Research On The Application Of Small Watershed Water System Census Based On 3S Technology

With the rapid development of economy,the pollution of rural water environment is becoming more and more serious,the efficiency of flood control and drainage is low,and the safety of water supply is more prominent,which seriously affects the beautiful and harmonious development of rural revitalization.Therefore,in order to meet the needs of economic development and ecological civilization construction,realize sustainable development,utilization and protection of water resources,and scientifically plan medium and long-term water conservancy development,my country carried out the first national water conservancy census from 2010 to 2012.The water system census shall be carried out for the backbone rivers with a drainage area of 50km~2 and above.However,with the continuous progress of society,the rapid development of urbanization,the destruction of the ecological environment and the continuous changes in the natural environment,the original river system census and results have certain shortcomings,especially for rivers with a drainage area of less than 50km~2.At present,there is no successful experience that can be used for reference in the water system census work in small watersheds,and a mature and effective work plan has not been formed.Therefore,carrying out a water system census based on 3S technology is conducive to flood control and drainage safety,water resources allocation,and water improvement.environment,which in turn contributes to rural revitalization and development.Relying on the 3S technology developed in recent years,this paper takes the Rongjiang River Basin in Jieyang City,Guangdong Province as the research area,and studies the collection and processing mode and census method of water system census data in small watersheds,and finally forms a complete set of data collection and results conversion plan,to provide reference for the development of water system census in similar small watersheds.Mainly include:(1)Using DEM data and 1:2000 RS remote sensing images,using GPS positioning technology and GIS spatial information management technology to study the extraction of water system spatial features in the mountainous areas and plains(towns)of the Rongjiang River Basin in Jieyang City.(2)Combined with vegetation coverage,topography,regional geological characteristics,etc.,use meteorological data,hydrological data,water supply and drainage planning data,3S technology and field investigation and review methods to conduct comprehensive attribute research on river systems.(3)Relying on the results of this census,extract the spatial characteristics and attribute characteristics of the census,and use Arc GIS mapping software to study the mapping technology of digital thematic maps.The 3S technology-based water system census established in this study shows that 3S technology has significant advantages in the process of water system extraction and census,improving the collection efficiency and reducing the workload.Combined with the actual situation of the Rongjiang River Basin in Jieyang City and the existing technical level,this paper optimizes and perfects the traditional census method,forms a new census method based on 3S technology,and completes the research on the production of digital thematic maps.Based on this water system census,a total of about 1,430 river systems were surveyed in the study area.Among them,the rivers with an area of less than 50 km2 in the mountainous area accounted for about 72%of the total number of rivers in the mountains,and the rivers in the plain area with a length of less than 5 km accounted for about 72%of the total rivers in the plain area.98%,the river network density in Beihe City,Rongjiang,in the plain area is about0.52km/km~2,and the attributes of most of the river systems obtained from the census have been improved.Finally,the census results are used for digital mapping research,and the Rongjiang River Basin in Jieyang City is generated.The electronic vector map of river water system provides effective support for the results of this water system census.