Climate Elasticity of Annual Runoff: Observation in Fifteen Forested Catchments on a Latitudinal Gradient in East Asia
Nobuaki Tanaka,
Yen-Jen Lai,
Sangjun Im,
Maznah Binti Mahali,
Venus Tuankrua,
Koichiro Kuraji,
Fera Cleophas,
Chatchai Tantasirin,
Mie Gomyo,
Chun-Wei Tseng,
Katsushige Shiraki,
Norifumi Hotta,
Yuko Asano,
Hiroki Inoue,
Anand Nainar
Affiliations
Nobuaki Tanaka
The University of Tokyo Hokkaido Forest, The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Furano 079-1563, Japan
Yen-Jen Lai
Experimental Forest, National Taiwan University, Nantou 55750, Taiwan
Sangjun Im
Department of Agriculture, Forestry and Bioresources, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
Maznah Binti Mahali
Faculty of Tropical Forestry, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
Venus Tuankrua
Department of Conservation, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand
Koichiro Kuraji
Executive Office, The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
Fera Cleophas
Faculty of Science & Natural Resources, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
Chatchai Tantasirin
Department of Conservation, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand
Mie Gomyo
Ecohydrology Research Institute, The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Goizuka-cho, Seto 489-0031, Japan
Chun-Wei Tseng
Taiwan Forestry Research Institute, Taipei 100, Taiwan
Katsushige Shiraki
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
Norifumi Hotta
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
Yuko Asano
Ecohydrology Research Institute, The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Goizuka-cho, Seto 489-0031, Japan
Hiroki Inoue
Arboricultural Research Institute, The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Kanou, Minamiizu 415-0304, Japan
Anand Nainar
Faculty of Tropical Forestry, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
In order to overview the impact of climate change on runoff from forested catchments over Asian countries, we collected water balance data from fifteen long-term catchment monitoring stations (total monitoring period 1975–2018, not continuous), spanning from Sabah, Malaysia (our southernmost site), to Hokkaido, Japan (our northernmost site). We then employed an elasticity analysis to the dataset to examine how the annual runoff from each catchment responded to inter-annual fluctuations in annual rainfall and annual mean air temperature. As a result, we found that (1) the annual runoff was sensitive to annual rainfall for all the catchments examined. In addition, (2) the annual runoff from seven of the fifteen catchments was sensitive to inter-annual changes in the mean air temperature, which was likely due to changes in forest evapotranspiration. Three catchments, however, exhibited an increased runoff in a hot year. Finally, (3) the annual rainfall from the previous year (carry-over soil moisture) was important in explaining the variation in annual runoff in two tropical montane forest catchments. This study may serve as one of the pilot studies toward a comprehensive understanding of the climate elasticity of runoff in countries over Asia, because the examined catchments are unevenly and sparsely distributed over the area.
