In recent years, the flood has become worse. The major causes can be divided into two categories: global climate anomalies and destruction of hydrological environment.
The greenhouse effect has caused the extreme anomalies of the global climate. Taiwan has been affected as well, resulting in concentrated rainy season, increased rainfall intensity, instantly increased river flow or flood due to poor drainage in the city.
In addition, due to recent economic development and people’s
pursuit of quality life, urbanization or economic development has been competing with rivers for space and land, and thus the natural hydrological environment has been undermined. For example, the dredging plain of the river are used for urban development, forcing the water to flood when it has nowhere to go. Besides, over-pumping of groundwater also caused subsidence. The water is forced to flow to the subsidence area, resulting in hazard when the water cannot be discharged. There are other similar instances which were caused by overlooking ecological and environmental protection when emphasizing economic development.