Spatial Distribution of Runoff Discharges Considering Wadi Channel Flow with Upscaling Technique Based on Homogenization

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

An Approach to the Adaptive Flood Control by Multi-Reservoir Systems

The aim of this study is to establish a procedure for the adaptive flood control by multi-reservoir systems. The multi-reservoir systems have several reservoirs located in series, parallel, or mixed type and several flood defence points. The foundamental idea is to combine the typhoon simulation techniques with the optimal operation techniques based on Dynamic Programming. That is to say, at every control time, many typhoons are simulated according to the stochastic structures of a typhoon. And for each simulated typhoon, an optimal release flow at the control time will be decided in a sense of a probability of exceedance, or a safety rate based on the frequency distribution estimated from the set of the above optimal release flow. Of course, the simulated results antecedent to the control time will be compared with the observed ; and through the feedback loop, the characteristic parameters will be corrected. From this point of view, we may consider this procedure as an approach to “the adaptive flood control”

Tide Prediction for the Downstream Boundary Condition of the Chao-Phraya River Integrated River Model Using Harmonic Analysis

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Salinity intrusion: its characteristics and impact - cases in the Asia Pacific region

[Abstract]: Anthropogenic impacts on hydro-geological systems can result in long term harm and the degradation of the resource if they are not adequately managed. While this is well known, and witnessed around the world, management options to prevent increasing damage to the surrounding environment are being developed on an individual site basis. Salinity intrusion with the eventual degradation of both land and water quality is one of the most common examples of this type of problem. This paper presents our observations and analyses of salinity intrusion at selected areas in the Asia Pacific region, namely in New Zealand, Australia, Japan and Sri Lanka. It discusses the characteristics of each site and analyzes the impacts on the environment. It also presents the management practices used to mitigate the resulting damage on the environment at each site

Optimal Planning of Flood Control Systems Based on Screening, Simulation and Sequential Models

The aim of this study is to establish the optimal flood control system accounted for by the comprehensive criteria on the whole river basin. Especially, we will examine the effects of flood control projects in the system consisting of multi-sub-basin and multi-defense points against flood inundation probability in time and space. We define the planning problem of flood control projects as the minimization problem of the construction cost among all alternatives while satisfying the required safety rate for the prevention of flood inundation. First, the better alternatives are extracted by using the random search method. Second, the optimal system on the exact basin model is determined by appliaction of the simulation method for them. Lastly, the optimal construction order of the final system is gained by Dynamic Programming with the criteria that the expectation of the inundation damage under construction is minimized. So, we call the above three steps i) Screening model, ii) Simulation model and iii) Sequential model in flood control planning, respectively

不確実性を考慮した多目的貯水池操作に関する研究

水量・水質は，貯水池操作において考慮されるべき最も重要な要素である。本研究では，貯水池操作の新たな方法を提案し，Barra Bonita貯水池(ブラジル)に適用を行う。最適化手法と人工知能を用いることが特徴で，ファジイ確率的動的プログラミングを用い，多数のファジイ目的を最適化することにより適切な操作手順を算出する。水質解析は，ニューラルネットワークモデルにより行う。また，有機体や栄養物は，ファジイ回帰モデルにより河川流量の関数として表現する。Water quantity and quality are considered to be the main driving forces the reservoir operation.Barra Bonita reservoir, located in the southeast region of Brazil, is chosen as the case study forthe application of the proposed methodology. Herein, optimization and artificial intelligence(AI) techniques are applied in the simulation and operation of the reservoir. A fuzzy stochasticdynamic programming model (FSDP) is developed for calculating the optimal operationprocedures. Optimization is applied to achieve multiple fuzzy objectives. Markov chaintechnique is applied to handle the stochastic characteristics of river flow. Water quality analysisis carried out using an artificial neural network model. Organic matter and nutrient loads aremodeled as a function of river discharge through the application of a fuzzy regression modelbased on fuzzy performance functions. The obtained results show that the proposedmethodology provides an effective and useful tool for reservoir operation.水量・水質は，貯水池操作において考慮されるべき最も重要な要素である。本研究では，貯水池操作の新たな方法を提案し，Barra Bonita貯水池(ブラジル)に適用を行う。最適化手法と人工知能を用いることが特徴で，ファジイ確率的動的プログラミングを用い，多数のファジイ目的を最適化することにより適切な操作手順を算出する。水質解析は，ニューラルネットワークモデルにより行う。また，有機体や栄養物は，ファジイ回帰モデルにより河川流量の関数として表現する。Water quantity and quality are considered to be the main driving forces the reservoir operation.Barra Bonita reservoir, located in the southeast region of Brazil, is chosen as the case study forthe application of the proposed methodology. Herein, optimization and artificial intelligence(AI) techniques are applied in the simulation and operation of the reservoir. A fuzzy stochasticdynamic programming model (FSDP) is developed for calculating the optimal operationprocedures. Optimization is applied to achieve multiple fuzzy objectives. Markov chaintechnique is applied to handle the stochastic characteristics of river flow. Water quality analysisis carried out using an artificial neural network model. Organic matter and nutrient loads aremodeled as a function of river discharge through the application of a fuzzy regression modelbased on fuzzy performance functions. The obtained results show that the proposedmethodology provides an effective and useful tool for reservoir operation

確率論的短期間分布型洪水予測

本研究では，流域における洪水流出量の確率的短期間予測を提供するため，分布型流出モデルに適合する降雨入力データを発生させる確率論的降雨パターンシミュレーション過程を開発する。移流ベクトルによる降雨シミュレーションモデルを降雨パターンの発達による不確実性を考慮し修正することで，6時間にわたる予測降雨パターンの発生を可能にする。分布型でのアンサンブル短期間洪水流出予測を提供するために，モンテカルロシミュレーションを用いる。A framework is proposed for using distributed rainfall-runoff models for real-timeprobabilistic flood forecasting. A stochastic rainfall pattern simulation model capable ofgenerating input for a distributed rainfall-runoff model is developed to facilitate a short-termprobabilistic forecast of river discharge at multiple locations in a watershed. Generation ofrainfall patterns over a 6-hour period is achieved using a translation vector rainfall forecastingprocess modified to account for uncertainties in rainfall pattern development. The stochasticrainfall generation model is coupled with a distributed rainfall-runoff model in a Monte-Carlosimulation to provide a short-term ensemble forecast of distributed flood discharge. Anadaptive updating procedure for the real-time reduction of forecast error suitable for use witha distributed rainfall-runoff model is developed for the system. An example application of theproposed probabilistic flood stage forecasting system is provided for a typhoon event thatoccurred in the vicinity of the Nagara River watershed located in Gifu, Japan.本研究では，流域における洪水流出量の確率的短期間予測を提供するため，分布型流出モデルに適合する降雨入力データを発生させる確率論的降雨パターンシミュレーション過程を開発する。移流ベクトルによる降雨シミュレーションモデルを降雨パターンの発達による不確実性を考慮し修正することで，6時間にわたる予測降雨パターンの発生を可能にする。分布型でのアンサンブル短期間洪水流出予測を提供するために，モンテカルロシミュレーションを用いる。A framework is proposed for using distributed rainfall-runoff models for real-timeprobabilistic flood forecasting. A stochastic rainfall pattern simulation model capable ofgenerating input for a distributed rainfall-runoff model is developed to facilitate a short-termprobabilistic forecast of river discharge at multiple locations in a watershed. Generation ofrainfall patterns over a 6-hour period is achieved using a translation vector rainfall forecastingprocess modified to account for uncertainties in rainfall pattern development. The stochasticrainfall generation model is coupled with a distributed rainfall-runoff model in a Monte-Carlosimulation to provide a short-term ensemble forecast of distributed flood discharge. Anadaptive updating procedure for the real-time reduction of forecast error suitable for use witha distributed rainfall-runoff model is developed for the system. An example application of theproposed probabilistic flood stage forecasting system is provided for a typhoon event thatoccurred in the vicinity of the Nagara River watershed located in Gifu, Japan

Distributed Runoff Model Linking Surface with Groundwater Processes

統合的な水文過程を解析するために、Hydro-BEAM(Hydrological River Basin EnvironmentAssessment Model)をベースとした多層メッシュ型流出モデルを提案する。表面流出にはキネマティックウェーブモデルを、不飽和地中流にはリチャーズ式を、地下水流には非圧地下水モデルを用いて時空間的な解析がなされる。ここでは窪地貯留や樹冠遮断に伴う降雨の初期損失が考慮されている。さらに、貯水池操作や人間活動に伴う土地利用変化に対応するために、流域分割や土地利用のダイナミクスが導入されている。ここで提案するモデルは異なる初期条件やパラメータを用いてキャリブレーションされ、地表水と地下水の直接的な結合(dynamic linkage)を検証するために、野洲川流域に適用された。A method with multi-layer and mesh-typed runoff model using Hydro-BEAM(Hydrological River Basin Environment Assessment Model) is proposed to analyze theintegrated hydrological processes. The spatiotemporal simulation is calculated with thekinematic wave model for surface runoff, Richard's equation for unsaturated subsurfaceflow and the unconfined flow for groundwater. The initial loss of rainfall due tointerception by depression storage reprocess is considered here. Moreover the basindivision and land use dynamics are introduced to encounter reservoir operation andland utilization with human activities. The proposed model is calibrated for differentinitial conditions and parameters, and applied into the Yasu River to verify the dynamiclinkage between surface and groundwater.統合的な水文過程を解析するために、Hydro-BEAM(Hydrological River Basin EnvironmentAssessment Model)をベースとした多層メッシュ型流出モデルを提案する。表面流出にはキネマティックウェーブモデルを、不飽和地中流にはリチャーズ式を、地下水流には非圧地下水モデルを用いて時空間的な解析がなされる。ここでは窪地貯留や樹冠遮断に伴う降雨の初期損失が考慮されている。さらに、貯水池操作や人間活動に伴う土地利用変化に対応するために、流域分割や土地利用のダイナミクスが導入されている。ここで提案するモデルは異なる初期条件やパラメータを用いてキャリブレーションされ、地表水と地下水の直接的な結合(dynamic linkage)を検証するために、野洲川流域に適用された。A method with multi-layer and mesh-typed runoff model using Hydro-BEAM(Hydrological River Basin Environment Assessment Model) is proposed to analyze theintegrated hydrological processes. The spatiotemporal simulation is calculated with thekinematic wave model for surface runoff, Richard's equation for unsaturated subsurfaceflow and the unconfined flow for groundwater. The initial loss of rainfall due tointerception by depression storage reprocess is considered here. Moreover the basindivision and land use dynamics are introduced to encounter reservoir operation andland utilization with human activities. The proposed model is calibrated for differentinitial conditions and parameters, and applied into the Yasu River to verify the dynamiclinkage between surface and groundwater