Introduction

Abstract

The Nilometer in Cairo may be considered as an ancient device of remote sensing, since it measures — for millennia — the water level of the river Nile not in the river itself, but rather in a historic tower building of very fine architecture near the river Nile. The type of remote sensing discussed in this book is, however, of a rather different type: It deals with techniques and methodologies the electronic age can offer to hydrologists and water managers. At present a rather small international community of hydrological scientists have developed - and are still developing — methods for application of remote sensing information to the solution of hydro- logical and water management problems. Although many of these techniques are already far advanced — several of them are operational — unfortunately many practitioners responsible for hydrological networks and water resources development are still reluctant to use these methods. This situation is due to several reasons, e.g. unavailability of relevant hardware and software, lack of knowledge in the application of remote sensing techniques, reluctance to change conventional and well established methods etc. It is the aim of this book to overcome these barriers and show to practitioners the potential of remote sensing and, hopefully convince them of the advantages of these techniques for their future work. They will soon see, that several of their problems which could not be treated at all so far will become tractable and other problems dealt with at present with difficulty may be solved in a much more elegant way.