Development of a conceptual model of the soil-moisture-plant sub-system of the hydrological cycle

The soil-plant-moisture subsystem is an important component of the hydrological cycle. Over the last 20 or so years a number of computer models of varying complexity have represented this subsystem with differing degrees of success. The aim of this present work has been to improve and extend an existing model. The new model is less site specific thus allowing for the simulation of a wide range of soil types and profiles. Several processes, not included in the original model, are simulated by the inclusion of new algorithms, including: macropore flow; hysteresis and plant growth. Changes have also been made to the infiltration, water uptake and water flow algorithms. Using field data from various sources, regression equations have been derived which relate parameters in the suction-conductivity-moisture content relationships to easily measured soil properties such as particle-size distribution data. Independent tests have been performed on laboratory data produced by Hedges (1989). The parameters found by regression for the suction relationships were then used in equations describing the infiltration and macropore processes. An extensive literature review produced a new model for calculating plant growth from actual transpiration, which was itself partly determined by the root densities and leaf area indices derived by the plant growth model. The new infiltration model uses intensity/duration curves to disaggregate daily rainfall inputs into hourly amounts. The final model has been calibrated and tested against field data, and its performance compared to that of the original model. Simulations have also been carried out to investigate the effects of various parameters on infiltration, macropore flow, actual transpiration and plant growth. Qualitatively comparisons have been made between these results and data given in the literature.

The impact on agriculture of the drawdown of shallow watertables

The promoters of the large groundwater developments implemented in the 1970's paid little attention to the effects of pumping on soil moisture. A field study, conducted in 1979 in the Tern Area of the Shropshire Groundwater Scheme, revealed that significant quantities of the available moisture could be removed from the root zone of vegetation when drawdown of shallow watertables occurred. Arguments to this effect, supported by the field study evidence, were successfully presented at the Shropshire Groundwater Scheme public inquiry. The aim of this study has been to expand the work which was undertaken in connection with the Shropshire Groundwater Scheme, and to develop a method whereby the effects of groundwater pumping on vegetation can be assessed, and hence the impacts minimised. Two concepts, the critical height and the soil sensitivity depth, formulated during the initial work are at the core of the Environmental Impact Assessment method whose development is described. A programme of laboratory experiments on soil columns is described, as is the derivation of relationships for determining critical heights and field capacity moisture profiles. These relationships are subsequently employed in evaluating the effects of groundwater drawdown. In employing the environmental assessment technique, digitised maps of relevant features of the Tern Area are combined to produce composite maps delineating the extent of the areas which are potentially sensitive to groundwater drawdown. A series of crop yield/moisture loss functions are then employed to estimate the impact of simulated pumping events on the agricultural community of the Tern Area. Finally, guidelines, based on experience gained through evaluation of the Tern Area case study, are presented for use in the design of soil moisture monitoring systems and in the siting of boreholes. In addition recommendations are made for development of the EIA technique, and further research needs are identified.

Obstacles and solutions to maximising biodiversity in major urban development schemes

The current rate of global biodiversity loss led many governments to sign the international agreement ‘Halting Biodiversity Loss by 2010 and beyond’ in 2001. The UK government was one of these and has a number of methods to tackle this, such as: commissioning specific technical guidance and supporting the UK Biodiversity Acton Plan (BAP) targets. However, by far the most effective influence the government has upon current biodiversity levels is through the town planning system. This is due to the control it has over all phases of a new development scheme’s lifecycle.There is an increasing myriad of regulations, policies and legislation, which deal with biodiversity protection and enhancement across the hierarchical spectrum: from the global and European level, down to regional and local levels. With these drivers in place, coupled with the promotion of benefits and incentives, increasing biodiversity value ought to be an achievable goal on most, if not all development sites. However, in the professional world, this is not the case due to a number of obstructions. Many of these tend to be ‘process’ barriers, which are particularly prevalent with ‘urban’ and ‘major’ development schemes, and is where the focus of this research paper lies.The paper summarises and discusses the results of a questionnaire survey, regarding obstacles to maximising biodiversity enhancements on major urban development schemes. The questionnaire was completed by Local Government Ecologists in England. The paper additionally refers to insights from previous action research, specialist interviews, and case studies, to reveal the key process obstacles.Solutions to these obstacles are then alluded to and recommendations are made within the discussion.

Corporate responsibility reporting of biodiversity in the supply chain

Industrial development, accompanying human population growth, has had a major role in creating the situation where bio-diverse materials and services essential for sustaining business are under threat. A major contributory factor to biodiversity decline comes from the cumulative impacts of extended supply chain business operations. However, within Corporate Responsibility (CR) reporting impacts on biodiversity due to supply chain operations have not traditionally been given equal weighting with other environmental issues. This paper investigates the extent of CR reporting in managing and publicising company biodiversity supply chain issues by reviewing a cross-sector sample of publicly available CR reports. The report contents were examined for suggestions of industrial sectorial trends in the level of biodiversity consideration. The reporting of environmental management system use within company supply chain management is assessed in the samples and is considered as a mechanism for responsible supplier partnership working.

Building environmental assessment scheme for residential building in Brunei

Building's construction activities, operation and demolition are increasingly recognised as a major source of environmental impact. One strategy for reducing such impacts is most widely known by the term Building Environmental Assessment (BEA). The research is an attempt to develop a new BEA scheme for residential buildings in Brunei which focussing on identifying BEA indicators that best suit for Brunei environment, social and economy. Studies show that Brunei residential sector needs urgent attention to transform its current consumption rate in more sustainable way. Recent launch of Brunei Green Building Council, mandatory energy efficiency guidelines and declaration of ambitious energy intensity reduction target, a new BEA scheme will help contribute sustainability target in residential sector. However the issues of developing a new BEA schemes using existing methods may face constraints in their effectiveness. In this regard, a consensus-forming technique-Delphi method-helps improve greater communication and gain consensus from experts in the construction industry through series of questionnaires. As a result, the final framework is produced comprises of 7 key categories and 37 applicable criteria that achieved high degree of consensus and importance.