@article{oai:kanazawa-u.repo.nii.ac.jp:00009302, author = {Ichikawa, Hisato and Seki, Hirakazu and Takami, Shinichi}, issue = {1}, journal = {Journal of Agricultural Meteorology = 農業気象}, month = {Jan}, note = {In a previous study (Ichikawa et al., 2008), we found experimentally and confirmed theoretically that a porous column, the primary part of a solar pump, enhanced water evaporation. The evaporation rate from the surface of a sand column was higher than that from the water surface. Our previous study also showed that there was an optimum height of the sand column at which the rate of evaporation was the maximum. Experimental results for the water evaporation rate changed continuously with increasing water table depth and had a maximum at a particular depth value. The evaporation rates calculated from a mathematical model based on Philip and de Vries (1957), however, changed discontinuously at a particular value of water table depth at which maximum evaporation occurred. Assuming that the local evaporation rate on the column surface varies, following a statistical normal distribution, we computed its average over the column surface. The rates thus computed changed continuously with increasing water table depth, which agreed well with the experimental results. We therefore conclude that the discrepancy in the previous study arose because the experimental results are averages over the surface, while those theoretically calculated without considering the statistical distribution are merely local values on the surface.}, pages = {51--56}, title = {Water evaporation rate from a radiation-heated porous material considering a local variation of matric potential}, volume = {66}, year = {2010} }