Abstract
Changes of soil water conditions in a soil profile were observed and estimated using a one-dimensional vertical soil water movement model for a dry evergreen forest area of Kampong Thom Province, Cambodia. The research site was in a dry evergreen forest where a meteorological observation tower had been established. Soil water matric potentials were measured at 20-, 50-, 100-, 150-, 200-, and 250-cm depths in an observation plot. Groundwater levels were observed at the site. Soil water matric potentials at each observation depth in a soil profile were simulated using a one-dimensional water movement model that was based on Richards’ equation. Results of observations and simulation revealed the following. (1) The site’s water-saturated zone was close to the ground surface during the rainy season. Water conditions in the unsaturated zone, which was above the groundwater level, were influenced strongly by groundwater. The groundwater level was 400 cm deep even in the dry season. The entire soil profile, from the surface to the bottom, never dried completely. (2) At the beginning of the rainy season, at the surface and subsurface depths of 20 cm and 50 cm, respectively, soil matric potentials were increased by rainfall events, which often supply water to the ground surface. Meanwhile, matric potentials at 200 and 250 cm depths were influenced directly by groundwater; they retained high potential values even during the dry season. In the middle zone, at depths of 100 and 150 cm, the soil was quite dried; the minimum matric potentials in the rainy season resembled those of the surface zone. (3) At the beginning of the dry season, matric potentials at 20- and 50-cm depths decreased because of soil water loss by transpiration of trees and evaporation from the ground surface.
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References
Hattori S, Deguchi A, Daikoku K (2004) Characteristics of transpiration in leaf-scale and forest floor evaporation in dry evergreen and dry deciduous forests in O Thom I watershed. In: Sawada H, Chann S, Shimizu A, Araki M (eds) Proceedings of the international workshop on forest watersheds 2004, Phnom Penh, Cambodia, 29 October 2004, pp 67–72
Mualem Y (1976) A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12(3):513–522
Nobuhiro T, Shimizu A, Kabeya N, Tsuboyama Y, Kubota T, Abe T, Araki M, Tamai K, Chann S, Keth N (2007) Year-round observation of evapotranspiration in an evergreen broadleaf forest in Cambodia. In: Sawada H, Araki M, Chappell NA, LaFrankie JV, Shimizu A (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo, pp 75–86
Ohnuki Y, Kimhean C, Shinomiya Y, Sor S, Toriyama J, Ohta S (2007) Seasonal change of soil depth and soil hardness at forested areas in Kampong Thom Province, Cambodia. In: Sawada H, Araki M, Chappell NA, LaFrankie JV, Shimizu A (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo, pp 263–272
Richards LA (1931) Capillary conduction of liquids through porous mediums. Physics 1:318–333
Shimizu A, Kitahara H, Mashima Y (1995) Change of soil moisture in areas with different vegetation and result of artificial precipitation experiment. IUFRO World Congress XX:24
Shinomiya Y, Araki M, Toriyama J, Ohnuki Y, Shimizu A, Kabeya N, Nobuhiro T, Kimhean C, Sor S (2007) Effect of soil water content on water storage capacity: comparison between the forested areas in Cambodia and Japan. In: Sawada H, Araki M, Chappell NA, LaFrankie JV, Shimizu A (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo, pp 273–280
Simunek J, Sejna M, van Genuchten MT (1998) Simulating water flow, heat, and solute transport in one-dimensional variably saturated media. U.S. Salinity Laboratory, USDA, ARS, Riverside, CA
Tani A, Ito E, Kanzaki M, Ohta S, Khorn S, Pith P, Tith B, Pol S, Lim S (2007) Principal forest types of three regions of Cambodia: Kampong Thom, Kratie, and Mondolkiri. In: Sawada H, Araki M, Chappell NA, LaFrankie JV, Shimizu A (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo, pp 201–213
Top N, Mizoue N, Kai S (2004) Estimating forest biomass increment based on permanent sample plots in relation to woodfuel consumption. J For Res 9:117–123
Toriyama J, Ohta S, Araki M, Kanzaki M, Khorn S, Pith P, Lim S, Pol S (2007) Soils under different forest types in the dry evergreen forest zone in Cambodia: morphology, physicochemical properties, and classification. In: Sawada H, Araki M, Chappell NA, LaFrankie JV, Shimizu A (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo, pp 241–253
van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:892–898
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Araki, M. et al. (2007). Changes of Vertical Soil Moisture Conditions of a Dry Evergreen Forest in Kampong Thom, Cambodia. In: Sawada, H., Araki, M., Chappell, N.A., LaFrankie, J.V., Shimizu, A. (eds) Forest Environments in the Mekong River Basin. Springer, Tokyo. https://doi.org/10.1007/978-4-431-46503-4_10
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DOI: https://doi.org/10.1007/978-4-431-46503-4_10
Publisher Name: Springer, Tokyo
Print ISBN: 978-4-431-46500-3
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