Research - Category I: Hydrology, Climatology & Hydraulics

Evaluation of the Effects of Surface Water and Ground Water Interactions on Regional Climate and local Water Resources
(Funded 1999-2000)

Principal Investigator: Xu Liang
Civil and Environmental Engineering
UC Berkeley
(510) 642-2648
liang@ce.berkeley.edu

Executive Summary:
The study of interactions between ground water and surface water over large scales and their effects on regional climate and local water resources has received notably less attention that the studies of the land-atmosphere interactions and the ground water-surface water interactions over small scales (e.g., hill-slope scale). However, the ground water and surface water interactions over large scales play a significant role in the hydrological system, water-quality, and land-atmosphere interaction studies. For example, the interactions are closely related to the state of soil moisture which plays an important role not only in the energy and water balances in the land-atmosphere system, but also in the drought and flooding, the water resources management, ecological system, and water-quality studies. Field observations have shown that the interactions between surface water and groundwater play a significant role in altering hydrological consequences (e.g., ground water and surface water hydrology) and water-quality over individual regions.

The goals of this study are 1) Improve the understanding of the interactions between surface water and ground water hydrology over large scales for moist, semi-arid, and arid regions within the context of regional and local climate systems, 2) Understand the two-way effects of the ground water-surface water interactions on the regional climate and local water resources, 3) Identify the degree of significance of multiple-direction water movement for the coarse resolution of a typical climate model where more than one down-slope flow direction is possible, 4) Understand the effects of re-infiltration of surface runoff along its flow paths and its related processes to the spatial distributions of energy and water budgets, 5) Improve the performance of land surface schemes over arid and semi-arid regions and 6) Improve the water-quality assessment and water resources management with the considerations of the influence of the local and mesoscale circulations, and the groundwater-surface water interactions. In addition, the degree of importance of the ground water-surface water interaction, the re-infiltration and its related processes, and multiple directions of overland flow network routing at different spatial scales It is expected that the research results from the proposed study will shed light on the water resources management for arid and semi-arid areas, the understanding of effects of regional climate on local ground water and surface water interactions, and better assessment of water-quality.