• The Tsukuba Experimental Watershed is located in the national forest, southeast of Mt. Tsukuba.
• This experimental watershed is the headwater of the Koise River, which is a tributary of the Tone River.
• In 1978, measurement was started at 3.76 ha watershed to understand the rainfall-runoff process and the effects of forest growth on the water balance.
• The measurement was temporally stopped for the period from 1993 to 2001, we restart it in 2002 and still continue.

Item	Daily precipitation	Daily runoff
Data source〵Location	Meteorological station	Main stream
※	1978-19871	1978-19871
※	2010-2017	2010-2017

Data source

1. Water Resources Lab. and Flood Control Lab., Forest Environment Division (1993) Statistical Reports of Hydrological Observation at the TSUKUBA Experimental Watershed (May, 1978~December, 1987). Bulletin of Forestry and Forest Products Research Institute, 364, 125-168 (in Japanese).

※ Please contact the following persons.

Location	Ishioka City, Ibaraki Pref.	Topography
River system	Tone River system
Latitude	36° 10'N
Longitude	140° 11'E
Altitude (m)	290 - 390

	Main stream
Area (ha)	3.76
Altitude (m)	290 - 390
Geology	Biotite gneiss
Soil	Brown forest soil
Vegetation	Planted forest of Japanese cedar and cypress except for ridge area occupied by deciduous oak
Annual mean temperature (ﾟC)	12.9*
Annual precipitation (mm)	1429**, 1543.6*

^*Averaged value for 2008 - 2010 (Iida et al., 2017)
^**Averaged value for 1972 - 1990 (Kabeya et al., 2014)

Weir of main stream	Observation tower
Click on a photo to enlarge.

Takanori Shimizu
Shin'ichi Iida

Forest Hydrology Laboratory,
Department of Disaster Prevention, Meteorology and Hydrology,
Forestry and Forest Products Research Institute, Japan