GIS and Remote Sensing for Natural Resource
Survey and Management
Abstract:
The socio-economic development of any country is based on land resources and
water resources. Due to increase in population, these resources are over
stretched often leading to resource depletion. There is need to prudently
manage these delicate resources. Remote Sensing and GIS techniques can be
applied effective measure to generate data and information for sustainable
development. After more than 25 years of satellite-based land remote sensing
experimentation and development, these technologies reached almost all
sectors of Earth science application. The use of remote sensing data and
derivative information has ever promise of entering into mainstream of
governing at local and regional level.
Global Scan Technologies, Dubai implements the latest advent in spatial
mapping technologies for natural resource survey and management and have
carried out various project for UAE Government Organisation. The application
includes :
- Landuse / Landcover study- Visual and digital
interpretation of satellite imageries are implemented to prepare
pre-field map based on spectral/tone/texture homogeneity. Pre-field
interpreted map and digitally enhanced satellite data is used on the
ground to identify different land use and land cover classes and to
generate geodatabase for the land use and land cover.
- Vegetation Mapping- The classification system is open
ended and is based on globally followed principles of vegetation
classification using Climate/ Physiognomy / floristics. Based on the
spatial extent, separability using remote sensing and ground information
on vegetation distribution a geodatabase has been generated for
Vegetation theme.
- Soil Mapping - The satellite data is interpreted
based on photo-elements like tone, texture, size, shape, pattern,
aspect, association etc. The first step in image-interpretation is the
delineation of landscape units. The discrimination of landscape units
and soil mapping units is based on lithology, relief, drainage pattern,
natural vegetation, and sometimes land use along with the associated
image elements . Field Survey is executed proceeding the preliminary
interpretation of satellite imagery. The soil mapping units is evaluated
for different land capability classes following USDA land capability
classification based on soil, topography etc., limitations
- Geology and Hydrogeology mapping- The first step in
generation of Geology and Hydrogeology Map is the Preliminary
interpretation of satellite imageries for demarcation of Lithological
boundaries, lineament ,other structural feature interpretation and
characterization of various geomorphic units.
Extensive field survey has been taken to verify the
pre-field interpretation data and finally the lithology, geomorphology and
structural maps are integrated to finalize the map and to generate
Geodatabase for Geology and Hydrogeology Themes.
Introduction
:
Global Scan Technologies, Dubai is implementing the latest and cost effective
solution for Thematic Mapping in United Arab Emirates and Worldwide. The
thematic mapping services includes Geology, Geomorphology, Hydrogeology,
Vegetation, Soil and Land use Land cover studies. The following article
enumerates such a study carried out for the part of Middle East Region.
A brief
methodology for execution of this project is explained as follows:
Methodology
Input data
The satellite data of the study area are procured from IRS-P6, LISS-III &
LISS-IV and has been used for Geology, Geomorphological, Soil, Vegetation and
Land use Land cover studies. Published soil maps, topographic maps, climatic
data etc. are also collected and used as collateral data.
Data Processing
The IRS P6 satellite data were geo-referenced and suitable Image enhancements
are applied to facilitate the delineation and interpretation of different
thematic information.
Data
Interpretation
Visual and digital interpretation methods were used to prepare pre-field
interpreted map. The satellite data is interpreted based on photo elements
like tone, texture, size, shape, pattern, aspect, association etc. These
pre-field interpreted maps and digitally enhanced satellite data are used on
the ground to identify different elements of various themes.
Field
Verification and Data Collection
Suitable field sampling designs in terms of line transects/ quadrants are
used to assess the interpreted elements and relate with satellite data. The
field data collections are aided by GPS in order to locate the ground
verification points on the image and for further incorporation of details.
For the all the sample collection and field points visited attribute
information on vegetation, geomorphologic, soil and topographic parameters
are also collected.
The detailed soil-site study was undertaken in each soil-mapping unit by
general traversing and by collecting surface soil, minipit and soil profile
observations at intervals depending on soil variability
The sample points were decided based on the geological / Geomorphological /
soil heterogeneity mapped from the satellite data.
Finalization
of Maps
Based on the pre-field interpretation, ground truth verification and available
secondary information final maps were prepared in 1: 25000 scales. Towards
this both visual and digital approaches are conjunctively used.
Themes
Specifications:
Land use Land
cover
The land use and land cover map is prepared using RESOURCESAT LISS IV
satellite data. The classification scheme was designed keeping in view of the
management practices addressing each land use/ land cover parcel, amenability
of these parcels for identification/mapping in LISS IV dataset. Under the
Level-I classification, Built up, Cultivated areas, Woody vegetation,
Grasslands, Wastelands, Wetlands and Water bodies were segregated. In
addition subclasses of Level-I LULC classes observed based on spectral
satellite data and were evaluated on the ground, to characterize them as
information classes. All the LULC classes were visually interpreted based on
tone/texture, contextual and ground information. The major information class
in the study area is 'built up areas' was consisting of urban and rural
fringe landscapes and the urban built up areas were dominated by residential,
mixed residential and industrial areas. The rural landscape essentially
consisted of settlements, camel camps and cultivated areas. Statistical data
of community wise built up area was generated and analyzed.
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Vegetation
The vegetation cover map is generated using IRS Resourcesat LISS III &
IV. The vegetation in the study area is regulated by desert climate,
seasonality, physiographic, geomorphologic and soil regimes. The vegetation
is broadly demarcated into natural and managed vegetation. The natural
vegetation mainly consisted of formations of Mangroves, Prosopis, Leptadenia.
The managed vegetation mainly consisting of avenue plantations, grasslands,
lawns, golf courses and palm /mixed plantations. Phyto-sociological analysis
was carried out after collecting sufficient number of sample data from the
natural vegetated areas. The vegetation mainly mangroves, Prosopis,
Laptadenia are further stratified into dense and open canopy density classes.
Further different categories of vegetation under each of the community has
been extracted and analyzed to understand the percentage of vegetation
present to that of vacant land. Such information on spatial distribution in
qualitative and quantitative terms would be useful in further exploring and
analyzing the aspects of biodiversity and ecological conservation
Soils
The soil is mapped using remote sensing satellite data IRS- P6 LISS IV. The
soils of the study area were classified upto series level and their
association's level as per the Keys to Soil Taxonomy (Soil survey staff,
2003). .
Essentially soil survey is a study and mapping of soils in the field. It is
the systematic examination, description, classification and mapping of soils
of an area and it comprises of a group of interlinked operations involving
- Preliminary
visual interpretation of satellite data
- Fieldwork
to study important characteristics of soils and associated land
characteristics such as landform, natural vegetation, slope etc.
- Laboratory
analysis to support and supplement the field observations.
- Correlation
and classification of soils into defined taxonomic units.
- Mapping
of soils - that is establishing and drawing soil boundaries of different
kinds of soils on standard geographical base map.
- Generation
of Geo-database for Soil
Geology
The geo-referenced satellite digital data was used to carry out 'on screen'
vectorization of geological parameters. Basically three vector layers were
generated in. The first vector consists of geological structure attributes
with length based classification second vector consists of geomorphic
attributes and the third vector consists of broad litho logical map. In the
case of image processing, spatial and spectral domain enhancement was carried
out using ENVI software. The following steps were involved:-
- Satellite data
has been be geo-referenced with the available map sheets.
- LISS-3 /
Liss-4 and AWIFS data were be acquired for the entire study area
- LISS-3 was
used for regional assessments and LISS-4 data was used for detail
assessments.
- These data
sets were co registered with other collateral data sets by taking common
Ground Control points (GCP).
- The satellite
data was enhanced both in spectral and spatial domain.
- A optimised
image was generated for visual / Onscreen interpretation.
- The existing
geological map was not available for the area and hence using geomorphic
analysis, field and published literature a broad level lithological map
was prepared.
- The geological
structure map was prepared with mainly on type of lineament with
emphasis on length, Faults and thrusts
- The
geomorphological map was prepared with emphasize on genetic
classification of landforms. The major group are coastal landforms,
aeolian landforms, and structural landforms.
- A pre-field
map was prepared using satellite data
- Ground
validation was carried out with emphasis on selective ground checks
- The ground
observation was incorporated at appropriate places to finalize post
field map
- All the three
themes have been integrated in GIS environment to generate
hydro-geomorphology map.
Conclusion
The generated theme can be implemented for further planning of the urban and
rural area .The action plan report can be created using the Geodata database
and total decision support system can be developed to depict location and
type of action / control measures recommended for sustainable development
plan of Natural Resource. Zonal and Community wise Soil resource development
plan, Water resource development plan, Vegetation resource development plan,
Land use and Land cover plan can be incorporated using statistics of the
personal Geodatase of the respective Theme.
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