Kansas State University

Water is a crucial component of human existence on our planet, and, therefore, understanding water balance and its modeling at large scales have been long-standing problems. What one gets from the water balance is how much of the rain that falls evaporates back to the atmosphere and how much runs off in rivers as a function of climate variables. An important application of such research is the ability to predict changes in streamflow — called streamflow elasticity — when climate changes. 

 

In this study, Behzad Ghanbarian, faculty in the geology department, and his colleagues propose a novel theoretic approach based on the knowledge of water flux dependences of both soil depth and vegetation growth rates.

 

They demonstrate that when changes in water storage are neglected, predictions of streamflow elasticity match very well with its observed median values across biomes and across continents. When typical storage changes are also incorporated into the predictions, they generate the entire distribution of observed values of the streamflow elasticity as a function of aridity index. What is particularly remarkable is that a predicted double peak in elasticity values also shows up in the data.