Spatio-temporal Distribution Of Seismic Disasters And Emergency Response

As earthquake disaster is one of the most severe natural disasters in China, the rapid analysis of spatio-temporal distribution of disasters and the studies on follow-up emergency responses have important theoretical and practical significance, which are the current focused issue of disaster management studies and arise general interests of governments at different levels as well.Since it is a comprehensive multidisciplinary research, involving structural geology, sociology, disaster management, public administration, crisis management and many other research fields, earthquake disaster studies must investigate the various aspects of the sequence chain of "earthquake-earthquake disaster-disaster response" within a multidisciplinary framework. However, the present studies have some shortages. For example, the scale of spatio-temporal distribution of earthquake disaster studies has limited application values on a particular emergency response event; structural geology focuses on the occurrence and evolution patterns of earthquakes, and emphasizes the natural properties of the disasters while is relatively weak in the study on its application to the post-earthquake relief mission. Furthermore, there is no detailed study on commanding management in the disaster relief mission and lack of theoretical basis and models for reference. These are worth in-depth studies.Oriented from the response to earthquake disasters, this thesis analyzes the spatio-temporal distribution of disasters and studies the following emergency response and rescue mission within the temporal and spatial framework of a specific earthquake. In space, taking the links between the foreland structural belt of the Longmen Shan Mountain and the disaster spatial distribution of the Wenchuan earhquake in 2008 as a case study, the paper studies the current structural patterns and features of disasters spatial distribution in the geographical environment by using the GIS spatial analysis, overlay analysis methods and the likes, in order to acquire the regularity of spatial distribution of earthquake disasters, and to establish a conceptual model of disaster damage based on the large-scale thrust nappe structure belt zone, thus to propose several major spatial modes of earthquake disaster rescue. In time, on the basis of the analysis on time successions of disaster situations after several major earthquakes, the paper selects death and injuered as index, by applying the statistical analysis, obtains the developing regularity of several major disaster indexes with time. Through this research, the thesis concludes the following results:(A) Spatio-temporal distribution of earthquake disasters in the disaster responseIn a specific earthquake response within the temporal and spatial framework, the current pattern of geological structure is the main constraints an earthquake disaster spatial distribution. The influences of structural changes before and after earthquakes on the disasters spatial distribution can be neglected. As the time of primary earthquake disaster is short, the major constrains on the disaster time distribution are the cognitive level and characteristic of the human beings, i.e., the social acquirement ability and level of earthquake disasters. Therefore, for the study on temporal and spatial distribution of earthquake disasters, this work will focus on the following two aspects:â…°) studying the spatial distribution of earthquake disasters from current geological structures;â…±) studying the time distribution of earthquake disaster damage from people's cognitive process on the disaster situation.(B) Spatial distribution of earthquake disaster1, According to the segmentation of in thrust and strike of the Longmen Shan mountain structural belt, the paper divides the Longmen Shan Mountain thrust structural belt into nine sub-regions. The comparison of different damage indexes of the Wenchuan Earthquake, such as, earthquake surface rupture zones, landslide collapses, damaged lakes, water conservancies and hydropower plants, aftershocks and seismic intensity which indicates the comprehensive disaster damages and so on, shows that the middle section of the Houshan belt is the worst damage area, the northern section of the Houshan Belt and middle section of the Qianshan belt are heavier damage ones, the northern part of the Qianshan Belt is moderately damaged, and the other sub-regions are slightly damaged.2, Establish the damage conceptual models based on zonation of the nappe structural beltThe thrust fault (normal to the direction of thrust) which controls zonation in the nappe direction is the first class influence factor of earthquake disaster damage distribution. And, in the large or giant nappe structure zone and perpendicular to the thrust fault, the tear fault which regulates the energy is the second class influence factor. Among these two influence factors, the catastrophic damages are still impacted by large scale specific sites and local environment. For example, the distribution of slides in the sub-zones and the XI degree formation in Yingxiu County are more or less obviously affected by the rigid blocks of the western Yangtze block in the Houshan belt. (C) Spatial distribution of professional rescue forces1. The first 3-day series of temporal and spatial distribution of the professional earthquake rescue forces after the earthquake reflecting the obvious movements from south to north of rescue forces (especially the external rescue forces) shows that the understanding of the damages in space is processing from the epicenter to the northeast. By analysis of the marching routes of cross-region professional teams and integrating the features of nappe structural terrain and the studies of spatial distribution of the Wenchuan earthquake damage, the thesis constructs a 3-category commanding management mode and the comb-shape spatial distribution form of rescue forces, then further develops an inter-regional earthquake catastrophic relief management framework and six spatial forms of rescue forces, and the rescue routes in different forms.2, The thesis analyzes the results of the Wenchuan earthquake rescue mission from different views ranging from the places where the rescue teams came from, the sources of disaster information, the elapsed time after the earthquake and the buried situation of victims. The analysis shows that even if the area suffered a lot, as the first professional forces who arrived the affected area, the provincial rescue teams were the major forces in rescuing the shallow buried survivors; and the effective information dissemination channel was a critical condition for a smooth and efficient operation; and the deeper the survivors were buried, the worser the rescue effects. More professional rescue teams with heavy equipments were needed.(D) Study of temporal distribution of disaster damages1, the overall trend of total earthquake disaster information is from zero up to saturation, reflecting the cumulative nature. Information increase is from zero to the maximum value then decreasing to zero. The incremental time to reach the maximum value is less than the saturation time of total information. From the mathematical concept, the time variation function of incremental is the derivative of that of total information.2. The change rate of the time curve of the deaths after the earthquake is non-homogeneous. In the initial period after the earthquake, there is a rapid growth process, the closer to the saturation the slower the time changes.The thesis selects 10 earthquake cases,4 of which are with more than 10,000 deaths. And the absolute numbers of deaths are all beyond 10,000 in the second day after the earthquake. In the other 6 cases with the death toll below 10,000, the absolute number of deaths in the second day is half of the total death toll. Most of them are over 80%. Due to the limits of the current acquisition technology, the information early obtained within 48 hours, or even within 24 hours, contributes a lot in determining the scales of the disaster. Currently, the efficiency in obtaining the death toll is relatively high, and using the real-time statistics of death toll after an earthquake to estimate the scale of disaster is also feasible.3, The death-time statistic is selected as the index and hour-increasing death index (K) is defined. In the 6 cases with more than 5,000 deaths, the increment K usually increases rapidly in 7 hours after the occurrence of earthquakes. The time of firstly reported the overall death numbers over 1,000 is mostly between 8-12 hours. To those earthquakes with about 1,000 death numbers, the time of firstly reported death toll over 100 mostly is within the same time span, but the time window tends to be less than 7 hours. To the major scale earthquake disaster, the information of disaster within 24 hours after the earthquake, especially the 8-16 hours is most important for determination of the disaster scales. Usually, the maximum K is within this time window which is valuable for the decision-making for earthquake emergency and relief mission.