Hidrologia s

ubterraneaThe future of hydrogeology
Clifford I. Voss

Introduction
“The Future of Hydrogeology” would seem to be an overly ambitious topic for a theme issue of Hydrogeology Journal or for any other journal. Only a modicum of common sense and experience provides the insight that predicting the future of a science is a task fraught with uncertainty that should be approached with caution and humility. Please be assured that the intent of this issue of the journal is not to predict the future but rather to instigate discussion and to inspire creative thinking about hydrogeology. In their articles, authors have presented personal opinions concerning the future evolution of their subjects based on their experience. This is an acceptable approach, considering that any view of the future can be no more than an educated guess. Most authors have given their opinion after an expert and insightful review of the evolution of their subject to the present time or after reviewing the current state of knowledge or practice of their subject. Consequently, this issue of the Hydrogeology Journal provides an exciting view of potential developments in crucial aspects of hydrogeology founded upon developments to date. The issue contains 30 articles on a variety of ‘future hydrogeology’ subjects considered from a variety of viewpoints ranging from philosophical to highly quantitative. There are two article types: full length Papers and four-page Essays. All of the articles have been invited. Regretfully, many important subjects are not addressed in this issue due to both the lack of space and the lack of time and resources to assemble the issue, but there is much here that will satisfy and stimulate readers, covering a broad range of important subjects. Table 1 presents a

summary of all subjects and articles included in this issue. In the table, articles have been grouped by the Editor in a somewhat arbitrary manner into six general topics. A few articles appear with both primary