Uncertainty Quantification for Multivariate Eco-Hydrological Risk in the Xiangxi River within the Three Gorges Reservoir Area in China

This study develops a multivariate eco-hydrological risk-assessment framework based on the multivari-ate copula method in order to evaluate the occurrence of extreme eco-hydrological events for the Xiangxi River within the Three Gorges Reservoir （TGR） area in China. Parameter uncertainties in marginal distri-butions and dependence structure are quantified by a Markov chain Monte Carlo （MCMC） algorithm. Uncertainties in the joint return periods are evaluated based on the posterior distributions. The proba- bilistic features of bivariate and multivariate hydrological risk are also characterized. The results show that the obtained predictive intervals bracketed the observations well, especially for flood duration. The uncertainty for the joint return period in ＂AND＂ case increases with an increase in the return period for univariate flood variables. Furthermore, a low design discharge and high service time may lead to high bivariate hydrological risk with great uncertainty.

An Interval Probability-based Inexact Two-stage Stochastic Model for Regional Electricity Supply and GHG Mitigation Management under Uncertainty

In this study, an interval probability-based inexact two-stage stochastic (IP-ITSP) model is developed for environmental pollutants control and greenhouse gas (GHG) emissions reduction management in regional energy system under uncertainties. In the IP-ITSP model, methods of interval probability, interval-parameter programming (IPP) and two-stage stochastic programming (TSP) are introduced into an integer programming framework;the developed model can tackle uncertainties described in terms of interval values and interval probability distributions. The developed model is applied to a case of planning GHG -emission mitigation in a regional electricity system, demonstrating that IP-ITSP is applicable to reflecting complexities of multi-uncertainty, and capable of addressing the problem of GHG-emission reduction. 4 scenarios corresponding to different GHG -emission mitigation levels are examined;the results indicates that the model could help decision makers identify desired GHG mitigation policies under various economic costs and environmental requirements.

Development of a random-forest-copula-factorial analysis(RFCFA)method for predicting propagation between meteorological and hydrological drought

In the context of global climate warming,the propagation of meteorological drought(MD)may aggravate the devastating impact of hydrological drought(HD)on water security and sustainable development.There are challenges in accurately predicting the propagation of drought and effectively quantifying the effects of uncertainty,especially in data-deficient regions.In this study,a novel method called RFCFA is developed through integrating random forest(RF),copula,and factorial analysis(FA)into a general framework as well as applied to the Aral Sea Basin(a typical arid and data-scarce basin in Central Asia)under considering the impact of climate change.Several findings can be summarized:(1)the projected future drought propagation probability of ASB is 39.2%,which is about 8%higher than historical level;(2)drought propagation is mainly affected by mean climate condition,catchment characteristics(i.e.,elevation,LUCC,and slope),and human activities(i.e.,irrigation and reservoir operation);(3)the lower propagation probability in spring is expected under SSP1-2.6 due to increased snow meltwater,and the drought propagation probability in autumn is the highest(reaching 45.4%)under the influence of reservoir operation;(4)the combined effects of meteorological conditions and agricultural irrigation can lead to a higher probability of future propagation in the upper river basin in summer.Findings are valuable for predicting drought propagation risk,revealing main factors and inherent uncertainties,as well as providing support for drought management and disaster prevention.

Perspectives on the impacts of climate change and their adaptation

The pressing impacts of climate change and the imperative for adaptation strategies emphasize the immediate necessity for proactive global measures.These challenges encompass the enhancement of climate modeling,the development of sector-tailored strategies,and the implementation of adaptation measures.Addressing these issues necessitates worldwide collaborations,sustainable practices,technological innovations.

Coupled planning of water resources and agricultural land-use based on an inexact-stochastic programming model

Water resources are fundamental for support of regional development. Effective planning can facilitate sustainable management of water resources to balance socioeconomic development and water conservation. In this research, coupled planning of water resources and agricultural land use was undertaken through the develop- ment of an inexact-stochastic programming approach. Such an inexact modeling approach was the integration of interval linear programming and chance-constraint pro- gramming methods. It was employed to successfully tackle uncertainty in the form of interval numbers and probabil- istic distributions existing in water resource systems. Then it was applied to a typical regional water resource system for demonstrating its applicability and validity through generating efficient system solutions. Based on the process of modeling formulation and result analysis, the developed model could be used for helping identify optimal water resource utilization patterns and the corresponding agri- cultural land-use schemes in more, a number of decision three sub-regions. Further- alternatives were generated under multiple water-supply conditions, which could help decision makers identify desired management policies.

Black titanium dioxide nanomaterials for photocatalytic removal of pollutants:A review

Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers.Recently,black TiO_(2)appears as a strong candidate in the improvement of sunlight harvesting,because of its excellent absorption capacity and utilization of solar radiation.Despite extensive applications in both environmental and energy fields,the use of black TiO_(2)as a photocatalyst in pollutant removal is ambiguous.The primary objective of the review is to comprehensively evaluate the applications of black TiO_(2)in photocatalytic removal of contaminants,including conventional organic contaminants,emerging contaminants,microbes,and heavy metals.The basic properties,photocatalytic mechanism,and synthesis of black TiO_(2)have been summarized and analyzed.Moreover,the stability and recoverability of black TiO_(2)have also been discussed.Finally,the perspectives of the application of black TiO_(2)in pollutant removal have been further discussed.

Total phosphorus accident pollution and emergency response study based on geographic information system in Three Gorges Reservoir area

In recent years,sudden water pollution accidents in China's rivers have become more frequent,resulting in considerable effects on environmental safety.Therefore,it is necessary to simulate and predict pollution accidents.Simulation and prediction provide strong support for emergency disposal and disaster reduction.This paper describes a new two-dimensional water quantity and the quality model that incorporates a digital elevation model into the geographic information system.The model is used to simulate sudden water pollution accidents in the main stream of the Yangtze River and Jialing River in the Chongqing section of the Three Gorges Reservoir area.The sectional velocity distribution and concentration change of total phosphorus are then analyzed under four hydrological situations.The results show that the proposed model accurately simulates and predicts the concentration change and migration process of total phosphorus under sudden water pollution accidents.The speed of migration and diffusion of pollutants is found to be greatest in the flood season,followed by the water storage period,drawdown season,and dry season,in that order.The selection of an appropriate water scheduling scheme can reduce the peak concentration of river pollutants.This study enables the impact of pollutants on the ecological environment of river water to be alleviated,and provides a scientific basis for the emergency response to sudden water pollution accidents in the Three Gorges Reservoir area.

An uncertain energy planning model under carbon taxes

In this study, an interval fuzzy mixed-integer energy planning model （IFMI-EPM） is developed under considering the carbon tax policy. The developed IFMI- EPM incorporates techniques of interval-parameter programming, fuzzy planning and mixed-integer programming within a general energy planning model. The IFMIEPM can not only be used for quantitatively analyzing a variety of policy scenarios that are associated with different levels of carbon tax policy, but also tackle uncertainties expressed as discrete intervals and fuzzy sets in energy and environment systems. Considering low, medium and high carbon tax rates, the model is applied to an ideal energy and environment system. The results indicate that reasonable solutions have been generated. They can be used for generating decision alternatives and thus help decision makers identify desired carbon tax policy.

Superwetting polyethersulfone membrane functionalized with ZrO_(2) nanoparticles for polycyclic aromatic hydrocarbon removal

Polycyclic aromatic hydrocarbons(PAHs)are persistent and widespread in the aquatic environment,causing potential hazards for human health.In this study,a superwetting and robust PES-PAA-ZrO_(2)nanofiltration membrane was proposed through surface modification for PAH removal with high efficiency.A ZrO_(2)coating was formed on polyethersulfone(PES)membrane surface through chemical bonding,thus the PES-PAA-ZrO_(2)membrane exhibited super-hydrophilicity,under-water oleophobicity,and excellent stability.In comparison with the original PES membrane,the water contact angle of the modified membrane was significantly decreased from about 50°to less than 10°,and quickly dropped to 0°within 1s.This provided a much lower energy barrier for water permeation due to its super-high water affinity.The wastewater treatment efficiency was increased by about 4 times after modification with more than 90%of PAH rejection rate.The excellent robustness of PES-PAA-ZrO_(2)membrane was verified under various conditions,which gave the membrane practical potential for long-term operation.