Preface
The authors of this book have been approached by consulting engineers: "You
know about remote sensing and thus you can obtain hydrological information
where no data exist, even without ground measurements, so that I can design the
required capacity of a drinking water supply reservoir in a developing country."
On the other hand, the authors have been told: "Remote sensing is not of much use
since it is still impossible to estimate ground water resources or surface water
flows from remote sensing data." The major aim of this book is to correct such
unjustified illusions as well as exaggerated criticism by providing the reader with
sound information on the potential - and the limitations - of remote sensing in the
field of hydrology and water management.
The book is meant to be a reference and text; it is not a collection of papers from
some meeting. The book is intended to provide methods to help the readers solve
their own problems in hydrology and water management. Therefore, scientific
issues are presented only as far as they are necessary for the application of remote
sensing. The reader will see that in some fields, (e.g. evapotranspiration, soil
moisture, hydrological modeling) the scientific development is still on the way,
while in others operational techniques are already available (e.g. snow melt runoff-model, land use classification and detection of land use changes, flood forecasting and control). Furthermore, the reader will realize, that in many cases remote sensing data are only auxiliary information to other data, e.g. digital maps,
digital elevation models, modem hydrometric data, etc. In almost all cases remote
sensing will not replace, but will augment traditional data.
The application of remote sensing in hydrology and water management requires
not only remote sensing data, but also access to the required hardware and software. Hopefully, the reader will realize that using and manipulating remote sensing data has become greatly simplified and cheaper in recent years. Tasks that had
to be done on expensive specialized computers a few years ago can now be accomplished on a desk top PC and high performance computer systems and the
powerful software are available at reasonable costs. It can also be seen that although some of the algorithms for transforming remote sensing data into hydrological information are becoming more and more complex (to handle data from
multiple satellites or merging satellite and traditional data), they are being distributed in a very user-friendly format. Furthermore, a combination of remote sensing
data, ground truth, (e.g. from modem hydrometric equipment) and powerful software domains such as GIS give the hydrologist or water resource manager extremely powerful tools to help solve their problems.
The readership of this book is expected to consist of hydrologists and water
managers, i.e. mainly civil engineers, environmental engineers, geo-scientists and
agricultural engineers. The information provided emphasizes possible applications
of remote sensing data to hydrological monitoring and modeling as well as for
water resources management decisions. New techniques are provided, which - due
to the unique characteristics of remote sensing information - have a structure dif-
The authors of this book have been approached by consulting engineers: "You
know about remote sensing and thus you can obtain hydrological information
where no data exist, even without ground measurements, so that I can design the
required capacity of a drinking water supply reservoir in a developing country."
On the other hand, the authors have been told: "Remote sensing is not of much use
since it is still impossible to estimate ground water resources or surface water
flows from remote sensing data." The major aim of this book is to correct such
unjustified illusions as well as exaggerated criticism by providing the reader with
sound information on the potential - and the limitations - of remote sensing in the
field of hydrology and water management.
The book is meant to be a reference and text; it is not a collection of papers from
some meeting. The book is intended to provide methods to help the readers solve
their own problems in hydrology and water management. Therefore, scientific
issues are presented only as far as they are necessary for the application of remote
sensing. The reader will see that in some fields, (e.g. evapotranspiration, soil
moisture, hydrological modeling) the scientific development is still on the way,
while in others operational techniques are already available (e.g. snow melt runoff-model, land use classification and detection of land use changes, flood forecasting and control). Furthermore, the reader will realize, that in many cases remote sensing data are only auxiliary information to other data, e.g. digital maps,
digital elevation models, modem hydrometric data, etc. In almost all cases remote
sensing will not replace, but will augment traditional data.
The application of remote sensing in hydrology and water management requires
not only remote sensing data, but also access to the required hardware and software. Hopefully, the reader will realize that using and manipulating remote sensing data has become greatly simplified and cheaper in recent years. Tasks that had
to be done on expensive specialized computers a few years ago can now be accomplished on a desk top PC and high performance computer systems and the
powerful software are available at reasonable costs. It can also be seen that although some of the algorithms for transforming remote sensing data into hydrological information are becoming more and more complex (to handle data from
multiple satellites or merging satellite and traditional data), they are being distributed in a very user-friendly format. Furthermore, a combination of remote sensing
data, ground truth, (e.g. from modem hydrometric equipment) and powerful software domains such as GIS give the hydrologist or water resource manager extremely powerful tools to help solve their problems.
The readership of this book is expected to consist of hydrologists and water
managers, i.e. mainly civil engineers, environmental engineers, geo-scientists and
agricultural engineers. The information provided emphasizes possible applications
of remote sensing data to hydrological monitoring and modeling as well as for
water resources management decisions. New techniques are provided, which - due
to the unique characteristics of remote sensing information - have a structure dif-