Summary of several key points of the flood risk map

1. Definition and purpose of a flood risk map

The flood risk chart is based on historical investigation, hydrological analysis, and flood simulation calculation, specify the flood scope, water depth, duration, flow rate and flood loss when a typical flood occurs in a region, as well as the flood control project and the distribution of flood control materials, flood refuge channels and location and other information are displayed in easy-to-understand form.

Flood risk maps are mainly used for flood insurance abroad. flood risk maps are one of the important measures for non-engineering measures in China, it plays an important role in reasonably arranging flood control projects, scientifically managing flood zones, and guiding flood control and rescue work, at the same time, it is of great significance in regulating land use and raising the national awareness of flood control and disaster reduction.

 

2. Differences between hydrology and hydraulics

Three flood risk analysis methods are recommended in the Guidelines for flood risk charts, namely, hydraulic, hydrological, and historical flood. What is the difference between "hydrology" and "hydraulics?

Hydrology is a branch of geophysical and natural geography. Studies on the movements, changes, and distributions of various forms of water in the atmosphere, on the Earth's surface, and in the earth's crust in terms of water volume and quality, as well as the associations and effects with the environment and human activities.

Hydraulics is to study the macroscopic mechanical movement of liquids represented by water and its application in engineering technology. Hydraulics includes hydrostatic and hydrodynamics.

 

3. Flood Risk diagram content requirements

(1) Basic Geographic Data is the standard data of surveying and mapping, which is layered according to the standards of surveying and mapping;

(2) water conservancy projects, including basic geography (if 50 thousand basic geographic data is not available, map expression reference 50 thousand Data Model) water conservancy projects, Flood Control and Drought Relief engineering facilities, emergency relief and risk-free transfer routes, and other elements;

(3) special elements of flood risks, including fenders, flood ranges, water depth, water depth and other deep lines, flood velocity, arrival time, and flood duration;

(4) The graphic data of water conservancy projects and flood risks are layered by table (Data layering and coding standard basis: topographic map scheme national standard, Flood Control and Drought Relief graphic scheme ).

4. Drawing Process of the flood risk chart

5. overall workflow of the flood risk chart and GIS product requirements

In the model design stage, the water Emy of sciences and universities and other scientific research institutions design relevant models. After the model is designed, GIS developers can develop a flood risk map Rendering System Based on AO or AE components. At the same time, through the development based on ArcGIS Server, we can develop BS systems to display, share, and manage flood risk maps online. Then, we can use onemap or portal for ArcGIS, we can build an advanced sharing platform to manage, apply, and share flood risk maps in a wide range.