River Systems & Causes of Flooding Flooding

Throughout history humans have found it desirable to construct cities along streams. Streams are sources of water for consumption, agriculture, and industry. Streams provide transportation routes, energy, and a means of disposal of wastes. Stream valleys offer a relatively flat area for construction. But, human populations that live along streams also have the disadvantage that the flow of water in streams is never constant. High amounts of water flowing in streams often leads to flooding, and flooding is one of the more common and costly types of natural disasters. A flood results when a stream runs out of its confines and submerges surrounding areas. z In less developed countries, humans are particularly sensitive to flood casualties because of high population density, absence of zoning regulations, lack of flood control, and lack of emergency response infrastructure and early warning systems. z Bangladesh is one of the most susceptible countries to flood disasters. About one half of the land area in Bangladesh is at an elevation of less than 8 meters above sea level. Up to 30 % of the country has been covered with flood waters. In 1991 more 200,000 deaths resulted from flooding and associated tropical cyclones. z In industrialized countries the loss of life is usually lower because of flood contro