DEM-based Study On Digital Representation Of Microrelief And Its Application Of Water Environment In The Jianghuai Plain

Farmland,canals,dams and other artificial transformation or human life is closely related to the typical micro-geomorphology widely distributed in the plains of China.Because this kind of micro-geomorphology is widely distributed,the elevation difference is small,and the form is complicated.It make difficult for existing grid DEM to perform effective digital representation and accurate digital terrain analysis.Leading to the existing grid DEM difficult to meet the needs of various applications in Jianghuai plains.For example,flood analysis and digital terrain analysis.Therefore,based on Jianghuai plain area,set up jianghuai plains microrelief digital classification system,and to build a microrelief terrain object with object-oriented thinking.It is seamlessly embedded in the grid DEM object,the formation of TODEM.This paper focuses on the characteristics,numerical classification and the concept of microrelief terrain objects,data organization and construction methods in the Jianghuai Plain.Achieve the following main research results:(1)Based on the DEM data of 30 m resolution,combination of geomorphology and natural geography in the plains of defined standards,the range of Jianghuai Plain area is determined from the geographical location.And the microrelief classification system of the Jianghuai Plain is established.(2)This paper chooses Hancun town as the study area,extracts the typical microrelief objects,realizes the construction of the microrelief terrain object in the study area and TODEM of the whole research area.Separately,based on the traditional grid DEM and TODEM,compare and analyze the TWI of the study area.The TWI can better reflect the regularity of spatial distribution and the regularity of runoff of the surface water which obtained by TODEM.(3)The scope of the study area TWI between 1.34-31.94,and the study area of farmland of TWI is between 6.46 and 19.46.The microrelief with the water storage of the TWI is greater than 19.46,for example rivers and canals.TWI the value of larger area,in addition to the distribution in the water area,mainly distributed in the study area in the southwest and drainage confluence.TWI the value of the smaller area,mainly distributed in the relatively high of study area,and river \canal,etc microrelief of slope area.(4)Clarified the TWI distribution characteristics in the study area by considering microrelief,and it has significance in terms of the surface water environment spatial distribution and runoff.