Complexity and Self-Organization in Soil-Atmosphere Interaction

土壤-大气相互作用的复杂性和自组织

• 批准号: 9705861
• 负责人: Ignacio Rodriguez-Iturbe
• 金额: $ 14.37万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 1999-03-02
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9705861&HistoricalAwards=false
• 关键词: Complexity; Self; Organization; Soil; Atmosphere

9705861 Rodriquez Soil moisture has been identified as the key variable to characterize the impact of the landscape in its relationship with the atmosphere. Recent studies have addressed the basic mechanisms of the phenomena and thus are constrained to very simple situations which do not incorporate the complex interactions which develop when there are different soil types with random spatial geometries evolving in time their degree of wetness (or dryness). We propose to implement a water balance dynamics which will incorporate only the main characteristics of infiltration and evapotranspiration. The dynamics is driven by rainfall which may be of two origins: one from external forcing which takes place randomly in time and space and another which takes place randomly over drier regions whenever soil moisture gradient above a critical threshold exist between neighboring areas. The modeling, although simple, will incorporate the main physical signatures of the processes involved. This kind of dynamics may drive the system toward a critical state where the evolution is a fratal in space and time. This type of complex systems tend to self-organize producing global characteristics product of solely local dynamics. We also plan to compare the results of the model with the space-time signatures of rainfall and soil moisture. Thus, a detailed analysis of the space-time structure of a mesoscale rainfall in regions of Kansas, Texas, and Oklahoma will be carried out and compared with the model. The structure of the soil moisture data from the Washita experiment will also be compared with the one obtained from the modeling scheme.

小行星9705861 土壤湿度已被确定为表征景观与大气关系的影响的关键变量。 最近的研究已经解决了这种现象的基本机制，因此局限于非常简单的情况下，不包括复杂的相互作用，当有不同的土壤类型与随机的空间几何形状随时间变化的湿度（或干燥度）时，发展。 我们建议实施一个水平衡动力学，将只包括入渗和蒸散的主要特点。 动力学是由降雨驱动的，降雨可能有两个来源：一个来源于随机发生的外部强迫 空间和另一种随机发生在干燥地区，只要邻近地区之间存在高于临界阈值的土壤湿度梯度。 建模虽然简单，但将包含所涉及过程的主要物理特征。 这种动力学可能会驱使系统向临界状态发展，在这种状态下，系统的演化在空间和时间上都是分形的。 这种类型的复杂系统往往会自我组织，产生完全由局部动力学产生的全局特征。 我们还计划将该模型的结果与降雨和土壤湿度的时空特征进行比较。 因此，一个中尺度降雨的时空结构的详细分析，在堪萨斯，得克萨斯州和俄克拉荷马州将进行比较模式。 从Washita实验的土壤水分数据的结构也将进行比较，从建模方案获得的。