Pathways for Participatory Water Governance in Ashaiman,Ghana: Learning from Institutional Bricolage and Hydrosocial Perspectives

Coupling a hydrosocial perspective with institutional bricolage, this research considers possibilities for participatory water governance in Ashaiman, a peri-urban settlement of Accra, Ghana. We explore three questions: (1) How do people in Ashaiman evoke ideas or experiences of water in general and water governance in particular? (2) What possibilities currently exist for engaging the community in key water-related decisions? (3) What possibilities exist for enhanced participatory water governance in this context, including potential for and interest in new institutions and engagement processes? Results of qualitative interviews and semistructured observation suggest that a siloed, water-centric approach inadequately captures everyday realities of water as hydrosocial and of existing institutions in Ashaiman. In contrast to “modern water,” we propose that water issues may be more meaningfully addressed as bundled with social welfare. Potential implications and alternative ways of understanding socio-institutional arrangements for participatory water governance are explored.     

Forty‐Nine Major and Trace Element Concentrations Measured in Soil Reference Materials NIST SRM 2586, 2587, 2709a, 2710a and 2711a Using ICP‐MS and Wavelength Dispersive‐XRF

Excellent agreement was noted in the concentration of major and trace elements in five NIST (National Institute for Science and Technology) soil reference materials (NIST SRM 2586, 2587, 2709a, 2710a and 2711a) between measurement results from wavelength dispersive‐XRF and ICP‐MS from two independent laboratories, and NIST certificate of analysis and literature data. We describe the variability in concentrations of up to forty‐nine elements (plus loss on ignition) and provide values for up to twenty‐one elements previously uncharacterised by NIST in these soil RMs. The additional characterisation provided in this investigation can be utilised to reduce the measurement bias of custom calibration routines and improve the quality of control checks developed using these NIST RMs.     

Observations of thermospheric neutral winds within the polar cusp and the auroral oval using a Doppler imaging system (DIS)

Two Doppler imaging systems (DIS) or wide-field imaging Fabry-Perot interferometers (FPI), have recently been commissioned, one at the Auroral Station, Adventdalen, Longyearbyen, Svalbard, and the second at the IRF, Kiruna, Sweden. These instruments can provide wide-field (600 * 800 km) images of neutral wind flows in the upper thermosphere, by measuring the Doppler shift of the atomic oxygen forbidden near 630 nm, which is emitted from an altitude of approximately 240 km. From the instrument in Svalbard, at mid-winter, it is possible to observe the dayside polar cusp and the polar cap throughout the entire day, whereas from Kiruna, the night-time auroral oval is observable during the hours of darkness. Measurements of thermospheric dynamics from the DIS can be used in conjunction with observations of ionospheric plasma flows and thermal plasma densities by the EISCAT-Svalbard radar (ESR) and by EISCAT, along with other complementary observations by co-located instruments such as the auroral large-scale imaging system (ALIS). Such combined data sets will allow a wide range of scientific studies to be performed concerning the dynamical response of the thermosphere and ionosphere, and the important energetic and momentum exchange processes resulting from their complex interactions. These processes are particularly important in the immediate vicinity of the polar cusp and within the auroral oval. Early results from Svalbard in late 1995 will be discussed. The DIS in Kiruna observed two interesting geomagnetic disturbances in early 1997, the minor geomagnetic storm of 10, 11 January, and the disturbed period from 7–10 February. During these events, the thermospheric wind response showed some interesting departures from the average behaviour, which we attribute to the result of strong and variable Lorenz forcing (ion drag) and Joule and particle heating during these geomagnetic disturbances.     

2.4 μm emission from the galactic centre region

It is shown that the 2.6 mm CO emission profile in the regions of two unidentified 2.4 m features observed near the galactic centre is consistent with an explanation of these features in terms of inhomogeneities in interstellar extinction. From our observations we estimate the mass to luminosity ratio of the galactic central bulge to beM/L _v=4.     

N-view reconstruction: a new method for morphological modelling and deformation measurement in volcanology

We present a method of reconstructing volcanic morphology using multiple digital views (N-view), captured at different angles around an object. This approach uses recent advances in the field of Computer Vision to provide accurate 3-D measurements of volcanic surfaces. Videogrammetry (digital image reconstruction) is used, as it is best adapted to numerical processing. The method is tested and now used in the laboratory on analogue volcanic cones. The method begins with calibrating the camera and finding image positions, using an accurate N-view calibration method. This is done by estimating internal and external parameters of the camera using several views of a specially constructed calibration target. The N-view reconstruction of the real object is then done by iteratively deforming an initial theoretical model of the surface. Laboratory tests show that reconstruction accuracy is about 10⁻⁴ m for a distance between the object and the camera of 0.5 m, and is potentially several orders of magnitude higher for surfaces of finer texture and using higher precision sensors. This is easily high enough to be useful for the accuracy required for morphological studies. It is also sufficient for monitoring most types of volcano deformation. The technique has the potential to detect morphology changes of the order of mm. Use of the method in the field requires a slightly different approach from that in the laboratory: textures and lighting are more variable, and the sensor and ground control point location and model calibration must be done differently. We provide case studies from laboratory tests and qualitative image analysis for two field cases: Piton de la Fournaise (Indian Ocean) and Santaguito (Guatemala). These illustrate the technique’s potential and explore problems of field application. Using current sensors, the method has the potential to provide sufficient precision for fine (mm–cm) scale reconstruction, and will represent a valuable, simple and flexible tool when compared with classical stereophotogrammetry techniques.     

Gelifluction: viscous flow or plastic creep?

This paper reports results from two scaled centrifuge modelling experiments, designed to simulate thaw‐related geli?uction. A planar 12° prototype slope was modelled in each experiment, using the same natural ?ne sandy silt soil. However two different scales were used. In Experiment 1, the model scale was 1/10, tested in the centrifuge at 10 gravities (g) and in Experiment 2, the scale was 1/30, tested at 30 g. Centrifuge scaling laws indicate that the time scaling factor for thaw consolidation between model and prototype is N², where N is the number of gravities under which the model was tested. However, the equivalent time scaling for viscous ?ow is 1/1. If geli?uction is a viscosity‐controlled ?ow process, scaling con?icts will therefore arise during centrifuge modelling of thawing slopes, and rates of displacement will not scale accurately to the prototype. If, however, no such scaling con?icts are observed, we may conclude that geli?uction is not controlled by viscosity, but rather by elasto‐plastic soil deformation in which frictional shear strength depends on effective stress, itself a function of the thaw consolidation process. Models were saturated, consolidated and frozen from the surface downwards on the laboratory ?oor. The frozen models were then placed in the geotechnical centrifuge and thawed from the surface down. Each model was subjected to four freeze–thaw cycles. Soil temperatures and pore water pressures were monitored, and frost heave, thaw settlement and downslope displacements measured. Pore water pressures, displacement rates and displacement pro?les re?ecting accumulated shear strain, were all similar at the two model scales and volumetric soil transport per freeze–thaw cycle, when scaled to prototype, were virtually identical. Displacement rates and pro?les were also similar to those observed in earlier full‐scale laboratory ?oor experiments. It is concluded therefore that the modelled geli?uction was not a time‐dependent viscosity‐controlled ?ow phenomenon, but rather elasto‐plastic in nature. A ?rst approximation ‘?ow’ law is proposed, based on the ‘Cam Clay’ constitutive model for soils. Copyright © 2003 John Wiley & Sons, Ltd.