Digital Ecological Model and Case Study on China Water Condition
|2.||Problems hindering the process of landscape model||3|
|3.||Digital ecological model||4|
|3.1.||Methods to build DEM||4|
|3.2.||Content of DEM||4|
During last 20 years, many ecologists paid their attention to landscape models, searching for principals of spatial pattern on ecological processes, and demonstrating the processes and constrained changes across scales. Only last 10 years the spatial simulation became really feasible, profiting from the theoretic progresses in landscape ecology, the fast development of computer technology and frequent application of remote sensing and geographic informational system in landscape ecology modeling. Evidences of interaction between remote sensing and ecological process communities increased. Plummer (2000) classified the approaches for using remotely sensed data in ecological process models into three alternating strategies.
Provide estimates of variables which were required for driving ecological process models,
To test, validate or verify predictions of ecological process models,
To update or adjust ecological process model predictions.
Using GIS in ecological studies has become more and more significant for spatial simulation. At the same time, ecological modeling carries through thorough reforms, for example object-oriented design in the modeling of biological systems are becoming more and more popular. Some environmental information systems or frameworks were built in order to provide software tools for ecological simulation study. As landscape modeling falls greatly with the development of information science, computer science, GIS, Global Position system, there are certain problems in the individual oriented models, like: ecologists must be programmers, models equal computer programs, there is no separation between models and experiments, analysis depends on models, there are no methodical supports, there is no interaction and visualization between theoretical ecology and field ecology.
2.Problems hindering the process of landscape model
There are some problems that hinder the process of landscape model. First of them is that no model can address issues at all scales, so for different researching scale numerous models should be built. Than explicit and inexplicit assumptions must be made according to researching subjects and region, which restricts model to be used in other regions. As all model programmers have to deal with the large amount of data that hinder them from focusing on ecological processes. Only little software is available for ecologists in order to make direct use of remotely sensed data to build their model or to do some statistical analysis. The last problem is that still the great gap between ecological model and GIS exists and thus prevents ecologists from making efficient use of GIS for spatial analyzing of the ecosystems. …