Kiryu Experimental Watershed - Japan
Kiryu Experimental Watershed
The watershed covers 5.99 ha and ranges in elevation from 190 to 255 m. A meteorological observation tower is located in a small catchment within the experimental watershed. The watershed is mainly covered by Chamaecyparis obtuse Sieb. et Zucc. (Japanese cypress, an evergreen conifer) planted in 1959. Pinus densiflora Sieb. et Zucc. and several deciduous broad-leaved tree species are sparsely present. In 1990's, pine-wilt disease has decreased P. densiflora stands. Eurya japonica Thunb. dominates the forest floor. The total leaf area index (LAI) ranges approximately from 4.5 to 5.5 with a little seasonal fluctuation. The entire catchment consists of weathered granite with abundant amounts of albite. The topographic map of the area shows a mild northward inclination of approximately 9.2 degrees. Winds flow mainly from the north during the day and from the south at night. The annual mean air temperature from 1999 to 2012 was 13.5 C, and annual mean precipitation from 1972 to 2012 was 1,651 mm. The site therefore has a warm temperate climate. Rainfall occurs throughout the year, peaking in summer. Little snow falls in winter.
General Characteristics, Purpose, History
KEW was originally established in 1967 to elucidate hydrological water circulations and relating role of forest, trees, and soil. KEW has one of the longest historical hydrological databases (1972 - now) and continuous research programs in Japan. Our research activity in this watershed aims not only basic hydrology, but also estimating gas exchanges between forests and the atmosphere, quantification of water, energy, carbon, nitrogen, and other chemical compounds dynamics and budgets in the forest ecosystem, and understanding of hydrological regimes.
The Kiryu Experimental Watershed (KEW) is located at 34o58’N, 136o00’E in Shiga Prefecture, Central Japan. Around this area, there use to be beautiful forests of Japanese Cypress covering the Tanakami Mountains. They were devastated about 1200 years ago because of fire and the excess use of timber to build Nara and Kyoto city (old capitals of Japan). The denuded situation continued for a long period. The forestation on the hillside has been carried out over the last 100 years for preventing soil erosion and for timber industry. Consequently, most of this area was covered with the plantation forests. KEW was originally established in 1967 to elucidate hydrological water circulations and relating role of forest, trees, and soil. KEW has one of the longest historical hydrological databases (1972 - now) and continuous research programs in Japan.
Affiliation and Network Specific Information