Vol. 12, No. 2, p. 95 − 96, June 2008 DOI 10.1007/s12303-008-0011-z
Our future resources, groundwater
1. INTRODUCTION
Water resources around the world are being increasingly impacted by climate change and human activities, such as altered precipitation patterns, changes in land-use types, or dramatic increases in the use of organic chemicals. These climatic and human influences may considerably reduce the sustainability of water resources. One of the grand chal- lenges in hydrology is to reduce human impacts, while con- tinuously providing the water needed for societal growth.
This special issue of Geosciences Journal consists of seven selected papers presented at the international sympo- sium on ‘Our Future Resources, Groundwater’ held in Korea from May 24 to May 26, 2006 to celebrate the 30
th
Anniversary of the Korea Institute of Geoscience and Min- eral Resources (KIGAM). The symposium aimed to provide a forum for local and international leaders in hydrogeology to meet and discuss the issues related to sustainable devel- opment of water resources. More than 150 scientists and engineers as well as decision makers and publics from Korea, United States, Germany, Canada, and France attended the symposium.
The selected papers are divided into three categories:
groundwater resources management and policy, groundwa- ter contamination and remediation, and flow and transport modeling in heterogeneous formations. Our hope is that this special issue will provide useful information for water resources management. We take this opportunity to thank all the participants of the symposium, and especially the authors, and reviewers who contributed to this volume.
2. CONTRIBUTION TO THE ISSUE
Schwartz et al. (this issue) examine two cases of ground- water contamination and remediation in Canada and the United States with a view toward assisting practitioners and regulatory agencies with oversight responsibilities to avoid common mistakes in site investigations. The first case study highlights the problems that can arise from an inadequate geologic understanding of a site, the importance of knowl- edge concerning the advantages and limitations of key tools
for site investigation, and how projects can benefit from early and ongoing peer reviews. The second case study explains difficulties in working on unique problems without an effective conceptual hydrogeologic model, the need to always be concerned about the quality of chemical data, and the need to be alert to behaviors that are beyond typical experience.
Sudicky et al. (this issue) present large-scale surface-sub- surface hydrodynamic model that was applied to a 17 km
2
subcatchment of the Laurel Creek Watershed in Southern Ontario, Canada. A steady-state condition was achieved in the model by calibrating the subsurface flow field to 16 observation wells where long-term hydraulic head data were available. The model was then subjected to several hundred hours of rainfall data and the resulting discharge hydrographs were compared with the measured hydro- graphs. The calculated subsurface hydraulic head distribu- tion and surficial rainfall-runoff responses, respectively, were shown to agree moderately well with those observed in the system during this period. These results suggested that the model is capable of reproducing surface and sub- surface hydrodynamic processes at the subcatchment scale although the results could be better through improved parameterization of the subcatchment and the manner in which the model simulates evapotranspiration processes.
Koo and Kim (this issue) perform numerical simulations to demonstrate variability in local groundwater recharge in response to monsoon rainfall in Korea. Monsoon in the summer provides more than 50% of the total precipitation in Korea, thus important for recharge to shallow aquifers.
This paper specifically examines impact of monsoon pre- cipitation on the water flux and thermal diffusivity in the vadose zone and variability of precipitation recharge in rela- tion to the monsoon rainfall by applying heat transport and infiltration models to 22-year time series soil temperature and meteorological data. The results demonstrate that the annual recharge is linearly proportional to the annual pre- cipitation with varying degrees of the correlation coeffi- cients depending on soil types.
Nordstrom (this issue) reports results of recent investiga- tion to determine the pre-mining groundwater quality at a molybdenum mine in northern New Mexico, USA. The pre-mining groundwater quality was inferred by studying a Yongje Kim*
Franklin W. Schwartz
Groundwater and Geothermal Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 305-350, Korea
Department of Geological Sciences, The Ohio State University, Columbus, Ohio 43210-1398, USA
96 Yongje Kim and Franklin W. Schwartz proximal natural analog site. This type of information,
combined with lithology, mineralogy, and mineral solubility controls, may provide constraints on pre-mining groundwater quality and is useful for establishing closure requirements of mines.
Lim et al. (this issue) present the effect of bio-geochem- ical processes on speciation, fate, and transport of arsenic using Shewanella sp., iron-reducing bacteria for batch and column test. The results from the laboratory tests suggest that in natural groundwater system, Shewanella sp. partic- ipates in the reduction of As(V) and sulfate, and sulfides produced by the microbial activity precipitate As(V) and As(III).
Yeh et al. (this issue) explain the need for high-resolution imaging techniques to characterize the subsurface and then discuss difficulties of traditional characterization approaches to meet this need. With suggestions of pros-and-cons of tomographic survey some recent advances in hydrologic/
geophysical characterization of the subsurface are presented using information fusion based on tomographic survey con- cepts.
Lee (this issue) presents numerical investigations and thermohydraulic evaluation of open borehole thermal energy storage (BTES) system operating under cyclic flow regime.
A 3-D numerical model for groundwater flow and heat transport is used to determine the annual variation of recov- ery temperature from the borehole thermal energy storage.
The model includes the effects of convection and conduc- tion heat transfer, heat loss to the adjacent confining strata, and hydraulic anisotropy.
ACKNOWLEDGMENTS: Appreciation goes to Dr. J.S. Ahn, Dr.
K.Y. Kim, and other organizing committee members to contribute for
the symposium and this special issue. Support from KIGAM and Sus-
tainable Water Resource Research Center (SWRRC) are also greatly
