Typhoon track change-based emergency shelter location-allocation model: a case study of Wenchang in Hainan province, China.

BACKGROUND: Determining the locations of disaster emergency shelters and the allocation of impacted residents are key components in shelter planning and emergency management. Various models have been developed to solve this location-allocation problem, but gaps remain regarding the processes of hazards. This study attempts to develop a model based on the change of typhoon track that addresses the location-allocation problem for typhoon emergency shelters. PURPOSE: To consider the changes in candidate shelters and number of evacuees due to the change in impact area with the progression of a typhoon. METHODS: The proposed model is composed of several static processes and solved by a modified particle swarm optimisation algorithm with a restart strategy. RESULTS: The model is illustrated with the case of the evacuation process for Wenchang in Hainan province during Typhoon Rammasun in 2014 and Typhoon Mirinae in 2016. For the case of Typhoon Rammasun in 2014, the residents from east to west need to evacuate in three phases. For the case of Typhoon Mirinae in 2016, residents in the northern communities need not to evacuate to candidate shelters because they are not affected by the typhoon. CONCLUSION: The proposed model has advantages compared with non-typhoon track change-based model in saving time spent in shelters for residents and saving public resources for the local governments. With the proposed model, a manager could efficiently evacuate residents by considering the typhoon conditions.

Increase of Elderly Population in the Rainstorm Hazard Areas of China.

In light of global warming, increased extreme precipitation events have enlarged the population exposed to floods to some extent. Extreme precipitation risk assessments are of great significance in China and allow for the response to climate change and mitigation of risks to the population. China is one of the countries most influenced by climate change and has unique national population conditions. The influence of extreme precipitation depends on the degree of exposure and vulnerability of the population. Accurate assessments of the population exposed to rising rainstorm trends are crucial to mapping extreme precipitation risks. Studying the population exposed to rainstorm hazard areas (RSHA) at the microscale is extremely urgent, due to the local characteristics of extreme precipitation events and regional diversity of the population. The spatial distribution of population density was mapped based on the national population census data from China in 1990, 2000 and 2010. RSHA were also identified using precipitation data from 1975-2015 in China, and the rainstorm tendency values were mapped using GIS in this paper. The spatial characteristics of the rainstorm tendencies were then analyzed. Finally, changes in the population in the RSHA are discussed. The results show that the extreme precipitation trends are increasing in southeastern China. From 1990 to 2010, the population in RSHA increased by 110 million, at a rate of 14.6%. The elderly in the region increased by 38 million at a rate of 86.4%. Studying the size of the population exposed to rainstorm hazards at the county scale can provide scientific evidence for developing disaster prevention and mitigation strategies from the bottom up.

Scenario-Based Multi-Objective Optimum Allocation Model for Earthquake Emergency Shelters Using a Modified Particle Swarm Optimization Algorithm: A Case Study in Chaoyang District, Beijing, China.

The correct location of earthquake emergency shelters and their allocation to residents can effectively reduce the number of casualties by providing safe havens and efficient evacuation routes during the chaotic period of the unfolding disaster. However, diverse and strict constraints and the discrete feasible domain of the required models make the problem of shelter location and allocation more difficult. A number of models have been developed to solve this problem, but there are still large differences between the models and the actual situation because the characteristics of the evacuees and the construction costs of the shelters have been excessively simplified. We report here the development of a multi-objective model for the allocation of residents to earthquake shelters by considering these factors using the Chaoyang district, Beijing, China as a case study. The two objectives of this model were to minimize the total weighted evacuation time from residential areas to a specified shelter and to minimize the total area of all the shelters. The two constraints were the shelter capacity and the service radius. Three scenarios were considered to estimate the number of people who would need to be evacuated. The particle swarm optimization algorithm was first modified by applying the von Neumann structure in former loops and global structure in later loops, and then used to solve this problem. The results show that increasing the shelter area can result in a large decrease in the total weighted evacuation time from scheme 1 to scheme 9 in scenario A, from scheme 1 to scheme 9 in scenario B, from scheme 1 to scheme 19 in scenario C. If the funding were not a limitation, then the final schemes of each scenario are the best solutions, otherwise the earlier schemes are more reasonable. The modified model proved to be useful for the optimization of shelter allocation, and the result can be used as a scientific reference for planning shelters in the Chaoyang district, Beijing.

Correlation between SNPs in CDH1 and gastric cancer in Chinese population.

BACKGROUND: Many recent studies revealed that the single nucleotide polymorphisms have considerable effects on the susceptibility of cancer, such as prostate cancer, lung cancer and gastric cancer. The E-cadherin, a calcium-dependent transmembrane glycoprotein encoded by CDH1 gene, is critical for epithelial construction, intercellular adhesion and cell migration. Some associations have been reported between single nucleotide polymorphisms and gastric cancer in the Chinese population. OBJECTIVE: To investigate whether the single nucleotide polymorphism in CDH1 gene is associated with the susceptibility of gastric cancer in the Chinese population. MATERIAL AND METHODS: The genotypes of 5 known single nucleotide polymorphisms (rs33935154, rs121964871, rs121964874, rs121964875, rs121964876) were determined in 359 gastric cancer patients and 368 healthy controls. High resolution melting curve detection and sequencing analysis were used in the present study. RESULTS: There is a statistical significance in the rs121964871 C>G polymorphism between gastric cancer patients and healthy controls (OR=1.769, 95%CI: 1.051-2.976). Elderly male individuals (>50 years of age) carrying this risk factor may be more susceptible to gastric cancer. CONCLUSIONS: The results indicated that the rs121964871 C>G polymorphism is associated with the susceptibility of gastric cancer in the Chinese population, with some age and sex-dependent tendencies observed.