THIS week the University of Glasgow is playing host to the 2013 conference of the Commonwealth Association of Surveyors and Land Economists (CASLE), an event that concentrates, in part, on how the survey and mapping sciences can inform society and help guide its decisions.
Two of the presentations highlight the importance of monitoring the migration of boundaries and lines that we otherwise assume are fixed in space. This is of vital importance because failure to act costs and will cost more in the future: householders affected by coastal erosion or river flooding will be the first to agree.
The first presentation examined the underlying susceptibility and position of the Scottish coastline to erosion changes as a result of natural sediment movement and the construction of artificial protection structures. The second sought to establish the position of the Lowest Astronomic Tide (LAT) as a baseline from which to measure the area of sea bed over which nations can claim sovereignty.
Loading article content
Both are good examples of the value of geodiversity to science and society. Geodiversity encompasses the ways in which Scotland's underlying geological make-up and the surface processes that shape landforms contribute to the nation's environment, economy and well-being. Resources such as coal, oil, gas, building stone, soils, rivers, beaches and coasts contribute so much to our socioeconomic well-being and provide the fundamental underpinnings of our ecosystems and their biodiversity.
The myriad ways in which a healthy biodiversity supports us is well understood, yet without geodiversity there would be no biodiversity, since all life depends on the variety of surface environments provided by rocks, landforms and the processes that form them. With an enhanced rate of climate change now upon us, those surface processes and ecosystems appear to be increasingly in a state of flux.
So why should we be bothered about the goods and services that geodiversity provides?
The survey work needed to establish the position of Lowest Astronomic Tide identified the landward movement in its position over recent decades to be much faster than the landward movement of the high water mark, confirmation of a more general 100-year long-term trend across the beaches of Scotland. More insidious, and largely unseen, is that the low water mark is now moving landward at a much greater rate than the high water mark, a clear indicator of coastal steepening and chronic loss of beach sediments.
Since beaches and the intertidal zone are major protectors of our coasts and of the human assets that lie behind them, their progressive loss is alarming. Intertidal habitats such as beach, saltmarsh, mud and sandflat are being lost at an increasing rate. It is becoming clearer that recent increases in the rate of coastal change are more than likely related to climate change. Society needs to better understand the processes responsible and place value on the protective services provided by existing intertidal habitats
Reliance on engineering strategies is only part of the answer. Many engineering structures have been found wanting by increases in impacts associated with river flooding, coastal erosion and landslides, presenting a clear argument that alternatives need to be considered. Part of this is to find the space to allow our landforms to adjust to changing conditions and better provide natural protection. The lines and boundaries that we draw on maps need to be able to move in order for geodiversity to adjust to new and changing conditions.
Clearly this is not the whole answer, but neither is our habitual response involving engineering structures. Interestingly, whilst we have a good grasp of the financial cost of engineering structures to mitigate river flooding and coastal erosion, we have no grasp of the overall financial cost and value to society of the protective function provided by healthy beach and sand dune systems.
Since the clock is ticking, it is high time we did. Scotland's Geodiversity Charter can be accessed at www. scottishgeodiversityforum.org.
Professor Jim Hansom is with the School of Geographical and Earth Sciences, University of Glasgow.