User Functions Subsystem

The User functions represents one of the two “sub systems” identified in the previous sections (the other is called Infrastructure)

User functions

The following functions or user categories can be identified:

  • basic functions: food production, water supply and energy supply
  • social functions: housing and recreation,
  • economic functions: transport, (sand) mining and industrial development
  • public functions: defence and sewage treatment

Natural resources


These functions use the natural resources of the coastal zone. They can be either renewable or non-renewable resources. Renewable means that the system can  regenerate the resources within a reasonable time interval, e.g. the recovery of the fish population or the decay of organic waste. Non-renewable means that the generation of the resources by the system will not take place within a reasonable time period, such as the extraction of minerals from the seabed or the disturbance of the seabed by dredging or dumping of waste.

Types of resources


The resources in the coastal zone includes the compartments air, water and land. In these compartments four major categories of resources can be distinguished:

    • Space; This includes space for activities of the users like agriculture, fishing, mariculture, industry, housing, recreation, etc. Typical criteria to express the availability of ‘space resources’ are surface area, elevation, length and depth (for example navigational depth).
    • Abiotic compounds; This category of resources includes building materials (for example sand and rock), oil and gas, ores and water; also air (of a specified quality) can be incorporated in this category.
    • Biotic resources; Flora and fauna used for protein and carbohydrate supply belong to the class of biotic resources.
    Absorption or purification capacity; The three compartments of the coastal resources space represent a certain capacity to absorb, store, decompose, diffuse and transport waste materials, emitted as a result of processes in the environment and (for the major part) activities of the users.



The problems in coastal zone management are generally directed on the resolution of conflicting claims on coastal and marine resources (common interests). Demands for resources are often directly related to the activities of the users, such as space for agricultural activities. But the (subsystem) Infrastructure will exert important claims on the resources as well, think of the enclosure of a coastal lagoon from the sea which may eliminate the nursery function of the lagoon for sea fish.