脉冲降雨—蒸发对土壤湿度影响的动力机制分析

土壤湿度直接作用于植被的呼吸、蒸腾和各种化学反应, 是生态气象学的重要的环境因素。降雨和蒸发作为土壤湿度的两个重要扰动因子, 对其进行定性的理论分析及定量的数值分析具有重要意义, 尤其在半干旱和干旱地区。蒸发对土壤湿度具有持续的耗散作用, 可以视为连续的, 而降雨作为湿度补充作用具有脉冲效应。为阐释降雨和蒸发对土壤湿度的影响, 该文通过建立脉冲降雨—蒸发对土壤湿度响应模型, 并对其进行定性分析, 得到此微分方程系统的周期解的充分条件。在此基础上, 通过Forcal对方程参数拟合, 并以Maple作为数值分析工具, 对此系统进行数值模拟。 

Analysis of the Dynamics Mechanism for Discontinuous Rain and Evaporation Affecting the Soil Moisture

Soil moisture directly affects on the vegetation respiration, transpiration, and various chemical reactions, it is an important eco-environmental factor in bionomic meteorology.Rainfall and evaporation are two important turbulent factors affecting soil moisture, qualitative and quantitative theoretical research on them with numerical analysis is important, particularly in semi-arid and arid regions.Evaporation has a constant dissipation effect on soil moisture, it can be regarded as continuous, while discontinuous rainfall has a pulse effect on the humidity.To explain the Rainfall and evaporation influence on soil moisture, this paper established the numerical model that pulse-rainfall and evaporation respond to soil moisture, and get the sufficient condition of the periodic solution in this differential system, with the qualitative analysis.On this basis, with Forcal parameter fitting of the equation and numerical analysis of Maple, we get numerical simulation of this system.