Study On Forest Resources Spatial Data Collecting And Analysis In HeFei City

The forest resources spatial data were collected by scanning and digitization method.Namely:according to the need of Hefei city forestry information management system,based on the data of forest resources management inventory, returning farmland to forest,seedings and flowers and so on,the spatial data(scale is 1:10000) collecting scheme of forest resources in Hefei city was designed based on Geoway3.5 software platform.We complied with《National Land Foundation Message Data Classification and Code》and《Forestry Topic Spatial Data Processing Technology and Standard》and other standards when we planed the scheme.We divided the spatial data of forest resources into 11 layers,and put forward the code each layer.At the same time,we put forward the quality controlling,graph editing, steps and technology process etc..We build the vector database of 1:10000 forest resources management inventory,returning farmland to forest,seedings and flowers and so on for three counties and four areas in Hefei.After these,we realized the correlation between forest resources spatial and attribute data,and analysed their characteristics by ArcGis9.0 in Hefei.The results are as follows:1.The forest types are abundant in these counties,but the ratio of protection forest is the biggest in all forest types,and they are 82.59%,77.63%and 52.70%in Feidong,Feixi and Changfeng County respectively;followed by the timber forest,in particular,its ratio is as high as 44.93%in Changfeng County.The proportion of protection forest is the biggest,and of the landscape forests are the fewest in four areas.As the urban area,we should increase the size of the scenic forest from viewing and pleasure.2.It is richer in tree species(group) in three counties.The area of Poplar is biggest in all tree species(group).It accounts for 69.04%,64.39%and 91.68%in Feidong,Feixi and Changfeng County respectively.The reasons are:1) good nature conditions;2) national policy;3) farmer's psychology.But it may also be seen that the tree structure of three counties is quite simplification.So we should adjust the tree structure and increase the proportion of other tree species especially in native tree species.The area of forest resources is less in four areas.This is because they lie in Hefei's urban and the woodland suited to planation is less.But we should enlarge the area of the forest resources according to the development of city especially in ecological environment as much as possiable.Moreover,we should increase landscape tree species,which can reflect an ecological city outlook of Hefei.3.The types of wooland are more abundant in three counties.The ratio of forested land is biggest among all woodland types.It accounted for 97.86%,75.10% and 99.45%in Feidong Feixi and Changfeng County respectively.The area suited to plantation is up to 20.83%for Feixi County,which show that the work of the planation can not be ignored,and the area of forest resources should be enlarged in the future.We should strengthen the tending for afforestation land.The types of woodland in four areas are less.All woodland are forseted land in Yaohai district.The ratio of forested land is 20.80%,97.80%,92.99%and 100%in Baohe,Luyang, Shushan and Yaohai district respectively.The area suited to plantation is the giggest in Baohe district,accounting for 77.80%,which means the heavy task of afforestation in the future.4.Because of increase of forestry investment by the government,the area of the returning farmland to forest get bigger and bigger in the three counties and four areas. The farmer support the forestery and get some farmlands and wasteland into woodlands.5.Hefei is located in hilly areas.So most of the stands originated from artifical.6.Most of gradient grades is level gradient in Zipeng Hill,which the area is the biggest and account for 82.78%.The second position is the gentle slope and account for 13.25%.The total area of the rest gradient grades is less than that of the gentle slope,which show that the fluctuation of terrain is not great in Zipeng Hill.It is not difficult to plantation.The soil and water loss may be very seldom as long as the vegetation preservation is done very well in Zipeng Hill.7.The area of flat aspect is the biggest in Zipeng Hill.It account for 22.31%and suits to plantation.8.Most of forest resources distribute in the flat slope and the gentle slope in Zipeng Hill.The main plantation tree species(groups) were Poplar,Pinus,Exotic Pinus and hardwood.Yet it also be found that there are the distribution of Poplar in the slope,steep slope,acute slope and the hazard slope.According to the growth habits of Poplar,it can only grow in the fiat slope and the gentle slope.From this point it can be explained to the blindness and unreasonable of plantation.