Glacial melt water is major water resourcess in and around La Paz, the capital of Bolivia in the center of South America. However, it is predicted that the glaciers in this area will disappearin 30 or 40 years because of climate change. In this study, water temperature around the end of the century in Tuni Reservoir, which is located at downstream of glaciers and provides domestic water to the cities nearby, were predicted with 1-dimensional hydraulic model using the outputs of a global climate model. The results indicate that surface temperature in the reservoir will basically depend on temperature rise. However, inflow rates will decrease about 60% by glacier disappearance and change more variably each year. So, it is important to consider how to take and convey water in the future.

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Lake Jusan is a brackish lake located in the down reaches of Iwaki River system and is one of the most famous places for Corbicula japonica in Japan. The aquatic environment in the lake and the river has long been changing under numerous natural and anthropogenic factors. The former includes changes in meteorological and hydrological systems, while the latter is composed of river improvement works, reclamation for farmland, etc. In this study, we first focused on topographical changes in Lake Jusan caused by the reclamation project completed in 1969 and by sedimentation. The influence on salinity fluctuation in the lake was investigated using computational hydraulic simulation and was found rather small. We then assessed influence of hydrological changes. In 1950s before large dams were constructed in the basin, drought occurred more frequently than 2000s, which seems to have caused excessively high salinity condition for habitation of C. japonica.

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Downstream control of turbidity currents resulted from turbid water inflows into a well-mixed reservoir by the use of a fence placed before a dam has been investigated experimentally, as a countermeasure to water quality control as well as sedimentation due to turbidity. In this study, the effects of fence deformation due to pressure differences between inside and outside of the fence upon the effects of displacement efficiency are considered as well. It is found that the fence is capable of effectively displacing the inflowing turbid water out of the reservoir, while maintaining the position of plunge point in stable condition. It is also suggested that deformation may degrade fence performance when the position of the fence is far shifted from original setting position.

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We have analyzed the dynamics of water, which is driven by sea water intrusion and wind, and the dynamics of sediment considering re-suspension of bottom sediments caused by wind waves in estuarine lake by a developed numerical model.Using this model, we have evaluated the potential habitat for Corbicula Japonica based on the following three points in Lake Jusan, such as 1) Retention time of salt water 2) Time-space variations of particle size distribution of bottom sediments and 3) movement of larvae of Corbicula Japonica.Simulation results indicated that area of which bottom elevation is shallower than T.P.-1.5m is the potential habitat in terms of suitable salinity and grain size of bottom sediments. Dynamics of water affects the success of settlement of larvae onto suitable habitat.We have evaluated important habitat for Corbicula Japonica in Lake Jusan based on above three points.

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Wetland comprises several functions including flood and sediment control, groundwater storage, irrigation, fishery, habitat of wild life and recreation. Although wetlands in developing countries will be potentially developed, quantitative evaluation of wetland functions are essential to manage such multi functional areas appropriately. In this paper, flood and sediment control functions of wetlands in Kushiyara River Basin, northeast region of Bangladesh are examined through field investigations and by use of observed hydrological data. The results quantitatively show significant effects of flood control and sedimentation in the wetlands.

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The Paddy Field Dam (PFD) is a flood mitigation measure using paddy fields with runoff control devices installed in drainage boxes of paddy field plots. Although the flood mitigation function by the PFD has been proven to be effective, the propagation of this measure is not an easy task due to lack of incentives to the upstream farmers. Authors have been proposing to find a governmental financial support system to create a farmers incentive to voluntarily introduce the measure. For the system to be established, the economic value of social function of the PDF needs to be estimated. This study attempts to make an economic evaluation that the Paddy Field Dam would bring about in the case of a polder area in Shirone district, Niigata city, where Paddy Field Dam project has been practiced since 2009. As a result of the evaluation using direct cost method, the value of the Paddy Field Dam project was calculated to be approximately 11,200yen/10 a/year.

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A traditional flood control technology, such as nokoshi and open levee is existing in Jobaru river in Saga Plain. In this research, a quantitative evaluation of these facilities' effect is performed by 1-D and 2-D numerical simulations. The 1-D simulation shows characteristics of nokoshi and open levee and also gives a boundary condition for the 2-D simulation. The 2-D simulation gives how the flood flow is treated in the retarding basin. The flow behavior is compared with the geotechnical investigation results in which sediments are sampled to estimate how the sediments were carried and settled down during the inundation.

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The breach discharge by overtopping flows is examined experimentally and numerically. The processof breach erosion is reproduced, employing laboratory-scale non-cohesive homogeneous embankments.The relationship between breach discharge and effective width of breach cross-section is identified by using experimental results. The relationship is compared with the one obtained from the on-site overflow experiments at Chiyoda conducted in 2010~2011. Breach discharge is calculated by the numerical model that simultaneously solves flood flows in a channel and inundation flows in a flood plain with the dynamic inundation model, which comprises the finite volume method on unstructured grid using FDS technique. It shows that breach discharge can be predicted comparatively by the use of the model with the h-q boundary condition and effective width of breach cross-section.

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The purpose of this study is to provide information about flood inundated areas for flood related risk assessment, mainly in local communities of developing countries where accurate Digital Surface Model (DSM) is not available. DSMs obtained by Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) issued by Japan Aerospace Exploration Agency (JAXA) are globally available at 10m grid size. However, the vertical direction error is about 6m; therefore, PRISM DSM needs to be corrected. In this study, authors propose a method to modify the PRISM DSM with ground-based observation using a highly accurate GPS. This paper explains the characteristic of the DSM, the method to modify the DSM using the GPS, as well as the result of an inundation simulation implementing the modified DSM.

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We developed a method for flood risk assessment in Tokyo metropolitan area. We estimated damage by inundation inside a levee at each prefecture based on a statistical method used in damage insurance field. On the basis of estimated damage, we developed flood risk curves in the Tokyo metropolitan area, representing relationship between damage and exceedance probability of flood. By analyzing the flood risk curves, we found out regional differences of flood risk. We identified high flood risk in Tokyo and Saitama prefecture. On the other hand, flood risk was relatively low in Ibaraki and Chiba prefecture. We found that these regional differences of flood risk can be attributed to both entire property value and ratio of damaged housing units in each prefecture.

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Torrential rainfalls over 50mm/h have been observed frequently in recent year and these rainfalls caused pluvial and fluvial floods in urban and rural areas. Evacuation of elderly person and traffic difficulties during pluvial flood in urban area are investigated here. As the inundation occurs in a short time, people have to evacuate through inundated road and avoid the traffic difficulties on their evacuation route. In this paper, this problem is discussed by using a commercial model, InfoWroks CS, of which accuracy is verified with the survey data of Osaka flood on 27, August, 2011. From the results, it can be shown the maps of walking and driving difficulties for pluvial flood.

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Recently, we often experience a localized torrential rain whose intensity is much larger than the design value for drainage network system. Numerical simulation ofinundation was conducted in order to estimate how hazardous the highly urbanized area of center of Tokyo is if such a heavy rain attacks there. There are several underground spaces including subway stations there, and a number of gates for stairs toward the space exist in the spots where the ground elevation is lower than the surrounding area. As a result of this study, it was concluded that serious inundation may occur in large scale underground space in this area. We also found out the gates leading to the space through which water flowing on road can enter.

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Although it is important to retain the flood water within the river channels by using dikes and reservoirs, these facilities alone cannot cope with excessive floods. In Japan, appropriate combination of facility-based and non-facility-based countermeasures is getting more important.To determine non-facility-based countermeasures, we need to simulate flood hazardous situation. However, simulation models which include only evacuating on foot are not enough because our society and our lifestyles are based on using cars.In this study, a evacuation simulation models which express the signal control is developed. This model leads to develop a model which includes using cars. The performances of this model have been tested in the several simulation results in actual flood-plain areas in Japan.

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Numerical simulations of flood flow in the Onga river basin and inundation flow in the Iizuka-city area due to torrential rain were performed by a numerical model for rainfall-runoff in watershed and flood inundation process in urban area with flood disaster-reduction system such as sewer network and drainage pump station. The rain-fall runoff, flood flow in rivers and inundation flows on the ground and free-surface-pressurized flow in the sewer network were simulated by a distributed hydrological model, the 2D free-surface flow model and dynamic network model for free-surface-pressurized flow combined with the Preissmann slot respectively. The characteristics of flood flow and inundation flow in Iizuka-city in the Onga river basin due to several torrential rain were examined based on the numerical results.

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Typhoons are anticipated to cause more severe damage in the future, thus TCs risk assessment have an important role in decision making for risk reduction. Although several typhoon risk assessment models were developed, these models were scarcely compared and their characteristics were also scarcely discussed. In this study, we tested three typhoon risk assessment models and compared their characteristics. Two models were from existing studies and one model was newly developed based on these two models. We assessed economic loss focusing on 25 years from 1985 to 2009, at four countries in Western North pacific: China, Japan, South Korea and Viet Nam. Furthermore, we estimated economic loss by typhoon at 2035 with and without climate change. Characteristics and trend of typhoon risk from present to future differed by models due to different model structures.

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It is necessary to support that flood forecast system offers river administrators information such as confidence interval of the predictive water level result and probability to exceed water level, because river administrators make a precise decision from flood forecast. Therefore, flood forecasting system with a distributed runoff model in consideration of an error of the predictive precipitation was developed. Two-variation exponential distribution was adopted as distribution of the errors between observed precipitation and predicted one. The accommodative high particle filter to a non-linear phenomenon was adopted as data assimilation method with observation data and was incorporated in flood forecasting system. As a result of having applied to a flood, the observed water surface level entered the confidence interval of the prediction for 3 hours and it was judged that the system was almost proper.

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This paper deliberates an ensemble flood forecasting method using high-resolution ensemble rainfalls. The authors use numerical ensemble rainfalls simulated by the Japan Meteorological Agency – Nonhydrostatic Model (JMA-NHM) with a 2-km resolution as inputs to a distributed rainfall-runoff/flood inundation (DRR/FI) model. The feasibility study of the ensemble river water-stage and flood inundation depth prediction to be used for the operational forecast is carried out with DRR/FI and ensemble rainfalls. The 2-km spatial resolution of the ensemble rainfalls by JMA-NHM has a potential to be used for even small Japanese river basins such as the Sayogawa River basin (191 km2), the application site in the paper. The paper presents the ensemble simulations of the 2011flood by Typhoon No.12 in the basin. The result shows that the water stage at a given point in the Sayogawa River exceeds the evacuation call level in some ensemble members. This indicates the possibility that the ensemble flood forecasting can be used as the additional information for the evacuation call.

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This study presented a method to assess the economical flood damages based on a hydraulic model, which took into account a spatial distribution of extreme precipitation estimated by statistical and meteorological characteristics. In order to calculate subsequent discharges due to an extreme precipitation, a regression relationship between catchment areas and coefficient of discharges was derived using the historical data of river discharges at 89 stations throughout Japan. The potential economic damage for a flood of 100-year return period was estimated to be 790 billion USD.

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The sewer system is one of the most important systems in urban infrastructure. The earthquake damage of sewer systems makes drainage by sewage difficult, and it affects runoff and inundation process system. The storm impact on earthquake damage of stormwater drainage systems was assessed on the supposition that a large-scale earthquake and heavy rain occurred in the upper catchment. The Tokyo Storm Runoff (TSR) model is applied for urban runoff analysis. The set-up of this model is based on so-called urban landscape GIS delineation that faithfully describes the complicated urban land use features in detail. The effects of earthquake damage of sewer system was examined based on the numerical model results.

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Ishikari River basin had gotten extensive damage from flood frequently. After flood preventions such as channel cut-off works, levee construction and dam construction etc., each region protected by the levee has become to have flood damage independently in Ishikari River basin. The different characteristics of flood damage can be seen in each region corresponding to characteristics of inundations population and land use etc. in the region. Flood characteristics of Ishikari River basin are composed of those of each region. We investigated the flood characteristics of each region in order to clarify the damage characteristics for flood exceeding the designed level in Ishikari River basin.

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To clarify the effects of difference from rainfall pattern on runoff phenomenon contributes to the further development of the flood control measures commencing with dam control. Elucidating those effects is very useful to examine flood control plan. In this study, authors made pseudo rainfall patterns based on Typhoon Kathleen in September 1947 in Tone upper river basin and examined the effects of difference from rainfall pattern we created on runoff phenomenon. Moreover, authors verified the flood-control ability of Yanba dam in Agatsuma basin. In consequence, it was indicated that peak discharge at Yattajima point of observation was up 15 percentage point from peak discharge in Typhoon Kathleen depending on rainfall pattern. Furthermore, it was indicated that Yanba dam is 4 percent effective in decreasing water level at Yattajima point.

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A method for impact analysis of a reservoir's prior release operations precedential to floods is developed as a fundamental study in this paper. A Monte Carlo simulation model of a reservoir's prior release operation coupled with artificial generation model of inflow predictions is proposed here. The inflow predictions can be generated with random errors based on given accuracies of the prediction so as to take impacts of inflow prediction's accuracy on the effectiveness of prior release operations into consideration. Impacts of prior release operations on flood mitigation and water storage for water utilization are then analyzed and discussed by use of proposed simulation model for assumed reservoir operations which are derived from an existing multi-purpose reservoir.

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A new flood control concept called 'Cascade method' which permits a dam to overflow from an emergency spillway around an upstream region with plural dams set in series in a river basin has been suggested. In this study, characteristics of the new flood control method are investigated for various inflow flood hydrographs whose shape is transformed systematically. As a result of this study, it is made clear that the new method can control more effectively for leaning forward inflow hydrographs. In addition, we propose another new type of a dry dam to encourage water-utilization. The new type has an outlet work for flood control with a slide gate which can be closed automatically depending on hydraulic pressure or buoyancy. We call this gate 'pressure gate'. The new type of dry dams constructed in series with a pressure gate strengthens still more flood control capability of the Cascade method.

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The new flood control method called as 'Cascade method' permitting a dam to overflow from an emergency spillway around an upstream region with plural dry dams set in series in a river basin was confirmed by the experiment with a model. In addition, it also became clear that the shape of a flood hydrograph into a most upstream dam reservoir influences effects of the Cascade method greatly. Furthermore, the flood control capability of another new type of a dry dam to encourage water-utilization was also clarified. The new type has an outlet work for flood control with a slide gate which can be closed automatically depending on hydraulic pressure or buoyancy. The physical experiment demonstrated that the new type of dry dams constructed in series with such a gate strengthens not only functions for irrigation but also a flood control capability of the Cascade method.

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A retarding basin, that temporarily stores stormwater to reduce downstream flow rate, is one of the most effective countermeasures to mitigate existing downstream flooding problems. Effectiveness of the basin is strongly dependent on design of an overflow levee. Experimental works have been commonly employed for the overflow levee design, because the flows around the levee are very difficult to be handled by theoretical and/or numerical methods. The objective of this study is to demonstrate that the numerical model along with appropriate boundary conditions is effective to calculate the stage-discharge relationship, that solves simultaneously flood flows in a channel and inundation flows in a flood plain with the dynamic model, which comprises the finite volume method based on unstructured grid using FDS technique.

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In order to enhance the emergency preparedness for large-scale floods of the Tone River, we categorized the inundation patterns and calculated fatality estimates. Drainage pump capabilities, in terms of operatable inundation depth and operatable duration limited by fuel supply logistics, were modeled from pump station data of each site along the rivers. Fatality reduction effects due to the enhancement of the drainage capabilities were calculated. We found proper operations of the drainage facilities can decrease the number of estimated fatalities considerably in some cases. We also estimated the difference of risk between floods with 200 years return period and those with 1000 years return period. In some of the 1000 years return period cases, we found the estimated fatalities jumped up whereas the populations in inundated areas changed only a little.

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In the Toga River which runs through Omote Rokko area in Kobe, the sudden water level rising by local heavy rain was often seen in several years. On July 2008, an unfortunate accident was occurred, 5 people were swept away and died by a swollen river. Recently, on July 2012, an unsafe incident was happened, many people got into dangerous situation. In this study, the frequency of occurrence on local heavy rain in Toga River basin was analyzed and the circumstance and problems of anti disaster measures in Omote Rokko rivers were examined. From the result of flood frequency analysis, the next similar situation might be happened in the decade ahead. Therefore, river administrator should review the existing countermeasures against local heavy rain and river users should also recognize the risk at local heavy rain.

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Change in household water consumption characteristics such as popularization of water saving appliances must be considered when reservoir operation plans are examined in the drought time or a long term water resource management plan is settled. In this paper we use a water consumption model which is established based on utility maximization and cost minimization problem to analyze the droughts damage when household water consumption characteristics change. We apply this model to two generations of two cities in Japan and compare the droughts damage according to the water consumption characteristics. We find that settling water supply restriction rule during droughts has been more difficult along with water consumption characteristics change.

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The total cost of an irrigation service is analyzed by applying the service science approach to study the Aichi Irrigation Scheme. By interviewing farmers and water user association members, the cost of construction and water management of irrigation facilities from an upstream dam to the downstream intake of a paddy field are collected and analyzed. At the Aichi Irrigation Scheme, irrigation is a service because it is produced co-operatively by a governmental water resources organization, a water user association and farmers. The main type of irrigation is supplemental irrigation to irrigation ponds. By estimating the cost and benefits of an irrigation scheme at a pond, the total cost payment system has strong characteristics of a fee paid for insurance against droughts.

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This study discusses the feasibility of maintaining storage capacity for small-scale hydropower generation by operating flood control dams flexibly.Currently in Japan, shortages in electrical supply have been a concern. It is hoped that this study will mitigate such shortages.For flexible dam operation, it is necessary to recover the dam's flood control capacity by releasing dam water ahead of predicted flooding. To obtain water for small-scale hydropower, a flexible dam operation using the cumulative forecasted rainfall for pre-releasing was considered. We examined such release by using the flood date of previous years. It was found that recovering flood control capacity of a dam is possible before the start of storing flood water. It was found that by using appropriate dam operation, there is a possibility for securing dam water for small-scale hydropower.

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This paper investigates influence of base flow discharge on stream temperature formation in a river network for refining a stream temperature network model. A base flow temperature at a spring water spot has been observed for several years in Ibo River Basin in Japan. The data indicate that there is a time delay with a few months in the peak temperatures between the surface flow and base flow, so that the base flow could give higher temperature input into the stream water body in winter and lower input in summer. A newly proposed base flow temperature model with the stream temperature network model shows very high prediction ability for the temperature distribution structures along the river network for all seasons.

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A numerical simulation model was presented to describe the material cycling along a river with floodplain, in which river continuum concept and flood pulse concept were modelled to be taken into account for considering the energy flow in river ecosystem. Using the discharge and the river channel conditions observed in Yahagi River, the dynamics of organic matter was illustrated. The organic matter entering into the river from terrestrial area is transported under the effects of physical and biochemical processes in each longitudinal segment of the channel. The results of the simulation show that the amount of organic matter transported during floods is about 28% in Segment.2.

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A large amount of radioactive material was released from Fukushima Daiichi Nuclear Power Plant into the atmospheric and coastal environments including water environment in lake and inner bay. The present study aims to clarify the movement of radioactive cesium-134 and -137 in urban watershed, river and lake. For this purpose, we conducted field measurements of radioactive cesium-134 and -137 in sediments in the watershed of Lake Teganuma. The results revealed that 1) the radioactive cesium concentration in roofs was appreciably larger than that in roads and general farmland mainly due to difference of sediment thickness, and 2) the radioactive cesium concentration of the bottom sediment was larger than 1000 Bq/kg over whole Lake Teganuma. The budget of the radioactive cesium concentration in the watershed was evaluated.

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Although previous studies pointed healing effects from waterfront, quantitative evaluations and factor of healing effects were still unknown. To evaluate quantitatively healing effects from river and coast and its associated factors, in this study, we measured simultaneously psychological stress and sound and thermal environments at six sites in which the measuring points were selected near waterfront and urban area in its neighborhood. The measured results indicated that 1) the measured values of salivary amylase activity, one of useful stress markers, in several waterfronts were appreciably lower than those in urban area, and 2) the healing effects in waterfronts were closely related to sound and thermal environments.

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It is important that residents do river environmental management,because reducing governmental burden, minization of the psuchological distance of residents and river and strengthening regional social network. Recently, these activities by cooperation of residents and administration are done.The purpose of this study makes clear the regional comparison and changing processes of the residential activities at the river.The year of starting activities increased in class A river. These activities increased from 1980s, and the most number of established party in 1988. As a result of analyzing the contents of actibities, it is shown that formation of a network which supports activity is important. An analysis of a possibility that activity will start was carried out. High potential river of environmental activity is elemntary school in the neighborhood, and much a afamily's number area.

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Nitrogen contamination in rural rivers may be caused due to pollutant load from plowed fields with excessive fertilization through groundwater. However there has been little information for discharge and pollutant load of groundwater into rivers. In the present study, we conducted field measurements to clarify the discharge and nitrogen flux of groundwater into the Takasakigawa River, flowing into Lake Inba-numa, with nitrogen contamination. The results indicated that: 1) nitrate concentration of groundwater was mostly higher than that of river water, and 2) discharge and nitrate flux of groundwater into the river were 73~92%, and 81~95%, respectively in the observed reach with 1.4 km in length. The source of the groundwater flowing into the Takasakigawa River were discussed using water quality data of groundwater in its watershed.

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This paper evaluated the long-term variations of the input loads of BOD and COD from Akashi river (128.4 km2) and sewerage to the sea using the public water quality observation data set and GIS population and land use analyses. We obtained the following results: 1) BOD and COD input loads from rivers from the late 1970s to 2000s have been reduced by 84% and 69%, respectively, 2) BOD input load from river basin including sewage-treated water has been reduced by 40% from the late 1970s to 2000s, while COD input loads are not reduced (6% increase), 2) BOD and COD input loads were provided 70% by the sewerage and did 30% by the river. These results show the sewage improvement makes the restriction of organic pollution in rivers though the population increased about three times since 1980s.

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Many small urban tidal rivers in Japan lack natural water sources. During storm period, untreated water flows into these rivers through a combined sewer system, causing pollution loads. This study aims to characterize the water quality and pollution load in a small urban tidal river during storm period, focusing on the discharge, water quality and pollution loads by classifying storm period into three phases: flood, transition and tide phase. The results indicated that most of the discharge, the organic pollutants, and the suspended solids were observed especially in the flood phase. Also, in the transition phase, there were no significant differences in water quality at different depths. Besides, dissolved oxygen changes in the transition and the tide phase could be explained by different factors.

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Recently, the reduction of pollutant load from watershed becomes significant issue for the water quality management at a closed water area. Countermeasure for the nonpoint pollution load is urgently needed. In this study, to predict and estimate the amount of pollutant runoff from watershed under the rain condition, a numerical model was developed. The rainfall-runoff relation was calculated by the runoff function method, and the amount of pollutant-runoff was represented as the function of specific discharge. This model was applied to the prediction of the temporal variation of suspended solids (SS) at four rivers which are flowing into Isahaya flood regulation pond, Nagasaki. Computed results of the flood discharge and the runoff load of SS have good agreements with observed results, and the usefulness of this model was shown.

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It is necessary to grasp a long term inflow load for the study of enclosed bay. The Ariake Sea is one of such bay and there are some missing data of river discharge flowing into this bay. In this study, our developed method to estimate the missing discharge data is applied to all major rivers flowing into this bay. Amounts of inflow loads are calculated using L-Q curves and pollutant load factors. Long term changes of the river discharges and loads into the bay are estimated from 1981 to 2010. A characteristic of inflow discharge's change and a relationship between red tide occurrences and the inflow discharges are also discussed. The inflow discharge and loads of COD, T-N and T-P are found not to be changing in the Ariake Sea from 1981 to 2010. An increase of the inflow discharge is considered to be a trigger for a red tide occurrence not in winter but in the season between spring to autumn in the Ariake Sea.

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This paper analyzed the behavior of sea breeze (hereafter SB) penetration to urban area in Kanto. In order to analyze SB penetration, we proposed a new method for SB-front detection using very high-resolution-geostationary satellite images, or MTSAT-2 Rapid Scan, with 1 km-spatial and 5 min.-temporal resolution. From the images, the detailed behaviors of SB were successfully visualized. For the selected SB events, the penetrations to in-land from Tokyo bay and Sagami bay were discussed using the point data of AMeDAS and Atmospheric Environmental Regional Observation System (AEROS), and also a result from the meso-scale simulation, where the important urban effects were parameterized (e.g., actual aero-thermodynamic parameters, anthropogenic heat and vapor emission). Along Tokyo-Saitama line, SB stagnation occurred in every sea breeze event. The observed higher air temperature and convergence resulted in increased vertical mixing, leading to SB stagnation.

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Matsuyama plain has an obvious contrast of land use in urban and rural area. The purpose of this study is to investigate the effects of differences in land use on the formation of clouds, using the summer time datasets from the observations of cloud base level, solar radiation, surface heat flux, air temperature and humidity. The followings are main outcomes. Cloud base level over urban area was higher than that over rural area when wind blew along the border of the abrupt change of land use. Solar radiation over urban area tended to be smaller than that over rural area in the afternoon of days with a percentage of sunshine ranging from 50% to 80%. This was demonstrated by the development of mixing layer estimated from surface heat flux.

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The classification of horizontal flow field above an urban area were conducted using doppler velocity distribution observed by Doppler lidar. The Doppler lidar measurement used for the current analysis, was conducted in Tokyo, from 20 August to 24 November, 2011. The measured velocity fields were classified visually into 4 groups; streak, fish net, front, and the others. And the each groupe has the different range in magnitude of Velocity Azmith Display (VAD) components; horizontal mean velocity, divergence and deformation. The atmospheric stability also affected to the existence of fish net pattern and to the spatial scale of streaky pattern. The effects of surface roughness and topography on the flow fields, such as the wakes of tall buildings triggering streaky patters and deformation of micro-front due to the small hills, were clearly illustrated.

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This paper discussed the land and sea breeze circulation (LSBC)between Ishikari and Yuhutsu areas in Hokkaido. The diurnal variation of LSBC during boreal summer(July and August) of 1985-2009 was mainly investigated by using various data. LSBC was observed between Ishikari and Sapporo up to 13km from coastal zones of the Japan Sea. Tomakomai to Atsuma area also showed LSBC around16km from coastal zones of the Pacific Ocean. For inland region that area from Chitose to Naganuma, southerly wind was observed all day long. The reason is related to a fact that this inland region has strong southerly wind associated with the meridional temperature gradient between Ishikari and Yuhutsu area. Thermal balance between SST and temperature of land could be important to control the horizontal scale of LSBC. In the La-Nina years, SST over the Japan Sea at the vicinity of Sapporo area was higher than the climatology, and LSBC was enhanced and expanded its spatial scale.

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Due to the massive earthquakes and tsunami on March 11 2011 in Eastern Japan, Fukushima Daiichi nuclear power plant was severely damaged and some reactors were exploded. Then radioactive particles were widely spread out. In this study, we modified the stable isotope mode of RSM (IsoRSM, Yoshimura et al.) to enable to simulate the transport of the radioactive tracers, namely iodine 131 and cesium 137, by including the dry and wet deposition processes. The control experiment with 10km resolution and the emission estimated by Chino et al. (2011) showed reasonable temporal results for Toukatsu area (eastern part of Tokyo metropolis and western part of Chiba prefecture), i.e., on 22 March, the tracers from Fukushima was reached and precipitated in a significant amount as wet deposition. Thus we conducted 4 experimental simulations to analyze the simulation uncertainty due to different meteorological pattern and different parameters for wet and dry deposition and diffusion. Though the temporal patterns of deposition of radioactive particles were somewhat similar each other in all experiments, we revealed that the impacts to the area mean deposition were quite large.

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Precise estimation of evapotranspiration is one of the important factors for air temperature estimationmodel. In order to estimate evapotranspiration considering the condition of land use recognition and soil moisture content, evapotranspiration model using advanced GIS delineation was developed. This model was applied to the upper Kanda river basin whose catchment area is dominated by urban area to estimate evapotranspiration in 2011. It was found that the model considering land use recognition and soil moisture content can estimate evapotranspiration by comparing the calculation result and observed value.

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The influences of meteorological factors on the variability of heat-island structure in the Fukuoka metropolitan area are investigated on the basis of observation data and numerical simulation by using a meteorological numerical model, i.e., Weather Research and Forecasting (WRF). The present results show spatial patterns of the heat island to be controlled by local wind systems. The heat-island intensity varies temporally depending on the formations of sea and land breezes, whereas the variation becomes relatively small under background wind dominated condition. The heat-island intensity takes a maximum value in nighttime and the value depends on the amount of the global solar radiation in daytime.

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We produced a portable and handy measurement system, which can measure both meteorological (air temperature, humidity, long and short wave radiation, wind velocity) and physiological (skin temperature, tympanic temperature, pulsation, rate of acceleration, thermal sensation) parameters. Using this measurement system, an observation along subjects' path ways was conducted during summer, from August 22-24, 2011, at the city of Tajimi, Gifu Prefecture, which is one of the hottest locations in Japan. From this observation, 1) detailed thermal environmental and physiological maps were made, which can detect localized hot and cool spots and their impacts for human health, 2) the close relation between subjects' measurements and conductive heat loss from their bodies was found. When they stopped walking, since their metabolic heat still remain higher, it cause tympanic temperature increased, 3) sweat rate had a correlation with the thermal load (SET*). The gender and BMI were also found to influence on the physio-meteorological relationships mentioned above.

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A satellite-based Land Data Assimilation System (LDAS-WRF) was developed by coupling the Weather Research and Forecasting Model (WRF) and Simple Biosphere model version 2 (SiB2), to physically introduce the soil moisture observations and improve the representation of land surface and lower boundary conditions in Numerical Weather Prediction (NWP). The LDAS-WRF assimilates the soil moisture, using passive microwave brightness temperature at the lower frequency, which has a high sensitivity to soil moisture. This system consists of a radiative transfer model which treats surface and volume scattering of surface soil layer as an observation operator and Ensemble Kalman Filter (EnKF) as a sequential assimilation algorithm. To evaluate the capability of the system, the LDAS-WRF was applied to a mesoscale region in the Tibetan Plateau. The results show that the soil moisture and land surface energy fluxes obtained by the LDAS-WRF are successfully improved compared with no assimilation case.

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This study presents idealized tests of a newly-developed data assimilation system for assimilating high-frequency vapor isotope observations from satellites, using an ensemble Kalman filter with the isotope-incorporated general circulation model. An LETKF-based four dimensional data assimilation system was newly developed for the first time to obtain dynamically and physically consistent analysis of both water isotope and meteorological variables. Moreover, we also aim at assessing the isotope observation impact on the dynamical fields (wind, temperature, humidity, pressure). Several numerical experiments have been performed with various synthetic observations using a model simulation as the "nature run". The control experiment assimilates conventional rawinsonde-like observations, and the test experiments with additional isotope observations showed general improvement in both isotopic fields and dynamical fields. The positive impact on the dynamical fields was surprisingly larger when the number of conventional observations was decreased. These results are promising, so that the satellite isotopic data could be very useful to analyze the atmospheric states, particularly for the past (before 19th century) when isotopic measurement data were a major source of observations.

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