Mitigating Impact of Devils Lake Flooding on the Sheyenne River Sulfate Concentration

Devils Lake is a terminal lake located in northeast North Dakota. Because of its glacial origin and accumulated salts from evaporation, the lake has a high concentration of sulfate compared to the surrounding water bodies. From 1993 to 2011, Devils Lake water levels rose by ~10 m, which flooded surrounding communities and increased the chance of an overspill to the Sheyenne River. To control the flooding, the State of North Dakota constructed two outlets to pump the lake water to the river. However, the pumped water has raised concerns about of water quality degradation and potential flooding risk of the Sheyenne River. To investigate these perceived impacts, a Soil and Water Assessment Tool (SWAT) model was developed for the Sheyenne River and it was linked to a coupled SWAT and CE‐QUAL‐W2 model that was developed for Devils Lake in a previous study. While the current outlet schedule has attempted to maintain the total river discharge within the confines of a two‐year flood (36 m³/s), our simulation from 2012 to 2018 revealed that the diversion increased the Sheyenne River sulfate concentration from an average of 125 to >750 mg/L. Furthermore, a conceptual optimization model was developed with a goal of better preserving the water quality of the Sheyenne River while effectively mitigating the flooding of Devils Lake. The optimal solution provides a “win–win” outlet management that maintains the efficiency of the outlets while reducing the Sheyenne River sulfate concentration to ≤600 mg/L.     

COMPARISON OF STOCHASTIC AND DETERMINISTIC DYNAMIC PROGRAMMING FOR RESERVOIR OPERATING RULE GENERATION1

ABSTRACT: Two dynamic programming models — one deterministic and one stochastic — that may be used to generate reservoir operating rules are compared. The deterministic model (DPR) consists of an algorithm that cycles through three components: a dynamic program, a regression analysis, and a simulation. In this model, the correlation between the general operating rules, defined by the regression analysis and evaluated in the simulation, and the optimal deterministic operation defined by the dynamic program is increased through an iterative process. The stochastic dynamic program (SDP) describes streamflows with a discrete lag-one Markov process. To test the usefulness of both models in generating reservoir operating rules, real-time reservoir operation simulation models are constructed for three hydrologically different sites. The rules generated by DPR and SDP are then applied in the operation simulation model and their performance is evaluated. For the test cases, the DPR generated rules are more effective in the operation of medium to very large reservoirs and the SDP generated rules are more effective for the operation of small reservoirs.     

长江口没冒沙演变过程及其对水库工程的响应

研究南槽没冒沙演变规律，可以为筑库引淡蓄水工程建设提供科学依据。根据该海区近百年来各个时期的海图和20年来的实测水文泥沙等资料以及2003、2004年的现场观测数据，探讨了没冒沙的形成及形成后的演变过程。研究表明：没冒沙的形成和发育经历了局部边滩冲刷、边滩沙嘴发育和沙脊形成3个阶段；近半个世纪来，沙体中轴位置在稳定强劲的涨落潮流作用下呈现出西北—东南走向的良好的稳定性，具有潮流脊性质。而蓄淡水库工程建设将有可能使南槽成为适应进出水沙量的新型河槽。     

北方湖库沉积物重金属区域特征及生态风险评价

以白洋淀、衡水湖、于桥水库、松花湖、大伙房水库和小兴凯湖沉积作为研究对象,通过对北方六湖库沉积物中Cu、Zn、Pb、Cr、Ni等重金属元素进行分析,并与国内外其他水域重金属污染情况进行多因素比较,探讨了六湖库主要重金属污染源的差异性,区域分布特征以及与国内外其他水域污染的相似性和区别.结果表明,六湖库沉积物重金属污染处于中等偏下水平.六湖库之间主要重金属污染源存在差别.沉积物重金属含量未出现明显上升的趋势.其中Zn、Pb存在富集现象,但Pb含量与历史数据相比出现下降,Zn的含量与其他地区相比整体偏高.大伙房水库沉积物重金属污染较重,Cu、Zn、Pb、Cr、Ni含量平均值分别为56.28,142.3,17.44,97.9,44.44mg/kg.小兴凯湖沉积物重金属含量最低,Cu、Zn、Pb、Cr、Ni含量平均值分别为2.41,63.90,13.37,56.36,26.09mg/kg.六湖库综合风险评价结果为大伙房水库>于桥水库>白洋淀>衡水湖>松花湖>小兴凯湖,重金属整体潜在生态风险指数为低.     

水源水库贫营养好氧反硝化菌群脱氮特性研究

为削减微污染水库中氮素的浓度,通过对西安市李家河水库沉积物进行定向富集驯化,筛选出以Pseudomonas菌为主、具有高效好氧反硝化特性的混合菌群-A1.摇床实验表明,贫营养好氧反硝化菌群A1在15h时硝酸盐氮去除率可达93.39%,硝酸盐氮平均去除速率为0.2073mg/（L·h）;总氮去除率为52.11%,总氮平均去除速率为0.1153mg/（L·h）,无亚硝酸盐积累.氮平衡分析表明,约45%的初始氮被去除转化为气体产物.响应面法（RSM）结果表明,C/N比9.96,温度22.67℃,pH8.01,转速91r/min,溶解氧8.55mg/L是去除总氮（TN）的最优条件.     

西安市文教区表层土壤中PAHs来源及风险分析

文教区土壤环境质量直接影响学生以及职工的身体健康。本研究应用高效液相色谱仪对采集的西安市文教区表层土壤样品中的16种优控多环芳烃(PAHs)进行含量检测,分析其组分特征、来源及健康风险。结果表明,西安市文教区表层土壤中∑PAHs含量为0.290~4.147μg/g,平均值为1.515μg/g,7种致癌多环芳烃的含量为0.079~2.093μg/g,均值为0.593μg/g,土壤PAHs污染较为严重。其中4环的高环PAHs为土壤PAHs污染的主要物质,平均占∑PAHs含量的40.72%。源解析结果表明西安市文教区表层土壤中PAHs主要来源于石油燃烧、煤及生物质等的不完全燃烧。终生癌症风险评价表明西安市文教区表层土壤中PAHs污染对其生活在周围的人群产生的终生致癌风险性较小,但71.4%的样点达到严重污染水平,产生的间接影响应引起足够重视。     

Obligations to animals are based on rights

Some feminist philosophers criticize the idea of human rights because, they allege, it encapsulates male bias; it is therefore misguided, in their view, to extend moral rights to non-human animals. I argue that the feminist criticism is misguided. Ideas are not biased in favour of men simply because they originate with men, nor are ideas themselves biased in favour of men because men have used them prejudicially. As for the position that women should abandon theories of rights and embrace an ethic that emphasizes care: women who made this choice would not so much liberate themselves from the patriarchy as they would conform to its representation of women as emotional, subjective and irrational. There is, then, no good reason to withhold ascribing rights to non-human animals, based on the criticisms of rights made by some feminists.Some of the material in the discussion of the feminist critique of rights originally appeared in my The Case for Animal Rights: A Decade's Passing inA Quarter Century of Value Inquiry: Presidential Addresses of the American Society of Value Inquiry, edited by Richard T. Hull, pp. 451–455. Amsterdam and Atlanta, GA: Rodopi, 1994. These passages are reprinted with the permission of the editor and publisher, whose thoughtful co-operation is gratefully acknowledged.     

大顶子山航电枢纽工程建库后上游水质总量控制研究

松花江大顶子山枢纽工程建设后,库区内水体流线及扩散规律的变化将影响库区内水质,受沿江排污影响,其规划目标的水环境容量将发生改变,因此对建库后上游水质总量控制进行研究很有意义.     

辽宁省白石水库环境工程地质问题综述

白石水库位于辽宁省北票市上园乡附近的大凌河干流上,是大凌河流域第一期开发的控制性骨干工程，水库建成后，将产生许多环境工程地质问题。从库坝区的地质背景出发，对水库渗漏、库岸再造与泥沙淤积、淹没与浸没、水库诱发地震、坝下冲刷坑稳定性等主要环境工程地质问题进行了综合评述。     

贵州赤水宝元-元厚地区油气遥感信息分析

本文通过对赤水宝元－元厚地区地质背景的分析，研究影响油气遥感无价值信息的主要因素，确定排除油气遥感无价值信息的基本原则，从而决定油气遥感有用信息，并作出地质解释，说明油气遥感直接勘探是一种快速、经济、有效的方法。