THE DEFINITION AND MEASUREMENT OF MINERAL CONSUMPTION

The concept of mineral consumption is considered in the context of a (metallic) commodity's progression from mine to manufacture and reasons are advanced as to why consumption is best measured at the point referred to as the “first processing stage.” Two methods for measuring consumption at this stage, one direct (“reported consumption”) and one deductive (“apparent consumption”), are described and the merits and drawbacks of the methods discussed. The article concludes with a brief review of the existing statistics on worldwide mineral consumption and suggests that there is the scope, and the need, for improvement. Dans cet article, la notion de la consommation minérale est envisagée dans le cadre de l'acheminement du minerai (métallique) de la mine à l'usine de transformation. II donne les raisons pour lesquelles la consommation peut se mesurer le mieux au niveau de la “phase de première transformation.” A ce stade, l'article décrit deux méthodes permettant de mesurer cette consommation: l'une directe (la consommation déclarée) et l'autre supposée (la consommation apparente). Les avantages et les inconvénients des méthodes y sont aussi discutés. En conclusion, l'article passe brièvement en revue les statistiques existantes sur la consommation minérale mondiale et suggère que la possibilité ainsi que le besoin d'amélioration se font sentir dans ce domaine. El concepto de consumo de minerales se examina dentro del contexto de la progresión del producto desde la mina a la manufactura y se sostiene que dicho consumo se mide mejor en la “etapa de primer procesamiento.” Se describen dos métodos para medir el consumo en esta etapa, el método directo (consumo reportado) y deductivo (consumo aparente). Se discuten las ventajas y desventajas de estos métodos. El artículo concluye con una revisión breve de las estadísticas existentes del consumo de minerales a nivel mundial y sugiere que existe la necesidad y la posibilidad para mejorarlas.     

MEAN AREAL PRECIPITATION FOR DAILY HYDROLOGIC MODELING IN MOUNTAINOUS REGIONS1

ABSTRACT: A procedure using detrended kriging has been developed to calculate daily values of mean areal precipitation (MAP) for input to hydrologic models. The important features of this procedure that overcome weaknesses in existing MAP procedures are: (1) specific precipitation-elevation relationships are determined for each time period as opposed to using relationships based on climatological averages, (2) spatial variability is incorporated by estimating precipitation for each grid cell over a watershed, (3) the spatial correlation structure of precipitation is explicitly modeled, and (4) station weights for precipitation estimates are determined objectively and optimally. Detailed cross-validation testing of the procedure was done for the Reynolds Creek research watershed in southwestern Idaho. The procedure is suitable for use in operational streamflow forecasting.