Combined with satellite image, river water area can be extracted by means of remote sensing to provide data foundation for flood season analysis.
Taking the Yitong River in Changchun, Jilin as an example, this paper analyzes the change of water surface area in summer to introduce the application of remote sensing technology in the study of river flood season.
It monitors the dynamic change of water area of Yitong River in urban district of Changchun and extracts the water area of Yitong River in four periods of June 20, July 26, August 21 and September 19, 2016 respectively.
According to statistics, the surface area of the four periods are 2.94 square kilometers, 3.07 square kilometers, 2.63 square kilometers and 3.61 square kilometers respectively.
The terrain in China is low in the west and high in the east, and most rivers run east-west. It can be seen by satellite images that Yitong river runs north-south, which shows that the Yitong River is more influenced by longitude and latitude in the flow direction, and it flows to higher latitudes.
According to preliminary statistics, the surface water area of Yitong River in summer fluctuates from 2.94 to 3.61m2, with occupying a small proportion of Changchun area 20,565m2. For Yitong River, the reach from the northern expressway to the Beihu Wetland Park is of wide river course and abundant water, and the change of surface area is also more significant
By further analysis, as the main factor affecting the size of river water area in summer is precipitation, the dynamic monitoring of surface area can reflect the changing trend of precipitation.