffusion, it has become the international standard for water balance studies, crop water requirement calculation, and hydrological modeling.	Canopy interception modeling quantifies the fraction of rainfall captured by plant canopies and subsequently evaporated back to the atmosphere before reaching the soil. Applied across agronomy, forestry, and hydrology, it partitions gross precipitation into throughfall, stemflow, and interception loss. By linking vegetation structure — particularly leaf area index and canopy storage capacity — to water balance components, the method informs irrigation scheduling, watershed management, and crop water-use estimation.	The soil moisture curve (or soil water retention curve, SWRC) describes the relationship between soil water content and soil matric potential (water tension). It characterizes how tightly water is bound in pores of different sizes: large pores drain at low tensions (wet soils), while smaller pores retain water at high tensions (dry soils). Quantifying this relationship is essential for water balance modeling, unsaturated flow prediction, and assessing plant-available water.