Remote Sensing of Desert Cities and Urbanization Management in West Asia Region Prof. Mohamed Ait Belaid Arabian Gulf University School of Graduate Studies Desert and Arid Zone Sciences Programme P.O. Box: 26671, Bahrain, Tel. 973-39 026 030 Fax: 17 239 552 belaid@agu.edu.bh ABSTRACT. This paper focuses on Remote Sensing (RS) of desert cities and Oasis, and urbanization management, particularly in West Asia countries. Furthermore, it presents the characteristics of urban and sub-urban areas in desert environment, the potential of satellite imagery and geographic information systems (GIS) in mapping urban areas, and monitoring urban changes over time. Urbanization, resulting from demographic, socio-economic and industrial development but also from immigration, is considered as a major issue. Two case studies have been conducted respectively in the kingdom of Saudi Arabia (2002), and in the State of Qatar (2005), in order to detect land use changes in the urban and sub-urban areas, by using remotely sensed data and geographic information systems technologies. The main objective is to assess the extent of urbanization, and to investigate its effects on other land use categories in Al-Ahsa oasis in Saudi Arabia, and in the city of Doha in Qatar. The studies were based respectively on two (1987, 2001) and (1986, 2002) satellite images taken of the study sites from Thematic Mapper sensor of Landsat satellite, topographical maps and ground observations. The adopted methodology consisted of three phases: 1) geographical study; 2) Satellite and ancillary data acquisition, 3) Land us mapping using satellite imagery; and 4) spatial analysis and modeling of the produced land use maps using GIS tools. The geographical study revealed that Al-Ahsa Oasis and the coastal city of Doha are suffering from urbanization encroachment and population growth. The interpretation of satellite imagery using remote sensing software (ER-MAPPER, ERDAS IMAGINE) enabled us to produce two maps of land uses and to identify the areas of the land use categories. The changes occurring respectively in the periods of 14 and 16 years were analyzed using geographic information system software (ARCGIS, ARC-VIEW). This proved that in Al-Ahsa oasis, urbanization has impacted the agricultural areas, sabkha, planned areas and sand areas. On the other hand, in Doha city, urbanization has impacted vacant areas, vegetation areas, sabkha, and sediments. Urbanization has also a negative impact caused by dredging and land reclamation activities. Deliverable products for the decision makers and managers are the following: Land use maps at a scale of 1/100000, Evolution map and matrix for a long period of time (14 and 16 years respectively), Integration of road networks and administrative boundaries to localize the urban changes, Impact assessment of urbanization on other land use categories, in term of extension, regression and neat evolution. 1. CHARACTERISTICS OF URBAN AREAS IN WEST ASIA REGION. The past 30 years brought about significant economic, political and technological changes, which have influenced the structure and the functions of urban areas in Wesrtern Asia countries. Three main factors have shaped the urban landscapes (UNESCWA, 1999): the 1970 oil boom, the large-scale movement resulted from the Gulf Wars, and globalization. Rapid economic growth, which occurred in most countries in the region over the past three decades, was accompanied by population growth and increased urbanization. There has been a massive migration of the population from rural to urban areas, as well as immigration of foreign labor into urban areas, especially in the Gulf Cooperation Council (GCC) countries. Urbanization has continued to increase at a faster rate than the total population (UNDP, 2001). All the countries of the Arabian Peninsula now have an average level of urbanization of about 84%, except Yemen with a level of 25%. Currently, almost the entire population of Bahrain (92.2%), Kuwait (97.6%) and Qatar (92.5%) are living in urban areas (UNDP, 2001). The number of large cities with more than one million residents is estimated at 12 cities. Economic development has brought dramatic improvement in the well-being of the western Asian population (UNDP, 2001). Despite these positive impacts, many cities, especially in the Mashriq region, are negatively influenced by many problems such as lacking adequate services for the urban poor. In such situation, human health and well-being are at a risk (UNDP, UNEP, WB, and WRI, 1998). Most of the large cities are crowded (urban poverty) and have higher levels of air pollution. As urban areas expand, prime agricultural land, coastal habitats and forests are transformed into land for housing, roads and industry. Land conversion activities range from draining and filling of marshes and wetlands to large-scale reclamation projects that extend shorelines into the sea. In Lebanon and most of the GCC countries, these activities have been carried out for decades. Dubai city, for example, increased in size by 92 km2 in 15 years (Doxiadis Asssociates, 1985). Likewise, the area of Bahrain increased by 47.3 km2 in 23 years, by continuing land reclamation along the coastal zones at the Persian Gulf for urban development (CSO, 1999). It is estimated that municipal waste generation in the region increased to 25 tones/ year in 1995 (Kanbour, 1997), which is double of the annual waste generation in Mashriq countries of Iraq and Syria. In the GCC countries, waste collection and disposal systems are fairly efficient compared to those in the Mashriq. Plants for composting municipal solid wastes and sewage sludge have been established in several countries (Kanbour, 1997). 2. STATUS OF SPATIAL DATA INFRASTRUCTURE (SDI) IN WEST ASIA. RS. GIS and GPS are valuable tools to provide information and data geo-referencing and modeling in terms of natural resources management, environmental monitoring and land use planning. In West Asia region, many research institutions, centers for studies, and universities have introduced these technologies and tools in every day life to support the decision making process. Remotely sensed data are gathered throughout national, regional or international dealers. The United Nations Regional Center for Space Sciences and Technology Education in Asia is been on operation since November 1995. There is another international initiative for establishing a new regional center in Western Asia, which currently involves Jordan, Saudi Arabia and Syria. These centers are expected to enhance the academic and professional capabilities and technical infrastructure in each region (UNISPACE-3, 1999). In addition, there are many other remote sensing centers in the GCC countries. The first center of remote sensing was established by the Institute of Space Research (ISR) at King Abdulaziz City for Science and Technology (KACST). It provides remote sensing imagery and data since 1987 for the public and private sectors (KACST, 2002). The second one was set-up recently in 1997, by United Arab Emirates, operated by Dubai Space Imaging (DSI). DSI sells information products and services, as well as imagery and will provide training in imagery analysis and GIS tools and applications (Baker et al., 2001). The third one is a UAE local Company called Global Scan Technologies (GST), which has its own satellite receiving station for Indian remote sensing and MODIS data (www.gstdubai.com). The fourth receiving satellite facility is owned by the Regional Organization for the Protection of Marine Environment (ROPME) based in Kuwait. A number of GIS and RS forums, are being held in the region, at bi-annual basis; for example: the GIS Conference and Exhibition in Bahrain (GIS-2002, GIS-2004), Map Middle East Conference (2005, 2006), ESRI Users Conference. 3. CASE STUDIES. Two multi-temporal case studies have been conducted respectively in the kingdom of Saudi Arabia (2002), and in the State of Qatar (2005), in order to detect land use changes in the urban and sub-urban areas, by using remotely sensed data and geographic information systems tools. The main objective is to assess the extent of urbanization, and to investigate its effects on other land use categories in Al-Ahsa oasis in Saudi Arabia, and in the city of Doha in Qatar. The adopted methodology and the results obtained are described briefly in this section. 3.1. Adopted Methodology. The adopted methodologies in the two case studies are slightly different, but the main steps are similar: a) Geographical Study; b) Satellite and Ancillary Data acquisition; c) Land Use Mapping; d) Data analysis and interpretation. a) Geographical Study. An intensive geographical study was conducted through the existing and available bibliography. It includes a description of physical conditions like climate, erosion, land, water, and vegetation; but also the characterization of the impact of human and animal pressures and severe climate conditions. More clearly, the study focused on urbanization encroachment, population/demography, and agricultural practices and land filling and reclamation in coastal areas. b) Satellite and Ancillary Data Acquisition Land use mapping requires satellite imagery (e.g. Landsat-TM), which has to be available in the catalogue at the appropriate period of time (year, season) and free of clouds. Existing cartographic data (topographic maps, road network maps, boundaries, etc.) are also necessary to be used in the process of registration and integration with satellite imagery. Finally, ground observations, and existing statistics are also of great importance for image interpretation and validation of remote sensing results. c) Land Use Mapping using Satellite Imagery Two satellite images were used for each city or oasis, corresponding to two different periods of time. The adopted interpretation techniques are: the standard supervised classification and the photo-interpretation assisted by computer. The whole process is guided by ground truthing and local knowledge. The ground truthing process aims at localizing and characterizing land use categories using GPS instrument. The result is a digital coverage layer, in which polygons represent different land use categories. A full database is attached to this coverage, in which every polygon is characterized by many attributes like, the category number, area and perimeter of polygons. d) Data Analysis and Interpretation using GIS. The analysis of the results produced in the previous section allow us to realize the pair-wise comparison of these two land use maps, as well as their statistical inventories, in order to detect possible changes in terms of area. Furthermore, we can investigate the impact of urbanization on other land uses and vise-versa. Finally, the “evolution matrix” is built-up for the two period of times, providing all possible changes involved and the corresponding areas in terms of extension and regression for all categories. 3.2. Case Study in the Kingdom of Saudi Arabia a) Presentation of Al-Ahsa Oasis Al-Ahsa is one of the biggest oases in Saudi Arabia, including three cities of Hufuf, Mubarraz and Al-Youn. The design of these cities has been changed consistently during the last 30 years, especially with the development of oil industry since 1970’s (Mufareh, 2002; UNEP, 2002). The population of Al-Ahsa oasis is estimated at 800,000 inhabitants, from which 78% living in urban areas and 22% in rural areas and villages. The main activity is concentrated in the agricultural sector (palm trees), but the agricultural area is declining due to climatic and anthropogenic factors, such as sand movement, urbanization encroachment, decrease of the level of ground water table, and lack of drainage (sabkha). The climate is arid, while the precipitations are ranging from 75 mm to 110 mm. We noticed also a sand movement coming from the North West and North direction. The study’s site covered a rectangle of 40 km by 55 km centering on Al-Ahsa oasis. Two multi-spectral satellite imagery, with 30m spatial resolution, were used to cover the two periods of time (Landsat (5) TM, October 1987, and Landsat (7) +ETM, October 2001). Topographic maps at a scale of 1/25000 and road network map were also used, along with ground observations b) Results Outlines The findings outlined from of the case study in Saudi Arabia are discussed below (Mufareh, 2002; Ait Belaid and Mufareh, 2002; Ait Belaid, 2003): Land use maps at a scale of 1/100,000, offering a diagnosis of urban and sub-urban areas at each period (1987 & 2001). The land use categories include seven thematic classes, namely: urban areas, urban planning, agricultural lands, sabkha, sand dunes, hills and water bodies. The total area of the study site is approximately 222,000ha. One evolution map for the period (1987–2001), illustrating the temporal evolution of land use categories. During 14 years, urban areas have been expanded by 5,326 ha and agricultural areas by 4,430 ha. During the same period of time, there was a decrease in the areas of sabkha by 8,063 ha, urban planning by 1,341 ha, sand dunes by 206 ha and hills by 146 ha. The evolution matrix was generated for Al-Ahsa oasis illustrating the major land use changes occurred. It signals also the land use categories, which are impacted by any change and vise-versa. During 14 years, urban areas have increased by 5,326 ha, from which 2,746 ha were converted from sabkha, 1,500 ha from urban planning, 972 ha from sand dunes and 513 ha from agricultural lands. In contrast, agricultural lands have increased by 4,430ha, from which 4,480 ha converted from sabkha, 1,654 ha from sand dunes, 184 ha from urban planning and 119 ha from urban areas. The agricultural lands experience many transformations, because we have at the same time a great extension of 6,520 ha and a regression of 2,090 ha. In conclusion, Al-Ahsa oasis is facing many problems, related to urbanization extension, deterioration of agricultural lands, formation of new sabkha and new sand dunes. These findings confirm the hypothesis of the geographical study. 3.3. Case Study in the State of Qatar a) Presentation of the City of Doha The city of Doha is located on the Western coast of the State of Qatar. It is the capital of the State and the largest city. It has been undergoing rapid growth, especially during the 1970’s and 1980’s of the last century, due mainly to the increasing oil revenues, which enhanced a sustained economic growth of the whole country. This has further evolving a rapid increase of the population of the city, resulting from both internal migration and external migration of foreign workers (labor). The total population of Doha city is estimated at 339000 inhabitants, according to the last population census of the year 2004. During the 1990’s, the State of Qatar initiated a number of tourism projects, which induced a large scale of coastal area dredging and reclamation activities. This study aims at using the techniques of Remote Sensing (RS) and Geographic Information Systems (GIS) to:
b) Results Outlines The major findings and results outlined from of the case study in the State of Qatar (Doha city) are discussed below (Al-Mannai, 2005):
The evolution matrix was generated for Doha city, giving the whole possible changes occurred between 1986 and 2002 due the human activities, which took place in the study area. The results show that urban areas were converted from the following categories: vacant areas (2917 ha), vegetation areas (644 ha), sabkha (259 ha), and finally sediment (160 ha). These classes were impacted by urbanization or land reclamation. Vegetation areas have also experienced different changes in the two senses: increase of vegetation area by 664 ha and at the same time decrease of vegetation area by 824 ha. 3.4. Comparison of the Two Case Studies The findings after the application of the methodology in the two case studies of Al-Ahsa Oasis and Doha city are compared in terms of scale, number of periods of time, the size of the study area, the typology, the methodology of analysis, projection system, ancillary data, and laboratory facilities. The details are presented in table 1 below.  4. Conclusions and Recommendations 4.1. Conclusions The cartographical and statistical results are valuable tools for the protection of agricultural lands and planning of urban and sub-urban areas located in the oases and coastal fragile cities. With Landsat-TM, 30 m resolution, the equivalent scale is 1/100,000. Consequently, the accuracy of land use maps produced depends on this scale. We considered two periods of time, offering two land use maps and providing one pair-wise comparison. The cumulative period is about 14 years for Saudi Arabia site, 16 years for the State of Qatar site. The dimension of the study site is 40 km by 55 km for Al-Ahsa oasis, and 20 km by 22 km in the case of Doha city, due to the size of the scene. It depends also on our interest in investigating urban areas as well as rural settlements relationships. The typology or the type of land use categories depends on the site itself and the objectives of the study. The thematic classes vary from Qatar (Doha city) to Saudi sites (Al-Ahsa Oasis). The over-all evolution matrix is very adequate and very informative. Practically, it gives the areas of all possible changes, but it is applicable only for two periods at ones. The costs of the two studies are similar. They are estimated at about 9 $US /km2 and the delivery time at about 5 months, including satellite imagery acquisition and processing and ancillary data preparation. 4. 2. Recommendations Based on the results of the two case studies, the following recommendations can be outlined:
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