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Item 3D_GPR_URBAN(2021-10)The versatility of ground penetrating radar (GPR) to solving different subsurface detection problems in urban settings is demonstrated. In particular, the advantage of the 3D approach to GPR surveying and how it complements the traditional 2D radargram outputs is demonstrated. These case studies include the mapping of man-made structures such as drain pipes and other utilities as well as natural, but non-geological targets in the form of tree roots. The non-destructive and non-invasive nature of GPR is also evident in the two case studies presented here.Item Responses of aquatic communities to physical and chemical parameters in agriculturally impacted coastal river systems(2017-04-05) Petersen, ChantelThe assessment of ecological integrity of river systems is a multidisciplinary research field necessary for effective river management. The objectives of the current study were: (i) to characterize the spatial and temporal distribution and community assemblages of macroinvertebrates and algae down a longitudinal gradient and; (ii) to determine the environmental variables that affect assemblage distribution. The study occurs in agriculturally influenced coastal rivers in the southern Cape, South Africa, over a period of two years (wet and dry seasons). At upstream sites low electrolytes (electrical conductivity: 12-30 mS m) and nutrients (total nitrogen: <1 mg L) were recorded. Moving down the longitudinal gradient agricultural influences impacted water quality and aquatic communities. Increased electrical conductivity (> 100 mS m) and nutrients were observed during the wet season. The downstream site showed a positive correlation between nitrogen, phosphates and silica and the river flow regime. Upstream sites were dominated by diatoms and macroinvertebrates indicative of low pH values, low electrolytes and oligotrophic conditions. The benthic substrate of the downstream site was dominated by benthic filamentous algae during the dry and wet seasons, which were associated with increased water alkalinities (34-48 mg L:dry; 24-63 mg L:wet), water hardness (CaCO3) (117- 133 mg L: dry; 24-67 mg L: wet) and nutrients (total phosphorus: 0.44 mg L: dry; 0.26 mg L:wet) under an altered flow regime. Mesotrophic conditions were a usual occurrence during both dry and wet seasons. The altered flow regime at this site played a role in algal and macroinvertebrate assemblages that occurred.Item 2006 Fynmeet sea clutter measurement trial: Datasets(CSIR, 2007-09-06) Herselman, PLRThis document provides an overview for the datasets (or subset thereof) recorded between July and August 2006 as part of the Fynmeet Sea Clutter Measurement Trial conducted at the Overberg Test Range at Arniston, South Africa. The trial was conducted over the period from 18 July to 4 August 2006. These datasets have been stored in structured Mathworks Matlab (*.mat) files and will be made available to research institutes or universities upon request.