Airborne remote remote sensing sensing activities activities over over the the North North Sea Sea

Airborne

Airborne remote remote sensing sensing activities activities over over the the North North Sea Sea

Inka Inka Bartsch Bartsch ^{1 1} a a nd nd H. Christian Hass H. Christian Hass ^{2 2}

Alfred

Alfred Wegener Wegener Institute for Polar and Marine Research Institute for Polar and Marine Research

1 1 Am Am Handelshafen Handelshafen 12, 27570 12, 27570 Bremerhaven Bremerhaven , Germany , Germany

2 2 Wadden Wadden Sea Research Station, Hafenstr Sea Research Station, Hafenstr. 43, 25992 List/ . 43, 25992 List/ Sylt Sylt , , Germany

Germany

The The investigation investigation areas areas over over the the North North Sea Sea

Grafic: B. Hennig 2004, Diploma thesis, university Cologne/AWI

July July 2002: 2002:

• • first first ROSIS test ROSIS test flight

flight at at Helgoland Helgoland Sept. 2003:

Sept. 2003:

• • 2nd ROSIS 2nd ROSIS flight flight Helgoland and Helgoland and Sylt

Sylt

• • spatially spatially high high resolution

resolution stereo stereo pictures

pictures

Goals and Methods Goals and Methods

http://www.helgoland.de/ba_06.htm

Goals:

• • Long- Long -term m term monitoring of onitoring of spatio- spatio -temporal dynamics of temporal dynamics of macroalgal dominated communities and tidal basins macroalgal dominated communities and tidal basins

• • Recognition and evaluation of change at level of Recognition and evaluation of change at level of major biotopes and for processes that affect the major biotopes and for processes that affect the Wadden

Wadden Sea Sea Application:

Application:

• • e.g. EU e.g. EU -water frame work directive, North Sea Status - water frame work directive, North Sea Status Report

Report Methods:

• • Mapping of biotopes, habitats, Mapping of biotopes, habitats, morphodynamics morphodynamics and and sediments in target areas

sediments in target areas

• • GIS techniques GIS techniques

• • High- High -resolution aerial photograph mosaics resolution aerial photograph mosaics

• • Hyperspectral Hyperspectral airborne images and their classification airborne images and their classification

• • Ground- Ground -truthing truthing in the field in the field Background

Background: Working area is relatively small, but partially not accessible : Working area is relatively small, but partially not accessible by boat or by boat or on foot

on foot Æ ÆTime series not achievable without remote sensing Time series not achievable without remote sensing

Helgoland

Königshafen

Sylt

Sylt/Rømø basin

N

Sylt

The The intertidal intertidal communities communities

Biotopes were described in recent years and mapping

study conducted with the help of airborne photos

Helgoland

1:2500 1:2500

N

Digital

Digital Orthophoto Orthophoto derived

derived from from Stereophoto;

Stereophoto; pixel pixel resolution

resolution : 28x28 cm : 28x28 cm

Digitised Digitised

geomorphological

geomorphological map map of intertidal zone

of intertidal zone

Æ Æ digital high digital high resolution resolution maps maps Æ Æ precondition precondition for for monitoring of

monitoring of small small - - scaled scaled biotopes

biotopes

Helgoland

Helgoland: rocky intertidal zone Helgoland: rocky intertidal zone

DEM calculated from

DEM calculated from aerial photographs aerial photographs and field measurements

and field measurements (1m grid) (1m grid)

Uncorrected ROSIS scene Helgoland,

infrared spectrum

ROSIS: R

O

S

I

S

widths 4 nm, 430-860 nm

Helgoland

Biotope

Biotope classification classification with with ROSIS, Helgoland ROSIS, Helgoland

1:1000 1:1000

ROSIS classes Dense brown algae

Green algal biotope B Sparsely vegetated

mussel fields

Green algal biotope A

ROSIS classes over biotope map

Helgoland

50 cm 10 km

Precondition for monitoring is spatial and temporal high

resolution.

Ground

marker

Sylt

N N 500 m

N N

0

-1 1 2 3

[m asl]

Sylt Königshafen

DTM calculated from aerial photographs and field

measurements (50 cm resolution)

Sylt

1936

2003 2002 1989

2004

Coastline

West coast:erosion

- 1936 - 1986: 2.5 m/y (=124.2 m) - 1986 - 2004: 1.3 m/y (=23.6 m) North coast:accumulation

- 1936 - 1986: 2.4 m/y (=119.7 m)

1986 - 2004: 6.9 m/y (=123.3 m);(more accumulation due to beach nourishments) Königshafen: balanced

- Little effect, however balance slightly negative

Tidal Channels

- no exceptional effects Human Impact

- the artificial island Uthörn built in the early 1940s

- a dyke built in 1937 changed the coastline considerably but had only little effect on the adjacent tidal basin

North Sylt:

morphodynamics North Sylt:

morphodynamics

8•26

‘ 8•24‘

55•02‘ Legend

20 04 20 03 20 02 19 89 19 36

N

Coastline analysis by T. Dolch erosion

accumulation

Sylt

Seagrass/green algae

Unspecified sediment types

Sublittoral sediment

Very moist, finer sediment

Color negative

ground resolution: <20 cm

R

O

S

I

S

hyperspectral, ground resolution: 84 cm, 84 optical channels

ROSIS spectral classes

ENVI analysis by B. Hennig, 2004

1000 m

Altitude: 1,500 m Speed: 110 kn Overlap: 10%

IGI CCNS AEROcontrol

Sylt

Outlook Outlook

• • Hypersepctral Hypersepctral classification classification has to be has to be improved improved by by a a combination combination of of field field , , laboratory laboratory and and sensor sensor

spectrometry spectrometry

• • Combination Combination of different of different sensors sensors desireable desireable in order in order to to improve improve spatial spatial and and spectral spectral high high resolution resolution

• • Only Only several several flights flights per per year year covering covering all all seasons seasons will

will give give a a holistic holistic picture picture of of the the dynamics dynamics of of coastal

coastal morphology morphology and and the the spatial spatial development development

of of major major biotopes biotopes Æ Æ looking looking forward forward to to the the UAV UAV

Thanks

Thanks are are also also due due to to

T. Dolch, AWI Sylt T. Dolch, AWI Sylt

B. Hennig, University Cologne B. Hennig, University Cologne

S. Thiemann, DLR Oberpfaffenhofen S. Thiemann, DLR Oberpfaffenhofen J. Weber, LVA Schleswig Holstein J. Weber, LVA Schleswig Holstein Th. Kersten, HAW

Th. Kersten, HAW - - Hamburg Hamburg