Post on 27-May-2020
The Application of
Geospatial Analyses in
Environmental Planning,
Sea-Level Modeling and
Geoscience Research
Robert A. Ross Qatar Petroleum Research
Jeremy Jameson ExxonMobil Research Qatar
Abdulali Sadiq Qatar University
Nasser Al-Mohannadi Qatar Petroleum Research
Eric Febbo ExxonMobil Research Qatar
Jurgen Foeken Qatar Petroleum Research
Christian Strohmenger ExxonMobil Research Qatar
Introduction: Spatial Referencing Possibilities
From this 2D Surface
To
To this 3D Subsurface
1. Most spatial referencing applications
are 2-Dimensional, focused on urban
management and planning.
2. This presentation reports on a feasibility
study to create 3-D and 4-D (temporal)
models of countries like Qatar.
3. Key aspects of surface geology, near-
surface geology and marine ecology
were considered in the feasibility study.
4. Recent advances in publication make it
possible to publish countrywide
datasets of key data
• ‘Everyone can make a map’-
dissemination of specialist
information to all decision makers
• Major elements of a 4-D model:
- High quality DEM (terrain model)
- Imagery (satellite and historical)
- Surface and soil geology
- Surface features analysis (faults, lineaments,
drainages, karst)
- Marine habitats, sediments and sensitivity data
- Geotechnical data
- Water table and composition data
- Hydrology and meterology
- Temporal – Changes over time
• Through web publication these data become
available to specialist and non-specialist for decision
making
Introduction: What are talking about? Building blocks
for a model
Terrain models- the foundation for mapping and
interpretations
• High resolution terrain models are first step in recognition of drainage patterns, surface
feature classification, geological interpretation and planning.
• Analytical products from terrain maps (eg curvature, derivatives) help identify features
• Qatar applications: recognition of karst, surface lineaments, drainages, land movement
studies (industrial, agricultural, tectonic)
Terrain DEM of
Qatar- elevations
in grey shade
Pleistocene Drainages
(wadis)
Structural Features
Lineaments
• Multi-spectral satellite and orthoimagery form the basis for
surface and marine classification
• Temporal analysis often based on historical imagery
• High quality simplifies geological and soil mapping
Overlaying Satellite Imagery - Characterization of
Surface Features
Satellite imagery, no
interpretation view from SE of
Qatar peninsula
Satellite Imagery- Advances in marine classification
Bathymetry output example at Area 3.
Recent Advances in multispectral imagery provide realistic bathymetric models for shallow marine habitat classification
Historical Data in Geotechnical Analysis
Hazardous karst areas identified using 1947 aerial photos and DEM
ABOVE: The original input data and the
importance of date metadata (‘47’ is
1947). Image shows the 1947 aerial
photo and modern satellite imagery
before combination through
georeferencing.
ABOVE: Georeferencing 1947 image to
identifiable terrain on satellite image.
Subsequent building development
masks some features. The ability to
identify features to reference photos is
vital. Need to retain older imagery.
Characterization of Surface Geology
View shows the distribution of
Holocene sabkha, Holocene
sands and Miocene .
• Bedrock geology and soils are basis for most civil engineering planning, agricultural management, and water studies
• Bedrock and soils classifications should be mapped to each other
• Should be integrated with surface features (lineaments)
Building blocks for countrywide geological models
• Water well cores and logs 0-400 m
• Shallow tops from oil and gas 400+
• Geotechnical cores 20-125 m
• Bedrock surface geology
• Structural dips, structural features
Elements of a geological model
• Countrywide grids of key stratigraphic horizons
• Attribute maps (composition, thickness etc) for each
horizon
• Search tool for all geotechnical and geological
literature
Building a Stratigraphic Model of Near-surface Geology
Sequence Boundary Sequence Boundary
Maximum Flooding Surface Maximum Flooding Surface
Transgressive Surface Transgressive Surface
SB1 SB1
SB2 SB2
HST HST
TST TST
LST LST
Example of Sequence Stratigraphic Framework
Making Intelligent Decisions:
More data = better decisions.
Before constructing a new building or asset, civil engineers need to assess:
• What borehole data are to be acquired?
• What borehole data are already available?
• Is the data relevant e.g. is the borehole deep enough?
• How do I get the previous reports and data?
Answer :
• Establish Qatar-wide geotechnical engineering database.
• Store, query, retrieve and analyze geotechnical engineering
data and legacy boreholes.
• Borehole data can be re-used in conceptual design stage.
• Analyze spatial patterns.
A Decision Tool for Civil Engineering and Planning
• Paleo-urban planning-
- How did people plan 5,000 years ago?
Time - 4-D Models as Tools for Research
Distribution of early settlements in Qatar reflect spatial relationships essential to survival in a harsh environment: 1) access to the sea; 2) fresh drinking water within 4 meters of the ground level; 3) beach rock and other building materials.
6,000 years ago, sea level was 2 metres higher than today. Map shows spatial analysis reflecting sea level 2 metres higher (purple areas). Areas of coastal plain where bedrock was within 4 metres of the old water table shown red.
Time - 4-D Models as Tools for Research
• Sea-level was 2 metres higher 6,000 years ago
Early Settlement ?
Time - 4-D Models as Tools for Research
• Making temporal (time) models dynamic
Time - 4-D Models as Tools for Research
Time - 4-D Models as Tools for Research
Post-Glacial History of the Arabian Gulf – What and When?
18,000 years ago - Glaciers in Zagros Mts. Cold and wet. Fresh water rivers and
lakes – green valleys. Sea level 120 metres lower than today.
14,000 years ago. Sea level gradually came into the Arabian Gulf. Sea level
starts to rise as the polar ice caps melt. Arid conditions like today. Rivers dry up.
Sand dunes.
12,000 years ago, glaciers melted . More arid conditions. Sand dunes moving.
10,000 years ago sea-level looks much the same as today.
Between 14,000 and 10,000 years ago sea-level rises at a rate of one metre
every 100 years.
10,000 to 6,000 years ago –Wet conditions return. Green areas and rivers.
6,000 years ago - sea-level was 2 metres above present day.
Research tool reconstruction - Sea-level history analysis and imagery
draped on bathymetry and terrain model in GIS
Time - 4-D Models as Tools for Research
Post-Glacial History of Arabian Gulf – Coast Today in Red
Summary and Conclusions
• Rapidly developing countries of the Arabian Gulf face unique
challenges balancing between the demands of development and
conservation.
• High-quality tools are needed in order to make sound decisions.
In most cases the consequences are irreversible.
• We have presented a ‘template’ for 4D models of the key features
of a country that could be deployed as an aid in making decisions.
• These models rely mostly on integration of existing data.
• The models are publishable, making them readily available to all.