Inflow Prediction for the Upstream Boundary Condition of the Chao Phraya River Model Using an Artificial Neural Network

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

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

洪水早期警報システムのためのチャオプラヤ川下流域統合モデル

チャオプラヤ川流域は国内生産の大部分を生み出すタイ国で最も重要な流域であるため, チャオプラヤ川の洪水はタイ国の経済に多大な損失をもたらす。本研究では, 早期洪水警報のための洪水予測情報を提供するために, 数値モデルが適用された。非定常流条件でHEC-RASがチャオプラヤ川本川の洪水流計算に適用される。この結果, 上流端, 下流端, 側方流の境界条件が必要となるが, これらはそれぞれANN, 調和解析, 多重線形回帰により推定される。河道のパラメータ, 河道内流量調整施設(チャオプラヤダム)のキャリブレーションにおいて, 相関係数が0.8以上, 境界条件の推定精度も相関係数90%以上が達成された。さらに本モデルを2011年の洪水に適用したところ, 1日先, 2日先, 3日先予測でそれぞれ98%, 96%, 95%の精度が得られた。Chao-Phraya river basin is the most important river basin in Thailand that produces the main country products; therefore, flood can make loss to the national economy. In this study, the mathematical models have been applied to prepare flood information for an early flood warning system. HEC-RAS is applied for discharge and water level simulation in the main channel of Chao-Phraya River with unsteady state condition; consequently, it required data in the upstream, downstream and lateral boundary that can be estimated by ANNs, Harmonic Analysis and Multiple Linear Regressions, respectively. The river channel parameter and inline structure calibration obtained 80% of correlation coefficient; besides, boundary data estimations can achieve the satisfied accuracy. Furthermore, the integrating of river flow model and boundary models obtained satisfied verification result during June to November, 2011. Thus, the integrated model can provide 4 days ahead of flood forecasting information.チャオプラヤ川流域は国内生産の大部分を生み出すタイ国で最も重要な流域であるため, チャオプラヤ川の洪水はタイ国の経済に多大な損失をもたらす。本研究では, 早期洪水警報のための洪水予測情報を提供するために, 数値モデルが適用された。非定常流条件でHEC-RASがチャオプラヤ川本川の洪水流計算に適用される。この結果, 上流端, 下流端, 側方流の境界条件が必要となるが, これらはそれぞれANN, 調和解析, 多重線形回帰により推定される。河道のパラメータ, 河道内流量調整施設(チャオプラヤダム)のキャリブレーションにおいて, 相関係数が0.8以上, 境界条件の推定精度も相関係数90%以上が達成された。さらに本モデルを2011年の洪水に適用したところ, 1日先, 2日先, 3日先予測でそれぞれ98%, 96%, 95%の精度が得られた。Chao-Phraya river basin is the most important river basin in Thailand that produces the main country products; therefore, flood can make loss to the national economy. In this study, the mathematical models have been applied to prepare flood information for an early flood warning system. HEC-RAS is applied for discharge and water level simulation in the main channel of Chao-Phraya River with unsteady state condition; consequently, it required data in the upstream, downstream and lateral boundary that can be estimated by ANNs, Harmonic Analysis and Multiple Linear Regressions, respectively. The river channel parameter and inline structure calibration obtained 80% of correlation coefficient; besides, boundary data estimations can achieve the satisfied accuracy. Furthermore, the integrating of river flow model and boundary models obtained satisfied verification result during June to November, 2011. Thus, the integrated model can provide 4 days ahead of flood forecasting information

The Effect of Irrigation Techniques on Sustainable Water Management for Rice Cultivation System - A Review

Rice serves as a fundamental sustenance for approximately half of the global population, particularly in Asia. Nevertheless, the cultivation of rice demands a substantial water supply, and the challenges associated with water deficits have been exacerbated by irregular rainfall patterns induced by global warming. Consequently, there is a critical need to reassess irrigation techniques to effectively tackle these issues. In this comprehensive review, the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) method was employed to systematically explore literature on irrigation techniques aimed at fostering sustainable water management in rice cultivation systems. The primary components of the framework encompass water consumption and water-related characteristics, soil-related characteristics, and plant-related characteristics, encompassing relevant components and indicators. Two alternative irrigation methods, namely alternate wetting and drying (AWD) and saturated soil irrigation (SSI), have been proposed to enhance water use efficiency (WUE) in rice cultivation compared to traditional continuous flooding (CF). These alternative irrigation methods do not adversely affect rice yield, both quantitatively and qualitatively. Furthermore, these alternative irrigation approaches have the potential to mitigate greenhouse gas (GHG) emissions, particularly methane emissions, in rice production. This review underscores the significance of data on alternate irrigation systems, providing valuable insights for researchers and policymakers in formulating strategies that align at every level for practical implementation. This is crucial as it is relevant to multiple organizations and stakeholders. Moreover, in the face of inclement weather conditions resulting from climate change, the study's findings indicate that research on farmers' adaptation, plant stress, and resilience within the rice cultivation system is still in its nascent stages. This highlights the pressing need for further exploration and advancement in these areas to develop effective strategies for coping with the challenges posed by climate change