The Study Of Marine Ecosystems Dynamics And Health-evaluating System

The marine ecosystems are important conditions of the living and developing of mankind, and supports significant material foundation of the economic development. However, it is damaged badly, such as the marine ecologic environment is destroyed, the marine ecologic resources are exploited excessively, HABs happen every now and then, etc. The dynamic properties are studied with modern nonlinear dynamics in this paper. Meanwhile the health evaluating information system for the marine ecosystem is established with object-oriented programming technique. Concrete achievements are as follows:First, a simple algae-phytoplankton nonlinear dynamical model was built. The author studied the model to analyze the relationship of the bloom recurrence. With one parameter changing continually, a hopf bifurcation was observed. To analyze the parameters, we can find the dynamic properties of the algae-phytoplankton nonlinear dynamical model.After studying the sustainable development degree for marine ecologic economic system and filtering the factors that influence the marine ecologic health, 23 attending factors are determined such as per capita GDP, fishery output value, dissolved oxygen, inorganic phosphorus, inorganic nitrogen, chemical oxygen consumption, etc. According to consulting the sample data, the relationship between the attending factors and the marine ecologic health degree and the levels are divided among the factors. The weights for every attending factor are determined with analytic hierarchy process (AHP). Finally the health evaluating system for the marine ecosystems is established.Then,with the health evaluating system,we use the Dot NET framework and SQL Server2000 database management system to establish the health evaluating information system of the marine ecosystems.And, using the the health evaluating information system, we can get the healthy level of the marine ecosystems.