Nigel Lawton
Postgraduate Research Student
MSci (Hons)
Academic and research departments
Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences.About
My research project
The analysis of urban growth and surface permeability informed by Earth Observation dataUrban growth and the associated reduction in surface permeability affects the hydrological cycle and can increase flood risk. Understanding past and future patterns of urban growth is therefore an important aspect of flood risk management. Earth observation data is widely used to classify urban land. However, when classified maps are used to characterise change over time, the uncertainty of the classification can hinder meaningful analysis.
This study aims to improve the mapping and analysis of patterns of urban growth, by using and developing methods for classification and pattern analysis that exploit the longitudinal nature of time series of earth observation imagery and are thereby less sensitive to inherent uncertainty.
Supervisors
Urban growth and the associated reduction in surface permeability affects the hydrological cycle and can increase flood risk. Understanding past and future patterns of urban growth is therefore an important aspect of flood risk management. Earth observation data is widely used to classify urban land. However, when classified maps are used to characterise change over time, the uncertainty of the classification can hinder meaningful analysis.
This study aims to improve the mapping and analysis of patterns of urban growth, by using and developing methods for classification and pattern analysis that exploit the longitudinal nature of time series of earth observation imagery and are thereby less sensitive to inherent uncertainty.
My qualifications
2016
Geology MSci
University of Bristol
Publications
L.A.Evenstar, R.S.J.Sparks, F.J.Cooper, M.N.Lawton (2018) Quaternary landscape evolution of the Helmand Basin, Afghanistan: Insights from staircase terraces, deltas, and paleoshorelines using high-resolution remote sensing analysis.
The Helmand Basin in southern Afghanistan is a large (310,000 km2), structurally controlled, endorheically drained basin with a hyperarid climate. The basin hosts a high elevation (~200 m) plateau (the Dasht-i Margo), 11 fluvial terraces (T11 to T1), 7 delta systems (D1 to D7), and 6 paleolake shorelines (SL1 to SL6) within the Sistan Depression on the western side of the basin. Mapping and surveying of these features by is integrated with geological observations to reconstruct of the basin. The fluvial systems, deltas, and paleolake shorelines are correlated with one another and with the younger terraces (T7 to T1). The shape of fluvial longitudinal profiles changes depending on whether they formed pre-, syn-, or post-growth of the Koh-i Khannesin volcano on the southern margin of the Helmand River. The age of the volcano (~0.6 Ma) and correlation of the terraces with the global history of constrain the age of the younger terraces to the late Pleistocene and indicates that the older terraces are middle Pleistocene (dating back to 800 ka). The Helmand Basin once hosted a large lake, called here the Sistan paleolake, which at SL6 times and before had a surface area >50,000 km2. Since that time the lake elevation and area have decreased, evolving to the present-day dried out Sistan Depression with small ephemeral playa lakes. Episodic formation of terraces, deltas, and paleolake shorelines is attributed to changes in base level modulated by related to .