A flood is caused by excess water surpassing the limits of its confines. Electrical storms are composed of lightning and thunder, typically accompanied by heavy precipitation. Each storm forms in large cumulonimbus clouds (thunderheads) stretching one to five miles in diameter with a height of 25,000 feet. A hurricane is a destructive tropical cyclone in the western Atlantic Ocean with winds exceeding 74 miles per hour. Hurricanes are usually accompanied by electrical storms and typically occur during summer and early autumn. In a mere day, a hurricane can release the amount of energy necessary to satisfy the electrical needs of the entire United States for about six months. The causes of natural disasters are many. Human activities play a role in the frequency and severity of disasters. A natural disaster is a disruption in the balance of the environment. The human factor raises the cost, in both property damage and loss of life. Understanding the causes of natural disaster can provide clues to their prevention. Immediate Causes There are two general categories of earthquakes — volcanic and tectonic. The former are quakes generated by volcanic activity beneath the earth’s surface. The latter type is the result of shifts in the plates of the earth’s subterranean crust. Geologists are not positive as to what specific causes may precipitate earthquakes. There are four common theories. One view suggests that there are continents, ocean basins, mountains, and plains that are in a state of balance. Thus, these masses keep their balance by slowly adjusting. Another idea is that the earth is cooling off, hence, shrinking. As it shrinks, quakes occur. A third theory speculates that convection current takes place inside the earth’s core, so that the warmer, lighter parts rise, while the cooler, heavier regions fall. These variables allegedly initiate quakes. Finally, some scientists argue that the continents are gradually drifting apart as a result of an original, one-continent breakup. The movement is believed to cause disturbances within the earth. Some of these theories are based upon information (i.e., evolutionary) presuppositions (“the present is the key to the past”). Hence, to that degree they obviously are incorrect. A Catastrophic Cause For the Bible student, the greater question is this: Is there possibly an ancient cause that created conditions which facilitate the many earthquakes that happen throughout the world daily? Incidentally, about 50,000 earthquakes occur annually that are significant enough to be felt without the aid of instruments. About 100 are powerful enough to be destructive in a major way. Earthquakes are measured on a scale of 1 to 12. The first 5 stages usually do little damage; from 6 onward, quakes become more violent — plaster cracks, chimneys fall, and the ground cracks open. If an earthquake measures 12, there is far-reaching devastation. But is there possibly an “historical” cause that so changed the features of the earth, that our planet is yet reeling from the blow? Many scholars believe this concept is entirely feasible. The aim of this course is to present a state of the art viewpoint on the concept natural disasters in connection with the question of the vulnerability of societies. A central component of the course is to discern between which processes and phenomena are natural and which may be influenced by human activity, as well as how extreme conditions may lead to catastrophes. Human exposure and sensitivity to natural forces has increased as a result of increased population, urbanisation, expansion of infrastructures, increased exploitation of natural resources and emissions to water, ground, and air. The course discusses the spatial perspective of where on the surface of the earth extreme situations occur, examining why just there, and how this may be linked to societies and human habitats. In addition we consider the roll played by political and economic systems in regard of the consequences of natural disasters. In conclusion, the course approaches societies’ and different organisations’ risk awareness and contingency plans in anticipation of disaster situations, as well as the role of the mass media in this regard. The course runs as an evening course with one tuition occasion a week. Floods According to the U.S. Environmental Protection Agency (EPA), barring fire, floods are the most common natural disaster affecting Americans. Floods are a factor in 90 percent of natural disasters. Flood events have both natural and man-made causes. Storm events can create flood waters that exceed the capacity of the environment or man-made structures. Levees and dams provide a false sense of security as became evident during the Great Flood of 1993 in the Upper Mississippi River valley. A painful lesson was learned. Wetlands destruction removed a natural means to absorb flood waters. Fires Fires are nature's environmental managers. They create and maintain ecosystems such as prairies and pine forests. In fact, prairies evolved with the presence of fire. The health of the ecosystem is dependent on this disturbance. Fires remove a buildup of litter on the soil surface, allowing nutrients to be released into the environment. It also creates favorable conditions for seed germination. Suppression of fire allows litter to accumulate, setting the stage for catastrophic fires. Plants and trees have adapted to the presence of fire. However, the higher temperatures of crown fires can kill plants entirely. These fires are more difficult to control. Suppression of fires is expensive, upward of $1 billion annually, according to the U.S. Forest Service. Drought Drought has had more widespread effects than any other natural disaster. Each year, drought costs the United States more than $6 billion. It's safe to say that droughts have greater impacts in modern times. More people are affected by loss of land and food crops as well as environmental damage. The immediate effects are overshadowed by secondary issues. Compacted, dry soils are vulnerable to topsoil loss and erosion. Dry conditions make fires more common. Evidence suggest global warming may be the cause for an increase in drought frequency and changes in the global climate. Weather Events Like drought, an increase in severe weather events has been recorded in the last 100 years by the National Climatic Data Center. While notification systems are in place, vulnerabilities still exist for property damage and crop loss. Development has also complicated the effects of such events. An increase in development leads to a decrease in wetlands and an increase in impervious surfaces such as roads and driveways. This creates a scenario for floods and flash flooding. As with drought, scientists believe a link between global warming and climate changes exists.
