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Urban Sprawl Impact Assessment on the Fertile Agricultural Land of Egypt Using Remote Sensing and Digital Soil

Database, Case study: Qalubiya Governorate

Shalaby, A. & Gad, A.

National Authority for Remote Sensing and Space Sciences, Egypt

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Motivations

The ever increasing population and urban sprawl in addition to landdegradation causes a huge pressure on the limited agricultural landand decrease in area per capita.

The amount, the rate and the intensity of urban sprawl and lose ofagricultural land need to be analyzed.

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Introduction

Urban sprawl is one of the main problems that threaten thelimited highly fertile land in the Nile Delta of Egypt.

Urbanization is an inevitable process due to progress anddevelopment however the encroachments of urban settlements onexpense of agricultural lands may pose dire consequences.

Therefore, changes of the land covers and the environmentalimpact of these changes should be carefully considered. For thispurpose

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Objectives

To study the urban sprawl using multi-temporalsatellite data

Integrating remote sensing and GIS in studying thespatial distribution of urban sprawl and its impact onagricultural land.

Study area of Al-Qalubiya Governorate

The Qalubiya Governorate is located on the eastern side of the River Nile, near the Delta head.

It is bounded from the south by both Cairo and Giza Governorates, from the north by

Dakahlia and Gharbia Governorates, from the east by El-Sharkia Governorate and from the

west by El-Monofia Governorate.

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* The climatic data of Qalubiya Governorate indicate that the total rainfallsdoes not exceed 7.2 mm/year.

The mean minimum and maximum annual temperatures are 16.5 and 31.0°C, respectively.

* The evaporation rates are coinciding with temperatures, where the lowestevaporation rate (1.9 mm/day) was recorded in January, while the highestvalue (7.6 mm/day) was recorded in June.

* Qalubiya Governorate is located under arid climatic conditions.

Climate of the study Area

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Materials

•Satellite data (TM, ETM+, and Egypt Sat-1

•Topographic maps (Scale 1-50,000)

• Field data

•Digital soil database

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Methodology flowchart

Post-classificationchange detection

Change detection map tabular data

Landsat TM 1993

Geo-referencing & rectification

Visual interpretation

Land cover Map 1987

Higher accuracy map 1993

Integration using GIS

Interpreted map

Landsat ETM+ 2001

Geo-referencing & rectification

Visual interpretation

Supervised classification

Land cover Map 2001

Higher accuracy map 2001

Interpreted map

Integration using GIS

Supervised classification

Egypt Sat-1, 2009

Geo-referencing & rectification

Visual interpretation

Supervised classification

Land cover Map 2001

Higher accuracy map 2001

Interpreted map

Integration using GIS

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Field workField work has been carried out to collect ground truth for image classificationand soil samples for soil mapping

Vertic Torrifluvents soil sub-great group

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Typic Torriorthents soil sub-great group

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The goal of image enhancement is to improve the visualinterpretability of an image

The purpose is to optimize the complementary abilities of the humanmind and the computer.

Because the mind is excellent at interpreting spatial attributes andidentifying obscure features (Lillesand and Kiefer, 1994).

Image enhancement and visual interpretation

12FCC, 4,3,2, of TM 1993

13FCC, 4,3,2, of ETM+ 2001

14FCC, 3,2,1, of Egypt Sat-1, 2009

151993

162001

172009

18Urban sprawl from 1992-2009

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100

200

300

Area (km2)

Area (km2)

Area (km2)year 89.981993133.542001262.102009

19Urban areas of 1992 overlaid on Capability map, Awal Shobra district

20Urban areas of 2001 overlaid on Capability map , Awal Shobra district

21Urban areas of 2009 overlaid on Capability map , Awal Shobra district

22Urban sprawl from 1992-2009

0

10

20

30

1993 2001 2009

Area (km2)

Area (km2)

Area (km2)year 14.92199319.85200125.202009

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Conclusion

Integrating visual interpretation with supervised classification ledto increase in the overall accuracy.

The study area has undergone a very severe land cover changes;increase in urban settlements and decrease in agricultural land,

Integrating GIS and remote sensing provided valuable informatione.g.. Area and spatial distribution urban expansion.

The closer the district to Cairo the faster the urban sprawl