The Study On Distributed And Shared Forest Resource Management System Infrastructure

Currently, the greatest challenge in construction of the digital forestry is data sharing.This research proposed an internet network-based digital forestry platform that focuseson the forest management through a model of "global design, regional implementation,local management, and information sharing ". It enables us to effectively use variousinformation of nature resource, constructed a new approach of distributive data storagemanagement for digital forest platform, built territorial storage and management modelfor a massive library of high resolution images, Proposed a method of handling theadjacent region borders by adjusting adjacent polygons, and established a approach ofdata sharing about the forest stands.The distributed and shared forest resource management system starts with basicinformation of forest management, based on the relative concentration of distributed datamanagement model, local departments are responsible for their own data generation andmanagement and serve others through internet. The regional and local forestryadministrations are responsible for establishing digital forestry their own. Theconstruction of national digital forestry will be progressively conducted according to theprogress of its regional and local development. Once regional or local digital forestrysystems are established, they can join into national digital forestry network and provideservices for local and national users.In this system, surface features are identified by their coordinates. Here MercatorProjection is used to project Earth's spherical surface to two-dimensional plane. A largenumber of satellite imageries or aerial photographs are mosaiced seamlessly according totheir spatial resolutions, and generate an image library containing various spatial andspectral resolutions. Based on the geographical coordinates of a certain region, the regionis divided with the method of quad tree till to reach the required resolution. The imageframing algorithm and fram encode rule was constructed, each quad tree is assigned aunique number as identification according to the predefined coding system. Theidentification number also corresponds to its geographic location. The code of image iscorresponding with its geographical location, thus it simplified the process of imagesearching, improved the searching efficiency.A geographic region is represented by a polygon which is formed by a series of lineswith specific arrangements, and lines are consisted of a series of points with a specificorder. The location of point is defined by its geographic coordinates. Thus, the system describes the administrative boundary and forest sub-compartment boundary by usingpolygons. These delineations and modification of borders are controlled by adjusting theneighboring polygons. The system proposed a new method of storing the adjacentpolygon information, and developed an algorithm to convert two types of storing formats,i.e. during delineation, nodes coordinates are stored, when nodes coordinates needchange, it converts to arc-based structure topology format. When the boundaries ofpolygons need to be adjusted, information of few associated polygons but not all polygonsneeded to be obtained. Splitting arcs of adjacent polygons and generating topology ofadjacent polygons are completed by the member function of adjacent polygons. After aseries of procedures, more associate polygons are updated.Forest stand is the basic object in forest management, and also is the basic unit offorest production management. From a software design point of view, the systemconstructed a forest stand class, the attributes of forest stand class include standcharacteristics commonly used in forestry production management, geographic locations,boundary information, and other information for system management, for example, theglobal identification. Particularly, forest stand boundary is defined by a closed polygonwhich consists of a group of points that represent latitude and longitude. This alsocharacterizes the uniqueness of forest boundary and enables the forest informationexchange and sharing. Digital forest uses XML format to store stand information, whichcan be recognized by both human and computer, and enhances the data sharing.Currently the system mainly focuses on developing data sharing service for forestproduction and management, therefore, the advantages of the system is far from fullyimplement. It is necessary to develop an application management system such asstatistical functions capable of analyzing forest sample plots, and provide services forforestry production and management.