Global Controls on the Catchment and Coast

The catchment and coast is an integrated system with water and sediment routing; nutrients; feedbacks and biodiversity all connected/influenced by the system. Understanding landscape processes is fundamental for fully understanding the Earth system and enabling improved environmental management.

Geomorphology as an eclectic science studies the origin and development of landforms, and how these forms combine to form landscapes. Its study helps explain how landscapes have developed in the past, function in the present and how they may change in the future. Such knowledge may then be used for environmental engineering, geological understanding, environmental policy and management; even archaeologists are interested to understand how erosional and depositional processes may influence artefact preservation.

1. Landscapes are shaped by movements of mass - rock, sediment or water. 
2. Landscape-shaping is influenced by multiple factors - tectonic, climatic, ecological 
3. Landscape processes operate at different temporal and spatial scales.
4. The Earth landscapes are dynamic. 
5. Landscape dynamics are complex - internal readjustments occur with changing conditions.
6. Landscapes are archives of the past and contain histories of their development.
7. Atmospheric warming and sea level rise is influencing landscape dynamics. 
8. Human activities are a geomorphic force, influencing the landscape dynamics. 
9. The Earth landscapes are becoming more hazardous; with greater population? 
10. Successful environmental management requires geomorphological knowledge. 

Common Pool Resources: Fisheries

A common-pool resource, fundamentally, is something shared.., a resource to which all users have free access. The actions of all individuals collectively affect the quality and quantity of the resource itself, giving rise to many interesting and controversial social dynamics.

The "tragedy of the commons" as previously stated, is based on a fundamental economic argument that people are rational, individual actors that obtain positive utility of a commons resource. Each user however, incurs negative environmental costs simply because the resource is shared. However, there will always be an incentive for a user to continue using the resource, because the positive utility is greater than the negative environmental impact.

The tragedy is incurred where the critical environmental threshold is reached.

Hardin (1968) 

Hardin saw the tragedy of the commons as an inevitable phenomena that might only be escaped with centralized top-down governance and a shift towards private property ownership - people, left to their own rational behaviours, are unable to solve the problem. 

Elinor Ostrom (2009 Nobel Prize in Economics) disagreed. A major alternative view to Hardin's approach is the idea of developing a social-ecological system that is self-governing in development and maintenance, which would prevent a system crash. 

Struggle is derived from conflicting values/interests, a lack of trust, biophysical limitations and complexity. Rules are generally designed with one set of social, economic, ecological or technological conditions in mind, and will become outdated as these conditions change. Further, the rules applied to one set of conditions are often not applicable to another set. Rules must evolve. 

Adaptive governance

Adaptive governance is required in complex systems in order to more efficiently provide information, deal with conflict, provide infrastructure and prepare the system for change. 

The Genius of Ted Ames

Ted Ames, a local fisherman, interviewed other retired fishermen, looking over nautical charts. Active fishermen will not divulge their own preferred fishing grounds, but have few reservations talking about where other fishermen go, and retired fishermen have nothing to lose. The triangulation of many data clouds from these fishermen eventually reconstructed a disappeared fishery - 'ghost cod.' This proved that cod did not move freely throughout all grounds, but behave as sub-populations. This implies that to fish out a whole sub-population is to drive it in to local extinction. 

This revelation begs the question of how well we actually understand the dynamics of the common-pool resources we use, and it must be remembered tat governance at the wrong scale creates a brittle system. 

Gilded Trap 

A gilded trap describes the increasing risk in a system of a crash in resource or market that may occur without warning. Social drivers such as population growth or market demand will increase the value of a resource, ergo its development and exploitation also increase. The ecological system will become more fragile, and far less resilient if shocked.
The difference between a trap and gilded trap is that in the former, there is a steady decline from a high social-system benefit to a low one, whilst for the latter the social system-benefit will stagnate for a while at a medium social-system benefit, before crashing very rapidly to a very low social-system benefit. This is far worse, since it can, without warning, devastate the economic system dependent upon it. Consider the island of Nauru, which yielded vast amounts of phosphate, decimated the environment until eventually the carrying capacity of the island dropped to a minimum, and the land could yield nothing.

The Gulf of Maine: Gilded Trap

As biodiversity drops, for instance in a fishing area, one more successful species is often targeted e.g. Maine lobster. In Maine, as fisheries biodiversity decreased, the percentage of lobster catches increased exponentially.  Social/environmental factors define the options and shape election processes as antecedent conditions, which meet a critical juncture whereby particular options are selected. From there, a structural persistence in these decisions produces and reproduces a socio-ecological trap with a reactive sequence to the situation.

In context, the coastal marine ecosystem of the Gulf of Maine was exploited by a relatively small, controlled fishery that fished for Atlantic cod. By the 1930's, the introduction of new catch technologies expanded the existing market and dramatically increased yield. A social trap developed as the tragedy of the commons became installed in the system, so that by the 1990's the collapse of coastal predatory finfish stocks were seen. The marine system became vulnerable and dominated by lobster populations, changes that coincided with a higher demand for lobsters. This led to the gilded trap; fishers switched from fishing a variety of stock to exclusively lobster, and this selective process that decimated the local biodiversity is not a series of choices that can be returned from. The Gulf is left with Homarus americanus monoculture, with an economic diversity 70% lower. Current successes derived from inflation-corrected lobster income is counteracted by the increased social and ecological consequences of future declines in lobster populations.

It can be easily seen in this case that collective actions from economically attractive opportunities often outweigh social/ecological risks associated. Strong initial financial gain reinforces the gilded trap for a time, and avoiding or escaping the trap requires managing for increased biological and economic diversity.

Coastal Habitats

Coastal habitats are controlled by the four types of tide; high/low/spring/neap, and by the geology of the landscape. The coastal zone is the area influenced by its proximity to the coast, and is split up in to 8 sub-zones:

• The offshore zone - sees no significant transport of sediment by wave action
• The littoral zone - sediment is transported by wave action
• The nearshore zone - sediment transport is limited to the low tide line
• The shore - subaerially exposed at least partially, experiences wave action
• The foreshore - Subject to waves in non-storm conditions
• The backshore - only subjected to wave action during storms
• The surf zone - a zone where waves break, extending from the breaker zone to foreshore
• The swash zone - The part of the coastline that experiences wave run up and backwash water 

Sediment sources

Terrestrial sediment is transported to the coast in the form of overland flow, flash flooding and rainfall. Steeper, more mountainous catchments will yield more sediment. 

The Tourism Cycle: A boom and bust cycle

Butler's Tourism Area Life Cycle model (TALC) presents the successive evolution of tourist areas over time, the changes in number of tourists visiting the area, and the quality of the area as a honeypot site. It is very unlikely that a tourism area is likely to be both environmentally friendly and economically viable, and Butler surmises that most sites are unfavourable on the environment, and, increasingly, not economically favourable either.

While there are different methods of presenting the tourism cycle and describing the evolution of a site, generally they all stipulate that exploration and public involvement first increases rapidly, before it begins to stagnate. At this point, several things could happen; reinvestment could be installed in to the area, and it will be rejuvenated; thus will tourism increase. An area may be simply consolidated, and there is a drawn region in the tourism cycle described as 'the critical range of elements of capacity.' Within this region, a tourism area will not decline as such, but will be maintained in its current state. If the area is not maintained, it will rapidly decline and lose a high amount of tourism focus.

The physical processes that occur in tourist regions are not typical of tourists or landscapes, but are a product of coupled systems. 

It is thought that under no practical circumstances would a tourism area ever be environmentally favourable on a region, regardless of whether it was economically favourable or not. This is because at the most basic level, humans settling in an area, urbanising it, altering the morphodynamics, hydrological system and the natural hierarchy, is ultimately impacting what was previously a natural stable state. However, it might be said that if a tourism area was to be created as a function of land regeneration, that may for instance have been fully degraded sites, then perhaps benefits may arise.

Further, if the tourism sector was more directly linked towards area regeneration and maintenance, then perhaps it would be possible to use the publicity (if awareness/education was encouraged) and subsequent funds to improve the vulnerability of an area. Not all tourism areas will follow the conceptual model Butler presents any where near as clearly as others; consider the establishment of the 'instant resort' - Cancun, Mexico.

Time scales

Daily changes in tourism revenue will not drive shoreline manipulations to increase tourism revenue and protect from coastal hazards. Similarly, rip currents and other fast nearshore hydrodynamics will not affect the patterns and fluctuations of tourism. 

Longer landscape evolution processes are also not affected by engineering; further, long-term economic trends do not directly drive alterations to the coast. 

Intermediate time scale processes are more influential. Consider the links between barrier-island processes and the initiation/growth of tourist resorts. There are direct links between governance and planning and the estimated probability of natural hazards occurring. Basically, human-landscape coupling is the strongest where natural physical processes significantly affect/render human landscapes vulnerable to changes and damage. These processes generally occur over intermediate timescales, from years to decades. Enough time to drive market investment in protection structures and respond to changes, but not enough time to generally do so efficiently. Landscape processes can directly cause loss and change construction costs, but also indirectly adversely affect the economy by changing human behaviour, feedback and response, altering insurance levels and market values. Econ/political activity directly changes landscape processes by altering the shapes of land and structures upon which natural processes operate.

Boom/bust cycles 

Spatial patterns will develop as the localising nature of protected resorts combines with continuous tourist demand and the eventual requirement of island migration and longshore sediment. This coupling is thought to produce high-frequency responses to storms and SLR, as well as boom/bust cycles. 

The dynamics of boom/bust cycles evolve over longer time frames and are a key characteristic of today's capitalist economies. It describes the periodic expansion and contraction of the economy, fluctuating job availability, productivity and market value. 

Coupled Systems I: Florida & Jevons' Paradox

Humans and landscapes were interacting linearly, without the formation of feedback loops that would operate on regional or global scales. Humans are now a geomorphic force, and geometric human settlements erase natural shapes. From this manifests a dynamic coupled human-landscape system that is both hierarchal and complex. Landscape dynamics are dominated by water, sediment and biological routing, moderated by oceanic, atmospheric and fluvial processes. Human dynamics are dominated by profit-maximizing market forces and political action dictated by the estimated economic effect. In the Netherlands, the human system is less strongly coupled to the landscape system because it has mitigated its natural hazards.

Complexity refers to the simultaneous presence of simple and complicated behaviours. 

Human impact on landscape processes

• Permanent loss of sediment from landscape modification
• Increased global temperatures 
• Alterations to atmospheric gas concentrations (chiefly carbon dioxide and methane)
• Species loss/extinctions 
• Alterations to oceanic system dynamics

 Human/landscape coupling 

• Levees along the Mississippi leading to wetland loss, reducing dampening effect
• Overfishing of cod in the N. Atlantic leaading to the collapse of fish economics. 
• Increased damage from wildfires has increased fire protection and response practices. 

Emergent behaviour: The behaviours which emerge as a consequence of the coupling between humans and landscape systems, and would not be exhibited by one system or the other on its own. It is a fundamental property of all hierarchal systems. 

Non-linearity describes the dynamics that indicate strong two-way coupling between elements, and the transformative, sharply transitional interactions between. Dissipation meanwhile describes an irreversible behaviour that reduces differences in space or time e.g. hillslope creep. Landscapes are self-organising. 

Human system hierarchy

Neuron-level processes ----- stream of consciousness ------ feelings ----- communication/language ------ emotions ---- moods ---- rational thought/analysis ---- personality --- patterns of economic relations ---- beliefs ---- world view ---- laws ---- customs. 

The human system hierarchy is much more complex than landscape systems (pattern characteristics --- boundaries of transition zones --- morphology---grains/fluid parcels). Therefore, it has a greater potential for diverse and complex dymamics. 

The prediction of system dymamics can be formulated, but only if they are approached as multi-dimensional problems as opposed to individual conditions. 

Human impact strength is enhanced at economic and political levels; the mechanisms concentrating wealth permit the continuous application of resources not possible for average individuals/societies. Resource investment leads to further wealth concentration (profit) allowing more focused resource application - a positive feedback loop described as Jevons' paradox. 

Jevons' Paradox example: Beach replenishment enhances property value; profit is increased, facilitating further protection/replenishment activities. With the price of sand increasing, how long will the feedback loop be maintained before the system collapses?

Population density, housing development and property values in coastal counties along Florida state are all increasing with the rise in hazard from storm impacts. The homes of today are 60% larger than in 1973. Paradoxically, it is seen that investment in hazard protection fuels further development. Coastal tourism and tax revenue from coastal properties are fundamental to the economy. 

Backfire: Rebound and backfire is derived from Jevons' Paradox, and is a problem where a more efficient use of a resource spurs an increase in demand and consumption. Increased consumption thereby erases the gains achieved from improving efficiency. Energy efficiency is termed 'the fifth fuel.' Consider the increase in refrigeration unit purchases as they became more efficient.

Jevons' Paradox: The more efficient we become, the more people can be sustained; the more people we can sustain, the more energy we consume. There is a choice between brief greatness and prolonged mediocrity. 

Landscape processes and the human system broken down

The most obvious connection between the landscape and economic system is the influence of natural events such as hurricanes on economic structures or human settlements. The economic system impacts the landscape system as structures are built e.g. increasing run off, albedo. In the coupled system, landscape processes affect the economic system is directly impacted by changing construction costs, influencing market behaviour and directly changing the shape and character of the land upon which economic processes occur. 

The political system marshals resources and forces changes in the landscape system according to economic criteria, and most decisions are made by political agents. Political activity alters landscape processes in the coupled system by changing the shape and character of the land to create a nonlinear system with different hierarchial levels. 

A Prediction System

New Orleans has strongly coupled interactions between economic development, gemorphology, flooding and levee construction. Its coupling can be modelled through the landscape parameters or economic factors. This is the first step towards a prediction system for the future of the Earth's surface. With this, new emergent behaviours may be predicted, and investigations may be conducted regarding the impact of free-will decision-making processes on the landscape. 

Potential Problems

Markets are dominated by decision-making based on the profit margin, however in the models used to incorporate this the potential cultural changes that may well manifest from wide-spread concern regarding changes to our environment are not taken in to account. There might also be resistance to market forces e.g. from indigenous groups.  

It might be said that these models do, by and large, point out the obvious. Residents of New Orleans for example will be well aware of the relationship between storm surges, levees and the Hinterland; they will know the long-term issues of such a system. So why do they still reside there, and not alter their ways of approaching storm/flood management? Clearly there are factors regulating this behaviour that is not categorically understood or easy to influence. 

Perception of hazard and risk underestimate or discount conditions because management strategies of hazards such as beach nourishment reduce/masks the seen impact of coastal hazards, without actualy changing the driving natural forces. Federal subsidies and flood insurance masks the true cost in the economic system of such hazards. 

The human-landscape system models may have to account for challenges, modification and alternatives to the market system, as the human hierarchical system evolves and changes with the landscape. 

The human system is complex; the landscape system is complex. The models will always have to be improved. People make decisions for a variety of reasons; perhaps their incentives are market-driven; altruistic; cultural; a case of trust in certain political embodiments. It remains to be seen whether the global perception that humans and the environment are connected can be refined, and whether a drive for a change/improvement in management may be achieved. 

Soft engineering & Ecosystem-based coastal defence

Delta ecosystems provide storm protection, nutrient and pollution removal, and carbon storage. Yet, in Pakistan, 1/5th of the Indus delta plain has been eroded since it was dammed in 1932; the Yellow River delta in China has retreated 300m in 35 years (Giosan et al., 2014), and it is thought that delta areas will increase a risk of flooding by 50% - the poorly preserved ones at least.

These regions are starved lands, and The Nile carries 98% less mud than it did a century ago. The naturally high subsistence rates of deltas are greatly exacerbated by human activities; the Chao Phraya delta in Thailand sinks by up to 15cm per year due to intensive groundwater exploitation. Methane extraction in the Po delta of Italy causes the same reaction. As the marshes weaken, the vegetation dies and soil formation slows significantly, speeding up land loss.

Natural deltas may rise in balance with sea level through sediment accumulation in regularly inundated wetlands. Conventionally engineered deltas do not see this land rise through sedimentation, since that process is cut off by flood-protecting structures such as dikes or dams. The land sinks due to human activities including soil drainage, and wetland loss causes severe water level rise.

It is postulated that nature-based engineering solutions might maintain sedimentation processes that drive land-level maintenance/accretion and flood storage through wetland conservation and restoration, chiefly by removing conventional engineering methods.

Conventional Coastal Engineering

Conventional engineering methods include building sea walls, dykes and embankments, but these constructions require continuous and costly maintenance, to a point where, with increasing flood risk, it may be becoming unsustainable. This, alongside the negative impact such structures have upon land subsidence, soil drainage and hindering natural sediment accumulation, has led to the introduction of ecosystem-based approaches. Conventional engineering approaches may protect the Hinterland (presumably), but does very little for the coastline itself. Which would be expected to last longer against changing sea levels and storms?

Conventional engineering often disturbs natural processes in ways that can accelerate local sea-level rise and increase long-term flood risk. When wetlands are disconnected from the rivers, the land no longer builds up with sea-level rise; deltas are incredibly susceptible to subsidence. Relying on conventional engineering poses severe risk to local populations, and unintentionally exacerbates long-term flood risk, compromising the sustainability of local communities. 

Restoration

The Future Earth and Sustainable Deltas 2015 is one example of an inititative whose findings are not being implemented, and hard engineering methods prevail with regards to Hinterland protection. Gaps in knowledge slow down the implementation of generic solutions, and it is often forgotten that the health of wetlands is crucial to delta resilience. It is surmised by Giosan et al., 2014 that biophysical and biogeochemical research on wetland processes must be expanded to address the wide range of deltaic conditions. Further, agricultural and industrial practices should be assessed to select sustainable practices.

Wetland reclamation leaves nowhere for flood waters to go, meaning storm surges that do occur will rise higher and propagate faster/further inland. Consider the Scheldt estuary in Belgium, where high water levels have increased by 1.3m from 1930.

Nature-based engineering largely involves restoration in order to provide greater water storage, improve the capacity to build up sediment, regain elevation and maintain a cost-efficient, self-sustaining environment in the future, which conventional engineering cannot offer.

Soft engineering methods

Beach nourishment is a positive feedback loop that does not stop the erosion process. It is only really implemented on developed coastlines, not under the motivation of ecological conservation. When shoreline erosion is compensated with sand from outside the system, it must be continuously repeated as the sand rectangle spreads down the shoreface at an exponential rate. There are numerous problems and benefits of beach nourishment. Interestingly, you are allowed to suck up three sea turtles in the U.S dredging schemes before it becomes punishable - naturally there are big enforcement problems regarding this cutting edge rule.

 Mismatching coastal material is a problem from a residence/tourism angle, particularly when fine sand is replaced with rocky cobble. Further, changing the material alters the heat absorption capacity of the sand, which impacts turtle egg development and the ratio of males:females produced. False crawls can also be initiated when a beach is so fine-grained it is too compact for the female turtles to dig. 

Ecosystem-based flood defense

Cities located in estuaries or deltas such as London are thought to benefit enormously from the restoration of tidal marshes/mangroves between the city and sea, since they act to provide extra water storage areas and friction to attenuate the propagation of storm surges. It generally reduces flood risk inland. The marshes are constructed by the landward displacement of historical dykes, or purposeful, controlled flooding of chosen regions. Marshes improve water quality, sequester carbon, produce fisheries, work with conservation and create recreational space. The delivery of scarce nutrients such as silica by tidal wetland water suppresses the growth of toxic algae but stimulates the growth of phytoplankon. There is often a worry that these constructed wetlands will soon become submerged however. A cost-benefit analysis for Humber estuary stretching over 25 years showed it is more cost effective to restore tidal marshes than maintain dykes.

Behind sandy coastlines, beach and dune barriers are essential, and produced by artificial sediment placement, and in the Netherlands, a 17km stretch of coastline has combatted coastal erosion through careful planning and sculpting of the shore. This has avoided the need for constant dredging. The construction of oyster reefs from gabions on sand flats further work to reduce waves, currents and erosion.

Limitations 

Ecosystem-based flood defenses generally require more space than conventional structures, which makes them difficult to implement in urban areas such a s New York or Tokyo. The more space there is between the sea and urban area, the more efficient these approaches become. For this reason, cities closer to the coastline would benefit more from a combination of conventional and ecosystem-based engineering methods. Where there is little space at all along the beach, seaward ecosystem creation (e.g. off-shore reef development) may be an option, but could destroy or disturb the existing ecosystems. 

Locations with low elevation and high tidal inundation are often far less successful at growing tidal marshes, and this is a problem that may be transferred across to mangrove forests, although very little data is known about tropical projects in the long-term. Engineering structures such as weirs or sluices can help with this, but will also rack up the total price. Soil properties and their influence over water filtration, wind waves, bioturbation, grazing and seed dispersal can also hamper wetland development. 

Public perception may be an extremely strong blocker to implementing ecosystem-based management strategies; chiefly regarding the idea that laboriously reclaimed valuable land should be given back to the sea. In the Netherlands, there is significant cultural and political objection to such projects, where 50% of the population live below sea level. Their long-time struggle against the seas has become a part of their cultural heritage, however perhaps societal opposition may be overcome with clear communication of the benefits of such defense schemes.

Further public resistance may arise from concerns that wetlands may facilitate mosquito breeding and disease transmission, particularly in tropical regions amongst the more vulnerable areas e.g. Asia.