Scenario Analysis And Evaluation Methods Of County-level Forest Management Planning

Nowadays,people have paid more and more attention to protection of ecology and environment.Forest resources have been drawn extensive attention due to its importance of environment.County-level forest management planning is of great significance for the sustainable development of forest.As a key forest county of Hunan Province,forest resources are rich in the jurisdiction of Guidong.However,most of the resources distribute in mountainous area,the management and protection are very difficult.Besides,there are many problems on forest structure,forest industrialization benefits and forestry property rights.Therefore,it is extremely important to draw up a long-term forest management plan.As a result of Guidong county abounds with mountains,it is difficult to carry out forestry investigation.Because traditional forest management drawing up method takes a lot of work load and time.So it is necessary to search for a more effective and precise method of forest management planning.This paper adopts scenario analysis method to analyze and evaluate the county-level forest management planning.The changes of forest resources under the influence of forestry policy and government land use planning can be reflected by the dynamic change process of land use types.Therefore,land use types are taken as the foundation to construct scenarios.In this paper,classification system of Guidong county land use data in 2010 and 2015 were obtained from remote sensing image,and land use data were reclassified as cultivated land,woodland,shrub land,grassland,water area,construction land and other classes.The changes of land use types were affected by many factors.From the perspective of availability and quantification,seven natural and man-made factors,including elevation,slope,aspect,distance from rivers,NDVI,distance from roads and distance from residential area,were selected as driving factors for land use type change in this paper.The suitability probability distribution raster data of 7 types of land use data were obtained through land use suitability probability calculation module of FLUS.According to conversion matrix of land use types,this paper obtained conversion cost matrix of land use types and field factor which were required by FLUS.Then,Kappa coefficient and FoM coefficient were used to verify the feasibility of the model before land use type scenario simulation.After the model passed through verification of precision,the paper set simulated target values of nature trend scenario,coordinated development scenario and woodland conservation scenario of land use types in 2050,based on the calculation results of land use data on Markov model,and the relevant provisions on the area of various land use types in the general land use plan of Guidong county(2006-2020)and the forest management plan of Hunan province(2016-2050).The results of 3 scenarios were analyzed and evaluated by multi-criteria decision analysis.This paper chose forest coverage rate,the accumulation of per unit area,large diameter ratio,carbon reserves and major forest product yield to represent forest resources quality,quantity,forest ecological service function and its economic benefits.Then,the best land use situation were obtained by compared with 2050planning objectives.Taking it as the basis,the implementation approaches of the forest management plan were obtained.The concrete results are as following:(1)Probability of suitability of land use typesFrom the perspective of availability and quantification,this paper selects elevation,slope,aspect,NDVI,distance from rivers,roads and settlements as driving factors,and then uses artificial neural network to calculate the probability of suitability of land use types.The root mean square error of the results is 0.201,which proves that the driving factors can explain the change of land use types,and the probability raster chart of suitability can be used for the scenario simulation of land use types.(2)The precision test of FLUSFLUS uses land use data in 2010 as the base period values to simulate land use types'simulated values in 2015.And compared with the real value of 2015,the Kappa coefficient is0.95,the FoM coefficient is 26.4%,that suggests that the model has higher consistency simulation results with real data,proof model is feasible,and can be used for land use type scene simulation.(3)Analysis and evaluation of simulation results of FLUSReferencing to the government's land use planning and forestry development policy planning,the paper constructs three scenarios.The natural trend development scenario subject to the law of land use change from 2010 to 2015.On the basis of protecting the regional ecological environment,the coordinated development scenario gives priority to the development of cultivated land and the woodland protection scenario of gives priority to the protection of woodland resources.FLUS model is used to simulate land use types data of 2050 in 3 scenarios,and MCDA is used to analyze and evaluate the results.In the multi-criteria evaluation system,forest coverage rate,forest volume per unit area,ratio of large-diameter timber,carbon reserves and yield of main forest products,can represent the quantity and quality of forest resources,ecological service function and economic benefit of forest resources,are selected as evaluation indexes.The Euclidean distance between 3 scenarios and the planning target is calculated to be1.258,1.242 and 0.548,respectively.The gap between the forestland protection scenario and the planning target is the smallest,which is the best forest management scenario.(4)Forest management zoning and implementation approachesIn Hunan province forest management planning(2016-2050),the division of forest management types in the area according to the natural geographical conditions of different regions on the basis of the study area is divided into mountain and water and soil conservation of water conservation forest areas,down-land and timber forest areas of soil and water conservation,soil and water conservation and low hilly mountain woody edible oil forest areas,plain and farmland soil and water conservation forest tries shelter forest areas are four partitions,and analyzes its business direction.By 2050,the increase of forestland area in the four operating zones will be 1263hm~2,2802hm~2,1385hm~2and 634hm~2,respectively.According to Hunan forestry management planning(2016-2050),the forest land in Guidong county is divided into 26management types,including masson pine protection and timber forest,pine protection and timber forest,fir protection and timber forest.Finally,according to the planning objectives and natural conditions under the optimal forest management scenario in the study area,the forest management countermeasures to improve the quality of forest resources,forest pest control and forest infrastructure construction were formulated to achieve the target value of 85.70%forest coverage and 161.58m~3/hm~2 per unit area.