深圳市水资源可持续利用主要矛盾及其实现途径探讨

深圳市本地水资源短缺,境外引水愈来愈受到限制,国民经济和人口却持续强劲增长,水资源供需矛盾将日益突出;境外引水和污废水排放及较小的纳污能力,导致水环境恶化,资源供需矛盾加剧;探讨了水资源可持续利用主要矛盾的成因可持续利用的途径。     

The regulatory framework, unplanned development and urban poverty: Findings from Dar es Salaam, Tanzania

The regulatory framework adopted in many urban areas of the developing countries has been blamed for aiming at unrealistically high standards and for being bureaucratic, thus putting legal land and shelter out of reach of poor households. The latter end up living in unplanned settlements, which develop irregularly, sometimes on marginal land, lacking basic infrastructure. Poverty is therefore perpetuated. This paper evaluates planning standards and administrative procedures as applied to a specific scheme at the outskirts of the city of Dar es Salaam, Tanzania. It is shown that the high standards for plot sizes and road reserves resulted into the production of only 3900 instead of 15,000 plots over the same area, had more realistic standards been adopted. The unit cost per plot would have been a quarter of what it came to be. Centralised and bureaucratic set-ups and procedures resulted into unnecessarily long periods before planning schemes could be implemented; or land, certificates of title or building permits made available to would-be developers. Many develop the land without these permits or titles. Land was much easier to get in unplanned areas but converting it to legality was virtually impossible.The policy framework supports the revision of planning standards; the incorporation of communities and the private sector in land delivery; and the decentralisation and streamlining of procedures. In practice, officials aim at high standards, centralised and lengthy administrative procedures, and direct public sector involvement in land delivery. Evidence is provided of the deleterious effects of the continued hesitation to address the regulatory framework whose revision downwards would result into more legal land being available, faster and at a lower cost; thus reaching more of the low income households, reducing unplanned development and making a positive impact on dealing with urban poverty.     

Projecting Canadian Grain Shipments

The magnitude of future grain exports will profoundly affect many segments of the Canadian economy besides agriculture. Changes in structure of the existing grain transportation system, for example, may be required because of substantial increases in grain movement from country elevators to terminal positions. Grain trade projections are reviewed and the implications discussed. Results indicate that Canadian grain exports may increase from the past five-year average of 534 million bushels to a 1980 level of 811 million bushels and with the possibility of a billion bushel export level being achieved. All segments of the economy affected by the Canadian grain industry must be prepared to adjust their future operations to efficiently accommodate the increased level of grain exports .     

A NOTE ON VICTORIAN WHEAT YIELD DISTRIBUTIONS

An analysis of wheat yield series from ten localities in Victoria was undertaken to investigate for independence of observations and to test for normality of the distributions. The conclusion was reached that Victorian wheat yield series are composed of random observations and form frequency distributions which display slight negative skewness. The situation may be different for other crops or for wheat in other areas.     

A NOTE ON DISTRIBUTED LAG MODELS OF MAIZE AND WHEAT PRODUCTION RESPONSE: THE KENYAN CASE*

In this note the supply responses in maize and wheat production are estimated from distributed lag models. The Nerlove model and the Fisher distributed lag model fit Kenyan data but more complicated models, like the polynomial lag model, do not. The calculated price elasticities suggest that Kenyan large-scale farmers are highly responsive to price changes. Some policy implications are drawn from the analysis.     

TOWARDS PRACTICAL GUIDELINES FOR MULTIPLE USE MANAGEMENT*

The general acceptance of multiple use as a desirable management goal has not been matched by practical guidelines to implement and achieve that goal. As Pearse [5] rightly noted, the most serious obstacles to applying multiple use principles are usually the lack of appropriate data and lack of established methodology. This study did not face prohibitive problems in valuing extra-market goods, but as with all multiple use studies, it did face the problem of applying the standard economic model of the multi-product firm. It is hoped this particular empirical application of the model contributes generally to the provision of guidelines for multiple use management.