KHW: Kahoku Experiment watershed

General site detail (Updated 15 May 2009)
 Site name
 Kahoku Experiment watershed (KHEW)
 AsiaFlux site code
 Location Kahoku, Yamaga-city, Kumamoto pref., Japan
 Position 33º 08' 13.3" N, 130º 42' 34.3" E
 (World Geodetic System 1984, Geographical map published from Geographical Survey Institute, Japan)
 Elevation about 165 m above sea level
 (World Geodetic System 1984, Geographical map published from Geographical Survey Institute, Japan)
 Slope 16 deg (average)
 Terrain type
 Rolling terrain
 Area 12.7ha
 Fetch 120 to 140m
 Climate warm temperate, Cfa
 Mean annual air temperature
 15.3 deg (2000-2007)
 Mean annual precipitation
 2130 mm (2000-2007)
 Vegetation type
 Planted coniferous forest
 Domestic species (Overstory)
 Sugi (Cryptomeria japonica), Hinoki  (Chamaecyparis obtusa)
 Dominant species (Understory)
 Evergreen Quercus and Castanopsis trees
 Canopy height
 10 - 35 m
 Age 48-55 years (Sugi), 32-55 years (Hinoki)
 LAI 3.6 to 5.2
 Soil type

Eddy Covariance method (CO2)
 System Closed-path system (CO2 flux), 
 Open-path system (H2O, CO2 flux)
 Wind speed 
 Three-dimensional sonic anemometer-thermometer  
 (DA600-3T KAIJO, Japan)
 Air temperature
 Three-dimensional sonic anemometer-thermometer  
 (DA600-3T KAIJO, Japan)
 Water vapor
 Open-path (LI-7500, LI-COR, USA), 
 CO2 Closed-path (LI-7000, LI-COR, USA)
 Measurement height
 51.0 m
 Sampling frequency
 10 Hz
 Averaging time
 30 min
 Data logger
 DR-M3a, TEAC, Japan
 Data storage
 Original data
 Raw data

 Observation items
  Levels/ Depth
 Global solar radiation(incoming)
 47.2 m Pyranometer 
 (CM14, Kipp & Zonen, Netherland)
 Global solar 
radiation (outgoing)
 47.2 m Pyranometer 
 (CM14, Kipp & Zonen, Netherland)
 Long-wave radiation(incoming) 
 47.2 m Infrared radiometer
 (CNR1, Kipp & Zonen, Netherland)
  Long-wave radiation(outgoing) 47.2 m Infrared radiometer
 (CNR1, Kipp & Zonen, Netherland)
 Net radiation
 47.2 m Net radiometer
 (NR-LITE, Kipp & Zonen, Netherland)
 PPFD (incoming)
 47.2 m Quantum sensor (LI-190, LI-COR, USA)
 PPFD (outgoing)
 47.2 m Quantum sensor (LI-190, LI-COR, USA)
 Direct / diffuse radiation
 51.0 m Pyranometer (CM3, Kipp & Zonen,  Netherland) with shadow-band (PSB-100,  Prede, Japan)
 Direct / diffuse PPFD
 Air temperature
 51.0, 41.5,  34.0, 22.0,  10.5m Platinum resistance thermometer 
 (HMP35C, VAISALA, Finland)
 Humidity 51.0, 41.5,  34.0, 22.0,  10.5m Capacitive hygrometer (HMP45D, VAISALA,  Finland), Wet bulb temperature (ML-020L, Eko,  Japan)
 Soil temperature
 0.05 m Thermistor
 (HOBO S-TMB-002, Onset, USA)
 Soil heat flux
 0.02 m 
 Heat flow transducer
 (HFT-3.1, REBS, USA)
 Soil water 
 0.05 m 
 Capacitance prove
 (ECH2O, Decagon Devises, USA)
 Wind speed
 51.0 m 
 Three-dimensional sonic anemometer-
 thermometer (DA600, KAIJO, Japan)
 Wind direction
 51.0 m Three-dimensional sonic anemometer-
 thermometer (DA600, KAIJO, Japan)
 51.0 m Barometric pressure sensor
 (PTB210, VAISALA, Finland)
 Precipitation 1.5 m Rain gauge: 0.5mm tipping bucket
 (RT-5, Ikeda Keiki, Japan)
 44.2, 38.5,  33.5, 27.0,  20.2, 13.5, 6.8,  1.0 m Closed-path CO2/H2O analyzer (LI-6262, LI-COR, USA)
 Soil respiration
 Ecological investigation Tree heights, stand density, diameter: 9  plot sampling in 1999. LAI: once a month  (LAI-2000, LI-COR, USA).
 Hydrological investigation
 Runoff from the watershed
 (V-notch and float flow meter)
 Sap flow measurement Granier sensors (handmade)
Observation Period and data Availability
 Measurement Period
 April 1999 to present
 Measurement Frequency
 Data Availability
 Kenzo Kitamura (kitamu93 [at]
 Takanori Shimizu (simizuta [at]
 Kyushu Hagino (hagin [at]
 Forestry and Forest Products Research Institute
 1 Matsunosato, Tsukuba, Ibaraki 305-8687,  Japan
 Tel:+81-298-873-3211 Fax:+81-298-874-3720
 Yasuko Mizoguchi (pop128 [at]
 Koji Tamai (a123 [at]
 Ishizuka S., Sakata T., Sawata S., Ikeda S., Sakai H., Takenaka C., Tamai N., Onodera S., Shimizu T., Kan-na K., Tanaka N., Takahashi M.: 2009, Methane uptake rates in Japanese forest soils depend on the oxidation ability of topsoil, with a new estimate for global methane uptake in temperate forest7, Biogeochemistry, 92(3):281-295

Kumagai T., Tateishi M., Shimizu T., Otsuki K.: 2008, Transpiration and canopy conductance at two slope positions in a Japanese cedar forest watershed, Agricultural and Forest Meteorology, 148(10):1444-1455

Kobayashi M., Shimizu T.: 2007, Soil water repellency in a Japanese cypress plantation restricts increases in soil water storage during rainfall events, Hydrological Processes, 21(17): 2356-2364

Shimizu, T.: 2007, ‘Practical applicability of high frequency correction theories to CO2 flux measured by a closed-path system’, Boundary-Layer Meteorology, 122, 437-438.

Kumagai, T., Aoki, S., Shimizu, T. and Otsuki, K.: 2007, ‘Sap flow estimates of stand transpiration at two different slope positions in a Japanese cedar forest watershed’, Tree Physiology, 27, 161-168.

Ishizuka, S., Sakata, T., Sawata, S., Ikeda, S., Takenaka, C., Tamai, N., Sakai, H., Shimizu, T., Kan-na, K., Onodera, S., Tanaka, N. and Takahashi, M.: 2006, ‘High potential for increase in CO2 flux from forest soil surface due to global warming in cooler areas of Japan’, Annals Forest Science, 63, 537-546.

Shimizu, T.: 2005, 'Kahoku Experimental Watershed - The Southernmost Observation Site of FFPRI FLUXNET -' , Asiaflux Newsletter, 13, 9-10.

Shimizu A., Shimizu, T., Miyabuchi, Y. and Ogawa, Y.: 2003, ‘Evapotranspiration and runoff in a forest watershed, western Japan’, Hydrological Processes 17, 3125-3139.AsiaFlux Newsletter Articles

 Tower, Electrical power (100V AC 60Hz)
Research Fund
Research grant #199903 (1999-2002) of the Forestry and Forest  Products Research Institute
Research grant #200303 (2003-2005) of the Forestry and Forest  Products Research Institute
"Evaluation, Adaptation and Mitigation of Global Warming in Agriculture,  Forestry and Fisheries:Research and Development" by Ministry of  Agriculture, Forestry and Fisheries of Japan (2006-present)
"Long-term Monitoring of Carbon Flux and Promotion of Data Network in  Asian Terrestrial Ecosystems" by Ministry of Environment, Japan (2007-  present)
Global Environment Research Account for National Institutes, Ministry of  the Environment of Japan