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.
