THE APPLICABILITY OF MORTON'S AND PENMAN'S EVAPOTRANSPIRATION ESTIMATES IN RAINFALL-RUNOFF MODELING1

ABSTRACT: Estimates of the upper constraint on actual evapotranspiration are required as input data in the majority of rainfall-runoff models. This paper compares and discusses the applicability of Penman's potential evapotranspiration estimates and Morton's wet environment evapotranspiration estimates in rainfall-runoff modeling applications. Morton's wet environment evapotranspiration depends only on the atmospheric variables and is the estimate of evapotranspiration that would occur when water supply is not limiting. It is a conceptually more correct representation of the upper constraint on actual evapotranspiration compared to Penman's potential evapotranspiration which is dependent on the water supply to the soil-plant surfaces. Although Penman's potential evapotranspiration and Morton's wet environment evapotranspiration are two different quantities, comparison of the two estimates using data from different climatic regions throughout Australia indicate that they provide similar magnitudes of the upper limit of actual evapotranspiration at moderate climatic conditions when reliable estimates are required in rainfall-runoff models. The two estimates can therefore be used interchangeably in rainfall-runoff modeling applications.     

ECONOMIC ANALYSIS OF WATER-SAVING TECHNIQUES IN IRAN1

ABSTRACT: The possibility of increasing the water supply for irrigation through adoption of more efficient water-application techniques as an alternative to new irrigation projects was studied in an irrigated region of Iran. Excessive water application at the farm level ranks high among the causes of water shortages in the selected region. An empirical analysis of the effect of water-saving technology on the farm operator's net return was made choosing two farms in the region as a case study. The problems facing these farms are common to most farms throughout the country. The results of the budgeting analysis of the selected farms indicated that an improvement in irrigation technique can result in the expansion of water supply and higher marginal value product for water. Comparing the costs of irrigation systems with the net returns resulting from the higher efficiency showed that such an investment is economically feasible.     

Assessment of Antifouling Effectiveness of two Natural Product Antifoulants by Attachment Study with Freshwater Bacteria (7 pp)

- Goal, Scope, Background. The traditional solution for keeping unwanted organisms from attaching to submerged surfaces is to apply anti-fouling coatings. The most common antifoulant was tributyltin (TBT). TBT systems were highly effective but were also toxic to non-target organisms. The use of the TBT based coatings will be completely banned by January 1, 2008. Therefore, there is an urgent need to seek out suitable non-toxic alternatives. Methods The aim of this work was to evaluate the effectiveness of capsaicin and zosteric acid as natural product antifoulants (NPAs) in deterring bacterial attachment. Two fresh water bacteria systems Pseudomonas putida (Pp) and bacteria isolated from Lake Erie (LE) were used to assess the attachment when the NPAs dispersed in the water. Effectiveness was ascertained based on the decrease in microbial attachment, limited toxicity, and minimum alteration of the coatings properties. Results and Discussion A significant inhibition of bacteria attachment was achieved when aqueous capsaicin concentration was increased from 0 to 40 mg/L. For instance, after 14 days the LE system depicted 93.5% and 98.5% less biofilm coverage for 20 mg/L and 40 mg/L capsaicin, respectively when compared to systems without NPA. Biofilm coverage was reduced by 92.5% and 98.2%, respectively with 50 mg/L and 500 mg/L zosteric acid. Conclusions Both capsaicin and zosteric acid was effective at preventing bacteria attachment. As the NPA aqueous concentration increased, biofilm formation decreased. Evaluating changes in aqueous pH, conductivity, dissolved oxygen, aqueous microbial population and biofilm formation suggested that the primary antifoulant mechanism of these two NPAs was to block the bacteria's active sites versus posing a lethal level. Recommendation and Perspective From the attachment study, zosteric acid appeared to be more effective in preventing bacterial attachment when the NPAs were dispersed in the aqueous environment. For practical applications, the antifoulant needs to be incorporated into a coating and have a slow release rate. Thus the ability to successfully incorporate zosteric acid into a coating, without deterring bacterial attachment, needs to be investigated.     

EDTA滴定法测定硫酸盐的检出限确定

在美国环保总署方法检出限程序的基础上，设计了一个能考虑样品空白和总硬度的可变性对样品测量值贡献的方法检出限程序，并按照此程序对EDTA滴定法测定硫酸盐的检出限进行了确定。对确定结果进行了信噪比和加标回收率检查，证明确定结果能客观地反映实验室对该方法的测试能力。     

The capital gains from trade are not enough: evidence from the environmental accounts of Venezuela and Mexico

In principle, a country cannot endure negative genuine savings for long periods of time without experiencing declining consumption. Nevertheless, theoreticians envisage two alternatives to explain how an exporter of non-renewable natural resources could experience permanent negative genuine savings and still ensure sustainability. The first one alleges that the capital gains arising from the expected improvement in the terms of trade would suffice to compensate for the negative savings of the resource exporter. The second alternative points at technological change as a way to avoid economic collapse. This paper uses the data of Venezuela and Mexico to empirically test the first of these two hypotheses. The results presented here prove that the terms of trade do not suffice to compensate the depletion of oil reserves in these two open economies.     

Magnitude of pesticidal contamination in winter vegetables from Hisar,Haryana

Monitoring of 80 winter vegetable samples during 1997–1998 for pesticidal contamination was carried out on GC-ECD and GC-NPD systems with capillary columns following multiresidueanalytical technique. The tested samples were found 100%contaminated with low but measurable amounts of pesticideresidues. Among the four major chemical groups, residue levels oforganophosphorous insecticides were highest followed bycarbamates, synthetic pyrethroids and organochlorines. About 32%of the samples showed contamination with organophosphorous andcarbamate insecticides above their respective MRL values. On thebasis of observations made in these studies, it is suggested thatmore extensive monitoring studies covering all vegetable cropsfrom different agro-climatic regions of the state be carried outto know exact level of pesticidal contamination, which may serveas basis for future policy on chemical use.     

某油气集输管线腐蚀失效分析

目的掌握管道腐蚀机理,有针对性地提出防腐方案。方法现场进行腐蚀管段截取和介质取样,采用腐蚀失效管段管材分析、腐蚀介质成分分析和腐蚀产物分析的试验方法,室内开展管道腐蚀失效原因检测和分析。结果失效管段内表面存在不均匀的沉积物,且部分位置发生了剥离脱落,存在裂缝。管道管材性能满足20#钢的性能指标要求。输送介质矿化度高,Cl-和SO42-含量高。腐蚀产物主要成分是几种Fe的氧化物和氢氧化物,如Fe(OH)2、Fe2O3和Fe O(OH)等,也含有部分氯化物和硫化物。结论管道在介质中主要腐蚀类型为腐蚀产物引起的闭塞腐蚀,介质内含有H2S,在含水条件下管道发生了O2和H2S腐蚀,最终使管壁减薄失效。     

生态环保扶贫减损增益和“绿水青山就是金山银山”转化研究

打通“绿水青山就是金山银山”转化路径是生态经济研究的重要内容,也是衔接脱贫攻坚和乡村振兴的有效途径.结合扶贫领域生态环境保护项目实施情况,从生态保护修复效益、环境污染治理效益、“绿水青山就是金山银山”转化效益方面构建了生态环境损益与“绿水青山就是金山银山”转化效益评估指标体系,并选择江西省崇义县进行案例研究.结果表明:①构建的生态环境损益与“绿水青山就是金山银山”转化效益评估指标体系包括生态保护修复实现的增值量、环境污染治理产生的减损量和“绿水青山就是金山银山”转化的经济收入.②崇义县良好生态环境实现的“绿水青山就是金山银山”转化效益初步显现,2018年崇义县“绿水青山就是金山银山”转化的经济收入为22.77×108元,是2013年的3.77倍,通过“绿水青山”向“金山银山”转化的经济收入得到逐步释放.③生态环保扶贫不仅可以提高区域生态环境质量,而且可以防止产生新的生态破坏与环境污染事件,通过发展生态经济,促进贫困地区县域经济绿色转型发展,巩固脱贫攻坚成果和支撑乡村振兴.研究显示,着眼于生态环保扶贫促绿色转型发展和生态产品价值实现,保护修复生态环境获得合理回报,“绿水青山就是金山银山”转化效益评估包括绿色有机农产品产值、生态旅游和生态补偿类收入,指标简单、可操作性强,可为生态环保扶贫政策优化和贫困地区可持续发展管理提供参考.      

UV/H2O2降解水中对乙酰氨基酚的动力学及反应途径

利用UV/H_2O_2间歇式光氧化反应器,考察该工艺降解水溶液中对乙酰氨基酚反应动力学和影响因素.结果表明,UV/H_2O_2可有效降解水溶液中的对乙酰氨基酚,降解过程符合拟一级反应动力学模型(R~2=0.990).通过考察影响反应的因素,如H_2O_2投量、紫外功率、pH值、共存阴离子(HCO_3~-、NO_3~-)浓度,研究结果表明,对乙酰氨基酚的反应速率常数随H_2O_2投量增大而增高,随着UV功率增强而增大;共存阴离子浓度的增加在一定程度上会降低反应速率常数;中性条件是降解体系的最适宜环境,此时的反应速率常数达到最大值.通过气象色谱/质谱(GC/MS)对中间产物的分析推测对乙酰氨基酚降解过程中首先形成了苯酚类物质进而被氧化生成易降解的物质.UV/H_2O_2对对乙酰氨基酚的矿化效果非常显著,在pH 7.0,紫外功率15 W,对乙酰氨基酚浓度42.0 mg·L~(-1),H_2O_2投加量为250.0 mg·L~(-1)时,总有机碳(TOC)去除率达到39%.     

中国资源的进出口与产出率：演化、挑战及对策

资源可持续利用是实现中国可持续发展和生态文明的重要保障,然而过去30多年经济的快速发展带来了严重的资源短缺和环境污染。为了揭示1949年以来尤其是改革开放以来中国资源利用与经济发展之间的关系,论文系统梳理中国资源供给状况,总结中国资源进出口及资源产出率演化特点、面临的挑战及相应的对策。研究发现：中国近年来进口以金属矿产、石油、部分固体废弃产品构成的自然矿产和城市矿产资源为主,主要出口以工业产品、水海产品等为代表的资源类型,进出口的结构类型随年份变化不大,但进口量呈现快速增长的态势;中国资源产出率逐步增长,达到1.6元/kg,但仍与发达国家有较大差距。为了应对面临的挑战,未来中国应着力提升在全球价值链的地位,同时国内应大力发展循环经济,提高资源产出率。