Potential impacts of sand and gravel extraction on the Hunter River,New South Wales

A number of investigations have been undertaken by the New South Wales Water Resources Commission to determine the regional and compound effects of large scale extractive industries on the stability of the Hunter River, New South Wales. Sedimentologic studies of bed material suggest that the Hunter River upstream of Denman has an armoured gravel bed that is immobile during regulated releases from Glenbawn Dam but is disrupted by moderate but less than bankfull flows. Annual bedloadyields have been computed by the bedload rating-flow duration technique for five river gauging stations. Approximate sand and gravel budgets for selected reaches of the Hunter River demonstrate that the present annual extraction rate from temporary sediment storages within the channel greatly exceeds the transport rate upstream of Denman and is approximately equal to the transport rate downstream of Denman. River degradation is imminent if extractive industries continue operating in the channel of the Hunter River     

Mean airstreams of Australia

Streamline analyses of mean monthly resultant surface winds over Australia are presented. Mean confluences represent either cyclone trajectories, or modal fronts. These analyses suggest that Australia's annual airstream climate is of two regimes: that of September to March inclusive, and April to August inclusive. The winter half-year is exemplified by a continental airstream source in southern Australia which diverges over virtually the entire continent. It continues into September and October, although dominating only the southern third to half of Australia, and is absent from November to March. During the summer half-year a new pattern emerges, with three maritime air stream sources represented over the continent: first, air from the Southern Ocean penetrates the south coast reaching its furthest northward extension from December to March inclusive; a second source originating over the Pacific Ocean dominates eastern and northern Australia; and a monsoon source originating over the Indian Ocean which flows overland affecting northern Western Australia. Two modal confluences are noted, one over northwestern Australia from November-February separating monsoon flow from that emanating from the east, and another extending from the west central coast east-southeastward to the southeast coast from November-March separating Southern Ocean air from that originating over the Pacific Ocean.     

TRADE CENTER EVOLUTION IN THE GREAT PLAINS*

ABSTRACT Empirical analysis has lagged behind the impressive additions to the theoretical literature on trade center systems during the past 15 years. This study of the trade center system in Saskatchewan is an attempt to begin to redress the imbalance and to test some of the recently formulated theoretical propositions. Communities are identified according to functional classifications for 1961 and 1981 with the aid of a cluster analysis program, and the validity of the groupings are verified using multiple discriminant analysis. Changes in the size, spacing, and function of clusters and individual communities during the 20-year interval are described and an effort is made to prdvide explanations for the changes observed.     

A CONTEXTUAL ANALYSIS OF THE JOURNEY-TO-SHOP WITH PRICE UNCERTAINTY*

ABSTRACT In this paper we extend the contextual theory of demand to consider rational consumer behavior when the household must deal with some random fluctuation in the prices it faces. Prices at stores reflect “advertised specials,” which are potential cost reductions random across goods, and random in-store price changes, which can only be observed by visiting the store. Our theory of rational behavior includes: (1) calculation by the household of an ex ante plan for its planning period; (2) modification to take account of advertised specials; and (3) rational search behavior to take advantage of random fluctuations observable only on a given day. This theory utilizes an active cash balance as a buffer against random variations from planned daily expenditures, and reformulations of trip circuits to account for patterns of cost-minimizing search.     

A HEDONIC MODEL OF INTERREGIONAL WAGES,RENTS, AND AMENITY VALUES*

ABSTRACT This paper develops a general multimarket hedonic model appropriate for a national, interregional study of wages, housing prices, and location-specific amenities. The model encompasses the effects of interregional location, intraurban location, and city size. Typically, hedonic studies focus on a single market such as labor or housing and ignore interactions implicit in a more global compensation mechanism. Examination of the comparative statics of our model indicates that single-market differentials are partial prices and are unreliable measures of amenity values in an interregional context. Unbiased amenity values are estimated for a comprehensive set of amenities using data on housing prices for 34,414 households and wages for 46,004 workers from the 1980 Census of Population and Housing. Statistically significant differences in housing prices and wages are found due to amenities.