Title: MONITORING THE EFFECT OF CHEMICAL WEAPONS ON LAND COVER OVER HALABJA
1MONITORING THE EFFECT OF CHEMICAL WEAPONS ON
LAND COVER OVER HALABJA CITY, IRAQbyJWAN
.M.AL-DOSKI
- Shattri B.Mansor and Helmi Zulhaidi Mohd Shafri
- Geospatial Information Science Research Centre
(GIS RC), - Faculty of Engineering
- Universiti Putra Malaysia
2Introduction
- The development and use of
satellite imagery and aerial photographs have
long been used for improving the effectiveness of
military operations from aerial photographs using
balloons to aircraft platforms and recently
satellite remote sensing( Corson, M.W. 2004).
Military planners have used remote sensing
satellite imageries as a tool of warfare, while
during the past decades, the majority of academic
researchers have made their efforts in using this
technology in non-military use such as Forestry
Hydrology , Geology , Agriculture, Environment,,
Landscape changes and finally war impacts (De
Sherbinin, A. 2002). - As had been shown in mankind's history,
there are many countries in which during their
advancement and evolution entered into wars which
left them in devastation with huge losses in life
and economic resources. For example, since the
past three decades, Iraq had engaged in series of
wars began with the bloody Iraq-Iran war which
started from September 1980 to August 1988 after
that Iraq- Kuwait war in 1990 which known as Gulf
War and finally the occupation by United State in
2003, made them the longest conventional wars in
the 20th century (Abrahamian, E. 2008). These
wars devastated Iraqi economy and left it saddled
with huge debts as well as a great loss in lives
(Dugdale-Pointon 2002) Up till this moment there
is no conclusive figures for the number
sacrifices and losses.
3Problem statement
-
- During the course of Iraq-Iran war, many parts of
Iraq were bombarded with hazardous chemical
weapons such as mustard gas, nerve agents, sarin,
Tabun, VX and cyanide. Halabja city is one of
those places that suffered heavy bombardment with
attendant destructive impact on human lives,
socio-economic and the environment. Since 1994,
many studies have been conducted on the impact of
war on the social, cultural and economy to better
understanding the interaction and relationship of
the war on natural phenomena as well as for
better managing and using available resources. No
study has been carried out on the impact of the
war on environment/land cover changes because of
lack of field survey data , apart from this most
of the areas were closed after bombing coupled
with political undertone and the harsh conditions
of war. In recent decades, remote sensing
satellite imageries are extensively used for
detecting war impacts however the ability of
these imageries are limited and difficult to
detect some war impacts for example,
bullet-pocked walls whereas the mass displacement
of local residents, re-vegetation in agricultural
areas occurs or new service roads are constructed
can lead to changes in land cover it would be
detectible easily by satellite imageries.
4Research Objectives
- The main goal of this research is to examine
change detection techniques to investigate
short-term changes before and after shelling with
chemical weapons as well as 10 years long-term
changes in land cover that had occurred in
Halabja. To obtain this, the following objectives
will be achieved - Applying three change detection methods (Image
differencing(NDVI) , hybrid classification and
post-classification techniques) to identify land
cover changes. - Create Land use/ land cover classification maps
as accurately as possible on a regional scale of
Halabja city. - Create the LULC changes maps for the study area
within the period of 1986 to 1990 as well as 1990
to 2000 using post-classification method. - Examine both qualitative and quantitative changes
to show the impact of the war on Halabja city.
5Research Questions
- In order to fulfill the above mentioned
objectives, the following research questions can
be made - Can the land use/land cover Changes in study area
be assessed using the applied satellite images? - How effective is the hybrid change detection
technique for image classification in the context
of the study area? - What are the land use/land cover changes in the
study area in two time periods? - How can post classification be used to strengthen
the justification of accuracy for the Hybrid
classification?
6Study area
- Regionally, Halabja city with a population of
about 70,000 is situated 80 kilometers from
southeastern city of Sulaimanya, about 150 miles
(241km) north-east of the Iraqi capital city
Baghdad and 16 Km away from Iraq-Iran boarder. It
lies in southeastern Sharazur plain. And
surrounding by ( Hawraman ) mountain and (
Balambo) mountain to the north and south borders
of Halabja. Geographically, Halabja is located
between 3510'59.22"N latitudes and 4558'59.05"E
longitudes with land area of about 592.7 square
miles.
7Study area
8Data Landsat scenes
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12Climate data
Iraq crop calendar
13Methodology
14Pre- processing1. Radiometric correction
- Absolute radiometric correction method was used
which is generally a two step process. The
first step is to convert the digital number (DN)
o f the sensor measurements to spectral radiance
(L). Secondly, conversion of measured DN to top
of atmosphere (P) reflectance units by using
following equations
15SATELLITE SUNSOLAR ELEVATION() SUNSOLAR ZENITH() SCENE_CENTER_SCAN_TIME
1986 imagery TM 61.1776237 105.0757542 065700379
1990 imagery TM 60.5546184 105.1066741 06532424
2000 imagery ETM 66.0654401 111.8446727 07245393
162. Geometric correction
- Geometric correction procedures address
errors in the relative position of pixels . The
images in this study were level-IT products which
mean geometrically corrected for making sure
further rectify and standardize were done on all
images by using automatic Image-to-image
registration to 2000 image (base image) with root
mean square error 0.5 consider acceptable
followed by projecting all images to a common
coordinate system (UTM) with a World Geodetic
System (WGS) 84 datum Zone 38 North. In order to
easy to compute, speed up and reduce time of
processing all images subsetted to (1477 samples,
929 lines) including only the area of interest
followed by resampling to a 30 m pixel size using
the polynominal warping method with nearest
neighbor algorithm to keep the original
brightness values of the pixels
Base Image Warp Images GCPs RMS
2000 Image 1986 Image 131 0.47
2000 Image 1990 Image 116 0.43
17Atmospheric correction
- Dark Object Subtraction (DOS) is a simple
image-based atmospheric correction . It was
performed on each image to remove absorption and
scattering of electromagnetic radiation or reduce
the influence of atmospheric scattering within
each scenes
18NDVI 1986
- NDVI is related to photosynthetic
activity of vegetation and it can calculate using
the following equation - NDVI NIR- R / NIR R
NDVI values range from -1.0 to 1.0. Typical
values are from 0.2 to 1 or above 0,6
represents a large amount of high
photosynthesizing and healthy vegetation.
According to (Wang, J. 2004) NDVI values between
-1.0 to 0.1 represents non- vegetative and
correspond to barren areas of rock, sand ,snow
,built- up area and water body. Conversely
sparse values 0.2 indicate shrub and grassland,
Moderate values(0.5) indicate vegetation field
while forests are represented by high NDVI values
(0.6)
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20NDVI 1990
21NDVI 1990 Classification
22NDVI 2000
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24NDVI statistic analysis
NDVI VALUE NDVI VALUE NDVI VALUE NDVI VALUE
IMAGES Min Max Mean Stdev
1986 -0.521281 0.770415 0.178504 0.137779
1990 -0.485578 0.771176 0.158516 0.13129
2000 -0.173588 0.562458 0.136942 0.059818
25Band differencing
Red band differencing
Green band differencing
Color composite image
Blue band differencing
26NDVI differencing methodIt can be calculate by
using NDVID NDVI time 1-NDVI t2
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28NDVI 2000-1990
29NDVI 1990-1986
30Prepare General Base map
31Spectral Angle Mapper 1986
32Spectral Angle Mapper 1990
33- The three satellite images were classified into
land use/ land cover classes base on( Anderson
et al (1976) land use/ land cover
Classification Systems) were modified to
classify the images into five classes as shown
in this table
Classes Definition
Water bodies Rivers, lakes, ponds, lagoons, dams, marsh wetlands
built-up area Residential and commercial services, office blocks, roads, rails
Forest land protective forests, timber forest , economic forest, firewood forest and forests of special use
Agriculture land All cultivated areas such as farmlands, crop fields including vegetable gardens, plantations, fallow plots
Rangeland Herbaceous Rangeland, Shrub and Brush Rangeland ,Mixed Rangeland
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