Simulation of the revegetation potential of coal mines in semi-arid climates

Abstract

A stochastic precipitation model was developed using data from the Betatakin ruins in Arizona. This was then coupled to a soil moisture model which used the Blaney-Criddle for the potential evapotranspiration estimate and the Hanson method for the actual evapotranspiration estimate. Using this combined model it was then possible to model the response of germinating and growing plants as the soil moisture fluctuated throughout the growing season. Three variations of the model were run, one which only considered the first year and normal precipitation, one in which irrigation was applied as needed and, in another, the plants had to grow and survive for a ten year period. The sensitivity analysis of the on year model showed that increasing the amount of moisture available for the germination process had the largest effect. The irrigation model showed that very little additional moisture would be needed to assure revegetation in the first year. The ten year model showed that even with revegetation in the first year the planted species would have to be drought tolerant. The conclusions of this study are that irrigation should be used in the first year of revegetation, using drought tolerant species, and then discontinued for the remaining liability period.