The DAKOTA (Design Analysis Kit for Optimization and Terascale Applications) toolkit provides a flexible and extensible interface between simulation codes and iterative analysis methods. DAKOTA contains algorithms for optimization with gradient and nongradient-based methods; uncertainty quantification with sampling, reliability, and stochastic finite element methods; parameter estimation with nonlinear least squares methods; and sensitivity/variance analysis with design of experiments and parameter study methods. These capabilities may be used on their own or as components within advanced strategies such as surrogate-based optimization, mixed integer nonlinear programming, or optimization under uncertainty. By employing object-oriented design to implement abstractions of the key components required for iterative systems analyses, the DAKOTA toolkit provides a flexible and extensible problem-solving environment for design and performance analysis of computational models on high performance computers.This report serves as a reference manual for the commands specification for the DAKOTA software, providing input overviews, option descriptions, and example specifications.4

A procedure for land‐surface zoning, related to the protection of groundwater against both point and diffuse pollution, is described. The procedure is based upon two independent elements: (i) Division of the entire land surface on the basis of the aquifer pollution vulnerability, which relates to protection of groundwater resources; and (ii) A series of special protection areas for individual sources, in which various potentially polluting activities are either prohibited or strictly controlled. The procedure is hydrogeologically based, but not so complex as to be unworkable in practice. For resource protection three classes of formation type are defined, with a further subdivision on the basis of depth to saturated aquifer. In the case of diffuse pollution, it will also be necessary to consider the nature of the soil cover in the area where the polluting activity occurs. For source protection, up to four special protection areas are specified, and the criteria used to define them are discussed.

An early warning system has been developed for groundwater flooding and trialled in the Patcham area of Brighton. It provides a fit-for-purpose approach for forecasting groundwater flood events in the Chalk and is capable of operating across longer time scales than had previously been possible. The method involves a set of nested steps or tasks. Initially, the catchment's response to recharge is determined and, using a representative hydrograph, a simple regression model that relates annual groundwater level minima and autumn and winter rainfall to subsequent annual maxima is developed. The regression model is then applied at the end of each summer recession using the observed annual minimum and estimates of winter rainfall to predict the following groundwater level maximum. Based on the results of this prediction a variety of steps may then be appropriate. Where the model predicts potentially high groundwater levels the frequency of groundwater level monitoring observations can be increased. A novel element of the method developed is the monitoring of changes in the matric potential of the unsaturated zone. Specific trigger levels to initiate either the next step of the method or promulgation of warnings of varying severity will be developed through experience of use of the system.

Groundwater flooding has been shown to be a significant component of the risk from flooding in the UK. Its inclusion within the EU Floods Directive highlights the need to understand more about the processes that control groundwater flooding and to define the associated risk. In this paper the main groundwater flooding scenarios are described and the challenges in estimating return periods and mapping risk set out. In addition, ongoing and recently completed work by the British Geological Survey which aims to improve the understanding of risk from groundwater flooding in the UK is presented.

There is a widely held belief that, over the last few decades, many rivers and wetlands have been significantly degraded. Clearly, groundwater abstraction has had a detrimental effect.However, other pressures such as channelisation, sedimentation, reduced rainfall, poor site management or land-use change can be contributing factors. Various policy responses are reviewed and some examples are given. It is concluded that, whilst groundwater abstraction does cause river and wetland degradation, the degree of degradation often depends upon the individual perspective; therefore a rigorous approach is required in quantifying such degradation and its actual causes, beginning with the establishment of clear objectives and the collection of appropriate data.