MATHEMATICAL MODELING OF GULF COAST ESTUARIES1

The environmental pollution problems prevalent in gulf coast estuaries are a cause of great concern to those in water quality management. This paper outlines the dominant characteristics which affect the properties of these estuaries including geography, tide and current effects, wind effects, salinity and density regime, nature and level of waste discharge, low inflow levels, dredging effects and present quality levels. Two basic levels of analytical modeling which are useful in water quality management are presented. The first is a relatively crude completely mixed estuarine model which permits economical evaluation of varying parameters. The second is a very general steady state model which permits analysis of stratified systems. The ESTPOL computer language designed to simplify the use of the steady state model is described. The practical use of the analytical models as management tools for the solution of Texas Estuarine quality problems is demonstrated.     

SOCIO-ECONOMIC IMPACTS OF RURAL WATER SUPPLES1

ABSTRACT Development of community water systems in rural areas through the Farmers Home Administration, U. S. D. A., has been marked since the initiation of the program in the early 1%O's. System development in Mississippi has been very rapid and now numbers the largest among the states excepting Texas. Concurrent with this growth, however, has been a concern for operational quality and efficiency as well as questions of community impacts. The paper is purposed with describing the results of research conducted relative to these areas and methods currently being employed or considered for dealing with problematic items.     

THE EFFECTS OF WATER RESOURCES DEVELOPMENT ON ESTUARINE ENVIRONMENTS1

ABSTRACT. The Texas Water Development Board, the principal water resource planning agency of the State, has been conducting extensive estuarine data collection activities and associated research to determine the required quantity and quality of fresh water inflows necessary to maintain various environmental conditions in Texas estuaries to preserve the estuarine ecosystems. These activities are a consequence of a statutory directive to the Board to make provisions in its State Water Plan for the effects of upstream water resource development on the associated estuaries. This paper reports on the results of the first phase of an extensive estuarine research project. The objectives of the research project are to (1) define the interrelationships between estuarine ecosystems and fresh water and nutrient inflows, and (2) develop and test quantitative simulation techniques which describe these relationships. In order to accomplish the first objective, physical and chemical water quality data and biological data on the estuarine ecosystems are being collected, compiled and analyzed. The second objective is being satisfied by the development of hydrodynamic and ecologic simulation models of the estuarine environment.     

MATHEMATICAL MODELS: PLANNING TOOLS FOR THE GREAT LAKES1

The Great Lakes Basin Commission has initiated a Framework Study to assess the present and projected water- and related land-resource problems and demands in the Great Lakes Basin. Poorly defined objectives; incomplete and inconsistent data arrays; unknown air, biota, water, and sediment interactions; and multiple planning considerations for interconnected, large lake systems hinder objective planning. To incorporate mathematical modeling as a planning tool for the Great Lakes, a two-phase program, comprising a feasibility and design study followed by contracted and in-house modeling, data assembly, and plan development, has been initiated. The models will be used to identify sensitivities of the lakes to planning and management alternatives, insufficiencies in the data base, and inadequately understood ecosystem interactions. For the first time objective testing of resource-utilization plans to identify potential conflicts will provide a rational and cost-effective approach to Great Lakes management. Because disciplines will be interrelated, the long-term effects of planning alternatives and their impacts on neighboring lakes and states can be evaluated. Testing of the consequences of environmental accidents and increased pollution levels can be evaluated, and risks to the resource determined. Examples are cited to demonstrate the use of such planning tools.     

An introduction to digital methods in remote sensing of forested ecosystems: Focus on the Pacific Northwest,USA

Aerial photography has been routinely used for several decades by natural resource scientists and managers to map and monitor the condition of forested landscapes. Recently, along with the emergence of concepts in managing forests as ecosystems, has come a significant shift in emphasis from smaller to larger spatial scales and the widespread use of geographic information systems. These developments have precipitated an increasing need for vegetation information derived from other remote sensing imagery, especially digital data acquired from high-elevation aircraft and satellite platforms. This paper introduces fundamental concepts in digital remote sensing and describes numerous applications of the technology. The intent is to provide a balanced, nontechnical view, discussing the shortcomings, successes, and future potential for digital remote sensing of forested ecosystems.     

Capturing change in European food assistance practices: a transformative social innovation perspective

The food system’s decreasing ability to deliver food security has led to the emergence of food assistance initiatives. Food assistance is highly contested; as some argue, it is a “failure of the state”, while others regard food assistance to be an “extension of the welfare state”. Either way, research suggests that actors within food assistance are rethinking their role in the food system. In this paper, we study three food assistance initiatives, in the Netherlands, Italy and Ireland, that perform new food assistance practices while embedded in specific institutional contexts, and analyse their potential to transform the food system, drawing on Transformative Social Innovation theory. Building on transition and social innovation theory, this recently developed theory distinguishes different levels within systems, named “shades of change”, that are associated with societal transformation. By exploring these “shades” of change in the analysis, we describe aspects of the initiatives’ novel practices, and in relation to the initiative and institutional relations their motivations and expectations. We compare the three cases and discuss how food assistance practices relate to and change (or do not change) the food system. In particular, we elaborate on how these three food assistance initiatives contribute in various ways to local food and welfare system innovation. In doing so, we offer a novel perspective on food assistance initiatives. We argue that they show dynamics that have the potential for more substantial transformation towards food security over time, by building momentum through “small wins”.     

Information systems and needs assessment in natural disasters: An approach for better disaster relief management

The paper addresses the issue of information in disasters relief. It begins by establishing the need for planning and systematic organization in disaster action, in order to produce a long term effect on the vulnerability levels of communities. Information is introduced as a key element in any phase of disaster management. The different informational needs are described by phases; information types and possible sources are briefly described. The organizational network of information collection is presented and the immediate need for research in this field is emphasized.     

Where to focus? Insights from safety personnel and external safety consultants on lessons learned about safety climate interventions – A qualitative approach

Introduction: Safety climate is important for promoting workplace safety and health. However, there is a dearth of empirical research on the effective ways of planning, designing, and implementing safety climate interventions, especially regarding what is going to be changed and improved. To address this gap, the present study sought to extract a comprehensive pool of compiled suggestions for safety climate intervention based on qualitative interviews with professionals in occupational safety and health management from potentially hazardous industries. Method: A series of systematic semi-structured interviews, guided by a comprehensive sociotechnical systems framework, were conducted with company safety personnel (n = 26) and external safety consultants (n = 15) of 21 companies from various industries. The taxonomy of five work system components of the sociotechnical systems approach served as overarching themes, representing different areas of improvement in an organization for occupational safety and health promotion, with an aim of enhancing safety climate. Results: Of the 36 codes identified, seven codes were based on the theme of external environment work system, four were based on the theme of internal environment work system, five were based on the theme of organizational and managerial structure work system, 14 codes were based on the theme of personnel subsystem, and six were based on the theme of technical subsystem. Conclusions: Safety climate intervention strategies might be most commonly based upon the principles of human resource management (i.e., codes based on the personnel subsystem theme and organizational and managerial structure work system theme). Meanwhile, numerous attributes of external/internal environment work system and technical subsystem can be jointly improved to bolster safety climate in a holistic way. Practical Applications: More systematic and organized management of safety climate would be available when various interrelated codes pertinent to a given context are carefully considered for a safety climate intervention.     

Transition to large-scale organic vegetable production in the Salinas Valley, California

Studying the management strategies suited to large-scale organic production, particularly during the mandated 3-year transition period from conventional management, is a unique research challenge. Organic production traditionally relies on small, diverse plantings and complex management responses to cope with soil fertility and pest pressures, so research should represent decision-making options of an organic grower at the farm scale. This study analyzes crop, soil, pest and management changes during the organic transition period on two ranches (40 and 47 ha) in the Salinas Valley, California in cooperation with a large conventional vegetable producer, Tanimura and Antle, Inc. Permanent transects were established across the two ranches at the onset of adoption of organic practices, and soil and plants were sampled at harvest of almost all crops, while all management operations were recorded by the co-operator. The 10 ha blocks were divided into many small plantings, and 17 different cash crop and cover crop species were planted during the transition period. Management inputs consisted of a range of organic fertilizers and amendments, sprinkler and drip irrigation, cultivation and hand-hoeing, and several types of organic pesticides. Results from the 3-year period followed these general trends: increase in soil biological indicators (microbial biomass and arbuscular mycorrhizae), low soil nitrate pools, adequate crop nutrients, minor disease and weed problems, and sporadic mild insect damage. Multivariate statistical analyses indicated that some crops and cultivars consistently produced higher yields than others, relative to the maximum yield for a given crop. Multi-factor contingency tables showed clear differences in insect and disease damage between crop taxa. Although Tanimura and Antle, Inc. used some of the principles of organic farming (e.g., crop diversity, crop rotation, and organic matter (OM) management), they also relied on substitution-based management, such as fertigation with soluble nutrients, initially heavy applications of organic pesticides, and use of inputs derived from off-farm sources. Their initial production of a large number of crop taxa in small plantings at staggered intervals proved to be an effective strategy for avoiding risks from low yields or crop failure and allowed them to move towards a smaller number of select, successful crops towards the end of the transition. This study demonstrates the feasibility of large-scale producers to transition to organic practices in a manner that was conducive to both production goals and environmental quality, i.e., increased soil C pools, low soil nitrate, and absence of synthetic pesticides.