**Spatial and Time Balancing Act: Coastal Geomorphology in View of Integrated Coastal Zone Management (ICZM)**

Gülizar Özyurt and Ayşen Ergin *Middle East Technical University, Civil Engineering Department, Ocean Engineering Research Centre, Turkey* 

#### **1. Introduction**

140 Studies on Environmental and Applied Geomorphology

Pelnard-Considere, R. (1956). *Essai de Theorie de l'Evolution des Forms de Rivage en Plage de* 

Roelvink, D., Reniers, A., van Dongeren, A., de Vries, J. V., McCall, R. & Lescinski, J. (2009).

Şafak, I. (2006). *Numerical Modeling of Longshore Sediment Transport*, M.S. Thesis, METU,

Trifonova, E. & D. Grudeva. (2002). *Sea Level Surface Variations in Bourgas and Varna Bays*.

USACE (1984). *Shore Protection Manual,* Department of the Army, U.S. Corps of Engineers,

Vafaei, A.R. (1992). *Mathematical Modeling of Shoreline Evolution in the Vicinity of Coastal* 

Vigo, I., Garcia, D., Chao, B.F. (2005). *Change of sea level trend in the Mediterranean and Black* 

Wang, P., Ebersole, B.A., Smith, E.R., Johnson, B.D. (2002). *Temporal and spatial variations of* 

Weggel, J. R. (1972). *Maximum Breaker Height,* Journal of the Waterways, Harbors and

Woodroffe, C.D. (2003*). Coasts, form, process and evolution*. Cambridge University Press,

Yurtsever, Y., & Payne, B.R. (1986). *Time-variant linear compartment model approach to study* 

Coastal Engineering Division, Vol 98, No. WW4, pp.529-548.

water resources: IAHS Publication No. 161, pp.545–561.

*surf-zone currents and suspended sediment concentration,* Coastal Engineering Vol.46,

*flow dynamics of a karstic groundwater system by aid of environmental tritium (a case study of south-eastern karst area in Turkey)*, in Gunay, G., & Johnson, A.I., eds., Karst

III, Rapport No. 1, pp.289-298.

Publishers, Ankara, Turkey, pp.151-155

*Structures,* M.S. Thesis, METU, Ankara, Turkey

*seas*, Journal of Marine Research 63, pp.1085–1100.

56(11-12), pp.1133–1152

Washington, DC 20314.

Ankara, Turkey

pp.175–211

623pp.

URL-1: http://www.ramsar.org

**Web references** 

*Sable et de Galets*, 4th Journees de l'Hydraulique, Les Energies de la Mer, Question

*Modelling storm impacts on beaches, dunes and barrier islands*, Coastal Engineering

Proc. of Second Int. Conf. on Oceanography of Eastern Mediterranean and Black Sea: Similarities and Differences of Two Interconnected Basins, TUBITAK

> Many coastal processes depend on the geomorphology of the coastal area. Although some areas are naturally prone to high risk, anthropogenic actions further alter their geomorphology, rapidly increasing the risk to coastal areas of disasters by disturbing the spatial and time balance of natural processes. It is a given fact that coastal zones are important social and profitable regions with high population densities. Thus, the management of these areas is critical but complex, calling for interdisciplinary approaches. Nevertheless, international and national agencies urge the application of integrated coastal zone management (ICZM) as the most efficient action for sustainable development in the face of diverse problems, such as climate change (IPCC, 2007). Restoring the balance of coastal landforms is one of the major aims of the ICZM process and the explanation of the geomorphological changes that occur on the coast is becoming increasingly important in order to manage coastal resources in a sustainable way (Woodroffe, 2002). While geomorphologic dynamics of coastal areas influence the character of society, the actions of society change the geomorphology at the same time. This is an iterative mechanism that has gained appreciation over the past century. Initially thought of as stand-alone impacts of human intervention on the shorelines, these impacts appeared as connected mechanisms through the dynamics of nature. In the end, they became a threat to human activity at many locations around the world. Additionally, time lag between human intervention and geomorphologic changes underlines the complexity of the management of coastal areas and the importance of scale as a concept for both ICZM and geomorphologic studies (Rotmans and Rothman, 2003).

> The determination of spatial and temporal scales is necessary at the start of any research for the well-defined discussion of the results. Although both scales control the level of detail and accuracy of the research, the impact of scale selection on integrated assessments is a well-known but understudied challenge (Rotmans and Rothman, 2003) with the use of different scales having a significant impact on the results, such as leaving important interconnected elements of the system out of the research area (for example, not including

Spatial and Time Balancing Act:

Spatial Scale (km)

local sediment flux (US Army Corps of Engineers, 2003).

Seiches\Tsuna

Fig. 1. Temporal and spatial scales of geomorphologic and coastal processes.

forces in the coastal zone (Woodroffe, 2002).

Bed form

Earth

quakes

Movement

The rate of the response of geomorphic features to coastal processes depends on the scale, with larger features taking relatively longer to change. For example, under large waves significant changes in small-scale bed forms can occur within a single wave cycle, but changes in large-scale bed forms are established some time after the occurrence of the main driving force. Winds, waves, tides, storms and stream discharge are important driving

**Volcanic** 

**Eruption**

Seasonal beach

Cultural influences

Glaciers Storms Delta El Nino

Seasonal Beach Cycles Cliff Erosion

Temporal Scale (years)

**Sea Level Change**s

Coastal Geomorphology in View of Integrated Coastal Zone Management (ICZM) 143

turn, it produces further variations in sediment-transport patterns which again cause changes in geomorphic features. These processes happen over a wide range of spatial and temporal scales (Fig. 1). For example, interaction with the near shore profile changes the properties of waves (generated by offshore storms) when entering the coastal zone (Woodroffe, 2002). The resulting wave and flow characteristics control the cross-shore and long-shore variations. The characteristics of the bottom slope and the variations of waves and tides dominate the dynamics of sediment fluxes, causing changes such as erosion and accretion. On the other hand, small-scale processes control the turbulent dissipation of breaking waves, the bottom boundary layer and the bed form mechanisms that shape the

tributaries or a river basin for a study of coastal erosion). Accordingly, local variability might be missed both in time and in space. The extent of the research area (whether it is a sand grain, a cliff, a coastal town or a region) is determined by a spatial scale using two axes: planform (also called 'long-shore') or profile ('cross-shore') (Woodroffe, 2002). A range of geomorphologic processes and human activities exist on both axes, influencing ICZM plans. The temporal scale is another multilayer factor that is important for the preparation of ICZM plans. Overall, geomorphologic scales exist across a wide range, from seconds to hundreds of years (Davies, 1993). On one side, human activities on coastal areas take a longer time to impact shorelines. First of all, most actions take a couple of years to carry out (for example, dams along river basins causing coastal erosion). Next, human use is expected to continue for 50 to 100 years (maybe more). This range of the temporal scale is also defined as the engineering timescale (French & Burningham, 2009). On the other hand, ICZM requires a long-term planning perspective, considering short-term benefits and solutions for urgent problems as well as integrating future risks, such as climate change. Although ICZM started as a form of shoreline management and flood risk planning, it evolved into a management concept, covering social, economic and ecological assets and including a diverse range of problems from natural disasters to man-made events - such as oil spillage - being generally accepted within coastal management literature (examples given in McFadden et al., 2007 such as Bower & Turner, 1997; Sorensen, 1997; European Commission, 1999; Kay & Alder, 1999; de Groot & Orford, 2000). Thus, different spatial and time scales exist within an ICZM plan (McFadden et al, 2007) and the geomorphology of coastal areas is one of the important parameters that define these scales.
