Spaced Out ::

Asmau Ahmed, Olga Duran, Yahya Zweiri, Mike Smith
Remote Sensing

Terrestrial hydrocarbon spills have the potential to cause significant soil degradation across large areas. Identification and remedial measures taken at an early stage are therefore important. Reflectance spectroscopy is a rapid remote sensing method that has proven capable of characterizing hydrocarbon-contaminated soils. In this paper, we develop a deep learning approach to estimate the amount of Hydrocarbon (HC) mixed with different soil samples using a three-term backpropagation algorithm with dropout. The dropout was used to avoid overfitting and reduce computational complexity. A Hyspex SWIR 384 m camera measured the reflectance of the samples obtained by mixing and homogenizing four different soil types with four different HC substances, respectively. The datasets were fed into the proposed deep learning neural network to quantify the amount of HCs in each dataset. Individual validation of all the dataset shows excellent prediction estimation of the HC content with an average mean square error of ~2.2×10-4. The results with remote sensed data captured by an airborne system validate the approach. This demonstrates that a deep learning approach coupled with hyperspectral imaging techniques can be used for rapid identification and estimation of HCs in soils, which could be useful in estimating the quantity of HC spills at an early stage.

Anders, N.S., Smith, M.J., Suomalainen, J., Cammeraat, L.H., and Keesstra, S.D.
Earth Science Informatics

Soil erosion, rapid geomorphological change and vegetation degrada-
tion are major threats to the human and natural environment. Unmanned Aerial Systems (UAS) can be used as tools to provide detailed and accurate estimations of landscape change. The effect of flight strategy on the accuracy of UAS image data products, typically a digital surface model (DSM) and orthophoto, is unknown. Herein different flying altitudes (126-235 m) and area coverage orientations (N-S and SW-NE) are assessed in a semi-arid and medium-relief area where terraced and abandoned agricultural fields are heavily damaged by piping and gully erosion. The assessment was with respect to cell size, vertical and horizontal accuracy, absolute difference of DSM, and registration of recognizable landscape features. The results show increasing cell size (5-9 cm) with increasing altitude, and differences between elevation values (10-20 cm) for different flight directions. Vertical accuracy ranged 4-7 cm but showed no clear relationship with flight strategy, whilst horizontal error was stable (2-4 cm) for the different orthophotos. In all data sets, geomorphological features such as piping channels, rills and gullies and vegetation patches could be labeled by a technician. Finally, the datasets have been released in a public repository.

Mike J. Smith, Flora Parrott, Anna Monkman, James O’Connor and L. Rousham
Journal of Maps

This paper outlines a collaborative project between a group of Fine Art and Geography students who helped develop and contribute to a conversation about recording ‘place’. Introducing methodologies from both disciplines, the project started from the premise of all environmental ‘recordings’ being ‘inputs’ and so questioned what could be defined as ‘data’ when encountering a location. Brunel’s Grand Entrance to the Thames Tunnel (London) provided the motivation for 10 objective and subjective ‘recordings’ which were subsequently distilled into a smaller subset and then used to produce a short film that was presented at an international conference. Important to the collaborative nature of the project were ongoing opportunities to share equipment, techniques, material and references across disciplines. It was an experiment to measure the potential for ‘mapping’ to capture physical and historical information, as well as embodied experience.

M.J. Uddin, Peter S. Hooda, A.S.M. Mohiuddin, Mike J. Smith and Martyn Waller
Catena

Land inundation is a common occurrence in Bangladesh, mainly due to the presence of two major river systems -the Brahmaputra and the Ganges. Inundation influences land use and cropping intensity. However, there is little information on the influences of the extent of flooding and cropping intensity has on soil organic carbon (SOC),particularly at the landscape level. To investigate these influences, we collected 268 surface (0-30 cm) soil samples from 4 large sites within the two alluviums deposits (the Brahmaputra river and the Ganges river), on a regular grid (1600 m). The findings show that SOC levels are generally low, reflecting the intensity of agriculture and land management practices. SOC variability was higher across the medium high land (MHL) and medium low land (MLL) sites than in the high land (HL) and low land (LL) sites. The relatively low SOC levels and variability in the HL sites indicate soils here might have reached to equilibrium levels due to higher land use intensity. Topographically higher lands (HL and MHL), due to less of inundation, had higher cropping intensities and lower SOC’s than lower lands (MLL and LL), which had lower cropping intensities, as they remain inundated for longer periods of time. The findings clearly demonstrate the intrinsic influence of land inundation in driving cropping intensity, land management practices and SOC levels.

Mike J. Smith (2019)
Journal of Maps

Creativity is one of those tropes that seems to do the rounds regularly in, well, creative circles. Almost by definition, it is levelled at the arts, in part because its base definition is along the lines of the ability to create. Withinthis context, cartography is well-poised because any map requires the cartographer to create a new, unrealised, graphic product.