The Accuracy and Reliability of Traditional Surface Flow Type Mapping: Is It Time for A New Method of Characterising Physical River Habitat?

Surface flow types (SFT) are advocated as ecologically relevant hydraulic units, often mapped visually from the bankside to characterise rapidly the physical habitat of rivers. SFT mapping is simple, non-invasive and cost-efficient. However, it is also qualitative, subjective and plagued by difficulties in recording accurately the spatial extent of SFT units. Quantitative validation of the underlying physical habitat parameters is often lacking, and does not consistently differentiate between SFTs. Here, we investigate explicitly the accuracy, reliability and statistical separability of traditionally mapped SFTs as indicators of physical habitat, using independent, hydraulic and topographic data collected during three surveys of a c. 50m reach of the River Arrow, Warwickshire, England. We also explore the potential of a novel remote sensing approach, comprising a small unmanned aerial system (sUAS) and Structure-from-Motion photogrammetry (SfM), as an alternative method of physical habitat characterisation. Our key findings indicate that SFT mapping accuracy is highly variable, with overall mapping accuracy not exceeding 74%. Results from analysis of similarity (ANOSIM) tests found that strong differences did not exist between all SFT pairs. This leads us to question the suitability of SFTs for characterising physical habitat for river science and management applications. In contrast, the sUAS-SfM approach provided high resolution, spatially continuous, spatially explicit, quantitative measurements of water depth and point cloud roughness at the microscale (spatial scales ≤1m). Such data are acquired rapidly, inexpensively, and provide new opportunities for examining the heterogeneity of physical habitat over a range of spatial and temporal scales. Whilst continued refinement of the sUAS-SfM approach is required, we propose that this method offers an opportunity to move away from broad, mesoscale classifications of physical habitat (spatial scales 10-100m), and towards continuous, quantitative measurements of the continuum of hydraulic and geomorphic conditions which actually exists at the microscale.

Through Class Darkly: Class in the British TV Noir

Class has always been at the heart of the television crime drama. Whether it is the post-war paternalism of Dixon of Dock Green (1955 – 1976), the harsh social realism of The Sweeney (1975-1978), or the almost mythical evocations of Britain in Heartbeat (1992 – 2010) and Midsomer Murders (1997- present), class and crime have always been seen as being inextricably linked. Since the 1990s, the British crime drama has been influenced by successive waves of cultural imports from, firstly, the US and then from Scandinavia. There is now a recognisable ‘genre’ for what we might think of as British TV Noir. Beginning with shows such as Cracker (1993 – 2006), Prime Suspect (1991 – 2006) and Messiah (2001) and continuing with dramas like Red Riding (2008), Southcliffe (2013) and Hinterland (2013 – present), the British TV Noir employs narratives and stylistic tropes that might usually be associated with the cinema of the 1940s. Although drawing influence from high profile shows such as Twin Peaks (1990 – 1991), Millennium (1996) and (latterly) The Wire (2002 – 2008), CSI (2000 – present) and The Killing (2007) these British Noir shows also articulate the nation’s shifting class system. As Susan Sydney-Smith has ably demonstrated, the crime drama is “historically contingent” (Sydney-Smith, 2002, p. 5) and shaped by the surrounding socio-political, as well aesthetic, context. To this end, this chapter traces the depiction of class in three key crime series – Prime Suspect, Red Riding and Southcliffe - and explores how social class, and more importantly, its changing face provides a constant background to the narratives and characterisations. These three texts were each produced at pivotal moments in Britain’s relationship to class – Prime Suspect was shown 6 months after Margaret Thatcher vacated office; Red Riding was produced in the midst of the global recession in 2008 and Southcliffe was made in the shadows of stringing welfare and immigration reforms. These texts span three successive political administrations and over two decades of social and political change. Understanding the relationship between criminal activity and class in these dramas however is far more complicated than simply reading the historical context through the text. Commensurate with its cinematic incarnation, TV Noir is both reflective and productive, employing visual and narrative tropes to manipulate, as well reflect, its audience’s moral and social positioning. The picture that emerges from an examination of class and the British TV Noir is one of suspicion and discontent. As Andrew Spicer suggests (with reference to British cinema) the Noir sensibility both depicts and critiques a society that it sees as being “class-ridden, racist and misogynist” (Spicer, 2002, p.202). This is certainly the case with the texts that are being examined here, as social positions and taxonomies are constantly being redefined and renegotiated.