| 1. |
Weitian Ding, Urumu Tsunogai, Fumiko Nakagawa, Masaaki Chiwa, Tamao Kasahara, Kenichi Shinozuka, Stable isotopic evidence for the excess leaching of unprocessed atmospheric nitrate from a forested catchment in Fukuoka, Japan, Japan Geoscience Union Meeting 2022, 2022.05. |
| 2. |
Tamao Kasahara, Hydrological Cycle and Water Resource, Virtual Seminar: Sustainable Development on Water Reclamation and Reuse, 2021.05. |
| 3. |
Y Li, T Kubo, T. Kasahara, Retention of nitrate in a headwater stream: effects of benthic and hyporheic zone, Environmental Technology and Management 2021 , 2021.11. |
| 4. |
Tamao Kasahara, Peng Ruixin, EFFECTS OF PARENT LITHOLOGY ON STREAM-GROUNDWATER EXCHANGE AND ORGANIC MATTER DECOMPOSITION IN HEADWATER STREAMS IN KYUSHU, JAPAN
, Society of Freshwater Science Annual Meeting 2019, 2019.05. |
| 5. |
Tamao Kasahara, Peng Ruixin, Stream-Groundwater Exchange and Organic Matter Decomposition in Headwater Streams with Different Parent Lithology in Kyushu, Japan
, EnvironmentAsia 2019, 2019.06. |
| 6. |
Pongsak (Lek) Noophan
Phanwilai Supaporn
Kevin D. Daniels
Tamao Kasahara
Shane A. Snyder, Comparison of Characteristics of Treated Effluents from Full-Scale Wetland Systems in Thailand, Japan, and USA, 12th IWA International Conference on Water Reclamation and Reuse, 2019.06. |
| 7. |
Tamao Kasahara, Yanda Li, Noboru Fujimoto, Masaaki Chiwa, Organic matter decomposition in the channel and streambed sediments at the downstream of headwater reservoirs, Society for Freshwater Science, Annual Meeting, 2017.06. |
| 8. |
Tamao Kasahara, Effects of Headwater Dams on Organic Matter Decomposition in the Stream Channel and the Hyporheic Zone, Environment Asia, 2017.06. |
| 9. |
Sun Haotian, 笠原 玉青, 大槻 恭一, Influence of stream-groundwater exchange on the spatial variations in streamflow in a steep headwater catchment , American Geophysical Union Fall Meeting 2015, 2015.12. |
| 10. |
笠原 玉青, Sato T, Sun Haotian, Dynamics and Stability of the Hyporheic Environment in Steep Headwater Streams in Western Japan , American Geophysical Union Fall Meeting 2015, 2015.12. |
| 11. |
笠原 玉青, 佐藤辰郎, Geologic Controls on Stream-Groundwater Exchange in Headwater Streams, The 3rd EnvironmentAsia International Conference on “Towards International Collaboration for an Environmentally Sustainable World", 2015.06. |
| 12. |
笠原 玉青, 池見 洋明, 佐藤 辰郎, 黒木啓孝, 篠塚賢一, 皆川朋子, 島谷 幸宏, STREAM-GROUNDWATER EXCHANGE IN NEIGHBORING STREAMS WITH DIFFERENT GEOLOGY , Joint Aquatic Sciences Meeting, 2014.05, Headwater streams are an important component of river ecosystem, yet its environment varies considerably from a stream to another, and it is difficult to develop environmentally concerned management strategies. In this study, we attempted to use geology as a factor to characterize headwater stream environment, such as channel morphology, substrate, and stream-groundwater exchange. The Kikuchi River watershed is located near Mt. Aso, the largest active volcano in Japan, and the geological structure are complex. Three neighboring headwater streams with similar baseflow but with different geology, granite, pelitic schist and welded tuff, were studied. Series of solute injection, and detailed topographic and substrate survey were carried out in each stream. The exchange rate was largest in the stream with pelitic schist, which had the largest number of steps and the coarser substrate. Least exchange rate was observed in the stream with welded tuff where bedrock exposure was widespread, and many steps were made by bedrock. Despite their geographical proximity, the stream environment considerably differed in three study streams, and geology may be a useful indicator characterizing the headwater environment. . |
| 13. |
大槻 恭一, 笠原 玉青, 恩田裕一, Development of Innovative Technologies for Enhancing Low Flow Discharge and Reducing Turbid Material from Overcrowded Forest Plantations by Intensive Thinning in Japan, Annual Conference of Korea Water Resources Association, 2012.05. |
| 14. |
笠原 玉青, Anh T. Le, NITROGEN RETENTION RATE IN AGRICULTURAL DRAINAGE CANALS IN CENTRAL THAILAND, 2012 ASLO Aquatic Science Meeting, 2012.07, Degradation of surface water quality, including eutrophication, is widespread in traditionally agricultural countries in Southeast Asia. This study surveyed nitrogen concentrations in drainage canals in the agricultural area in Central Thailand and examined nitrogen retention rate. Ammonium was consistently the dominant form of inorganic nitrogen in canals, and the concentrations regularly exceeded the national water quality standard of 0.5 mgL-1, occasionally reaching > 15mgL-1. Ammonium retention rate of the canal with highly elevated ammonium concentration was estimated using co-injection of conservative tracer and ammonium. The median ammonium retention was 10.2 mgL-1 and relatively high, in part due to in-channel vegetation and slow flow velocity. Removal of the vegetation resulted in reduction of ammonium retention rate by about one third in the study canal. Though currently retention rate of canals is not considered in water quality improvement plan, the results of this study suggest that consideration of canal capacity, together with other measures, is useful and important in controlling nutrient pollution in the region. . |
| 15. |
Sun Haotian, 笠原 玉青, 大槻 恭一, Spatial Variation in Seasonal Fluctuation of Water Yield in a Small Forested Catchment, 3rd International Conference on Forests and Water in a Changing Environment, 2012.09. |
| 16. |
Chen Wei Chiu, 大槻 恭一, 笠原 玉青, The difference of whole-tree water use between ring- and diffuse-porous trees, 3rd International Conference on Forests and Water in a Changing Environment, 2012.09, Evapotranspiration from forests is influenced by several factors, like climate, site location, LAI and also species (Hornbank and Swank, 1992). When calculating catchment-scale transpiration, some scientists may want to know the whole-tree water use is differed among broadleaved species, including ring- and diffuse-porous species, and is it large enough to influence water-cycle components with different forest types.
Among several techniques which can quantify water use in mountainous area, sap flux measurement provided credible results for three spatial scale estimations of transpiration, that is, tree-to-tree, tree-to-stand and stand-to-catchment (Kume et al. 2012). However, there are some errors that we have to taking into account during each step of up-scaling. Radial and azimuthal variations are the most important part when determine the stand-scale transpiration.
In this study, we conducted sap flux measurement by using Granier sensors and measured the radial and azimuthal variations of individual tree scale of several broadleaved species in the Research forest of the Kyushu University. Our objective was to verify if different species may have significant variation within sap flux characteristics and we hope this result can represent the mechanism of how to calculating stand-scale transpiration in a mix broadleaved forest.
. |
| 17. |
Sodouangdenh Somsanouk, 笠原 玉青, 大槻 恭一, Differences in Groundwater-Stream Water Interaction in Loosing and Gaining Reaches of a Headwater Stream, 3rd International Conference on Forests and Water in a Changing Environment, 2012.09. |
| 18. |
笠原 玉青, Bethany T. Neilson, Noah Schmadel, Stream Water and Groundwater Exchange Characterized by Groundwater Flow Modeling and Stream Tracer Experiment, 3rd International Conference on Forests and Water in a Changing Environment, 2012.09. |
| 19. |
笠原 玉青, Sodouangdenh, Somsanouk, 大槻 恭一, 恩田裕一, 芳賀弘和, 北部九州の源流域における浸水・湧水区間での河床・河畔域での水の動きの違い, 日本森林学会124回大会, 2013.03, Stream-subsurface exchange in a gaining and loosing reach of a small forested watershed in northern Kyushu
was studied, using hydrometric measurements from wells and piezometers installed in the riparian zone and
streambed. There are three stream gauging stations in the watershed of approximately 3 ha, identifying loosing
upstream reach and gaining downstream reach, during relatively high flow period. Vertical hydraulic gradient
measured in the streambed showed steeper downwelling trend in the upstream reach than in the downstream
reach. The response of riparian water table to rain events differed between upstream and downstream reaches,
suggesting that stream-subsurface exchange dynamics differs between the two reaches.. |
| 20. |
孫昊田, 笠原 玉青, 大槻 恭一, 斎藤隆実, 恩田裕一, 芳賀弘和, 九州北部の森林小流域における地下水と連動した流出量の時空間変動, 日本森林学会124回大会, 2013.03, The relation between stream flow and groundwater at different depths was examined to study the contribution
of groundwater to streamflow generation. In a small forested catchment of approximately 3 ha, there are three
stream gauging stations and two riparian wells at 3m and 20m depths. During May to September, water yield from
the upstream catchment was greater than the one at the watershed outlet, and groundwater wells gradually shifted
to upwelling trend. The remaining of the year the trend was reversed, water yield higher at outlet and groundwater
wells showing downwelling trend. These results suggest that contribution of deep groundwater at the
headwaters begins in rainy season, increasing water yield upstream, and continues through summer months. From
winter to spring months, relatively shallow groundwater contribution dominates.. |
| 21. |
Yang Xiang, Makiko Tateishi, Takami Saito, Tamao Kasahara, Kyoichi Otsuki, Yuichi Onda, Changes in evapotranspiration from Cryptomeria japonica and Chamaecyparis obtuse stands after thinning（1）Transpiration, 日本森林学会, 2013.03. |
| 22. |
Sodouangdenh Somsanouk, 笠原 玉青, 恩田裕一, Spatial Variation of Stream-groundwater exchange in a Steep Headwater Stream, 応用生態工学会, 2013.09. |
| 23. |
Ｓｕｎ Ｈａｏｔｉａｎ, 笠原 玉青, kyoichi otsuki, 恩田裕一, 芳賀弘和, Spatio-temporal Variation of Water Yield before and after Forest Thinning in a Small Japanese Forested Catchment, 水文・水資源学会, 2013.09. |
| 24. |
TAMAO KASAHARA, Yuko Yasuda, Kyoichi Otsuki, Changes in distribution of fine sediments in the hyporheic zone during high flow events, American Geophysical Union, 2013.12. |
| 25. |
Sothy Hun, Makiko Tateishi, TAMAO KASAHARA, Kyoichi Otsuki, Yuichi Onda, Analysis of sediment transport in a thinned headwater Yayama catchment in Fukuoka, 森林学会, 2014.03. |
| 26. |
Chen Wei Chiu, TAMAO KASAHARA, Kyoichi Otsuki, Stand-transpiration estimates in a temperate mixed forest based on sap-flux measurement, 森林学会, 2014.03. |
| 27. |
Makiko Tateishi, Yang Xiang, Hiroki Matsuda, Takami Saito, Sun Haotian, Kyoichi Otsuki, TAMAO KASAHARA, Yuichi Onda, Comparison of the evapotranspiration and its components before and after thinning in Japanese cedar and Japanese cypress forest, EGU, 2014.05. |
