Catchment storage and residence time in a periodically irrigated watershed

Understanding anthropogenic impacts on water storage and water flow pathways in catchments is an ongoing challenge in hydrology. Here, we study the dynamics of subsurface storage and residence time of water in a catchment in Berkeley, California, that is within a regional park but contains diverse land use within its perimeter, including a periodically irrigated golf course. Our study combines several isotopic tracers with water budget data to examine sources of water in a stream draining the site. Irrigation water, applied to a small area of the watershed, is a minor component of the water budget. However, geochemical tracers reveal that irrigation water is a significant fraction of stream flow downstream of the golf course during baseflow and during precipitation events. Isotopic tracers indicate that the watershed has a preference to release young water for stream flow generation, resulting in contrasting tritium ages for stream water and groundwater of 1.3 ± 0.5 year and 8.2 ± 1.7 year, respectively. We determined that the older water is a very small component (0.7%) of the stream water in the tail of an assumed exponential distribution. We used the seasonal variation of stable water isotopes in precipitation and stream water over two water years to explain the damping of the isotopic signature of stream water, which yields information about the catchment's response to the input signal. The methods described here may be applicable to other urban or suburban headwater catchments in areas with a component of non-natural recharge from, for example, leaky infrastructure, storm water routing or dry season irrigation.     

Between outside and inside? Prison visiting rooms as liminal carceral spaces

This paper suggests that although carceral space seems to be sharply demarcated from the outside world, the prison wall is in fact more porous than might be assumed. The paper critiques Goffman’s theory of the ‘total institution’ by deploying a geographical engagement with liminality to theorise prison visiting rooms as spaces in which prisoners come face-to-face with persons and objects which come from and represent their lives on the ‘outside’. Drawing on a specific empirical example from recent research into imprisonment in the contemporary Russian prison system, it uses the example of visiting suites designed for long term ‘residential’ visits to explore the ways in which visiting spaces act as a space of betweenness where a metaphorical threshold-crossing takes place between outside and inside. The paper specifically explores the expression of that betweenness in the materiality of visiting, and in the destabilisation of rules and identities in visiting space. It contests the sense of linear transformation with which liminal spaces have previously been associated, suggesting that rather than spaces of linear transition from one state to another, liminal spaces can constitute a frustratingly repetitive, static or equilibriating form of transformation which is cumulative rather than immediate, and relates this suggestion to the wider study of prison visitation.