**4. Detecting change over time along the Gulf coastline**

Aerial photography and freely available satellite imagery were used to determine coastal change. These types of data and related dates are listed in Table 1.

All LANDSAT satellite imagery used was downloaded with geo-location properties included. ASTER data were geo-referenced using the satellite ephemeral data and block adjusted where necessary. The 1934 aerial photography was 3rd order polynomially georeferenced using common features located on the 1967 Corona imagery and the 1955 uncontrolled mosaic was triangulated to the same Corona data. All data were projected to UTM Zone 39 in WGS84 datum.

The coastline for each data set was determined using heads-up digitizing techniques from data enhanced to discriminate the land-water interface. Land use/cover classes (developed, agriculture and partial developed) were captured in the same way. Caution was exercised in compiling coastline changes due to the differing spatial resolutions of the imagery used; the methods of geo-location; and the state of the marine environment at acquisition. Some adjustments were necessary to increase the accuracy of the data. From the initial observations of the imagery it became obvious that there had been little change between 1934, 1955 and 1967 with minor changes detected in the 1972/73 data. A base coastline was established using the 1967 Corona data set that covered 95% of the coastal region of the Saudi Arabian Gulf. The area of sabkha was initially determined by Mah (2004) using supervised classification techniques. Small areas of in-fill were determined using a density slicing technique and both results combined into a single dataset. All coastal and land cover

Anthropogenic Induced Geomorphological Change Along the Western Arabian Gulf Coast 199

through annual mangrove plantations. It is envisaged that with the development of additional mangrove intertidal habitat, that the Creek's ecological value will increase, and the area will became an important nursery habitat for fish and crustaceans as well as

Tanajib – Manifa Embayment on the northern coastline is the most recently developed coastal area to facilitate the expansion of the oil industry. The embayment is very shallow and to allow oil operations in the area; and to minimize impacts associated with dredging, boat traffic, cable networks, pipelines and oil spills; a causeway and marine pads (small islands used for drilling) were developed (Map 4). To further reduce the impact of these structures on the marine ecosystem, the company responsible went to great lengths to minimize the overall footprint of the causeway and pads (width and length reduced by almost half), and there was no dredging allowed within the embayment. The direction and exact location of the causeway was also redesigned to minimize impact on subtidal habitats and the natural water circulation patterns. Water circulation was modeled and changes were made to the design of the causeway to maximize circulation, resulting in the causeway being built parallel to the water current direction, and incorporating 14 bridges. Existing fishing navigation channels remained intact, and constant monitoring was instigated during all construction and initial operation work to ensure compliance with marine environmental

Map 4. Change in Land Use and Coastline for Tanajib from 1967 until 2010

The majority of the population in this area are employees who work at the Tanajib industrial facilities. The change in the district has occurred as the offshore oil reserves have required primarily industrial infrastructure development. This expansion included offshore causeways, rig pads and service facilities for production platforms. Development was estimated to cover only about 200 Ha in 1967 and apart from recent oil and gas processing facility construction of just under 12,000 Ha at Manifa, little has changed within the general

migratory birds.

standards.


data were included in a database to calculate areas and distances, and where required statistics were calculated.

Table 1. Remote Sensing Systems Used to Determine Change

The Saudi coastline was divided into three coastal areas, Northern, Central and Southern coastlines. Data presented in this Chapter will illustrate changes in these coastal areas caused by development. A summary of changes along the entire Gulf coastline is also included.
