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Rainfall–runoff modeling is a complex hydrological issue that still has room for improvement. This study developed a coupled bidirectional long short‐term memory (LSTM) with sequence‐to‐sequence (Seq2Seq) learning (BiLSTM‐Seq2seq) model to simulate multi‐step‐ahead runoff for flood events. The bidirectional LSTM with Seq2Seq learning (LSTM‐Seq2Seq) and multilayer perceptron (MLP) was set as benchmarks. The results show that: (1) root mean absolute error is reduced by approximately 19% up to 27%, and the Nash–Sutcliffe coefficient of efficiency is improved by 14% up to 34% for 6‐h‐ahead runoff prediction for BiLSTM‐Seq2Seq compared LSTM‐Seq2Seq and MLP; (2) The BiLSTM‐Seq2Seq model has good performance not only for one‐peak flood events but also for multi‐peak flood events; and (3) BiLSTM‐Seq2Seq can mitigate the time‐delay problem and time lag is shortened by 39% up to 69% in comparison to LSTM‐Seq2Seq and MLP. These results suggest that the time‐delay problem can be mitigated by BiLSTM‐Seq2Seq, which has excellent potential in time series predictions in the hydrological field. [ABSTRACT FROM AUTHOR]

Forecast errors of multiple information sources of a cascade hydropower system cause risks of water and energy supply in real‐time operation. Mechanisms minimizing multiple risks with budgeted cost under oscillations of multiple forecast uncertainties through robust operation are not yet well‐investigated. This study proposed a multiobjective robust optimization (RO) and decision‐making framework comprising series of models for risk analysis, robust control, and decision making. The risk analysis model identifies and analyzes dependent risks that stem from forecast errors of supply and demand‐side information by Copula functions. A RO model was established for minimizing risk probabilities, vulnerabilities of ecological protection, water and energy supply, as well as revenue loss from energy. Thereafter, a multiattribute decision‐making model was incorporated for determining the compromise solution from competing non‐dominated solutions. The proposed framework was applied to the cascade hydropower system of the Xiluodu, Xiangjiaba, Three Gorges project and Gezhouba reservoirs on the Yangtze River, China. The principal findings were as follows. (a) Addressing the singular forecast uncertainty of streamflow is inadequate to obtain robust solutions. (b) In a normal year, RO can reduce the average conditional value‐at‐risk of ecological water shortfall, consumptive water shortfall, and energy shortfall by 25.1%, 35.3%, and 16.5% than that of chance‐constrained programming. (c) Multiple risks are dispersed through risk avoidance and hedging that reduces outflow variance and homogenizes mean outflow, lowering down efficiencies of energy production and water usage as a tradeoff. The proposed model framework could be applied to inform operation of cascade hydropower systems. Key Points: Holistic multiobjective robust optimization model framework for reservoir operation under supply and demand uncertainties was developedConflicts of reducing risk probabilities, vulnerabilities, and revenue loss for ecological protection, water supply, and energy were quantifiedMechanisms of tradeoffs in multiobjective robustness with energy production through risk hedging and avoiding were discovered [ABSTRACT FROM AUTHOR]

Abstract: Multiple uncertainties exist in the optimal flood control decision‐making process, presenting risks involving flood control decisions. This paper defines the main steps in optimal flood control decision making that constitute the Forecast‐Optimization‐Decision Making (FODM) chain. We propose a framework for supporting optimal flood control decision making under multiple uncertainties and evaluate risk propagation along the FODM chain from a holistic perspective. To deal with uncertainties, we employ stochastic models at each link of the FODM chain. We generate synthetic ensemble flood forecasts via the martingale model of forecast evolution. We then establish a multiobjective stochastic programming with recourse model for optimal flood control operation. The Pareto front under uncertainty is derived via the constraint method coupled with a two‐step process. We propose a novel SMAA‐TOPSIS model for stochastic multicriteria decision making. Then we propose the risk assessment model, the risk of decision‐making errors and rank uncertainty degree to quantify the risk propagation process along the FODM chain. We conduct numerical experiments to investigate the effects of flood forecast uncertainty on optimal flood control decision making and risk propagation. We apply the proposed methodology to a flood control system in the Daduhe River basin in China. The results indicate that the proposed method can provide valuable risk information in each link of the FODM chain and enable risk‐informed decisions with higher reliability. [ABSTRACT FROM AUTHOR]

Cu-Au mineralization is rare in the Jurassic-Early Tertiary batholiths related to the India-Asia collision. Geochemical analysis and U-Pb isotope chronology was carried out on Shuangbujiere biotite hornblende granodiorite from the Zedong area. Zircon grains of the biotite hornblende granodiorite show oscillatory growth zonation and have high Th/U ratios of 1.08-2.39, indicating a magmatic origin for the zircons. Geochrological test yielded a LA-ICP-MS U-Pb age of 51.5±1.0 Ma, suggesting that the emplacement age of the biotite hornblende granodiorite is Early Eocene. The Shuangbujiere biotite hornblende granodiorites have geochemical features characteristic of adakite and are associated with a calc-alkaline metaluminous I-type granite enriched in Sr, high in Mg# (49.6-54.9) and Sr/Y, and depleted in Y and Yb. These results indicate that this intrusion formation may have been associated with crustal thickening caused by the early collision of the Indian and Eurasian Plates. As the process of crustal thickening continued, the heating of the underplated basaltic magma caused the thickened lower crust amphibolite to dehydrate the melt and form a high-K calc-alkaline adakitic melt at about 848°C. Meanwhile, magma mixing of the underplated basaltic melt and high-K calc-alkaline adakitic melt formed a high-Mg# adakite representative of the sys-collisional tectonic setting. [ABSTRACT FROM AUTHOR]

The article focuses on a research paper analyzing the platinum-group element (PGE) constraint on the origin mechanism of the Hetaoshu PGE deposit in the Xiaoguanhe Region in Panxi Area, China. The concentrations of PGE, copper and nickel in rock samples show that the ore forming elements consists of nickel and copper. It also evaluates the impact of sulfide segregation on the ore-forming process of Hetaoshu deposit.

The article discusses a study on lead isotopic geochemistry of Nuri copper-tungsten-molybdenum (Cu-W-Mo) Deposit and highlights its implications in Shannan Area, Southern Tibet, China. It mentions that ore sulphides of Nuri deposit have the same lead isotopic compositions as magmatic rocks. It states that ore sulphides have localized distributions within Gangdese batholith range. It also mentions that ore-bearing intrusions and ore sulphides have lead isotopic composition.

The article discusses the trace elements characteristics of rocks in Nuri, Tibet, China. Topics include emergence stratum of Nuri mine being characterized by Lower Cretaceous Bima Formation, use of ME-MS61r method to analysis the trace elements of rocks, and intrusive rock of Nuri Mine containing quartz diorite porphyry, granodiorite and quartz diorite.

The article presents a study that highlights characteristics of trace elements of rocks in Chengba mine, Tibet. The study shows that intrusive rocks of Chengba mine are depleted in high field strength elements such as zirconium and titanium and are enriched in large ion elements such as thorium and uranium. Also the study reveals that acidic intrusive rocks of Chengba has higher potassium oxide content and low magnesium oxide content.

The article offers information on the research "The Curves of Seven REE and Their Geological Significances of Porphyry Mo (Cu) Deposit of Chengba, Tibet, China" by Song Xuebing and colleagues. It concludes that the curve types of seven rare earth elements (REE) which significance is clearly useful in determining the successions of intrusive, interpreting the genesis and evolution of magma as well as analyzing the process of mineralization.