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801.
采用统计学及质量控制的一些基本理论及方法对污水处理厂的运行数据进行分析,得出城市污水处理厂BOD5、COD、SS、TN、TP等主要出水指标呈正态分布的规律;城市污水BOD5、COD、TN、TP等指标间存在显著线性相关性的结论.研究结论可用于污水处理厂制定经济合理的出水监测方案以及对污水处理厂运行可靠性等进行评估. 相似文献
802.
803.
Sustainable use of water and land resources requires that these scarce resources be appropriately allocated among various
competing human activities. Worldwide, there is a realization now that sustainable river basin management should be accorded
the highest priority, because it deals not only with technical, but also with ecological and socioeconomic aspects, and thus
calls for a multidisciplinary and integrated approach. However, most of the policy and planning documents have either remained
silent, or have made only implicit reference to the importance of environmental water demand (EWD) and its quantification.
Therefore, in the light of its importance, a methodology has been evolved in this article for quantifying EWD for various
forested areas in two distinctly different Indian river basins: Brahmani (humid zone) and Sabarmati (dry zone). The article
analyzes and discusses EWD estimates at three different spatial levels: river basins, states, and districts within them, and
finally presents a comparative analysis of all these results. Findings of the present study will be immensely useful in understanding
various ecological issues connected with water resource projects and proposals in these river basins. 相似文献
804.
Determining a remeasurement frequency of variables over time is required in monitoring environmental systems. This article
demonstrates methods based on regression modeling and spatio-temporal variability to determine the time interval to remeasure
the ground and vegetation cover factor on permanent plots for monitoring a soil erosion system. The spatio-temporal variability
methods include use of historical data to predict semivariograms, modeling average temporal variability, and temporal interpolation
by two-step kriging. The results show that for the cover factor, the relative errors of the prediction increase with an increased
length of time interval between remeasurements when using the regression and semivariogram models. Given precision or accuracy
requirements, appropriate time intervals can be determined. However, the remeasurement frequency also varies depending on
the prediction interval time. As an alternative method, the range parameter of a semivariogram model can be used to quantify
average temporal variability that approximates the maximum time interval between remeasurements. This method is simpler than
regression and semivariogram modeling, but it requires a long-term dataset based on permanent plots. In addition, the temporal
interpolation by two-step kriging is also used to determine the time interval. This method is applicable when remeasurements
in time are not sufficient. If spatial and temporal remeasurements are sufficient, it can be expanded and applied to design
spatial and temporal sampling simultaneously. 相似文献
805.
Tarsitano E 《Environmental management》2006,38(5):799-809
In urban ecosystems, the ecological system has become completely unbalanced; this, in turn, has led to an increase in well-known
problems such as air pollution, ground pollution, and water pollution. This imbalance has also led to the growth and spread
of pathogens harmful to man, animals, and plants. Urban sustainability indicators, both global and local, also “indicate”
the percentage of population, but these refer only to the human population, not the animal population. Cities need good waste,
water, and air management, effective traffic planning, and good zoning of businesses, crafts, and services; over and above
these activities, cities also need for planning to take into account the existence of pets (dogs, cats, and etc.) and nonpet
animals (insects, birds, mice, etc.). Cities tend to be designed around humans and “on a human scale,” without taking into
account the fact that a huge animal population is living side by side with people. That explains why overcrowding tends to
go hand in hand with urbanization; all these populations, including humans, need to adapt to new spaces and often need to
drastically change their behavior. This is a fact that must be included when drafting sustainable city plans. The supposed
strategy is that of “integrated-participatory” control of the interactions between the environment and animals in the cities.
Strategy will focus on the development of integrated approaches and tools for environment and animal management in the context
of urban settings. This will require such specific methods as ecological balance sheets and ecoplans for the planning, management,
and control of the interrelation among environment, animal, and public health. The objective is to develop a better understanding
of urban biodiversity and of urban ecosystem functioning, in order to understand and minimize the negative impacts of human
activities on them. The research will focus on assessing and forecasting changes in urban biodiversity, structure, function,
and dynamics of urban ecosystems, with relationships among society, economy, biodiversity, and habitats. 相似文献
806.
Applying Integrated Urban Water Management Concepts: A Review of Australian Experience 总被引:2,自引:0,他引:2
Mitchell VG 《Environmental management》2006,37(5):589-605
This article explores recent Australian experiences in the application of the concept of integrated urban water management
(IUWM) to land development sites through the review of 15 case studies. It discusses lUWM’s emergence and comments on the
success or otherwise of Australian experience in its application. The understanding of IUWM is maturing within the Australian
water industry, an occurrence that has been facilitated by demonstration sites such as those reviewed. Successes include the
translation of IUWM concepts into well-functioning operational urban developments, significant reductions in the impact of
the urban developments on the total water cycle, and the increasing acceptance of the concept within the water and land development
industries. However, there is still room for greater integration of the water supply, stormwater, and wastewater components
of the urban water cycle, improved dissemination of knowledge, enhancement of skills in both public and private organisations,
and monitoring the performance of systems and technologies. 相似文献
807.
河口近岸水体中颗粒态重金属的潮周期变化 总被引:11,自引:4,他引:7
对长江口崇明东滩近岸水体中颗粒态重金属的潮周期变化特征及其影响机制进行了研究.结果表明,受粒度影响,底层水体中颗粒态Cu、Pb、Fe、Mn、Zn、Cr、Al的总量分别高出表层沉积物的184%、99%、56%、62%、147%、50%和45%,其中Cu、Pb、Fe、Mn、Zn、Al可还原态部分在底层水体悬浮颗粒物中的含量也明显高出表层沉积物的2~3倍,但与重金属总量相比,上述元素的可还原态部分所占比例与表层沉积物相差不大.在5次潮汐循环过程中,颗粒态重金属均在涨潮初期、高平潮前后及落潮末期出现较高含量.这种变化主要与水动力条件有关,当水体流速增大时,从底部沉积物再悬浮起来的颗粒态重金属对水体中的永久性悬浮颗粒起了很大的稀释效应.水体中的盐度、DO及pH等环境因子对潮周期内颗粒态重金属的变化影响不大. 相似文献
808.
赣南小流域的水文地球化学特征和主要风化过程 总被引:17,自引:4,他引:13
对赣南花岗岩小流域进行采样、测试及分析,发现其河水含有较低的矿化度,水化学组成以Na ,Ca2 ,Cl-1和HCO-3为主,溶解性Si的含量明显较高,代表了典型硅酸盐地区河流的相应化学组成.通过Gibbs图分析,赣南流域大部分地区受大气降水的影响比较显著,"蒸发-浓缩"类型的小流域也较多.根据主成分分析和因子分析的结果,定量地估算了大气中CO2和三类岩石对河水中各种离子的贡献比例.与黄河相比,赣南流域受硅酸盐岩风化作用强烈,但主要影响因素仍是碳酸盐和蒸发盐岩,二者对赣南流域溶解质的贡献率分别为42.8%和29.2%,大气中CO2对河水溶解质的贡献率为21.4%,低于世界平均水平.主要风化反应以岩盐和方解石的溶解为主,Si/(Na* K)比值较低,说明风化反应在表生环境中进行,其产物是富含阳离子的次生矿物. 相似文献
809.
In mine water pollution abatement, it is commonly assumed that known mine waste sites are the major pollution sources, thus neglecting the possibility of significant contribution from other old and diffuse sources within a catchment. We investigate the influence of different types of pollution source uncertainty on cost-effective allocation of abatement measures for mine water pollution. A catchment-scale cost-minimization model is developed and applied to the catchment of the river Dalälven, Sweden, in order to exemplify important effects of such source uncertainty. Results indicate that, if the pollution distribution between point and diffuse sources is partly unknown, downstream abatement measures, such as constructed wetlands, at given compliance boundaries are often cost-effective. If downstream abatement measures are not practically feasible, the pollution source distribution between point and diffuse mine water sources is critical for cost-effective solutions to abatement measure allocation in catchments. In contrast, cost-effective solutions are relatively insensitive to uncertainty in total pollutant discharge from mine water sources. 相似文献
810.