A Study On Subcompartment Region Slope Extract Algorithm

With the rapid development of "Smart Forestry",the combination of forestry science and information technology becomes more and more close.However,the level of automation is still low in the process of forestry investigation,which now is mostly based on field investigation.During the actual survey,limited by the complex terrain of forest and other external factors,a part of the subcompartments' information is mainly depended on the visual inspection of investigators,some unreachable subcompartments even can only be surveyed through remote observation.Slope value is one of the most important investigation factors of subcompartment,its visual error is very great.In addition,with the help of professional instruments,the accuracy of measurement can only be guaranteed at the measuring point,without considering the overall tilt of the subcompartment.At present,in the field of forestry investigation,there is still lacking a reliable method for calculating the region slope of one subcompartment.It has brought a lot of inconveniences to the development of forestry investigation.Therefore,this study proposed a region slope algorithm to improve the data quality and reduce the workload of the forest investigation.In this paper,we first analyzed the existing slope algorithms,and found that most of the previous researches focused on the single cell slope calculated from DEM data.There are few studies on calculation of region slope.In order to understand the mathematical and geographic meaning of slope deeply,this paper introduces Horn algorithm as a representative algorithm of single cell slope and puts forward a new algorithm based on the 3×3 window and DEM called Quad.High precision single cell slope can be used as one of the standards for region slope.Subsequently,this study discussed the geographic characteristics of subcompartments,and then combined with the geographic definition of slope,we proposed a region slope algorithm based on the main aspect longitudinal section and altitude regression.Finally,a comparative experiment of various commonly used algorithms is carried out using the DEM and subcompartments of Anji County,Zhejiang Province.The results show that the algorithm proposed in this paper can take the place of the traditional field investigation method and extract the slope of subcompartments automatically.