Modeling grassland primary productivity using piecewise stationary,piecewise linear mathematics

A methodology for characterizing a complex ecological process — primary production — using linear mathematics is presented. The resulting model uses a limiting factor approach for calculating realized productivity based on prevailing conditions of moisture, temperature, incident radiation and available nutrients. Processes such as leaching and respiration are keyed to environmental variables. Simulation values are presented and compared to measured data.     

US nonfuels minerals policy

Nonfuels minerals policy in the USA flows from the differential and unique reactions of these industries to general economic policies in the areas of taxation, land use, environment, and international trade. To search for nonfuels minerals policy as direct statements by the US government on nonfuels minerals is futile. Nevertheless, the industries are unique in many characteristics, and the application of these general policies to the minerals industries creates unique situations. This uniqueness has been recognized by a virtually constant policy review over the past 10 years. The current effort is just beginning, and to prejudge now the outcome of this discussion is premature. However, it is not premature to argue that because of the uniqueness of these industries, it may be expected that their problems will be receiving public attention for many years to come.     

FUTURE SOURCES OF COOLING WATER FOR POWER PLANTS IN ARID REGIONS1

ABSTRACT: Electric generation facility water requirement will increase substantially in the future in the Western United States because new power plants are to be constructed at inland sites rather than on the coast. At the inland locations, power plants will have to compete with agriculture and public users for fresh water supplies, and will be constrained by environmental legislation to dispose of cooling waste water in lined evaporation ponds. The various options for power plant cooling are analyzed in respect to cost, water consumption, and environmental hazard, and also in respect to their compatibility with existing state and federal regulations. Several proposals for balancing the water requirements of various users in water-scarce areas are reviewed and criticized.