Research On Forest Resource Date Updating And Distribution Pattern Of Laibin City Based On GIS And RS

Monitoring the change of vegetation coverage and studying the renewal and pattern of forest resources have important reference value for implementing corresponding forestry management measures.Based on the data of Woodland Change and Landsat 8 OLI in 2014 and 2017,the maximum likelihood method was used to extract the vegetation coverage and woodland information.Combined with field survey data and vegetation coverage changes,vegetation cover,forest resource accumulation,tree growth factors and spatial distribution of forest resources were discussed.Reasonable suggestions were put forward for regional forest management and management,and guidance was provided for the management strategy of forest stands under the new pattern of forest resources.The study shows that vegetation cover is good in most areas and vegetation coverage is on the rise.1.Based on the secondary survey data of forest resources in 2014 and 2017,combined with Landsat 8 OLI remote sensing data,the maximum likelihood method was used to extract forest land information,and the classification results were verified by field survey data.The overall accuracy was 94%,and the Kappa coefficient was 88.75%.The classification effect was good.According to the change characteristics of vegetation coverage,the increase of vegetation coverage in the study area is higher than that of the decrease,and the main manifestation is that bare land type is transformed into forest land type,and the forest vegetation coverage is further improved.The distribution of vegetation coverage in the study area is concentrated in the two wings,less in the central area,and keeps an upward trend as a whole,but the local vegetation coverage shows a downward trend.2.Using Visual Foxpro 9.0 database to build a model,the model can reflect the intrinsic relationship between the changes of forest resources.Accumulation volume,annual growth rate,growth of tree height DBH,and regeneration of forested forest were 11 million 332 thousand and 500 m3,17.3% higher than that before regeneration,and 258 thousand hectares of woodland,14.2% higher than before.The automatic renewal model of forest resources is established to complete the automatic renewal of forest resources.3.Using statistical stepwise regression method,the growth models of tree species classification,such as height,diameter at breast height,volume and so on,were established,After F test and t test,the model was updated by using the optimal growth model to measure tree factors of subcompartment stand.The results show that the system error of the models are small,and the models meets the requirements of the code.The models have better practicability and reliability.4.Analyze the distribution of forest resources under the new pattern.In 2017,the proportion of timber forest in Laibin city is too large.Under the new management measures,the vegetation coverage is relatively improved,and the forest quality is getting better and better.It will provide new resources for the development of forestry.The areas with reduced vegetation cover are mainly timber forests,while the destruction of logging and refining habitats is strong,and the ecological quality of the area is relatively unstable.Combined with the actual situation of forest resources,the paper puts forward the forest management measures and suggestions under the new pattern.