On Limits to the Use of Linear Markov Strategies in Common Property Natural Resource Games

We derive conditions that must be satisfied by the primitives of the problem in order for an equilibrium in linear Markov strategies to exist in some common property natural resource differential games. These conditions impose restrictions on the admissible form of the natural growth function, given a benefit function, or on the admissible form of the benefit function, given a natural growth function.

长春市水资源可持续利用对策

在对长春市水资源概况及其开发利用现状进行简要分析的基础上,识别出长春市水资源开发利用中的一些问题,并提出了开源节流,治理污染,调整工业布局,控制城市规模等长春市水资源可持续利用对策。     

Assessment Of A Natural Wetland For Use In Wastewater Remediation

An environmental study was conducted to assess various aspects of the water and sediment quality of a natural wetland to determine its feasibility for advanced wastewater treatment in Louisiana. Nitrate (NO₃), nitrite (NO₂), ammonia (NH₄), total Kjeldahl nitrogen (TKN), total phosphorus, chloride, total organic carbon, pH, trace metals, fecal coliform, dissolved oxygen (DO), and biochemical oxygen demand (BOD) were monitored. Productivity of a dominant shrub, Iva frutescens, in the wetland was also assessed. Research results indicated that gradients of chloride and salinity concentrations showed a broad mixing of the discharged fresh water into the more saline natural brackish waters. This provided an ideal pattern for nutrient assimilation by the receiving marsh. NH₄ was reduced in the range of 50–100% when all combinations of sources and outflows were considered. For total phosphorus and TKN, reduction ranged from 0–95.1% and 11.2–89.7%, respectively. Some nutrient concentrations in the effluent outlet, NO₃ in particular, were lower than background concentrations found in the reference wetland. Sediment and water showed no significant deficiency or toxicity problems for the major nutrients and metals analyzed. The secondary effluent discharges had little demonstrable negative impact on the wetland during the study period from 1995 to 1996.     

Mapping Patterns of Human Use and Potential Resource Conflicts on Public Lands

Focusing on a 2.2 million hectare area surrounding the Lolo National Forest in western Montana, USA, we illustrate a GIS method for predicting patterns of human use on public lands and highlighting potential for impacts on fish and wildlife species. Data inputs include human population count (derived from the 1990 Census), roads and trails, and the predicted distributions of bull trout (Salvelinus confluentus) and 41 terrestrial vertebrates of special concern. Because results highlight areas where conflicts between humans and resources may occur, they are of potential use to land managers. This approach can be applied wherever data are available, and inputs can be varied according to the topics of interest.     

Using Resource Economics to Anticipate Forest Land Use Change in the U.S. Mid-Atlantic Region

Demands for forest, farm, and developed land are evolving in the U.S. mid-Atlantic region. The demand for land in developed uses, as well as demands for various forest and farm products are changing in response to population growth, demographic shifts, and market forces. As demand factors change so do relative land values. Land area in future forest, farm, and developed uses may shift as landowners re-evaluate relative net benefits from land use alternatives. This study examines the effects of various land demand and supply factors on the determination of land use patterns in the mid-Atlantic region. Driving variables include costs and benefits from various uses, population density, and measures of land quality. Model parameters are estimated using a binomial logit procedure. Results from the study are used to estimate proportions of forest area on a county by county basis. Simulated forest landscapes under hypothetical future conditions are prepared and illustrated using geographic information system (GIS) techniques.     

Community Exchange and Training in the Suid Bokkeveld: A UNCCD Pilot Project to Enhance Livelihoods and Natural Resource Management

Community knowledge exchanges have played a key role in developmental processes in the Suid Bokkeveld community of South Africa. Two exchange visits were undertaken with the support of the Department of Agriculture and an NGO, the Environmental Monitoring Group, which have led to local economic development and enhanced capacity to manage natural resources in a sustainable manner. These pilot projects were undertaken within the framework of the Community Exchange and Training Programme of the Global Mechanism of the United Nations Convention to Combat Desertification (UNCCD). The methodology applied included facilitation to develop a community-based vision for development, in terms of which the community exchange process was designed. A Facilitation Team of service providers conducted preparatory workshops, and identified potential partner communities. Two exchange visits were carried out, one focused on Rooibos production and marketing, and the other on community-based eco-tourism. Following report-back and planning workshops, emerging community-driven initiatives were supported through their formative stages. The initiatives have not only resulted in enhanced livelihoods, but the methodology has also been applied widely in a number of different contexts.     

Resource Use Rates and Efficiency as Indicators of Regional Sustainability: an Examination of Five Countries

We examine trends from 1970 to the mid 1990's of some variables related to development and sustainability for Costa Rica, Korea, Mexico, the Netherlands and the United States: first, by calculating energy and agricultural efficiencies over time, second, by examining the environmental impacts of economic activities, and third, by estimating ecological footprints. We find that many "optimistic" arguments about sustainability have been misleading, and that there is little or no indication that we are becoming any more sustainable or even efficient. Total quality-corrected energy consumption has increased for all five countries and the renewable energy portion is decreasing. The efficiency of turning energy into both agricultural production and GDP has declined for all countries except for the US. In general, there is a remarkable linearity between resource use and economic and agricultural production over all countries and all years, suggesting severe biophysical constraints to sustainable objectives. On the other hand, per capita ecological footprints have decreased somewhat in Costa Rica, Mexico, and the United States, while national ecological footprints have tended to remain constant except for Korea. While there has been a reduction of specific pollutants in the United States, some of this has been achieved by exporting heavy manufacturing industries. We conclude that continued population and economic growth in each country is likely to make the achievement of any kind of sustainability increasingly unlikely. Sustainability, if that is desirable, requires a very different approach than what we have undertaken to date.     

Time-Consistent Equilibria in Common Access Resource Games with Asymmetric Players Under Partial Cooperation

Given a differential game, if agents have different time preference rates, cooperative (Pareto optimum) solutions obtained by applying Pontryagin’s maximum principle become time inconsistent. We derive a set of dynamic programming equations in continuous time whose solutions are time-consistent equilibria for problems in which agents differ in their utility functions and also in their time preference rates. The solution assumes cooperation between agents at every time. Since coalitions at different times have different time preferences, equilibrium policies are calculated by looking for Markov (subgame perfect) equilibria in a (noncooperative) sequential game. The results are applied to the study of a cake-eating problem describing the management of a common property exhaustible natural resource. The extension of the results to a simple common property renewable natural resource model in infinite horizon is also discussed.     

流动注射分光光度法测定天然水中亚硝酸根

采用流动注射分析技术,以N-(1-萘基)乙二胺为显色剂在540nm比色,建立了流动注射分光光度法测定亚硝酸根含量的方法。在30个／h样分析速度下,检测限为0．008mg／L。用于天然水样测定,结果令人满意。     

吐鲁番盆地水资源利用对策初探

就干旱缺水的吐鲁番盆地水资源利用问题提出了一些建议。     

中国西北地区水资源的开发和利用

我国西北地区地广人稀,水资源比较贫乏,而且时空分布极不均匀,极大地影响了该地区人民的生活,限制了该地区的经济开发,因此大力开发西北地区面临的首要问题即水资源问题。本文从西北地区水资源的自然分布、开发利用水资源中存在的问题及有效的解决途径三方面进行了简要的综述。     

淮北市水资源保护与规划

系统论述了淮北市水资源现状和存在问题,提出了保护水资源环境、促进可持续发展而采取的有效工程措施。     

支撑流域资源补偿的监测技术与方

归纳了支撑太湖流域环境资源区域补偿的主要监测技术与方法,主要涉及补偿因子优选、补偿河流（段）及断面的优化、补偿因子浓度限值的研究、补偿监测的实施等。     

高效液相色谱-原子荧光联用测定天然水中烷基汞

应用在线紫外光照射-高效液相色谱分离-冷原子蒸发/氢化物发生-原子荧光光谱法(HPLC-UV-CV/HG-AFS)测定天然水中烷基汞,实验比较两种前处理方法-巯基棉富集和液液萃取,优化分析条件,建立一种简便、选择性好、高灵敏度分析天然水中烷基汞的方法.取1L水样时,甲基汞和乙基汞的检出限(3S/N)分别为0.3和0.6...     

河南省资源环境基尼系数分析

选取2013年河南省资源和环境污染指标进行资源环境基尼系数和绿色贡献系数分析。结果表明,2013年河南省资源消耗、SO2、NOX、烟(粉)尘、COD和NH3-N排放量的资源环境基尼系数分别为0.17,0.32,0.19,0.37,0.28和0.25。指出,烟(粉)尘排放的资源环境基尼系数已接近0.4的国际警戒线;河南省应对烟(粉)尘排放分配加以控制和调整;郑州、南阳和许昌的经济贡献率均大于其资源消耗和污染物排放占全省的比例,对全省的公平性分配贡献较大。     

Biological Roles of Trace Metals in Natural Waters

For decades there has been an intense interest in the toxic effects of trace metals on biological organisms in the environment. This period of time has seen increasing improvements in analytical techniques for the measurement and study of trace metals and their subsequent application to a broad spectrum of water systems around the globe. This work has included studies of the geographical distributions of trace metals in different water types in the ocean, the modes of transport and uptake of trace metals and the study of historical changes in trace metal accumulation. Early research highlighted strong similarities in the behaviours of many trace metals and those of well-understood chemical nutrients such as phosphate, nitrate and silicate, known to be essential for phytoplankton growth in the ocean. This suggests that phytoplankton regulate the trace metal composition of seawater for their own benefit. A major achievement in this regard has been the ability to measure, at the sub-nmol/L level, trace metal species that are complexed by naturally-occurring organic ligands of biological origin in ocean waters. It is now clear that the free ion activities of many essential and/or toxic trace metals are regulated by highly specific, strongly complexing ligands exuded by marine phytoplankton. This research encourages a new paradigm in which the growth rates and species composition of primary marine organisms are affected by trace metals at concentration levels orders of magnitude lower than is conventionally believed. As a consequence, the capacity of natural waters to assimilate trace metal-contaminants may be correspondingly much lower than is currently thought reasonable.     

Natural radioactivity and chemical concentrations in Egyptian groundwater

Measurements of natural radioactivity in drinking water have been performed in many parts of the world, mostly for assessment of the doses and risk resulting from consuming water. A study of the radionuclide and chemical components in groundwater from Beni Suef Governate, Egypt has been carried out. Fifty water samples were analyzed by gamma ray spectroscopy to determine the ²²⁶Ra, ²³²Th, and ⁴⁰K concentrations; major elements, pH, alkalinity, and conductivity were also measured. The specific activity values ranged from 0.008 to 0.040 Bq/l for ²²⁶Ra, from 0.003 to 0.019 Bq/l for ²³²Th, and from 0.025 to 0.344 Bq/l for ⁴⁰K. The annual ingestions of these radionuclides, using local consumption rates (average over the whole population) of 1.5 l day^???1, were estimated to be 8.59, 4.86, and 83.47 Bq year^???1 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. The estimated values and weighted means of these radionuclides compare well with the world average. The estimated effective doses from drinking water were found to be 2.4 ??Sv year^???1 (²²⁶Ra), 1.1 ??Sv year^???1 (²³²Th), and 0.51 ??Sv year^???1 (⁴⁰K). Contribution of these radionuclides to the committed effective dose from 1 year consumption of drinking water is estimated to be only 4%.     

自然环境中微塑料样品的采集与分离方法

综述了自然环境中微塑料样品采集与分离方法的研究进展,介绍了水环境、土壤与沉积物、环境空气、生物体等不同介质中微塑料的采集方法、技术原理和使用条件,以及密度分离、筛选分离、滤膜过滤等分离提取和预处理方法,提出了建立统一的微塑料采样指南,开展空气中微塑料富集、采样、分离和检测标准方法研究等建议。     

Natural attenuation of coal combustion waste in river sediments

The weathering of coal combustion products (CCPs) in a lotic environment was assessed following the Tennessee Valley Authority (Kingston, TN) fly ash release of 2008 into surrounding rivers. Sampled materials included stockpiled ash and sediment collected from 180 to 880 days following the release. Total recoverable concentrations of heavy metals and metalloids in sediment were measured, and percent ash was estimated visually or quantified by particle counts. Arsenic and selenium in sediment were positively correlated with percent ash. For samples collected 180 days after the release, total concentrations of trace elements downstream of the release were greater than reference levels but less than concentrations measured in stockpiled ash. Total concentrations of trace elements remained elevated in ash-laden sediment after almost 2.5 years. A sequential extraction procedure (SEP) was used to speciate selected fractions of arsenic, copper, lead, nickel, and selenium in decreasing order of bioavailability. Concentrations of trace elements in sequentially extracted fractions were one to two orders of magnitude lower than total recoverable trace elements. The bulk of sequentially extractable trace elements was associated with iron-manganese oxides, the least bioavailable fraction of those measured. By 780 days, trace element concentrations in the SEP fractions approached reference concentrations in the more bioavailable water soluble, ion exchangeable, and carbonate-bound fractions. For each trace element, the percentage composition of the bioavailable fractions relative to the total concentration was calculated. These SEP indices were summed and shown to significantly decrease over time. These results document the natural attenuation of leachable trace elements in CCPs in river sediment as a result of the loss of bioavailable trace elements over time.