Dataset Information

Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake.

ABSTRACT: Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers influenced by the 2008 Wenchuan (Ms 8.0) Earthquake. The rivers flow from the Longmen Mountain with significant topographic relief to the flat Chengdu plain. In the upstreams, sediment supply increased because of the landslides triggered by the earthquake, causing deposition in the upstream mountain reaches. However, the downstream plain reaches suffered undercutting instead of deposition, and among those rivers, Shiting River was the most seriously affected, with the largest undercutting depth exceeding 20?m. The reasons for this unexpected undercutting are proposed herein and relate to both natural and anthropogenic causes. In addition, we also demonstrate, at least for certain conditions, such as rivers flowing from large-gradient mountain regions to low-gradient plain regions, that upstream sediment pulses may induce aggradation in upstream and degradation in downstream, causing the longitudinal profile to steepen to accommodate the increasing sediment flux.

SUBMITTER: Fan N

PROVIDER: S-EPMC5114544 | biostudies-other | 2016 Nov

REPOSITORIES: biostudies-other

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Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake.

Fan Niannian N Nie Ruihua R Wang Qiang Q Liu Xingnian X

Scientific reports 20161118

Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers influenced by the 2008 Wenchuan (Ms 8.0) Earthquake. The rivers flow from the Longmen Mountain with si ...[more]

PMID: 27857220

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Project description:IntroductionMultiple injuries have been highlighted as an important clinical dimension of the injury profile following earthquakes, but studies are scarce. We investigated the pattern and combination of injuries among patients with two injuries following the 2008 Wenchuan earthquake. We also described the general injury profile, causes of injury and socio-demographic characteristics of the injured patients.MethodsA retrospective hospital-based analysis of 1,871 earthquake injured patients, totaling 3,177 injuries, admitted between 12 and 31 May 2008 to the People's Hospital of Deyang city (PHDC). An electronic, webserver-based database with International Classification of Diseases (ICD)-10-based classification of earthquake-related injury diagnoses (IDs), anatomical sites and additional background variables of the inpatients was used. We analyzed this dataset for injury profile and number of injuries per patient. We then included all patients (856) with two injuries for more in-depth analysis. Possible spatial anatomical associations were determined a priori. Cross-tabulation and more complex frequency matrices for combination analyses were used to investigate the injury profile.ResultsOut of the 1,871 injured patients, 810 (43.3%) presented with a single injury. The rest had multiple injuries; 856 (45.8%) had two, 169 (9.0%) patients had three, 32 (1.7%) presented with four injuries, while only 4 (0.2%) were diagnosed with five injuries. The injury diagnoses of patients presenting with two-injuries showed important anatomical intra-site or neighboring clustering, which explained 49.1% of the combinations. For fractures, the result was even more marked as spatial clustering explained 57.9% of the association pattern. The most frequent combination of IDs was a double-fracture, affecting 20.7% of the two-injury patients (n = 177). Another 108 patients (12.6%) presented with fractures associated with crush injury and organ-soft tissue injury. Of the 3,177 injuries, 1,476 (46.5%) were fractures. Most injuries were located in the head (22.9%) and lower extremities (30.8%).ConclusionsMultiple injuries are put forward as an important component of the injury profile after this earthquake. A pattern of injury combinations and spatial aggregation of injuries was also found. Clinical diagnosis and treatment should be adapted to care of these patients. More studies are needed to generalize these findings.

Project description:BackgroundRelatively few studies have compared posttraumatic stress disorder (PTSD) symptoms following a disaster among children of different ethnicities. We sought to investigate the differences in PTSD symptoms between the ethnic Hui and Han child survivors of the 2008 Wenchuan earthquake in China.MethodsThis study collected data from 1,951 Han and 247 Hui child survivors of the 2008 Wenchuan earthquake in China. The children ranged from 7 to 15 years of age. Earthquake-related exposures were measured using a modified version of the PsySTART Rapid Triage System. PTSD symptoms were evaluated using the University of California, Los Angeles PTSD-Reaction Index (UCLA PTSD-RI). Personality characteristics were assessed using the Junior Eysenck Personality Questionnaire (JEPQ). Multiple linear regression was used to investigate the association between the ethnicity and the severity of PTSD symptoms. Multiple logistic regression was used to investigate the association between the ethnicity and the percentage of screening positive for PTSD symptoms.ResultsThe average UCLA PTSD-RI total score of the ethnic Hui group (27.01 ± 9.24) was significantly higher than that of the ethnic Han group (25.12 ± 9.17) (t = -3.05, p = 0.002), as were the avoidance/numbness (Hui: 10.02 ± 4.82; Han: 9.04 ± 4.60, t = -3.12, p = 0.002) and arousal scores (Hui: 9.36 ± 3.64; Han: 8.79 ± 3.42, t = -2.44, p = 0.015). The percentage of screening positive for D criteria (arousal symptoms) also differed significantly between the ethnic Han (41.9%, 95% CI [39.7-44.1%]) and Hui (48.6%, 95% CI [42.3-54.9%]) groups (χ2 = 3.97, p = 0.046). Ethnicity was associated with the avoidance/numbness symptom score following adjustments for sex, age, personality traits and earthquake exposure experiences by multiple linear regression (B: 0.61, 95% CI [0.04-1.17], p = 0.035). The initial significant associations between the ethnicity and the arousal symptoms score and the PTSD total score disappeared while adjusting for the subjective earthquake exposure experiences (Model 5: arousal symptoms, B = 0.41, 95% CI [-0.01 to 0.83], p = 0.056; PTSD, B = 1.00, 95% CI [-0.07 to 2.07], p = 0.066). The initial significant association between the ethnicity and the percentage of screening positive for D criteria disappeared while adjusting for the objective earthquake exposure experiences (Model 4: OR = 1.32, 95% CI [1.00-1.75], p = 0.052).ConclusionThis study is the first to report the relationship between the ethnicity and PTSD symptoms among child survivors following a disaster. The findings of this study suggest that the trauma-focused cognitive behavior therapy could also be an effective treatment for Chinese ethnic Hui and Han children who are suffering from PTSD. Future research could be designed to examine whether cultural differences in perceptions and interpretations may account for the variations in subjective experiences. More attention should be paid to the ethnic minority children with PTSD in the future.

Project description:BackgroundThe factors influencing pubertal timing have gained much attention due to a secular trend toward earlier pubertal onset in many countries. However, no studies have investigated the association between the Great earthquake and early puberty. We aimed to assess whether the Wenchuan earthquake is associated with early puberty, in both boys and girls.MethodsWe used data from two circles of a survey on reproductive health in China to explore the impact of the Wenchuan earthquake on early puberty , and a total of 9,785 adolescents (4,830 boys, 49.36%) aged 12-20 years from 29 schools in eight provinces were recruited. Wenchuan earthquake exposure was defined as those Sichuan students who had not experienced oigarche/menarche before May 12, 2008. Early puberty was identified as a reported onset of oigarche/menarche at 11 years or earlier. We tested the association between the Wenchuan earthquake and early puberty in boys and girls. Then, subgroup analysis stratified by the age at earthquake exposure also was performed.ResultsIn total, 8,883 adolescents (4,543 boys, 51.14%) with a mean (SD) age of 15.13 (1.81) were included in the final sample. In general, children exposed to the earthquake had three times greater risk of early puberty (boys, RR [95% CI] = 3.18 [2.21-4.57]; girls: RR [95%CI] =3.16 [2.65-3.78]). Subgroup analysis showed that the adjusted RR was 1.90 [1.19-3.03] for boys and 2.22 [1.75-2.80] for girls. Earthquake exposure predicted almost a fourfold (RR [95%CI] = 3.91 [1.31-11.72]) increased risk of early puberty in preschool girls, whereas the increase was about twofold (RR [95%CI] = 2.09 [1.65-2.64]) in schoolgirls. Among boys, only older age at earthquake exposure was linked to early puberty (RR [95%CI] = 1.93 [1.18-3.16]).ConclusionsWenchuan earthquake exposure increased the risk of early puberty in boys and girls, and preschoolers were more at risk than schoolchildren. The implications are relevant to support policies for those survivors, especially children, to better rebuild after disasters.

Dataset Information

Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake.

Publications

Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake.

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