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A new parameter optimization and uncertainty assessment procedure using the Bayesian inference with an adaptive Metropolis–Hastings (AM-H) algorithm is presented for extreme rainfall frequency modeling. An efficient Markov chain Monte Carlo sampler is adopted to explore the posterior distribution of parameters and calculate their uncertainty intervals associated with the magnitude of estimated rainfall depth quantiles. Also, the efficiency of AM-H and conventional maximum likelihood estimation (MLE) in parameter estimation and uncertainty quantification are compared. And the procedure was implemented and discussed for the case of Chaohu city, China. Results of our work reveal that: (i) the adaptive Bayesian method, especially for return level associated to large return period, shows better estimated effect when compared with MLE; it should be noted that the implementation of MLE often produces overy optimistic results in the case of Chaohu city; (ii) AM-H algorithm is more reliable than MLE in terms of uncertainty quantification, and yields relatively narrow credible intervals for the quantile estimates to be instrumental in risk assessment of urban storm drainage planning.

In this research, a novel framework is proposed for temporal downscaling rainfall records to address the problem of insufficient temporal resolution of rainfall during the refined hydrological simulation. This framework consists of three main steps: (1) The existence of the fractal features of the original rainfall series with different temporal scales (month, week, day, h) can be judged by the dominant frequency of Hilbert marginal spectrum, and geometric shape similarity of different time scales on the basis of the ensemble empirical mode decomposition (EEMD). (2) Based on the previous fractal interpolation theory, an improved algorithm that couples with a threshold to control the number of interpolation points for the specific interpolation intervals and a parameter to captures the high intermittentness of rainfall series is developed, which can achieve the conservation of the total rainfall quantity. (3) EEMD method is applied again to compare and evaluate the fit of the downscaled records to observed records from the perspective of IMF components, and various statistical indicators (e.g., root mean square error, correlation coefficient, Nash–Sutcliffe efficiency coefficient, fractal dimension) are applied to quantify the performance of improved fractal interpolation algorithm. Three sets of observed hourly rainfall series (from 2016 to 2018) of Chaohu city, Anhui, China, were investigated using the new framework, EF (EEMD + improved fractal interpolation algorithm). First, in order to validate the applicability of the EF framework, the observed hourly rainfall sets were aggregated into daily, weekly, and monthly sets and subsequently, the EF framework was employed to downscale above sets back into daily and hourly scale. Then, a long-duration rainfall event with hourly scale in early July 2016 was downscaled to 5-min time series using EF framework and equipartition method, respectively. Finally, simulation results based on MIKE URBAN software were compared for EF framework and equipartition method. The results of our work reveal that: (a) EEMD is a reasonable identification tool for fractal characteristics of rainfall records. (b) the improved fractal interpolation algorithm not only reasonably preserves key statistical indices (e.g., low-order moments, autocorrelation, power spectra), but also captures the overall trends and inherent details of the rainfall. (c) Based on the digital simulation and model analysis, the storm sewer peak flows obtained by the EF framework are larger than that of equipartition method.

Characteristics, distribution, source, and ecological risk level of polycyclic aromatic hydrocarbons (PAHs) in sediments along Yangtze River Estuary Deepwater Channel were investigated. Total concentration of fifteen PAHs of study area ranged between 89.52 and 208.02 ng/g (mean value 140.48 ng/g). PAHs ratios and the statistical analysis showed that local fossil fuels high-temperature combustion (vehicular exhaust, anthropogenic combustion and pyrogenic sources) was the main PAHs origin. According to sediment quality guidelines (SQGs) and other criteria, the potential ecological risks of PAHs in sediments along Yangtze River Estuary Deepwater Channel are at low to medium levels, but the presence of dibenzo[a,h]anthracene (DBahAnt) requires more study and evaluation of potential toxicological effects.

This study examined physical and mental health, health symptoms, sensory and functional limitations, risk factors, and multimorbidity among older Medicare managed care members to assess disparities associated with race/ethnicity.We used data on 236,289 older adults from 208 Medicare plans who completed the 2012 Medicare Health Outcomes Survey to compare 14 health indicators across non-Hispanic whites, blacks, American Indians/Alaskan Natives, Asians, Native Hawaiians/Pacific Islanders, multiracial individuals, and Hispanics. Logistic regression models that clustered on the plan estimated the risk of indicators of adverse health and functional status.Even after controlling for key patient sociodemographic factors, race/ethnicity was significantly associated with most adverse health indicators. Except for Asians, all racial/ethnic minority groups were significantly more likely than whites to report poor mental health status, presence of most health symptoms, sensory limitations, and activities-of-daily-living disability. Important differences were observed across racial and ethnic groups.Despite some exceptions, elders of racial/ethnic minority background are generally at higher risk than non-Hispanic whites for a broad range of adverse health and functional outcomes that are not routinely assessed. Limitations include bias related to self-reported data and respondent recall. Future research should consider ethnic subgroup variations; employing newer techniques to improve estimates for smaller groups; and prioritizing and identifying opportunities for care improvement of diverse enrollee groups by considering specific needs. To improve the health status of the elderly, service delivery targeting the needs of specific population groups, coupled with culturally appropriate care for racial/ ethnic minorities, should also be considered.