Shared socioeconomic pathways (SSPs) are being developed internationally to perform cross-sectoral assessments of climate change impact, adaptation and mitigation. SSPs consist of five scenarios including both qualitative and quantitative information in terms of challenges in mitigation and adaptation to climate change. In this study, we quantified scenarios for risk of hunger consistent with the qualitative future visions of the SSPs and clarified the factors that influence risk of hunger by using the AIM/ CGE model. We found that: 1) Future risk of hunger differs significantly according to social conditions; 2) the factors that cause large differences in risk of hunger among SSPs are population, inequality of food distribution, and mean percapita food calorie intake; and 3) inequality of food distribution is an important factor that influences risk of hunger in long-term assessments.

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 The present study evaluates the effect of climate change on Japanese rice production, price, agricultural income, and regional economies by using the recursive-dynamic regional computable general equilibrium (CGE) model. This model is associated with crop-growth models and global climate model. The simulation results demonstrate that future climate change will increase Japanese rice production for the country as a whole, but that the price of rice will decrease. As a result, agricultural income will decrease, despite the increase in production in the northern and eastern Japan, such as Hokkaido, Tohoku, and Kanto (including Niigata Prefecture). Climate change will not benefit rice farmers in these regions. However, the western region will benefit, despite the decrease in production, and consumer surplus in most regions will increase. As such, the impacts of climate change are complicated and differ by region. To consider policy countermeasures, the CGE model can provide useful information.

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 Global warming is a serious problem that cannot be avoided any longer. This problem has impacted on weather and climate. Therefore the snow (snowfall, snow accumulation and snowmelt) will be changed greatly in the future compared with the current situation.
 In this study, we analyzed the impact on the ski business due to the changes of snow amount by the global warming. Firstly, we estimated by regression analysis the relationship between the snow amount and the number of visitors of the ski areas in the Toyama Prefecture. Secondly, the data of snowfall in current and future were created by using the observed data and data from Soil Vegetation Atmosphere Transfer model and Global Climate Model. Thirdly, by using the data of snowfall in the future under global warming as well as the relationship of the snow amount and the number of visitors, we calculated the effect of snowfall on the business income and the number of visitors in the future. Finally, we surveyed to the ski area owners for adaptation methods against the global warming.

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 In Japan, after contracting the World Heritage Convention of UNESCO in 1992, 17 sites have been inscribed on the World Heritage List by the end of 2013. Among them, the Shirakami Mountain Range is registered as a World Natural Heritage Site, by the primeval natural forest of beech which spread there and by public benefits associated with it. But the beech is on the verge of decline with the progress of global warming. If it is determined to have lost the outstanding universal value by monitoring after registration as the World Heritage Site, it will be deleted from the World Heritage List. In this study, it is assumed that deregistration of the Shirakami Mountain Range on the list is an impact on the World Natural Heritage Site by global warming, and we have analyzed impacts on tourist visits there. At this time, by using the contingent behavior method based on the travel cost method, we have estimated changes of the recreational value of the Shirakami Mountain Range.

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 In this study, the new computable general equilibrium model with simplified technology selection in Japan was developed, and this model was applied to the new mitigation target in Japan in 2020, which was announced in November 2013. If only the short-term cost effective energy saving technologies are introduced, the GDP loss in 2020 will be more than 1% compared with the BaU scenario. The simulation results represent that the GDP loss in 2020 will be less than 1% compared to the BaU scenario, when the countermeasures to promote the energy saving technologies by 2020 such as subsidy for energy saving technologies and acceleration of their introduction will be introduced widely. Moreover, when the energy saving technologies will be introduced sufficiently and the investment will be maintained, GDP in 2020 will be able to become more than that in the BaU scenario.

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 In order to form a recycling-oriented society, workshops, industrial parks and metropolis are the important elements. Therefore, industrial symbiosis model attracts more and more attentions nowadays.Base on the concept of industrial symbiosis model, YUCHUAN Circular Economy Industrial Park has been constructed. It recovers waste such as construction waste, sewage sludge and stone charcoal produced by the thermal power station within and surrounding Tianjin city and replace them respectively with mortar and reuse them as concrete vesicant and fertilizer. Furthermore, symbiosis model has been set up for company to company. Sewage treatment plant and building materials manufacturing plant utilizing the residual heat produced by the thermal power station. Instead, the thermal power station utilizing the sewage water as cooling water. In that, the resources and energy consumption efficiency of the industrial park, has been improved.
 This research takes Tianjin city as a regional example, case studying the YUCHUAN Circular Economy Industrial Park, and conduct quantitative evaluation, utilizing LCA methodologies, towards industrial symbiosis model's environmental load reduction, comparing it to the status of waste disposal.And the result shows that environmental impact of CO₂ emissions of industrial symbiosis model is much small.

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 The problem of heat environment in urban area has become more obvious recently. One of the causes of this problem relates to the urban land covers. Especially, artificial land surfaces such as concrete, asphalt and so on have been expanded under urbanization and have made the problem more worsen continuously. Therefore, this study firstly acquired the fine land cover information by using the object based classification method which has become popular recently. Then, the acquiring land cover information was verified the accuracy compared with actual land covers. Moreover, relationship between land cover information and land surface temperatures were analyzed by two different statistical methods of the ordinary least squares and the geographically weighted regression. Finally, the reproducibility of the land surface temperatures by both methods were examined.

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 Publication of PM_2.5 data in Shiga prefecture has been insufficient so far, and the actual situation of PM_2.5 isn't grasped.In this study, at Seta hill, Shiga prefecture, we continuously measured PM_2.5 concentration and analized the component of metals and inorganic ions. Trajectories of air masses were also calculated. It was deduced that one of the main causes of PM_2.5 high concentration at Seta hill was yellow dust(Asian dust). Elemental components (Al, Ca, Fe, Mg, Si) contained in yellow dust were detected from PM_2.5 collected in a yellow dust day. The results of inorganic ions analysis confirmed that SO₄^2- was more than NO₃^- and mainly distributed as (NH₄)₂SO₄ in the fine particles. The results of analysis of the chemical component and calculation of the trajectories of air masses showed that high concentrations of PM_2.5 except for yellow dust day were due to transboundary pollution from China and Korea, and anthropogenic SO₂ emissions from domestic urban areas and volcanic SO₂ emissions.

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 For the advancement of a recycling society, it is necessary to quantify the material stock and flow, ranging from natural resource input to waste, that are caused by human socio-economic activities. Global material analysis using detailed scales and uniform data is needed, but restricted due to data availability. In this study, the correlation between PALSAR (Phased Array type L-band Synthetic Aperture Radar) data and building area in Kanto region of Japan were evaluated by combination of multiple-resolutions and land use/land cover. The results show a strong correlation between SAR and building area in the case of mesh cells larger than the satellite resolution since the inherence noises were reduced by the process of averaging when increasing mesh cell size. It was observed that strong correlation can be omitted by prior omission of forest areas with land use/land cover data as it is for our previous study.

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 The heavy rain disaster is increasing in Japan. Activities of the disaster risk management based on communities are important in small and aged community. The purposes of this paper are arranging the subjects of the community based disaster prevention activities and supporting to flood risk in these community. The research region is Susa distrct in Hagi city which the record torrential rain fall caused heavy flood disaster on 28th September, 2013. Social researches were carried out for this disaster. Official announcement time for evacuation advisory was later than the standard. The residents evacuated in the very dangerous situation. The local government should give refuge preparation informormations considering with necessary time for refuge of aged persons.

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 The damage caused by various disaster phenomena was quantified in the form of map information, and these economic damages were estimated on 2 disasters, namely flood and storm surge . Map information and GCM data were utilized after the data formats were unified. The estimated costs of these disasters were calculated in current, 2050 and 2100 climates by using several GCM modesls and climate scenarios. The probability of simultaneous incidence of these 2 disasters was estimated using the influence functions. The influence functions were estimated by the relations between air pressure and high tide and between air pressure and precipitation. This probability of simultaneous incidence was involved. The damage under current-climate was estimated to 78 billion YEN, which is 1.4 times biggher than flood statistics. The damages will be between 1.1 trillion YEN and 1.2 trillion YEN under 2050 climate and 1.2 trillion YEN and 1.4 trillion YEN under 2100 climate.

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 This study estimates future beach erosion in Japan due to sea level rise and evaluates its uncertainty. Future beach erosion rate in Japan is estimated to be 47% for the sea level rise of 0.26 m which is the lower limit value and 91% for 0.82 m which is the upper limit value of future sea level rise reported in IPCC AR5. The erosion rate also corresponds to estimation values in an existing study which was estimated using a different beach dataset. It is inevitable that most of beaches in Japan will be affected seriously by the sea level rise even if we take into account the uncertainty in the estimation.

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 We estimated theoretical hydropower potential and its future change at the global scale under four climate change scenarios. River discharge was calculated with a global hydrological model, H08. Future bias-corrected meteorological data sets produced from five general circulation models were used as input meteorological data. The global theoretical hydropower potential for 1960-1989 was estimated 43,890TWh, and showed larger increasing trends under warmer climate scenarios. We also estimated hydropower generation from simulated seasonally-varying river discharge under an assumption of a plausible specification design of hydropower plants based on flow-duration curves. Estimated hydropower generation also showed increasing trends, similar to the theoretical hydropower potential, but its future change was smaller. Geographical distribution of future changes in the working efficiency of hydropower plants were similar to that of the theoretical hydropower potential, whereas geographical distribution of future changes in the efficiency of river water utilized for hydropower generation is far from that of the theoretical hydropower potential. Based on future changes of these two efficiencies, we classified global land regions into four and discussed the effects of future climate change on water resources and hydropower generation for each classification.

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 The purpose of this study is to evaluate the effect of subsidies for residential photovoltaic systems on promoting the installation of the systems using a panel data analysis. The analysis is implemented in the prefectural level from FY2002 to FY2011, including the periods that the subsidies were not implemented. The results suggest that the subsidies show a statistically-significant effect for promoting the installation. However, it is also clarified that the price decline of residential photovoltaic systems is the most effective for promoting the installation, meaning that the effect is higher than that of the subsidies. It is due to the time and effort against the users for receiving the subsidies.

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 On the occurrence of the disaster such as earthquake and heavy rainfall in the mountain, small village is isolated from the society for the long term. As a measure for this problem, it is necessary to develop a supplying system for the emergency power using natural energy to the temporary shelter. We think that the Sabo dam with river sedimentation is available for electric generation. In this study, we investigated the waterwheel structure available for the Sabo dam with large amount of river sedimentation in order to supply the emergency power. We demonstrated the efficient form of the waterwheel, the water conduit and the ramp for stable rotation of the waterwheel. And, we showed the effectiveness of the river sedimentation controlled by the water conduit for the small hydroelectric generation.

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 This article quantifies the value of the energy service demand reduction such as transport demand and basic materials production. A global computable general equilibrium model named as AIM/CGE (Asia-Pacific Integrated Assessment/Computable General Equilibrium) model was used for the analysis associated with multiple future scenarios by 2050. The scenarios with and without energy service demand reduction are compared and the loss of gross domestic production (GDP) caused by climate mitigation is analyzed. There are three major findings. First, 25% energy service demand reduction in transport, building and basic material industry sectors reduces 1.0 of GDP loss (from 4.0 % to 3.0%) in 2050 under the 450ppm CO₂ equivalent concentration stabilization scenario. If the stabilization target is softened to 550ppm equivalent, the value of the energy service demand reduction decreases and becomes 0.5% (from 1.2% to 0.7%). Second, the value of the building sector's energy service demand reduction is higher than those of other sectors. This is due to two factors. One is that the emissions of building sectors are higher than other sectors. The other is that household expenditure change can directly influence on GDP.

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 A residential electricity demand model is developed for the purpose of simulating electricity demand profile in typical one-day period of any category of families, DINKs, or singles in local climate conditions, utilizing national fundamental urban-region-based statistics such as PT(Person Trip Survey), National Census, Household Expenditure Survey and Survey on Time Use and Leisure Activities. The experiments of Monte-Carlo simulations in Kobe East urban area highlight considerable fidelity of the pilot model, illustrating time profile of cooking, housekeeping, watching TV and others in air-conditioned rooms in 7 categorized housing units with mobility and 20 timeconsuming activities. The scheme of aggregating process for district-based energy management is introduced by using demographic, building stock and other urban indicators in GIS.

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 In aiming at continuous development, global warming is a challenge that must be acknowledged. It would be necessary to shift to the low-carbon society in order to solve this challenge. When examining the environmental load of urban structure, it is desirable to consider and analyze life cycles at various scales. In this study, we estimate future CO₂ emission scenarios from Japan's prefectures. We compared the effects of energy-saving measures such as compacting of urban areas and photovoltaic systems have on the CO₂ emissions.
 The result for the Business As Usual (BAU) scenario was 1,985 million tons of CO₂ emissions from 2045 to 2049. However, a scenario of energy saving measures reduces CO₂ emissions to 1,250 million tons, a 40% reduction. It was found that the introduction of photovoltaic affected the results most significantly.

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 The purpose of this study is to estimate the impact of economic damage due to the slope failure with global warming. Extreme rainfall is obtained with General Circulation Model outputs and RCP scenarios(GCM : MIROC5.0, MRI CGCM3, GFDL CM3.0, HadGEM2-ES, RCP senarios: RCP2.6, RCP4.5, RCP8.5), and calculated slope failure probability and sediment hazard economic damage in Japan(present year period, 2050 year period, and, 2100 year period). Sediment hazard adaptations is evaluated using economic damage results and sediment high risk area information is analyzed to mitigation of furture life. The results obtained are as follows; 1) As 2050 year period economic damage evaluation, all RCP senarios are indicated increase by 1.5-2.5billion yen compared to present economic damage. 2) As 2100 year period economic damage evaluation, RCP8.5 senario is indicated increase by 0.5billion yen compared to 2050 year periopd economic damage, and other senarios are similar to 2050 year period. 3) When adaptation measures were taken, additional economic damage in the future could be kept below 2.0 billion yen.

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 In March 2013, surface depression of asphalt pavement over 300m was found at the point of elevation 1950m to 5th station of Mt.Fuji on Yamanashi Prefectural forest roads Takizawa line. It was widely reported in the media. On the other hand, The World Heritage Committee of UNESCO decided on June 22,2013 to inscribe Mount Fuji on the U.N. agency's prestigious World Heritage list. It is necessary to clarify the factors Takizawa roads depression and apply knowledge maintenance in the future.
 In this study, based on the field survey, it is considered the terrain , rain and temperature. In addition, it is considered the factors for predisposition and incentive by weather observation and soil test for the ground material of Takizawa forest roads.

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 The purpose of this study makes a prediction of landslide in Thailand using different resolutions of GCMs and probability model of landslide. These data of spatial resolution are 0.05 degree (latitude /longitude) of grid data. To advance projection of precipitation, we used GCM data which is released by CMIP5 (Coupled Model Intercomparison Project Phase 5) on the internet. We used 3 models (MIROC5, MRI-CGCM3, GFDL-ESM2G) and each model has 5 scenario (hs1, 2.6, 4.5, 6.0, 8.5). We set the target period of analysis, which are current climate (1900-2006), near future (2006-2035), mid future (2036-2065), and far future (2066-2095). We obtained landslide probability in whole Thailand per grid, model, scenario, and the target periods.

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 The Indonesia's government has submitted the emission reduction target of 26% from business as usual levels by 2020 under the Copenhagen Accord. We evaluated possibility and feasibility of the target for agriculture and land-use sectors. Moreover, we clarified the lowest mitigation cost with the combinations of mitigation measures for meeting the target in the sectors. As results, the costs for meeting the target are expected to be US$147 million/ year for land-use sector and US$1.39 billion/year for agriculture sector in 2020.

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 Among Southeast Asian countries in which population and economic growth is expected, Indonesia is considered especially important in terms of mitigation of global warming because of its population size, wide forestland, and high agriculture production. For such a country where population and economy are growing, increase of food and energy demand is expected, and GHG emission from AFOLU (Agriculture, Forestry and Other Land use) sector has a significant share, we propose an integrated approach for low-carbon society scenario. The methodology was applied in Indonesia and one BaU (business as usual) scenario and three CM (countermeasure) scenarios were developed, and showed an example to consider net effect of biofuel.

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 On January 15,2013, heavy monsoon rains resulted in severe flooding in Jakarta city, West Java, Indonesia, which had resulted in 40 deaths, 45,000 refugees, and terrible economic damage. Jakarta city has experienced severe floods in 1996, 2002, 2007, 2013 and 2014. Such extreme flooding events might become more frequent in the future due to the impacts of land use change (urbanization) in the upstream region and climate change. Thus, it is important to understand the characteristics and mechanism of the 2013 Jakarta flood to prepare for the next flood disaster. In this paper, characteristics and several social factors contributing to the 2013 Jakarta flood were described, and a physically-based distributed rainfall-runoff inundation model was applied to the Ciliwung River basin in order to simulate the 2013 January flood in Jakarta. Simulation results matched reasonably well with the observed data, and it was found that the flood inundation occurred at the river section with the shortage of capacity flow in the lower part of the Chiliwung River.

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 Meltwater is one of the valuable water resources in LaPaz and ElAlto, Bolivia. We conducted simulations of glacier variation of Huayna Potosi West Glacier, Bolivia (16ºS) under the current climate condition and three types of global warming conditions. The simulation is carried out for thirty years. Mass balance and glacial melt were estimated for each 50m elevation zone with Enhanced Temperature Index (ETI) model. Four type of meteorological dataset for the input to ETI model are produced; one assume current climate condition based on observation and the other three assume temperature rise ratio of 0.024, 0.034 and 0.044°C/year derived from general circulation models.
 Simulation under the current climate condition shows that glacial area and meltwater decrease to 4% and 52% of present by the end of next three decades. Accumulation and abluation area reach equilibrium condition by next one decade. The other simulations under different temperature rise also show that glacier does not disappear in the next three decades although the response of glacier shrinking to climate change becomes high with temperature rise. Glacial area decrease by 21-44% of present by the end of next three decades. Annual meltwater is 12% increase to 39% reduction. There are large uncetainties of glacier metl for 30years due to high altitudinal distribution of glacieal area around Equilibriun-Line Altitude.

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 The objective of this research is to study the relationships between the biomass of the submerged aquatic vegetation, the nutrients, and the primary production in the Condoriri River. Field measurements were conducted to determine variations of physicochemical parameters, biomass, and nutrients in water and aquatic plants during dry and wet seasons. Macrophyte biomass had correlations of negative gradients with electric conductivity (EC) (R²=0.33, P<0.03) and phosphorus content (R²=0.47, P<0.01). Alkaline pH>7.5 and EC (132.5 μS·cm^-1) affected the growth of the aquatic plants. The nutrient loads during the wet season were related to high macrophyte biomass. Submerged aquatic vegetation influenced the river metabolism in both seasons. Primary production and macrophyte biomass exhibited a good agreement (R²=0.79).

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 Almost river length was very short and steep slope in Kagawa Prefecture. The flood occurs and it becomes a problem in the river especially. It is necessary to manage usually so that the river shape may influence at the flood. From this reason, it is important to grasp the river characteristics at the flood. However, in order to obtain frequent topography data at a river, it is necessary to expend large amounts of time and cost. Therefore, if it is possible to estimate river characteristics from numerical simulation, it will be practically effective for river management.
 In this study, river characteristics are investigated through river cross-section surveying. Moreover, reproducibility of flood was discussed by numerical calculation using one and two-dimensional model and two-dimensional model which considered drag coefficient of vegetation.

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 Tropical Cyclone (TC) activity is an important feature of China's climate that can have important impacts on precipitation and cause extensive property damage. In particular, precipitation from TCs contributes a significant portion of overall precipitation in China. This study deals with TCs that influenced China and focus on TC precipitation's temporal and spatial regularity analysis. Surface TC precipitation datasets were generated by interpolation of precipitation contour maps based on station-observed precipitation from Typhoon Yearbook¹⁾ compiled by Shanghai Typhoon Institute of China Meteorological Administration (CMA_STI), and the interpolation results were verified by satellite-based derived precipitation data products from Fengyun(FY-2C)²⁾ geostationary Meteorological Satellite. Based on the interpolated precipitation data (STI), two aspects were found in this research. Firstly, the TC precipitation gradually decreased from the southeast to the northwest of China, and the main area of TC precipitation concentrated in the southeast of China, including Hainan, Fujian, Zhejiang and Guangdong, while the most significant TC precipitation fluctuations arise in Shanxi, Henan and Hebei provinces. Secondly, there is no trend that was detected to pass 95% confidence level in annual TC precipitation and maximum TC precipitation from 1951 to 2008 in China, but a cycle of 5.43 years based on 95% confidence level was detected to be existing for annual maximum TC precipitation in China.

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 The purpose of this study is to investigate the effects of heavy rainfall increased in recent years on the social infrastructure, and to make a proposal on strengthening design criteria for water management in the future. Damage surveys of the outflow of the railway embankment and river channel blockage by floodwood by Akita and Iwate heavy rainfall on August 9 , 2013 are carried out. The results of the surveys and analysis are as follows; (1) The damages of social infrastructure related to the shortage of cross-sectional area of river, and caused by combined factors consist of topography and land cover of the affected area and sediment, slope and vegetation of upstream area. (2)The cases resulted from lowness of river improvement rate and development priority of small rivers. (3)To reduce damage in the future, it is necessary to accumulate data of the complex factors around the infrastructure at the time of heavy rainfall and to develop the knowledge by analysis.

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 MPS method is a Lagrangian numerical analysis method, which does not necessary to set the lattice. Thus, it is effective for the analysis with complicated boundary such as free surface flow. On the other hand, since it is possible that particles varying the relative position of each other in MPS method, it courses a problem of non-uniformity occurs in the spatial distribution of the particles, thereby generating pressure fluctuation. The pressure fluctuation problem has been considered as the most important issue towards the practical use of particle method.
 So far there are some ways to solve the problem, but the pressure fluctuation can not be erased fundamentally. To deal with the problem, Tamai, Koshizuka had proposed the higher-order accuracy differential model that can properly take into account the spatial arrangement of the particles. But so far this model has not been well verified when applied to uncompressible flow simulation.
 The present study has firstly comfirmed that compare to the old methods, Tamai, Koshizuka's new model can solve the issue more effectively. Secondly, we try to use the new model to simulate the static pressure distribution but found that it has problems when dealing with the Neumann boundary condition. So that we proposed a way of setting the Neumann boundary condition when using the new differential model and got a very good result in static pressure simulation.

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 Pakistan experienced an extreme rainfall event in July to August 2010. Two of the major contributing factors behind this extreme event were upper level stagnant blocking over western Russia and meandering pattern of Indian monsoon. In this study, monsoon patterns were identified. The kind of monsoon pattern that affected 2010 Pakistan flood consists of 64% of total flooding events in Pakistan. We focus on sea level pressure anomaly on 3 identified patterns of monsoon meandering. In 2010 Pakistan flooding case, the sea level pressure anomaly over the Middle East was lower, whereas, the anomaly over Northwestern Russia was higher. Moreover, 2010 Pakistan flooding case was affected by stagnant upper level (500hPa) blocking to descend cold air from Siberia to Pakistan. The number of monsoon meandering pattern which affects Pakistan flood tended to increase from June to August. On the other hand, the number of simultaneous occurrence of upper level blocking tended to decrease from June to August.

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 To understand impacts of global warming on benthos communities in stream ecosystems, we analyzed relations of macroinvertebrate densities to water temperature conditions in a set of headwater reaches with various altitude, ranging from 100 to 850m, within the Natori River System. We ran a distributed hydro-thermal model with input data of air temperature in future scenarios (near and far future) and projected changes in water temperature in the headwater reaches in the futures using 8 global climate models (GCMs). We projected the density of benthic macroinvertebrates in the futures using the estimated water temperature as a predictor variable of simple linear regression models obtained in the headwater reaches under present conditions. Considering lower marginal ranges in uncertainty of the density of Plecoptera, it might decrease as much as 85% of present densities or extinct even in the near future with the lowest or highest radiative forcing, respectively.

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 Object of this study is to predict distribution of dioxin deposited on the bottom of Tokyo Bay by means of a 3-dimensional flow model linked with a diffusion model. On the basis of the load fluxes from rivers, the distribution of concentration (separately for dissolved dioxin and small and large particulate dioxin) in seawater and mass of dioxin sedimentation to the bottom of the bay were calculated by the models.
 We have divided the bottom sediment layers into 3 layers: the boundary layer (between sea water layer and the particle layer), the bioturbated layer, and the diffusion layer; and constructed an analysis model that treats the coupling of matter between sea water and the bottom sediment layer.
 Results were compared to the published observation data in order to examine applicability of the used models.
 Estimated dioxin concentrations in the sediment show good agreement with the observed data.
 From the analysis, it was estimated that 80% of the dioxin inflow into the bay is deposited onto the bottom, and that 16% flow out of the bay. Dioxin sedimentation is greater in the inner and middle parts of the bay, and decreases in the direction toward the bay entrance.

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 In Okinawa Island, the nature restoration project with the river improvement is essential to the river environmental regeneration, which induces the restoration of ecosystem in river and brackish water region. The results of water quality survey, river fish investigation and potential analysis of river environmental activity are employed and analyzed to classify and evaluate 61 rivers in Okinawa Island for the nature restoration planning. The water quality survey for DO, turbidity, T-N and T-P represents the evaluation of pollution load from the catchment area and the information of fish habitats, for the influence of river structures. The analysis revealed the priority of the nature restoration project among 61 rivers in Okinawa Island. The rivers in central region of Okinawa Island are found to have high priority on the nature restoration project.

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 In Mekong river basin, population increase and economic growth may cause the water pollution problem in the future. This study aimed to assess spatial water quality environment in main stream and tributaries of Mekong river. For that purpose, liner regression model to estimate unit of nutrient pollution loading and water circulation model to estimate river discharge were developed, and then river nutrient concentration was also calculated. As a result, estimated unit of nutrient pollution loading expressed the characteristics of wastewater treatment process and agricultural level in Mekong river basin. Calculated river discharge and annual average river nutrient concentration were good agreement with observed data.

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