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The simulated heatwaves alone caused such drastic negative effects on Deleatidium survival and mobility that mainly antagonistic interactions were observed with the other stressors, though delayed synergisms between imidacloprid and the second heatwave also affected mayfly mobility. Time-cumulative toxicity of imidacloprid was evident, with imidacloprid first affecting mayfly mobility after 12 days but eventually causing the strongest effects of all manipulated stressors. However, lethal effects of imidacloprid could only be detected in the absence of heatwaves and starvation, possibly as a result of selection for stronger individuals due to prior exposure to these stressors. Our findings demonstrate that heatwaves of increasing severity will critically affect sensitive freshwater organisms such as mayflies, and that the impacts of widespread pesticide use on freshwater ecosystems under global climate change cannot be ignored.Extreme floods caused by dam breaches, dike breaches, and rainstorms cause significant erosion and deposition in the flooded area. Furthermore, geomorphic changes have various impacts on different land use types, which is an important aspect extreme flood outcomes. The impact type and degree depend on geomorphic variations and land characteristics. However, neither the amount of geomorphic variations nor its impact on the inundation area have been fully understood. Firstly, we propose the use of a numerical simulation method to calculate erosion and deposition depths of the whole inundation area caused by extreme floods. Secondly, combined with the characteristics of erosion, deposition, and land use types, the impact type of geomorphic changes on different land use types were divided into positive, negative, and negligible impacts, and the impact degree was expressed by two indices of impact grade and impact score. In addition, the calculation methods of the two indices were put forward. Then, we propose a method for evaluating the impacts of geomorphic changes on the whole inundation area from five aspects of mesh, land use type, overall erosion region, overall deposition region, and overall inundation area. Combined with the simulation of the flood process caused by dam breach of Luhun Reservoir in China, this method was verified, and the results showed that (a) geomorphic changes had a negative impact on 94.7% of the inundation area, and only part of the water bodies were positively affected and the towns were not affected, accounting for 2.1% and 3.2% respectively; (b) the negative impact degree of each land use type in descending order was grassland, town, cropland, forest, shrubland and water body; and (c) the area of deposition was larger than that of erosion, whereas the severity of negative impact was opposite.We applied the global 3-D chemical transport model GEOS-Chem to examine the anthropogenic and meteorological contributions in driving summertime (JJA) surface ozone (O3) trend in China during the Clean Air Action period 2012-2017. The model captures the observed spatial distribution of summertime O3 concentrations in China (R = 0.78) and reproduces the observed increasing trends in two most populated city clusters North China Plain (NCP) and Yangtze River Delta (YRD). Trend of simulated maximum daily 8-h average (MDA8) O3 concentration is 0.58 ppbv yr-1 in NCP and 1.74 ppbv yr-1 in YRD in JJA 2012-2017. Sensitivity studies show that both changes in anthropogenic emissions and meteorology favored the MDA8 O3 increases in these two regions with respective contributions of 39% and 49% in NCP, and 13% and 84% in YRD. In NCP, the 49% meteorology impact includes a considerable contribution from natural emissions (19%). Changes in biogenic VOCs, soil NOx, and lightning NOx emissions are estimated to enhance MDA8 O3 in NCP with a rate of 0.14, 0.10, and 0.14 ppbv yr-1, respectively. In YRD, natural emissions made small contributions to the MDA8 O3 trend. Statistical analysis shows that higher temperatures and anomalous southerlies at 850 hPa in 2017 relative to 2012 are the two major meteorological drivers in NCP that favored the O3 increases, while weaker wind speed and lower relative humidity are those for YRD. We further examined the trend of fourth highest daily maximum 8-h average (4MDA8) O3 among a specific month that linked with extreme pollution episodes. Trends of simulated 4MDA8 O3 in NCP and YRD are 34-46% higher than those of MDA8 O3 and are found more meteorology-induced. Our results suggest an important role of meteorology in driving summertime O3 increases in China in recent years.Benthic macroinvertebrate communities are used as indicators for anthropogenic stress in freshwater ecosystems. To better understand the relationship between anthropogenic stress and changes in macroinvertebrate community composition, it is important to understand how different stressors and species traits are associated, and how these associations influence variation in species occurrence and abundances. selleck chemicals llc Here, we show the capacity of the multivariate technique of double constrained correspondence analysis (dc-CA) to analyse trait-environment relationships, and we compare it with the redundancy analysis method on community weighted mean values of traits (CWM-RDA), which is frequently used for this type of analysis. The analyses were based on available biomonitoring data for macroinvertebrate communities from the Danube River. Results from forward selection of traits and environmental variables using dc-CA analyses showed that aquatic stages, reproduction techniques, dispersal tactics, locomotion and substrateple anthropogenic stressors and ecosystem health, but more data sets should be analysed in the same manner.A simple and rapid method employing non-suppressed ion chromatography with electrospray ionization tandem mass spectrometry has been developed for the direct determination of trace-level haloacetic acids (HAAs) in water samples. Using 70/30 (v/v) acetonitrile/1 M aqueous methylamine as the mobile phase, three IC columns - AS16, AS18 and AS24 from Thermo-Scientific - were tested, respectively, with the AS16 column exhibiting the best overall performance with respect to resolution and retention time. To assess the effects of mobile phase composition on retention time of HAAs, the AS16 column was further tested using (i) different proportions of acetonitrile to aqueous methylamine, (ii) different proportions of acetonitrile to aqueous solution at fixed methylamine concentrations, and (iii) different concentrations of methylamine at fixed proportions of acetonitrile to aqueous solution. With a low proportion of aqueous solution, van der Waals and/or hydrogen-bonding interactions appeared to play an important role in governing HAA retention, i.