**2. The framework for China flash flood early warning research**

In the first place, temporal forecasting, spatial forecasting and developing of early warning system are considered as the three portions of the research system of flash flood early warning [9]. But in fact, early warning should give forecasting information as much as possible, better including both spot and time. So it is unreasonable to separate temporal forecasting with spatial forecasting. They should work together to tell people where and when disaster outbreak in advance. After synthetical consideration, we divide flash flood early warning research into two categories: long-term warning and real-time warning.

Based on the statistical regularity and disaster-causing mechanism, flash flood long-term warning is intended to forecast the occurrence possibility of flash floods in one mountain village or a zone in a relatively long period of time. This aspect of research can give decision maker an overall perspective of flash flood disasters to assist them with making out flash flood prevention and control plan. Also, this risk assessment can improve the government's ability of flash flood risk management and advertise to the public. The research framework of flash flood long-term warning is shown in **Figure 1**. In this framework, Chinese scholars mainly forecast flash floods based on statistical regularity rather than disaster-causing mechanism.

Different from the long-term warning, the flash flood real-time warning tries to tell us whether one mountain village will be in danger of flash flood in advent days, even in advent hours. Based on the long-term warning achievement and the flash flood disasters prevention

**Figure 1.** The research framework of flash flood long-term warning.

and control situation, real-time warning indicators would be calculated by integrating multisources data to provide scientific basis for drawing up contingency plan and improving mass prediction and disaster prevention and so on.

Although the entire research framework of flash flood real-term warning is shown in **Figure 2**, but some sectors, such as indicator system and simulation of disaster, draw little attention of scholars. Besides this, increasing researchers turn their attention to multi-sources data acquiring and applying in calculation of flash flood real-time warning indicators to struggle with data deficient. Furthermore, some experts in software engineering start taking part in the construction of flash flood early warning system platforms, including data management system, information transmission system and application visualization system.

**Figure 2.** The research framework of flash flood real-time warning.

increase of flash floods. The casualties of flash flood disasters are continually mounting those years. Thus, flash flood disasters become one of the most life-threatening water disasters in

As flash floods are distributed extensively and its influence sphere highly concentrated, it is unreasonable and uneconomical to prevent flash flood disasters mainly via engineering measures. To cope with this, the government of China draws up a guidance, prevention in the first place and integrating prevention with control, non-engineering measure as the main and combining it with engineering measures [7, 8]. Since then flash flood early warning draws wide attention of China scholars. Against this background, it is essential to get an overall review of China research about flash flood early warning in the past years. Drawing lessons from the past, which is the main objective of this chapter, would provide effective references

In the first place, temporal forecasting, spatial forecasting and developing of early warning system are considered as the three portions of the research system of flash flood early warning [9]. But in fact, early warning should give forecasting information as much as possible, better including both spot and time. So it is unreasonable to separate temporal forecasting with spatial forecasting. They should work together to tell people where and when disaster outbreak in advance. After synthetical consideration, we divide flash flood early warning research into

Based on the statistical regularity and disaster-causing mechanism, flash flood long-term warning is intended to forecast the occurrence possibility of flash floods in one mountain village or a zone in a relatively long period of time. This aspect of research can give decision maker an overall perspective of flash flood disasters to assist them with making out flash flood prevention and control plan. Also, this risk assessment can improve the government's ability of flash flood risk management and advertise to the public. The research framework of flash flood long-term warning is shown in **Figure 1**. In this framework, Chinese scholars mainly forecast flash floods based on statistical regularity rather than disaster-causing mechanism. Different from the long-term warning, the flash flood real-time warning tries to tell us whether one mountain village will be in danger of flash flood in advent days, even in advent hours. Based on the long-term warning achievement and the flash flood disasters prevention

for engineering practice and outline the future prospects.

two categories: long-term warning and real-time warning.

**Figure 1.** The research framework of flash flood long-term warning.

**2. The framework for China flash flood early warning research**

China [6].

148 Engineering and Mathematical Topics in Rainfall
