The hotelling valuation of natural resources: some further results

This paper tests the Hotelling Valuation Principle (HVP) for natural resources using data from oil and gas ‘pure plays’ such as royalty trusts and master limited partnerships. The results support the HVP which specifies that the value of any mineral reserve may be predicted by the market price of the resource, net of extraction costs. Regression results also indicate that a Box-Cox transformation of variables provide a better means of estimating the functional relationship between the value of an exhaustible natural resource and its market price.     

我国鲟鱼类资源及其保护与发展途径

鲟鱼类为北半球古老的大型经济鱼类，栖息于太平洋、大西洋和内陆水域，是世界著名的经济鱼类．近年来在有关科研项目的支持下，对我国境内的11种鲟鱼类资源进行了生物学、生态学等方面的一系列调查研究．本文着重论述了鲟鱼类的自然分布、经济与科研价值，分析了资源现状及其衰退原因，并提出今后资源保护与发展的8个途径．     

药用抗癌真菌资源的筛选

本文以抗癌真菌的研究结果和分类方法的基础，提出了寻找潜在药用抗癌真菌的方法，描述了国产抗癌真菌的分类分布；     

山东省地下水资源的开发利用

山东省地下水资源分布不均,各地开发利用程度差别较大.本文论述了近年来该省地下水在开发利用过程中存在的问题及其对环境的影响,提出了合理开发地下水资源的对策与措施.     

社会主义市场经济体制下的区域规划

建立社会主义市场经济体制，就是要使市场在国家宏观调控下对资源配置起基础性作用。经济体制的改革对区域规划提出了新的要求．它决不意味着取消或削弱区域规划，而是要更好地发挥区域规划在发展区域经济中的宏观调控作用。区域规划是区域经济发展的超前研究，其价值在于具有比较准确的发展预见性，能够提出正确的发展方向和战略。区域规划的核心内容是指导资源优化配置，但它并不具有直接的资源流动机制，只能作为资源流动的信息机制。区域规划发挥宏观调控作用的必要条件是政府立法，公益性设施列入国家或地方的计划，在实施中争取社会舆论和社会投资的支持，对经济落后区域的开发采取国家扶持的政策。     

跨世纪人口压力对中国生态环境的影响及对策

人口是人口，资源与环境系统中最根本的主导因素，人口增长过快，将直接加大对资源与环境的压力，并影响人口素质的提高，根据我国人口庞大的基数，过快的增长速度，独特的人口结构和较低的文化素质现状，对生态环境造成的压力进行了系统分析，进而提出了控制人口增长，改善生态环境和全面发展国发经济的对策，以保证跨世纪人口，资源，环境呈现协调，持续，健康的发展趋势。     

DIFFERENCES BETWEEN MODELED SURPLUS AND USGS-MEASURED DISCHARGE IN LAKE PONTCHARTRAIN BASIN,LOUISIANA1

ABSTRACT: A one-layer decreasing-availability monthly water balance model is used to estimate monthly surplus that flows into the Lake Pontchartrain Basin from the Amite, Tickfaw, Natalbany, Tangipahoa, and Tchefuncte Rivers for water years 1949 through 1990. The modeled annual surplus for each drainage basin is compared to gauged annual discharge obtained from the United States Geological Survey. This provides an estimate of the differential success of the model over watersheds of various sizes, and also suggests appropriate adjustment factors to be used in future water balance analyses of similar basins in humid subtropical climate regions. Results show that annual surplus values agree well with the USGS values, after an annual adjustment of about 140 mm (11 to 28 percent of the basin surplus) is subtracted from the annual modeled totals to compensate for overestimation by the model. However, inter-annual variability is high in the annual cycles. Winter and spring discharges can also be modeled successfully.     

REGIONAL SCALE TREND MONITORING OF INDICATORS OF TROPHIC CONDITION OF LAKES1

ABSTRACT: The U.S. Environmental Protection Agency has proposed a sample survey design to answer questions about the ecological condition and trends in condition of U.S. ecological resources. To meet the objectives, the design relies on a probability sample of the resource population of interest (e.g., a random sample of lakes) each year on which measurements are made during an index period. Natural spatial and temporal variability and variability in the sampling process all affect the ability to describe the status of a population and the sensitivity for trend detection. We describe the important components of variance and estimate their magnitude for indicators of trophic condition of lakes to illustrate the process. We also describe models for trend detection and use them to demonstrate the sensitivity of the proposed design to detect trends. If the variance structure that develops during the probability surveys is like that synthesized from available databases and the literature, then the trends in common indicators of trophic condition of the specified magnitude should be detectable within about a decade for Secchi disk transparency (0.5–1 percentiyear) and total phosphorus (2–3 percent/year), but not for chlorophyll-a (> 3–4 percent/year), which will take longer.     

MEETING FUTURE PUBLIC WATER SUPPLY NEEDS: A SOUTHWEST PERSPECTIVE1

ABSTRACT: Most southwestern cities were founded along rivers or in areas having springs or readily available ground water. Because of the generally sparse precipitation, the renewable fresh water supply in the Southwest is smaller than most other areas of the United States. Despite the arid climate, water use has increased rapidly, first in the form of irrigation, and more recently the use in cities. This has caused extensive development of local water resources and overdraft of ground water basins in some areas. It is difficult to implement new local supplies and importation projects due to a myriad of environmental and legal constraints and a general shortage of public funds. Various opportunities and plans for water management, both on the demand and supply sides, are discussed. Evolving water strategies in four metropolitan areas - El Paso, Albuquerque, Las Vegas, and Phoenix - and issues regarding the Central Arizona Project are presented.     

HYDROLOGIC SCENARIOS FOR SEVERE SUSTAINED DROUGHT IN THE SOUTHWESTERN UNITED STATES1

ABSTRACT: This paper considers the risk of drought and develops drought scenarios for use in the study of severe sustained drought in the Southwestern United States. The focus is on the Colorado River Basin and regions to which Colorado River water is exported, especially southern California, which depends on water from the Colorado River. Drought scenarios are developed using estimates of unimpaired historic streamflow as well as reconstructions of streamflow based on tree ring widths. Drought scenarios in the Colorado River Basin are defined on the basis of annual flow at Lees Ferry. The risk, in terms of return period, of the drought scenarios developed, is assessed using stochastic models.