TY - GEN
T1 - Modeling the Continental Hydrology
T2 - Engineering, Construction and Operations in Challenging Environments - Earth and Space 2004: Proceedings of the Ninth Biennial ASCE Aerospace Division International Conference
AU - Niu, Guo Yue
AU - Yang, Zong Liang
PY - 2004
Y1 - 2004
N2 - Considerable progress in continental hydrological research has been made recently that includes sub-grid-scale variability of precipitation, canopy interception, through flow, and hill-slope runoff production. Many such studies have focused on one single process at a time. This work aims to examine the interplay between canopy interception, throughflow and runoff using the NCAR Community Atmosphere Model (CAM2) coupled with NCAR Community Land Model (CLM2). The simulations are compared with the observed runoff from the University of New Hampshire-Global Runoff Data Center (UNH-GRDC) 0.5 degree monthly climatological composite runoff fields. The simulations from the CAM2/CLM2 show an excessive canopy interception and low soil moisture content over the climatologically wet regions, especially in the Amazon basin. A series of experiments are conducted which explicitly account for the sub-grid-scale variability of precipitation and its effects on canopy interception and throughflow. These experiments incorporate changes in the treatment of topography-induced runoff. The results have demonstrated that the interception and runoff processes are intimately coupled, and that their schemes should be changed together to ensure the improvement in the hydrological simulations. The simplified topography-based runoff model (TOPMODEL) and the sub-grid interception scheme proposed in this study, when used together, result in better simulations of runoff. With these proposed schemes, the water budgets show favorable changes in the Amazon basin in that canopy evaporation is reduced, runoff is increased, and soil is wetter.
AB - Considerable progress in continental hydrological research has been made recently that includes sub-grid-scale variability of precipitation, canopy interception, through flow, and hill-slope runoff production. Many such studies have focused on one single process at a time. This work aims to examine the interplay between canopy interception, throughflow and runoff using the NCAR Community Atmosphere Model (CAM2) coupled with NCAR Community Land Model (CLM2). The simulations are compared with the observed runoff from the University of New Hampshire-Global Runoff Data Center (UNH-GRDC) 0.5 degree monthly climatological composite runoff fields. The simulations from the CAM2/CLM2 show an excessive canopy interception and low soil moisture content over the climatologically wet regions, especially in the Amazon basin. A series of experiments are conducted which explicitly account for the sub-grid-scale variability of precipitation and its effects on canopy interception and throughflow. These experiments incorporate changes in the treatment of topography-induced runoff. The results have demonstrated that the interception and runoff processes are intimately coupled, and that their schemes should be changed together to ensure the improvement in the hydrological simulations. The simplified topography-based runoff model (TOPMODEL) and the sub-grid interception scheme proposed in this study, when used together, result in better simulations of runoff. With these proposed schemes, the water budgets show favorable changes in the Amazon basin in that canopy evaporation is reduced, runoff is increased, and soil is wetter.
UR - http://www.scopus.com/inward/record.url?scp=1942439098&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1942439098&partnerID=8YFLogxK
U2 - 10.1061/40722(153)40
DO - 10.1061/40722(153)40
M3 - Conference contribution
SN - 0784407223
SN - 9780784407226
T3 - Engineering Construction and Operations in Challenging Environments Earth and Space 2004: Proceedings of the Ninth Biennial ASCE Aerospace Division International Conference
SP - 284
EP - 289
BT - Engineering, Construction and Operations in Challenging Environments - Earth and Space 2004
PB - American Society of Civil Engineers (ASCE)
Y2 - 7 March 2004 through 10 March 2004
ER -