and Hydrogeology 1 INTRODUCTION TO HYDROGEOPHYSICS 12 SUSAN S. HUBBARD and YORAM RUBIN 1 Lawrence Berkeley National Laboratory, Earth Sciences Division, Berkeley, CA 94720 USA. sshubbard@lbl. gov 2 Department of Civil and Environmental Engineering, UC Berkeley, Berkeley, CA 94720, USA In this chapter, we discuss the need for improved hydrogeological characterization and monitoring approaches, and how that need has provided an impetus for the development of an area of research called hydrogeophysics. We briefly describe how this research area has evolved in recent years in response to the need to better understand and manage hydrological systems, provide discussions and tables designed to facilitate navigation through this book, and discuss the current state of the emerging discipline of hydrogeophysics. 1. 1 Evolution of Hydrogeophysics The shallow subsurface of the earth is an extremely important geological zone, one that yields much of our water resources, supports our agriculture and ecosystems, and influences our climate. This zone also serves as the repository for most of our municipal, industrial, and governmental wastes and contaminants, intentional or otherwise. Safe and effective management of our natural resources is a major societal challenge.weiterlesen