(4 09 188
XIII Congress of the International Society for Photogrammetry
Helsinki, Finland - July 1976
Invited Paper - Commission VII
REMOTE SENSING OF WATER AND WETLANDS
by
Charles E. Olson, Jr.
School of Natural Resources
The University of Michigan
Ann Arbor, Michigan, 48109, USA
ABSTRACT
Applications of remote sensing in water and wetland inventory and monitoring programs are
growing rapidly. This growth parallels the earlier development of remote sensing of terrestrial
features. Techniques for accurately mapping location and outline of water bodies and discrimin-
ating between different types of wetland vegetation are operational. Progress is being made in
remote determination of water quality, dynamics of wetland circulations, and standing plant bio-
mass. Greater attention needs to be placed on the development of quantitative methods, on under-
standing wetland dynamics, on determining the spectral characteristics of water and wetland
materials, and on adapting remote sensing techniques to needs of decison makers.
RÉSUMÉ
L'application de la télédétection a l'inventaire de l'eau et des zones humides et aux
programmes monitoires croit rapidement. Cette croissance est paralelle au développement antér-
ieur de la télédétection des caractéristiques physiques du terrain. Les techniques de la carto-
graphie précise de la situation et du contour d'un corps d'eau et celles de la discrimination
entre les divers types de végétation des zones humides sont en marche. On fait des progres avec
la détermination à distance de la qualité de l'eau, de la dynamique de la circulation des zones
humides, et de la bio-masse de la flore. On doit s'occuper davantage du développement des
méthodes quantitatifs, de la connaissance de la dynamique des zones humides, de la détermination
des caractéristiques spectrales de l'eau et des matiéres des zones humides, et de l'adaptation
des techniques de la télédétection aux besoins des administrateurs.
ZUSAMMENFASSUNG
Die Verwendung von Fernerkundungen zum Zwecke der Wasser- und Moorland-Inventur und Über-
wachung ist am raschen Ansteigen. Dieses Wachstum ähnelt der früheren Entwicklung der Fern-
erkundung zum Zwecke der Messung von Landschaftsformen. Techniken für die exakte Messung der
Wassergrenzlinien sowie der Moorlandpflanzentypen wurden erfolgreich entwickelt und sind anwend-
ungsreif. Fortschritte werden in der Messung von Wasserqualitáten, Dynamik der Wasserzirkulation
und der Pflanzenbiomassen gemacht. Mehr detaillierte Arbeit und Untersuchungen sind auf den
folgenden Teilgebieten notwendig: (1) der Entwicklung von quantitativen Messmethoden; (2) des
Verstehens der Moorlanddynamik; (3) der Analyse der Spektralcharakteristiken von Wasser und
Moorlandmaterialien; und (4) der praktischen Verwertbarheit von Fernerkundungsergebnissen für
politische Entscheidungszwecke.
INTRODUCTION
Any complete assessment of water and wetlands must treat the entire hydrologic cycle and the
contributions and interrelationships of each of its elements. This is a tremendous challenge,
but one full of opportunities for remote sensing. Descriptions of these opportunities and our
current capabilities are included in Chapters 18 and 19 of the MANUAL OF REMOTE SENSING, recently
published by the American Society of Photogrammetry. Rather than summarize the material in that
MANUAL, it is the intent of this paper to identify areas that need additional work if we are to
utilize remote sensors more effectively in meeting water and wetland information needs. These
needs are not limited to enquiries as to how much water is located where, but encompass concerns
for the biological, chemical, and physical characteristics of water as: (1) a dynamically changing
commodity in its own right; (2) an essential component of aquatic and wetland ecosystems; and
(3) an indicator of environmental quality on a world-wide basis.
OPERATIONAL CAPABILITIES
Man's use of land can have important effects on water quality over considerable distances, and
analysis of land-use must be a part of water-wetland monitoring programs. For example, seepage
from livestock feed lots located above geologic fractures, and runoff from automobile junk yards
on river banks, contaminate ground water and streams, respectively. Identifying such problem
land-uses is a first step in correcting them. Many techniques developed for land-use mapping have
proved so useful in water and wetland situations that applications of remote sensing to water and
wetland inventory and monitoring have developed in directions that parallel earlier terrestrial
work. Black-and-white, color, and false-color photography has long been used to determine the
location and areal extent of water bodies, and is routinely used for mapping vegetated wetlands
and adjacent uplands. More recently, satellite data have been used effectively for similar map-
ping of large areas at small scale. Recent work with calibrated thermal line-scanners has shown
that heated effluent plumes can be consistently mapped and dispersal patterns determined; and
airborne radars are routinely used to monitor sea- and lake-ice in, and adjacent to, commercial
shipping lanes.
