矿区生态环境脆弱度动态评价的随机Petri网方法

Application of Stochastic Petri-net in Dynamic Evaluation of Ecological Environmental Vulnerability in Mining Area

为了建立矿区生态环境脆弱化过程的仿真模型,动态评价矿区生态环境脆弱度,采用了随机Petri网(SPN)。将库所集划分为了破坏状态集、修复状态集和虚库所集,并给出了它们的表示及计算方法。利用状态值记录各库所实际量的改变情况,将脆弱度的计算融入到网系统的运行过程中,给出了基于SPN的脆弱度算法。案例研究构建了一个简化的脆弱度计算SPN模型,绘制了与其同构的马尔科夫链,计算了多条样本曲线的脆弱度值及各可达标识的稳态概率,进行了进一步的性能分析,验证了所提方法的有效性。该方法可为预测矿区生态环境脆弱度分析提供科学参考。

In order to establish the simulation model of vulnerable process of ecological environment in mining and evaluate ecological environment vulnerability dynamically, stochastic Petri-net （SPN） was adopted. The place set was divided into destruction state set, repair state set and virtual place set. Ways of representation and calculation method of these three types of places were given respectively. The state value of a place was to record actual change quantity of this place. The calculation of vulnerability was integrated into network system running naturally. Vulnerability algorithm based on SPN was given. In case study, a simplified SPN model was established. Its isomorphic Markov chain was drawn. We also calculated the average vulnerability using a large number of vulnerability-time sample data and steady state probability of each reachable marking. A further performance analysis then was conducted and so verified the effectiveness of the proposed method in this paper. The method can provide scientific reference for analysis of ecological environment vulnerability.