Predictions in Ungauged Basins: Promise and Progress (Proceedings of symposium S7 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 303, 2006, 505-516.

 

PUB Working Group on Orographic Precipitation, Surface Water and Groundwater Interactions, and their Impacts on Water Resources

 

Xu Liang1, L. Ruby Leung2, Maoyi Huang3, Yun Qian2, Mark S. Wigmosta2, George B. Matanga4 & Dave Matthews5

1       University of California, Berkeley, California, USA

2       Pacific Northwest National Laboratory, Richland, Washington, USA

3       Department of Global Ecology, Carnegie Institution of Washington, Stanford, California, USA

4       US Bureau of Reclamation, Sacramento, California, USA

5       US Bureau of Reclamation, Denver, Colorado, USA

 

Abstract  This paper introduces the motivations, objectives, and scope of a PUB working group to investigate the linkage between orographic precipita­tion, surface water and groundwater interactions, and their impacts on water resources. The ultimate goal of the working group is to assess the reduction of uncertainties in hydrological predictions for ungauged basins through im­provements of two important physical processes of land–atmosphere interac­tions: orographic precipitation and surface water and groundwater interactions. In particular, we will focus on, in our current work, cold season orographic precipitation, snowmelt recharge to groundwater bodies, and their impacts on water resources. Our objectives are to: (1) improve the prediction of cold season orographic precipitation processes in mountainous regions and estimate their impacts on hydrological predictions and regional climate through land–atmosphere interactions; (2) improve our understanding of snowmelt recharge to groundwater bodies and surface water and groundwater interactions; and (3) improve the management of water resources through improved understanding and predictions of snowpack and surface water and groundwater interactions. Preliminary results are presented based on a regional-scale coupled land–atmosphere model that has been recently developed to address science questions of the working group. The model includes a subgrid parameteriza­tion of orographic precipitation and dynamic surface water–groundwater interactions. Simulations with and without the dynamic groundwater compo­nent have been compared to investigate the potential impacts of surface water and groundwater interactions.

 

Key words  dynamic groundwater table; orographic precipitation; regional climate model; snowmelt recharge; land surface model; snowpack; surface water and groundwater interactions; water resources