Distributed Land-Cover Change Simulation Using PVM and MPI

Computer simulations are used in landscape ecology to simulate the eeects of human land-use decisions on the environment. Such decisions are innuenced by both ecological and socioeconomic factors which can be represented by spatially explicit multidisciplinary data. The Land-Use Change Analysis System (or LUCAS) was developed to study the eeects of land-use on landscape structure in such areas as the Little Tennessee River Basin in western North Carolina and the Olympic Peninsula of Washington state. These eeects include land-cover change and species habitat suitability. Using a geographic information system (GIS) to store, display and analyze map layers derived from remotely sensed images, census and ownership maps, topological maps, and output from econometric models, a parallel/distributed version of LUCAS (pLUCAS) was developed for simulations on a network of workstations. Targeting distributed computational environments reeects the resources available to most land-use planners, forestry personnel, and wildlife managers. A performance evaluation of two pLUCAS distributed models on an ATM-based network of 12 SUN Ultra-2 workstations is presented. Particular emphasis is given to the range of speed improvements (relative to serial runs on a single SUN Ultra-2 workstation) that can be obtained using the PVM or MPI message-passing environments .