sthan,
ht
he
er.
an
nd
ns,
nd
ief
his
nd
REMOTE SENSING OF SUSPENDED SEDIMENTS IN SURFACE WATERS, USING
MODIS IMAGES.
j Mobasheri, M. Reza,
Physics Department, KNT University of Technology, Tehran, Iran.
Mobasheri@jik-ac.org
Mousavi Hamid,
Khoozistan Water & Electricity Organization Ahvaz, Iran.
KEY WORDS: Remote Sensing, Coast, Estuary,
ABSTRACT:
Retrieval, Algorithms, Suspended Sediment.
Collecting information about (Suspended Sediment Concentration) SSC, in coastal Waters
and estuaries is vital for proper management of coastal environments. Traditionally, SSC used to be
measured by time consuming and costly point measurements. This Method allows you to accurately
measure SSC only for a point in space and time. Remote sensing from air-borne and space-borne
sensors have proved to be a useful method to such studies as it provides an instantaneous and
synoptic view of sediments that would otherwise be unavailable. The reason for success of remote
sensing in such surveys is the strong positive relationship that exists between SSC and remotely
sensed spectral radiance L; . This Spectral radiance could be in the sun reflected and/or scattered or
thermal terrestrial wavelength bands.
Many workers have shown that the relationship between SSC and Ly, strongly depends on
the intervening atmospheric constituents as well as the suspended material and depth.
To find an algorithm relating SSC to L;
of Persian Gulf, a three-month field measurem
had MODIS sensor on board of Orbview-3 over
fifteen trips were collected. Also the environm
and water temperature, current direction and sp
humidity were measured simultaneously.
over Bahmansheer River Estuary at the North-West
ent (April to June 2003) were conducted while we
-passed the scene simultaneously. Ninety samples in
ental parameters such as atmospheric visibility, air
eed of water at the sampling point, wind speed and
The collected samples were analyzed thoroughly by measuring density, diameters of the
sediment particles and determining the sediment constituents. Total density were ranging between
30 to 500 (mg/lit), the range of particle diameter were from less than a micrometer to more than 20
micrometers and finally it was found that the sediment were composed of Quartz, Kaolinite,
Orthoclase, Chlorite, Calcite, Gypsum, Muscovite, Halite, Anhydrite, Apatite, Biotite, and low
amount of Albite. It is found that the spectral characteristics of these compositions are partly
responsible for the reflected and/or scattered energy in different bands while the correlation
between larger suspended particle density and L,
parameters on the results were discussed. It is bel
reason for the poorness of the correlation coefficie
1- Introduction
Since the late 1970's remote sensing
studies of suspended sediments have been made
using the fact that suspended sediments increase
the radiance emergent from surface waters in
were profound. Also the effects of environmental
ieved that the atmospheric aerosols are the main
nts.
the visible and near infrared region of the
electromagnetic spectrum (Ritchie and Schiebe
2000). Most researches that had a large range
(Le, 0-200+ mg/l) of suspended sediment
concentration has found a curvilinear
relationship between suspended sediments and
1289