Dynamic Assessment of Spatiotemporal Population Distribution Based on Mobile Phone Data: A Case Study in Xining City, China

Abstract High-resolution, dynamic assessments of the spatiotemporal distributions of populations are critical for urban planning and disaster management. Mobile phone big data have real-time collection, wide coverage, and high resolution advantages and can thus be used to characterize human activities and population distributions at fine spatiotemporal scales. Based on six days of mobile phone user-location signal (MPLS) data, we assessed the dynamic spatiotemporal distribution of the population of Xining City, Qinghai Province, China. The results show that strong temporal regularity exists in the daily activities of local residents. The spatiotemporal distribution of the local population showed a significant downtown-suburban attenuation pattern. Factors such as land use types, holidays, and seasons significantly affect the spatiotemporal patterns of the local population. By combining other spatiotemporal trajectory data, high-resolution and dynamic real-time population distribution evaluations based on mobile phone location signals could be better developed and improved for use in urban management and disaster assessment research

The Livelihood Vulnerability of Rural Households in Earthquake-Stricken Areas—A Case Study of Ning’er, Yunnan Province

Earthquakes happen suddenly and are immensely destructive. They not only destroy entire societal production and infrastructure systems but also seriously interfere with daily life and reduce opportunities to earn income in earthquake-affected areas. In this paper, using the Ning’er Ms 6.4 earthquake in 2007 as an example, we analyzed the livelihood vulnerability of rural households in Ning’er County, Yunnan, based on data from questionnaires and on-site interviews. The results showed that on the whole, local rural household livelihoods are relatively vulnerable in the earthquake-affected area of Ning’er. The main reason for the high level of vulnerability of rural households is the lack of single or multiple incomes. Due to the shortage of household income, the capacity of rural households to manage the aftermath of an earthquake is low. Improving the income allocation and transformation level and expanding methods of earning income is an effective way for rural households to decrease livelihood vulnerability in earthquake-prone areas. Some suggestions are given for local rural households to enhance their livelihood income levels in the event of earthquakes

Risk assessment of people trapped in earthquake based on km grid: a case study of the 2014 Ludian earthquake, China

China is one of the most earthquake-prone countries in the world. The highest-priority mission after an earthquake is to rapidly save lives, and to minimize the loss of life. Rapid judgment of the trapped personnel location is the important basis to identify the emergency supply demands and carry out the search and rescue work after the earthquake. Through analyzing the main influencing factors, we constructed an assessment model of people trapped in collapsed buildings caused by the earthquakes. The accuracy of the estimation results from the model was then tested against the actual investigation data in 2014 Ludian earthquake-hit area. Results showed that, the trapped personnel distribution assessed by this model is generally concordant with that obtained by the actual survey in Ludian earthquake. The grid-based assessment of people trapped in earthquakes can meet the requirements of key search and rescue zone identification and rescue forces allocation in the early stage of earthquake emergency. Although there were some limitations in the study, it offers a simple and rapid approach for assessing the trapped people losses based on basic empirical data. The approach can be further improved to provide more information and suggestions for earthquake emergency search and rescue

Scenario-based seismic vulnerability and hazard analyses to help direct disaster risk reduction in rural Weinan, China

Seismic vulnerability and hazard analyses play a significant role in comprehensive risk mitigation and seismic emergency planning, especially for the rural Weinan prefecture in northwestern China with a complex construction infrastructure and a high population density. Traditional methods assessing potential physical seismic damage prior to an earthquake are providing an incomplete picture for seismic risk assessments and post-disaster situations, and are insufficient for local authorities to plan mitigation strategies effectively. This study presents a novel perspective on scenario-based seismic vulnerability and hazard assessment. First, an in situ survey was carried out in three villages, Helan, Zhaojia, and Dongyu Village in the plain, loess, and mountain area respectively. Then, a quantitative analysis of building vulnerability and associated human homelessness under different seismic intensities was conducted based on the RISK-UE vulnerability index method. Finally, we estimated and analyzed other seismic impact scenarios. Results showed that the mean building vulnerability index is 0.69, 0.70, and 0.76 for Helan, Zhaojia, and Dongyu Village, respectively. Considering the possible displaced populations, Dongyu Village will have the highest proportion of homeless people. If an earthquake causes intensity greater than VII, Dongyu Village would suffer landslides and isolated-communication. The residents would have to rely on self-rescue and mutual rescue. These findings can be a potential guide to decision making in disaster risk reduction in rural Weinan

Creating an earthquake scenario in China: A case study in Weinan City, Shaanxi province

In efforts to address government-identified gaps between top-down policies and local-level preparedness approaches, a team from China, the UK and the US undertook a transdisciplinary, participatory project to develop an earthquake scenario for two administrative districts of Weinan, Shaanxi province, located east of Xi'an. We designed the scenario study and communication materials, a first of their kind in China, to help local agencies describe and communicate earthquake risk to local decision-makers and the public. Weinan was destroyed by the 1556 M8¼ Huaxian earthquake, China's deadliest so far, and damaged by the 1568 M~7 Shaanxi Gaoling earthquake (also known as the M6¾ Northeast Xi'an earthquake). We chose a repeat of this 1568 event, because earthquakes of the size of the 1556 Huaxian event are extremely rare in the Weihe basin (and similar tectonic environments worldwide). We modelled the ground motion of the 1568 event, prepared a loss estimate, conducted field charrettes comprising field work and local consultations, and carried out disaster issue-focused social surveys to understand Weinan's main earthquake risk problems. We used a storytelling approach to create two science-based narratives, in Chinese and English, of the scenario earthquake's aftermath. One is a short graphic novel with earthquake mitigation and preparedness tips for the general public; the other is a narrative story with technical content and recommendations for relevant local agencies. The narratives can help people visualize the estimated losses and impacts, and provide mitigation and preparedness recommendations that, if implemented, will help reduce earthquake damage and consequences