Water resources data for the 1993 water year for Idaho consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of ground water. The two volumes of this report contain discharge records for 189 stream-gaging stations and 39 irrigation diversions; stage only records for 4 stream-gaging stations; stage only for 7 lakes and reservoirs; contents only for 23 lakes and reservoir; water-quality for 61 stream-gaging stations, 489 wells, and 6 lakes sites; daily totals for 1 precipitation gage; and water levels for 571 observation wells. Additional water data were collected at various sites not involved in the systematic data collection program and are published as miscellaneous measurements.
ABSTRACT Coastal dunes support a biodiverse wetland habitat, dune slacks, which depend on a seasonally fluctuating, but near‐surface, groundwater level. Any long‐term change in the hydrological regime will impact the ecology. Analysis of long‐term water level hydrographs, using a methodology prescribed for surface water flow gauging data, provides a set of ecohydrological ‘indicators of alteration’. These indicators collectively form a robust quantified measure of change that provides a basis for assessing the ecological impact that may result from a changed hydrological regime. This method was tested using monthly frequency water level data from three west coast UK coastal dunes, over periods of up to 37 years. Mean hydrological variables derived from the hydrographs were compared pre‐impact and post‐impact for a variety of perturbations: medium‐term climate variation and pre‐shoreline and post‐shoreline erosion. The method provided a valid quantification of hydrological change. The low frequency of water‐level data measurements compared with continuous flow‐gauge data precluded analysis of change in inter‐annual variability or perturbation (coefficients of variability) because of the likelihood of missed extreme flood and drought. Principal components analysis was used to identify associations between hydrological indicators and highlighted redundancy among some indicators such as measures of frequency and duration but orthogonality, i.e. independence, of others such as mean water levels and duration of drought. The hydrological effects of climatic variation over a 37‐year period, of management interventions and erosion events that occurred at the three coastal dunes were small compared with the likely impact from projected climate change predictions. Copyright © 2012 John Wiley & Sons, Ltd.
Abstract Aim To quantify the responses of alpha and beta diversity to multivariate gradients, incorporating variation in environmental and management variability in coastal dune slacks. Location United Kingdom dune slacks. Methods Plant community composition, plant nutrient status and soil characteristics were measured for 164 quadrats in 41 dune slacks across 12 coastal sand dune systems. Data were collated on climate and atmospheric deposition. Hydrological regimes at daily resolution were modelled and calibrated using daily‐to‐monthly site measurements, from which we calculated quadrat‐level hydrological metrics. Alpha diversity (richness, Shannon diversity and Pielou's evenness) metrics and beta diversity (turnover and nestedness) for species and genera were calculated across three spatial levels from sand dune system (highest) to dune slack to quadrat (lowest). Results Diversity patterns depended on the spatial and taxonomic level considered. At smaller spatial levels (between dune slacks and between quadrats), alpha and beta diversity varied along gradients driven by soil characteristics, water table depth and atmospheric deposition. At larger spatial levels (between sand dune systems), patterns of beta diversity were a consequence of plant nutrient status. There was little variability in alpha diversity along this same gradient, with only small changes in Pielou's species evenness. Patterns at a coarser taxonomic level (genus) mirrored those at the species level. Main conclusion We show that patterns of variation in plant diversity are dependent on the spatial level considered, but taxonomic level made little difference in understanding these patterns. Therefore, if we do not consider patterns across different spatial levels, important environmental and management drivers could be missed. The high biodiversity value and degree of threat to these European protected habitats makes such understanding invaluable for their conservation.
