Assessing the characteristics of extreme precipitation over northeast China using the multifractal detrended fluctuation analysis

Abstract

[1] Extreme climate events have inflicted severe and adverse effects on human life, social economy, and natural ecosystems. In this study, the precipitation time series from a network of 90 weather stations in Northeast China (NEC) and for the period of 1961-2009 are used. An objective method, the multifractal detrended fluctuation analysis method, is applied to determine the thresholds of extreme events. Notable occurrence frequency and strong intensity of extreme precipitation (EP) mainly occur in Liaoning Province and the piedmont regions in Changbai Mountains and Xiao Hinggan Mountains. Generally, EP frequency shows a nonsignificant negative trend, whereas EP intensity has a weak and nonsignificant positive trend for the entire NEC in the period of 1961-2009. To assess EP severity, we propose an EP severity index (EPSI) combining both EP frequency and intensity, rather than separately analyze the EP frequency or intensity. Spatial gradients of EPSI are observed in northeast-southwest and northwest-southeast directions over NEC. The EPSI in northwestern and southeastern NEC are low (0.02-0.3), whereas high EPSI (0.34-0.83) occurs in the southwestern and northeastern portions of the region. Higher EPSI (0.4-0.83) occurs in southern Liaoning Province, which decreases along the southwest-northeast direction. The spatial patterns of EPSI are associated with the circulation over East Asia. Areas that have a short distance from sea and that locate in the windward slope of mountain will probably accompany high EP severity over NEC.

Did streamflow or suspended sediment concentration changes reduce sediment load in the middle reaches of the Yellow River?

“…For the proportion of trend comparison in different percentiles, daily series were normalized before applying the M-K test and Sen's slope estimation by equation (Du et al, 2013) …”

Large scale climate and rainfall seasonality in a Mediterranean Area: Insights from a non‐homogeneous Markov model applied to the Agro‐Pontino plain

“…Different criteria may be used to define extreme precipitation. (Du et al, ; Du, Wu, Zong, Meng, & Wang, ): a) absolute or arbitrary or fixed threshold method (Jones et al, ; Klein Tank & Können, ; Bell, Sloan, & Snyder, ); b) standard deviation method (Henderson & Muller, ; Gong & Ho, ), which considers events that exceed k‐standard deviations from the long‐term mean; c) percentile‐based method (Xu, Xu, Gao, & Luo, ; Huang, Qian, & Zhu, ; Kothawale, Revadekar, & Rupa Kumar, ; Li, Zheng, Liu, & Flanagan, ; Xu, Du, Tang, & Wang, ), where the exceedance of a specified percentile of the empirical marginal distribution is used to define the event.…”

Investigating the variation and non-stationarity in precipitation extremes based on the concept of event-based extreme precipitation

“…The determination of threshold is a key factor in the generation of EP series. Du et al (2013) grouped the methods of threshold determination into three categories: the fixed value method, the standard deviation method and the percentile-based method. In practice, the percentile-based method were widely used in many regions over the world because of its efficiency and simplicity (Bell et al, 2004;Wang and Zhou, 2005;Du et al, 2013).…”

“…Du et al (2013) grouped the methods of threshold determination into three categories: the fixed value method, the standard deviation method and the percentile-based method. In practice, the percentile-based method were widely used in many regions over the world because of its efficiency and simplicity (Bell et al, 2004;Wang and Zhou, 2005;Du et al, 2013). In most cases, the EP was based on the 90th (Gemmer et al, 2011), 95th (Bell et al, 2004;Zhai et al, 2005), 97.5th (Wang and Zhou, 2005) or 99th (Gemmer et al, 2011) percentiles of daily precipitation data, which represent moderate to extremely unusual events and were demonstrated to be appropriate in various regions (Alexander et al, 2006;Ghosh et al, 2012;Vittal et al, 2013).…”

“…Usually, frequency is defined as the number of EP per year, intensity is referred to the peak precipitation amount. However, Du et al (2013) argued that the commonly used intensity definition would be inappropriate sometimes, and hence proposed a modified intensity index by considering the local tolerance capacity (i.e., threshold), which was defined as the value of the precipitation amount exceeding the threshold divided by the corresponding threshold. They expected that, by comparing the EP events with different thresholds and precipitation amount, the modified index was more suitable than the usually used one.…”