著者

Yuki Kita Dai Yamazaki

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.17, no.2, pp.15-20, 2023 (Released:2023-04-01)

参考文献数

19

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Many studies have proved that hydrological extreme values estimated from decadal observation data and river inundation simulations are associated with various uncertainties; however, few studies have evaluated the uncertainties associated with internal climate variability. We used large-ensemble river inundation simulations to quantitatively evaluate uncertainties in river depth at the Takahama monitoring station and flood extent in the Yodo River basin. Using a single 60-year ensemble, the river depth for a 1,000-year return period (RP) flood scale have uncertainty between –11.7% and +9.2% in a 3,000-year flood simulation. Thus, the RP of the simulated river depth ranges from 207–3,441 years. To maintain the RP uncertainty within ±300 years would require a simulation of ≥1,200 years. The flood extent uncertainty with an RP of 1,000 years was found to be –8.4% and +7.6% based on a 3,000-year simulation for the lower Yodo River basin. According to this result, the RP of the simulated flood extent ranges from 340–3,060 years. These results suggest that the decadal data used in conventional flood risk analyses potentially contain large uncertainty related to internal climate variability in the RP for water depth and flood extent by approximately 0.3–3-fold.

著者

Takahiro Sayama Ryoko Araki Kodai Yamamoto Apip

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.15, no.2, pp.23-30, 2021 (Released:2021-04-15)

参考文献数

38

被引用文献数

2

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Extensive deforestation in tropical regions may significantly influence the hydrological cycle. However, subsurface runoff processes in thick soil layers in humid tropical forests are poorly understood; thus, the impact of land-use changes in such regions remains unclear. To understand runoff generation mechanisms in the humid tropics, we monitored groundwater and soil moisture dynamics in a forested hillslope in Sumatra, Indonesia. We also conducted field and laboratory experiments to determine soil hydraulic characteristics and used the results to simulate vertical infiltration and groundwater recharge. Although the soil is categorized as silty clay loam, the high infiltrability and high water retention capacity of the soil enabled infiltration during storm events and recharge to groundwater. Within the 4–5 m thick soil layer at the foot of the hillslope, the shallow groundwater table quickly responded to rainfall and did not drop below a depth of 2–3 m, possibly due to continuous flow contributions from the upslope. Overall, this study demonstrates the importance of subsurface flow and vertical infiltration in thick soil layers in humid tropical regions.

著者

Vo Ngoc Quynh Tram Hiroaki Somura Toshitsugu Moroizumi

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.15, no.3, pp.77-83, 2021 (Released:2021-09-10)

参考文献数

33

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The drought impacts in the Dakbla watershed were assessed based on a combination of hydrological modeling and drought indices. Three drought indices, the Standardized Precipitation Index (SPI), Standardized Soil Moisture Index (SSI), and Streamflow Drought Index (SDI) were utilized to evaluate the drought features of meteo-hydrology and agriculture. The results indicated that these indices are well adapted to the local conditions, especially the 12-month time scale. Evaluations of drought features on the watershed scale could provide more specific information regarding drought risk than regional-scale/district-level assessments, because a watershed is a hydrologically fundamental unit to consider water resources management. Additionally, evaluations of drought impacts using the SSI showed longer and higher trends than those using the SPI and SDI in terms of drought duration and frequency. Considering the spatial distribution of drought frequency, the areas predominated by agricultural land in the target watershed had higher drought risk. Thus, assessment of agricultural droughts along with meteo-hydrological droughts is extremely important to support realistic local drought management strategies by considering water availability, water balance, and soil characteristics, especially in specific agricultural areas.

著者

Tetsuya Takemi Rui Ito Osamu Arakawa

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.10, no.3, pp.81-87, 2016 (Released:2016-11-12)

参考文献数

23

被引用文献数

7 19

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Typhoon Mireille (1991) caused devastation over Japan. Assessing the impacts of such an extreme typhoon under global warming is an important task to prevent and mitigate future natural disasters. This study investigated the influences of global warming on the strong winds of Typhoon Mireille by conducting pseudo-global warming (PGW) experiments with a regional model. Since significant damages to forest areas occurred in Kyushu and Tohoku, we compared the typhoon impacts in these two regions. It was demonstrated that on average the mean wind speeds induced by Typhoon Mireille become stronger in Kyushu and weaker in Tohoku under the PGW conditions than under the September 1991 conditions. The difference between the two regions in the future is due to the simulated typhoons under PGW being stronger at lower latitudes and weakening more rapidly at higher latitudes. Thus, the impacts of Typhoon Mireille under a warmed climate are considered to be more severe at a lower latitude and weaker at a higher latitude.

著者

Tsuyoshi Takano Hiroyoshi Morita Piamsa-nga Napaporn Varameth Vichiensan Shinichiro Nakamura

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.17, no.4, pp.85-91, 2023 (Released:2023-12-08)

参考文献数

21

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In Asian megacities undergoing rapid urbanization such as Bangkok, heavy rainfall exacerbates traffic congestion owing to inadequate drainage systems. This study statistically analyzed the extent to which rainfall affects urban traffic speed and how this impact varies depending on regional environmental factors and traffic demand trends, utilizing probe vehicles and rainfall data from 2018 to 2020 in Bangkok. The results clearly indicate that both the intensity of rainfall during driving and previous cumulative rainfall significantly reduce traffic speed. This impact is particularly pronounced during morning and evening rush hours, and in areas with a high proportion of narrow roads or in low-lying areas. On the other hand, areas with rich urban green space, which naturally absorb and retain water, tend to mitigate the speed reduction due to rainfall. This study highlights the fact that the impact of rainfall on traffic varies with time and location, suggesting that the exacerbation of rain-induced congestion can be more effectively mitigated by coordinated improvements in drainage facilities, traffic management and land use.

著者

Kansei Fujimoto Taichi Tebakari

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.17, no.4, pp.77-84, 2023 (Released:2023-11-29)

参考文献数

30

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Satellite products are expected to play important roles in water-related management and public welfare, particularly in developing countries. Higher-resolution precipitation products are required to cope with increasingly severe water-related disasters. In this study, we propose a new satellite precipitation estimation algorithm based on deep learning that uses data from multiple satellite infrared (IR) bands and geographic information (e.g. elevation, latitude, and longitude) as input. For the deep learning model component, we use various image segmentation models, including U-Net, PSPNet, and DeepLabv3+. Cosine similarity and correlation coefficients for precipitation rate were used to determine the IR bands of the input data; five bands were used as IR. Four input datasets were constructed: IR alone; IR and elevation data; IR and latitude/longitude; and IR, elevation data, and latitude/longitude. When PSPNet or DeepLabv3+ was used as the deep learning model, and elevation and latitude/longitude were added to IR as input data, the mean square error and fraction skill score showed improved accuracy over GSMaP_MVKv7 and PERSIANN-CCS; precipitation overestimation was eliminated. These results indicate that deep learning models can be used to estimate precipitation from satellite IR observations with high resolution and accuracy.

著者

Mariko Saito Maki Tsujimura Siti Nurhidayu Abu Bakar

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.17, no.2, pp.28-35, 2023 (Released:2023-05-10)

参考文献数

44

被引用文献数

1

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This study aims to clarify the contributions of pre-event water to storm runoff using environmental tracers (dissolved inorganic ions and stable isotopes) in a tropical forested catchment in Puchong, Selangor, Malaysia. We performed intensive sampling campaigns of stream water and throughfall for two storm events in July and November 2018. The discharge showed a low peak of 0.13 mm/h in event 1, with 18 mm of total rainfall, whereas event 2, with 50 mm of total rainfall, showed a quick discharge peak of 1.17 mm/h and a slow recovery of 0.39 mm/h. The nitrate concentration in the stream water during event 2 was higher than that in event 1. The temporal variations in nitrate ions indicate that subsurface water provided a dominant stormflow in event 2. Hydrograph separations using silicate as a tracer revealed that pre-event water was the dominant component of the storm hydrograph (58–98%). Our results suggest that pre-event water plays an essential role in storm runoff of headwaters in humid tropical regions.

著者

Jun Inaoka Ken’ichirou Kosugi Naoya Masaoka Tetsushi Itokazu Kimihito Nakamura Masamitsu Fujimoto

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.16, no.4, pp.80-86, 2022 (Released:2022-11-25)

参考文献数

25

被引用文献数

1

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Previous studies have proven that rainfall–runoff characteristics in headwater catchments are affected by many factors, including topography, geology, and vegetation. However, only a few studies have explained the geological effects on rainfall–runoff characteristics based on observations from various catchments. In this study, we conducted runoff observations in 19 headwater catchments in two forests with different geological characteristics; based on these observations, we further conducted direct runoff and hydrograph recessions analyses. The runoff characteristics of the catchments were significantly affected by their local geological settings. Some catchments did not follow average trends, especially catchments with large baseflows, because of the effects of geological structures, such as dips and strikes in sedimentary-rocks and joints in granite. These catchments were likely to have wetter riparian zones, thereby facilitating direct flow, even in the case of reduced rainfall.

著者

Yohei Sawada Shinichi Okugawa Takayuki Kimizuka

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.16, no.4, pp.73-79, 2022 (Released:2022-10-27)

参考文献数

25

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Verification processes of rainfall-runoff modeling are important to improve the skill of hydrological models to reproduce water cycles in river basins. It is ideal that newly developed models are compared with many benchmarking conventional models in many river basins as part of the verification process. However, this robust verification is time-consuming if model developers prepare data and models from scratch. Here we present a useful dataset which can accelerate the robust verification of hydrological models. Our newly developed dataset, Multi-model Ensemble for Robust Verification of hydrological modeling in Japan (MERV-Jp), provides runoff simulation by 44 calibrated conceptual hydrological models in 135 Japanese river basins as well as meteorological forcing which is necessary to drive conceptual hydrological models. By comparing simulated runoff with river discharge observations which are not used for the calibration of hydrological models, we find that the best models in the 44 models can reproduce observed river runoff with KGE larger than 0.6 in most of the 135 river basins, so that the runoff simulation of MERV-Jp is reasonably accurate. MERV-Jp is publicly available to support all hydrological model developers to robustly verify their model improvement.

著者

Alexis Mojica Bolívar Duarte Fidedigna Vergara Milagros Pinto-Núñez Reinhardt Pinzón José Pérez María Gabriela Castrellón Carlos A. Ho Margie Gómez

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.16, no.1, pp.18-24, 2022 (Released:2022-03-11)

参考文献数

29

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Monitoring and quantifying hydrological flows in the vadose zone is complicated to analyze due to the effects of rainfall in the tropics, the dynamic interactions among rains, the vegetation layer, moisture in the soil, and the entire regolith. Quantifying subsurface hydrological flows at specific scales and high resolution presents further difficulties. To overcome these issues, resistivity methods can play an important role. This paper examines the results of gravimetric moisture content monitoring in the Panamanian tropics through time-lapse electrical resistivity tomography analysis. Changes in the electrical properties of soil were quantified through six tomographic tests performed between February 2012 and March 2013 along with a profile. Significant changes in resistivity were identified between February (dry season) and May, and August and October (rainy season), with negative percentages (–60%) indicating the effects of rain infiltration at the surface and positive percentages (60%) linked to moisture absorption in the soil, electrode relocation for each test or inversion processes. Additional laboratory analyses of soil samples were carried out to obtain gravimetric moisture content tomograms. The changes of this parameter in the subsurface horizons, and the percentage differences in the calculated resistivity values, are helpful for determining the impact of rain on the soils.

著者

Chamal Perera Shinichiro Nakamura

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.16, no.2, pp.40-46, 2022 (Released:2022-04-07)

参考文献数

23

被引用文献数

3

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Identifying the complex patterns of human-flood interactions over longer periods of time is very important in floodplain management activities. The recently introduced socio-hydrology (SH) model contributes to capture these long-term behaviors of human-flood systems. This model can be utilized to explain the long-term dynamics of human-water interaction in floodplains. The current SH model exclusively illustrates the impact of river floods on floodplain communities. However, in some river basins, urban floods (due to high intensity rainfall) are dominant, whereas in other river basins, both river floods and urban floods influence the dynamics of the system. It is often difficult to distinguish the type of flood from actual local disaster data sets. In this study, we proposed an improvement to the existing SH model to capture the dynamics of both river floods and urban floods based on a case study from the Lower Kelani Basin, Sri Lanka, using simulated historical flood damages. The improved model was applied to capture flood damages in the target watershed, and the results further emphasize the importance of flood risk perception in flood damage reduction.

著者

Naoya Shibata Fuko Nakai Kensuke Otsuyama Shinichiro Nakamura

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.16, no.1, pp.32-39, 2022 (Released:2022-04-01)

参考文献数

38

被引用文献数

3

---

The Asian monsoon and Japan’s steep terrain structure make it a flood-prone country. These natural, flood-prone features have prompted Japan to develop unique social norms for flood risk management. Over the last decade, human-flood interaction models have been developed in socio-hydrology (SH), being applied and validated in various countries. This study applied the SH model for the Naganuma District of Nagano City, Japan, an area that was affected by Typhoon Hagibis in 2019. Additionally, the SH model was examined for its applicability in Japan using sensitivity analysis. To the best of our knowledge, this is the first study to apply the SH model in a real-life scenario in Japan. The results suggest that there are differences between the output from the existing SH model and the actual human-flood interactions in Japanese society. This paper also provides recommendations to improve the Japanese SH model and inform associated future research agendas in Japan.

著者

Inna Syafarina Arnida Lailatul Latifah Yosuke Miura Tomoko Nitta Kei Yoshimura

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.15, no.4, pp.98-104, 2021 (Released:2021-12-04)

参考文献数

32

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The surface water formation parameter (Kw) currently used in malaria transmission models can dramatically affect larval development calculations. However, the parameter is often unrealistic due to the unavailability of observational datasets. This research presents an adjusted Kw by reference to an entomological inoculation rate (EIR) over the period 1983–2006, tuning the parameter by minimizing root mean square deviation of the water fraction from model calculations and satellite observations from 2014–2018. A scaling factor, topography factor, and inverse distance weighting were used to reduce the gap between macro- and microscales and to derive the appropriate spatial distribution of Kw for a projection period from 2020–2100. The average EIR over the projection period under Representative Concentration Pathway (RCP) scenarios 2.6, 7.0, and 8.5 in West Africa decreased by –29%, –43% and –35%, respectively, from the historical period. By contrast, for central southern Africa, the respective values increased by 3%, 6%, and 29% from the historical period. The reduced EIRs under RCPs 7.0 and 8.5 in West Africa were mostly affected by temperature, while monthly mean precipitation triggered a decrease in EIRs under RCP 2.6. By contrast, consecutive wet days have the most influential role in increasing the EIR in central southern Africa under all RCP scenarios. This research will help policy-makers eradicate vulnerable malaria areas and improve related policy design.

著者

Adisorn Champathong Daisuke Komori Masashi Kiguchi Thada Sukhapunnaphan Taikan Oki Tosiyuki Nakaegawa

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.7, no.2, pp.36-41, 2013 (Released:2013-06-08)

参考文献数

25

被引用文献数

20 23

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We projected future river discharge in the Chao Phraya River basin and evaluated the uncertainty in future climate projections by using different resolutions and ensemble experiments of the Atmospheric General Circulation Model of the Meteorological Research Institute (MRI-AGCM). We also obtained estimates of precipitation, evaporation, runoff, and river discharge under climate conditions projected for the late 21st century. The results show that precipitation is projected to significantly increase in the future during April to August, excluding May. The projected river discharge at Nakhon Sawan located in the central region shows a peak in September, a delay of one month after the maximum monthly mean precipitation. The estimated reduction in river discharge for January and February was robust based on all members of the 60-km mesh MRI-AGCM ensembles changing in the same direction as that of the 20-km mesh MRI-AGCM. The uncertainty assessment conducted in this study could lead to increased robustness in projected changes in mean river discharge in the late 21st century for this basin.

著者

Yukiko Hirabayashi Haireti Alifu Dai Yamazaki ‪Gennadii Donchyts Yuki Kimura

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.15, no.2, pp.37-43, 2021 (Released:2021-06-22)

参考文献数

23

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Floods are major natural disasters that have considerable consequences worldwide. As the frequency and magnitude of flooding are expected to be affected by ongoing climate change, understanding their past changes is important for developing adequate adaptation measures. However, the limited spatiotemporal coverage of flood gauges hinders detection of changes in flooding, particularly in poorly gauged regions. Here, we propose a method using surface water data of river floodplain inundation as a proxy of the magnitude and frequency of flooding. Surface water data − Aqua Monitor which represented the probability linear trend changes in land and water surface area based on 30-m Landsat images between 1984–2000 and 2000–2013 was used in this study. The changes in water surface area over the floodplain obtained from Aqua Monitor showed high correspondence with historical trends observed or simulated annual maximum daily discharge, indicating the potential to detect changes in frequency and magnitude of flood from satellite data. In regions where changes could be measured with sufficient satellite images, 29% showed an increase in water surface area in the flood plain, 41% showed a decrease, and 30% showed small or no changes.

著者

Izuru Takayabu Noriko N. Ishizaki Tosiyuki Nakaegawa Hidetaka Sasaki Waranyu Wongseree

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.15, no.1, pp.1-8, 2021 (Released:2021-02-13)

参考文献数

39

被引用文献数

3

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The diurnal cycle of precipitation over northeast Thailand during the Southeast Asian summer monsoon season was examined using non-hydrostatic (5-km grid) and convection-permitting (2-km grid) regional climate models. The results indicate that these fine grid models exhibit a better performance in terms of representing the diurnal cycle of precipitation due to the realistic orographic representation. The models successfully simulated the local circulation corresponding to the intensification of precipitation and were consistent with the satellite-based observed diurnal cycle of precipitation. The model simulation indicated that the convergence area over the mountain on the south of the Khorat Plateau occurred in the afternoon in association with the occurrence of precipitation. The convergence area migrated northward and contributed to the precipitation peak over the plateau during the nighttime. A bias in terms of the amount of precipitation in the 5-km grid model was partially removed through the convection-permitting 2-km grid model.

著者

Nobuhito Mori Tomohiro Yasuda Hajime Mase Tracey Tom Yuichiro Oku

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.4, pp.15-19, 2010 (Released:2010-03-03)

参考文献数

11

被引用文献数

126 187

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The influence of global climate change due to greenhouse effects on the earth’s environment will require impact assessment, mitigation and adaptation strategies for the future of our society. This study predicts future ocean wave climate in comparison with present wave climate based on the atmospheric general circulation model and global wave model. The annual averaged and extreme sea surface winds and waves are analyzed in detail. There are clear regional dependences of both annual average and also extreme wave height changes from present to future climates. The wave heights of future climate will increase at both middle latitudes and also in the Antarctic Ocean, with a decrease at the equator.

著者

Kazuyoshi Nishijima Takashi Maruyama Mathias Graf

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.6, pp.23-28, 2012 (Released:2012-03-13)

参考文献数

11

被引用文献数

17 27

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This paper performs a quantitative impact assessment of the climate change on typhoon wind risk, focusing on residential buildings in Japan. The risk is assessed based on (1) the typhoon event set extracted from the simulation by the super-high resolution atmospheric general circulation model developed within the KAKUSHIN program; (2) the probabilistic typhoon modeling scheme developed by our group; (3) a fragility model empirically estimated on the basis of the damage report of typhoon Songda in 2004 and the reproduced wind field by a mesoscale meteorological model; JMA-NHM. The main results are that in the future (2075–2099) at most locations of Japan: (1) extreme wind events (10-minute sustained wind speed exceeding 30 m/s) are more likely to occur; (2) the median of the annual maximum wind speed decreases; (3) the expected number of damaged residential buildings decreases, assuming that the profile of the building portfolio remains unchanged. Based on these results, the assumptions and inputs to the assessment are critically reviewed. Thereby, the needs of further research efforts toward more credible and comprehensive assessment are addressed.

著者

Keisuke Ono So Kazama Seiki Kawagoe Yoshiyuki Yokoo Luminda Gunawardhana

出版者

Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

雑誌

Hydrological Research Letters (ISSN:18823416)

巻号頁・発行日

vol.5, pp.69-72, 2011 (Released:2011-11-02)

参考文献数

11

被引用文献数

3 7

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A gigantic earthquake with a magnitude of 9.0, the maximum ever recorded in Japan, struck the Tohoku region of Japan on 11 March, 2011. As a result, as many as 745 reservoirs in Fukushima prefecture were damaged. The failure of the earth-fill dam at the Fujinuma reservoir in Fukushima prefecture resulted in eight deaths in a village downstream. This was only the second such dam to fail completely in the recorded history of Japan, the first being Mannou Lake dam. The failure was caused by the Ansei Nankai earthquake in 1854. According to official records, of the 210,000 reservoirs in Japan, at least 20,000 dams are vulnerable to future earthquakes. Therefore, it is imperative that the failure mechanism of the Fujinuma reservoir be understood. As such, we developed several theories to explain what happened. Adherence to recommendations made in this report will reduce the potential for damage in future catastrophic events.