基于生态足迹法的营口市水资源承载力研究

定量评价水资源承载力可为水资源的可持续利用及经济社会的可持续发展提供科学依据。根据水资源状况,采用生态足迹法,利用水资源生态足迹模型与承载力模型,研究了2014—2020年营口市水资源生态足迹、水资源承载力和水资源负载指数的动态变化。结果表明：营口市水资源生态足迹相对平稳,其中,农业用水生态足迹占比最高,居民生活用水、城镇公共用水、生态环境用水生态足迹总体缓慢升高,工业用水生态足迹下降明显,但有回升趋向。营口市水资源生态足迹远高于水资源承载力,表明出现了严重的水生态赤字现象,但水资源承载力波动上升与水资源负载指数逐渐下降,反映了近几年来水资源对生态系统和经济发展的支撑维系能力有了一定程度的增强,水生态赤字现象有所改善,水资源压力有所减轻。营口市水资源承载力有所提升,水资源供需矛盾有所缓和,但水资源生态安全形势依旧严峻,仍需加大调水与节水力度,优化水资源配置,保护水资源。     

水资源生态足迹分析——以安康市为例

根据生态足迹分析方法,建立了水资源生态足迹概念模型,确定了计算水资源帐户生态足迹所需的3个关键参数,即平均水资源产量、均衡因子和地区产量因子,计算了安康市1996—2007年水资源生态足迹和生态承载力。引入水资源生态足迹压力指数、万元GDP水资源生态足迹、累积水资源生态足迹等指标,利用水足迹模型评价水资源可持续发展程度的全面性和对比性。结果表明,计算结果可客观评价安康市水资源可持续发展与利用情况,为地区水资源的可持续利用与管理提供了科学的依据。     

基于主成分分析的德阳市水资源承载力研究

以德阳市水资源承载力为研究对象,在梳理和阐述水资源承载力概念及研究现状的基础上,选取了13个指标构建水资源承载力评价指标体系,运用主成分分析法对德阳市2013—2014年水资源承载力进行了比较分析和综合评价。研究表明,德阳市水资源承载力的第一驱动因素是经济发展与人口因素,水资源利用效率和水资源禀赋因子也是影响德阳市水资源承载力的重要因素。德阳市水资源承载力时间上总体呈上升趋势,但全市水资源承载力具有较为明显的空间分布不均的特点。     

水资源研究中几个问题的探讨

本文讨论了区域水资源的评价问题.无论是地表水、地下水,还是土壤水都是来源于大气降水,降水资源才是区域总水资源;同时讨论了区域水资源的平衡原理.降水资源转化了截留水、地表水、土壤水和地下水4项水资源.该文对这2种不同的水体进行了深入讨论,着重论述了土壤水资源的概念及其特征.并对潜水蒸发和水资源的价值问题提出了看法.     

水资源红线的理论阐释与制度实践

水资源红线是为了实现水资源的节约利用和提高水资源利用效率而设定的用水总量控制目标和水效率控制目标。资源红线是生态文明建设的核心内容,我国水资源现状决定了划定水资源红线的迫切性和重要性。水资源红线为水资源利用量设定最高限度,同时为生态安全设置最低限度。构建完备的水资源红线制度应当着力完善水量管理制度、水资源利用制度和水资源节约制度。     

大连市水资源承载力动态研究

区域水资源承载力是进行区域生态建设和确定社会经济发展规划的基础。介绍了基于主成分分析理论的区域水资源承载力评价方法,建立了反映大连市水资源承载力的指标评价系统,并对大连市2001—2008年的水资源承载力进行了定量分析。研究结果表明,近年来大连市水资源承载力逐年减弱,水资源已经成为制约大连市社会经济与生态环境协调发展的主要因素。针对这种现状,提出了大连市水资源可持续利用的若干对策。     

水资源足迹计算模型研究——以南京市为例

在生态足迹理论的基础上探讨了水资源足迹的概念。基于水资源生产力，推导出水资源足迹和水资源承载力的计算公式，用水资源赤字和水资源盈余来衡量水资源利用的可持续性。以南京市为例进行模型实证研究，计算了2003～2007年南京市水资源足迹和水资源承载力，结果表明南京市水资源足迹增长明显，水资源承载力总体平稳，赤字从2004—2007年呈指数增长趋势。实证研究表明模型结果可以在一定程度上衡量生产消费对水资源的影响。     

成都市水资源可持续利用评价及对策

通过调查成都市近年来水资源量及水资源开发利用现状(包括供水设施、供水现状、用水结构、用水效率等),分析了其变化趋势,针对成都市水资源现状,建立了成都市水资源可持续利用评价指标体系,并采用AHP-模糊评价方法,对2010~2013年成都市水资源可持续利用水平进行评价。结果表明,成都市水资源可持续开发利用能力很弱,水资源的短缺是制约成都市水资源可持续发展能力的重要因素。最后针对可持续利用中存在的问题,提出了相关的对策与建议。     

青海省水资源利用的问题及对策

青海省地处江河源头,水资源保护与利用不仅关系本省社会经济发展的水资源保障,还影响到中下游地区的生态安全。文章对青海省水资源开发利用中存在的问题进行了讨论,按照充分合理利用水资源的宗旨,提出了实现水资源可持续利用的对策建议。     

水资源配置决策 科学与动态并重

水资源配置是在水资源归国家所有的前提下,对水资源使用权的分配管理。近年来,水资源分配的重要性逐渐得到认识和重视。水事纠纷,尤其是北方地区省际水事纠纷的加剧促进了水资源分配立法管理的步伐。     

Energetics and environmental costs of agriculture in a dry tropical region of India

The present article, based on a study of five village ecosystems, assesses the energy efficiency of rain-fed agriculture in a dry tropical environment and the impact of agricultural activity on the surrounding natural ecosystems. Agronomic yield is insufficient to meet the food requirement of the human population, hence 11.5%–49.7% of the required amount of food grains are imported from the market. Energy requirements of five studied agroecosystems are subsidized considerably by the surrounding forest in the form of fodder and firewood. Natural ecosystems supply about 80%–95% of fodder needs and 81%–100% of fuelwood needs. The output-input ratio of agriculture indicated that, on average, 4.1 units of energy are expended to obtain one unit of agronomic energy. Of this, 3.9 units are supplied by the natural ecosystem. In addition, 38% of the extracted firewood is marketed. The illegal felling and lopping of trees result in ever-increasing concentric circles of forest destruction around the villages and together with excessive grazing results in savannization. The forests can be conserved by encouraging fuelwood plantations (0.7 ha/ha cultivated land) and developing village pastures (1.6 ha/ha cultivated land) and reducing the livestock numbers. Agricultural production in the region can be stabilized by introducing improved dry farming techniques such as intercropping, planned rainwater management, and adequate use of fertilizers.     

OXYGEN DEMAND IN ICE COVERED LAKES AS IT PERTAINS TO WINTER AERATION1

ABSTRACT: Winterkill, the death of fish under ice due to oxygen deficiency, threatens hundreds of shallow lakes in the upper Midwest of the United States every winter. For decades, attempts have been made to prevent winterkill, usually through aeration, with mixed results. In large part, the failure of strategies to prevent winterkill can be linked to a lack of understanding of winter limnology and in particular, of oxygen dynamics under ice. Most winterkill lakes behave as closed systems with regard to oxygen. Consequently, the oxygen content of an ice and snow covered lake is essentially a function of the amount of initial storage and the rate of depletion. Should the stored oxygen be insufficient to prevent near anoxia before melting of the ice cover occurs, winterkill will result. Most oxygen consumption in ice covered lakes is due to bacterial respiration and chemical oxidation at the sediment/water interface, the remainder occurring in the water column. Oxygen consumption (and thus depletion) is a function of the velocity and oxygen concentration of the near sediment water. This is due to the fact that oxygen transport to the sediment is mediated by a diffusive boundary layer adjacent to the sediment surface. Winter oxygen depletion rates decrease when the oxygen concentration of the overlying water falls below about 3 mg/l. Aeration techniques which increase the oxygen concentration and velocity of the near-sediment water also increase the oxygen consumption (depletion) rate.     

Environmental assessment of packaging: Sense and sensibility

The functions of packaging are derived from product requirements, thus for insight into the environmental effects of packaging the actual combination of product and package has to be evaluated along the production and distribution system. This extension to all related environmental aspects adds realism to the environmental analysis and provides guidance for design while preventing a too detailed investigation of parts of the production system. This approach is contrary to current environmental studies where packaging is always treated as an independent object, neglecting the more important environmental effects of the product that are influenced by packaging. The general analysis and quantification stages for this approach are described, and the currently available methods for the assessment of environmental effects are reviewed. To limit the workload involved in an environmental assessment, a step-by-step analysis and the use of feedback is recommended. First the dominant environmental effects of a particular product and its production and distribution are estimated. Then, on the basis of these preliminary results, the appropriate system boundaries are chosen and the need for further or more detailed environmental analysis is determined. For typical food and drink applications, the effect of different system boundaries on the outcome of environmental assessments and the advantage of the step-by-step analysis of the food supply system is shown. It appears that, depending on the consumer group, different advice for reduction of environmental effects has to be given. Furthermore, because of interrelated environmental effects of the food supply system, the continuing quest for more detailed and accurate analysis of the package components is not necessary for improved management of the environmental effects of packaging.     

海洋石油开发中含油污水处理与溢油防治技术

海洋石油工业清洁生产的关键是防止油污染,而油污染的主要来源是日常排放的含油污水中的油及事故性溢油。首先概述了海上含油污水的处理方法及其原理,并结合实际论述了主要采用的处理工艺,并分析了各工艺技术的处理效果和存在的问题。文章还叙述了海上溢油事故及防止溢油事故发生所应采取的多方位预防措施;建立管理体系,加强管理,通过培训来提高全员操作管理水平,建立溢油处置应急计划和组织系统。在溢油控制方面建立海上溢油漂移模拟程序,对溢油进行实时监控,并对采用的溢油处理装置及方法进行了评述     

Sustainable Land Use Requires Attention to Ecological Signals

This case study details the difficulties of landscape management, highlighting the challenges inherent in managing natural resources when multiple agencies are involved, when the land users have no incentive for conservation, and when government agencies have too few resources for effective management. Pumping of groundwater from the aquifer of La Costa de Hermosillo in the state of Sonora, Mexico, began in 1945 and developed so quickly that by the late 1950s salinity intrusion from the Gulf of California was occurring in the wells. In the 1970s, the irrigatable land in La Costa peaked at 132,516 ha and the extracted volume of water from the aquifer peaked at around 1.14 billion cubic meters annually. By the 1980s, 105 wells of the total of 498 were contaminated with seawater and, therefore, identified for closure. At present La Costa de Hermosillo still represents 15% of the total harvested land, 16% of the total annual production, and 23% of the gross agricultural production of the state of Sonora. However, there are approximately 80,000 ha of abandoned fields due to salt water intension, lack of water and/or lack of credit available to individual farmers. This unstable situation resulted from the interplay of water management policies and practices, and farm-land policies and practices. While government agencies have been able to enforce better water use for agricultural production, there remains a significant area that requires restoration from its degraded state. For this piece of the ecosystem management puzzle, government agencies have thus far been unable to affect a solution.     

GROUND WATER OF THE ISLAND OF MONTREAL,CANADA1

ABSTRACT: The geochemistry and nature of the flow of ground water not only control the supply potential but constitute clues to the whole geology of an area. A study has been made of the largest available assemblage of data from 161 wells for the Island of Montreal collected by the Geological Survey of Canada in 1951–53. Data indicated that the system is generally subartesian, flowing from the principal topographically high areas towards the shores of the Island. As the probable use is about 13% of the estimated recharge of 140 million liters per day, most wells could be supplied by local recharge. The study has confirmed the predominance of calcium bicarbonate ground water from the carbonate sequence. The waters appeared to be saturated with respect to CaCO₃ in all but 10 wells. The presence of other types of waters suggests the effects of the igneous intrusions of the area, the post-glacial marine submergence and the upward movement of waters from deep sources through fault and other structural zones. Confirmation of the significant variations in chemical composition in some neighboring wells indicated the future need for repetitive sampling from specific horizons for chemical and isotopic analyses.     

The effect of the activation of carboxyl group and hydrogen migration on reaction pathway during the pyrolysis of triglycerides

ABSTRACT

This study investigated the activation of carboxyl group and hydrogen migration on the pyrolysis products of triglycerides. It was found that the activation of carboxylic group determined the efficiency of the decarboxylation reactions. The activation of carboxyl group influenced the pyrolysis products. The glycerol mono-stearate and glycerol mono-oleate were used as the model compounds to analyze the cracking of the ester bond. It was found that the first intermediate formed was RCOO·, but not RCO·. Large amount of ketone was found in the pyrolysis of stearate, while not in that of oleate. In comparison, alcohol was found in pyrolysis products of oleate, while not in stearate. The results indicated that during the pyrolysis process, the carbon-carbon double bond influenced both the cracking of the C-C bond and the transformation of the oxygen-containing functionalities. The activation of carboxyl group and hydrogen migration played essential roles in the determination of the formation of the pyrolysis products. In addition, the mechanism for the evolution of the acid, ester, ketone, aldehyde, alcohol, and other heavy compounds during the pyrolysis was also proposed.     

药用红花氮,磷,钾吸收与转运规律

药用红花Ｎ、Ｐ、Ｋ三要素在整个生育期中，主要向该时期生长最活跃的部位运转，以确保其生长发育所需。在植株各器官形成初期，该器官中的Ｎ、Ｐ、Ｋ含量较高．在植株不同器官中，以叶中的养分含量最高。植株中Ｎ、Ｐ、Ｋ三要素含量的顺序为：Ｋ＞Ｎ＞Ｐ。药用红花对Ｎ、Ｐ、Ｋ养分吸收的高峰时期为分枝孕蕾期，占整个生育期的百分率分别为：８３．３％、５５．４％、５２．９％．Ｋ的吸收主要在生育前期和中期，Ｎ和Ｐ在生育后期还有较大的吸收量。每生产５００ｋｇ干花需吸收Ｋ２Ｏ０．８２ｋｇ、Ｎ０．３２ｋｇ、Ｐ２Ｏ５０．１７ｋｇ．Ｎ、Ｐ、Ｋ养分的转移主要发生在主茎叶和茎，其中以Ｋ的转移率最大．     

Negotiating in the absence of trust: exploring the interactions between officials and residents in a waste management project in Copacabana,Bolivia

This study investigates the effects of the absence of trust in shaping relationships between officers and managers in Copacabana, Bolivia, particularly regarding the construction of a sanitary landfill for the city. The article builds on an abductive thematic analysis of observation and interview data. The data suggest that prior negative experiences and the absence of shared values are common arguments used by the residents to negotiate the conditions of public programme implementation. The study is inspired by the literature identifying the specific components of trust and the literature on lack of trust and distrust as it highlights the positive effects of scepticism. I conclude that a climate in which trust is absent leads residents to counter the risks involved in accepting the project. These findings can be used to revise and refine the well-established thesis that lack of trust leads to rejection.     

Nutrient Sources and Transport in the Missouri River Basin,with Emphasis on the Effects of Irrigation and Reservoirs1

Brown, Juliane B., Lori A. Sprague, and Jean A. Dupree, 2011. Nutrient Sources and Transport in the Missouri River Basin, With Emphasis on the Effects of Irrigation and Reservoirs. Journal of the American Water Resources Association (JAWRA) 47(5):1034‐1060. DOI: 10.1111/j.1752‐1688.2011.00584.x Abstract: SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some areas. Sediment mobilized from stream channels was a source of phosphorus in medium and larger streams. Irrigation on agricultural land was estimated to decrease the nitrogen load reaching the Mississippi River by as much as 17%, likely as a result of increased anoxia and denitrification in the soil zone. Approximately 16% of the nitrogen load and 33% of the phosphorus load that would have otherwise reached the Mississippi River was retained in reservoirs and lakes throughout the basin. Nearly half of the total attenuation occurred in the eight largest water bodies. Unlike the other major tributary basins, nearly the entire instream nutrient load leaving the outlet of the Platte and Kansas River subbasins reached the Mississippi River. Most of the larger reservoirs and lakes in the Platte River subbasin are upstream of the major sources, whereas in the Kansas River subbasin, most of the source inputs are in the southeast part of the subbasin where characteristics of the area and proximity to the Missouri River facilitate delivery of nutrients to the Mississippi River.