Impacts of Bakken Shale Oil Development on Regional Water Uses and Supply

The Bakken shale play in western North Dakota is one of the largest unconventional oilfields in the United States, but published research about impacts on the region's water resources is rare. In this study, besides examining North Dakota water management policies and activities, we also analyzed three datasets: the Bakken horizontal well completion data (2008‐2014), North Dakota permitted water consumption data (2000‐2014), and groundwater level and streamflow observations in western North Dakota (2000‐2014). We found from 2008 to 2014, the annual total industrial water uses for Bakken shale oil development ranged between 0.5 and 10% of statewide total consumptive water use. The percentage increases were between 3.0 and 40% within the Bakken oil production region. The increased population of temporary oilfield service workers contributed additional domestic water use, which was equivalent to ~15% of annual industrial water use for the shale oil development in the Bakken. Despite being in a semiarid region, the impact of Bakken development on regional water supply was limited because the water in the Bakken was adaptively managed and the region received on average over 20% more precipitation than normal during 2008‐2014. Of the 15 glaciofluvial aquifers under study, 12 have seen water levels increasing or unchanged and the water levels for the remaining 3 aquifers have decreased.     

Developing inventory and monitoring programs based on multiple objectives

Resource inventory and monitoring (I&M) programs in national parks combine multiple objectives in order to create a plan of action over a finite time horizon. Because all program activities are constrained by time and money, it is critical to plan I&M activities that make the best use of available agency resources. However, multiple objectives complicate a relatively straightforward allocation process. The analytic hierarchy process (AHP) offers a structure for multiobjective decision making so that decision-makers’ preferences can be formally incorporated in seeking potential solutions. Within the AHP, inventory and monitoring program objectives and decision criteria are organized into a hierarchy. Pairwise comparisons among decision elements at any level of the hierarchy provide a ratio scale ranking of those elements. The resulting priority values for all projects are used as each project’s contribution to the value of an overall I&M program. These priorities, along with budget and personnel constraints, are formulated as a zero/one integer programming problem that can be solved to select those projects that produce the best program. An extensive example illustrates how this approach is being applied to I&M projects in national parks in the Pacific Northwest region of the United States. The proposed planning process provides an analytical framework for multicriteria decisionmaking that is rational, consistent, explicit, and defensible.     

淮河流域水污染物排放总量分配的可持续性评价

本文借鉴经济学中反映经济发展状况和贫富差异程度的基尼系数理论,评价淮河流域水污染控制因子COD排放总量在流域四省分配的可持续性,即已确定的总量分配方案是否符合研究区域的经济社会环境状况.本文是在现有环境基尼系数应用上的一种论证性评价,用基尼系数反推已经确定的总量分配方案是否公平合理,为国家污染物总量分配评价提供一定的参考.     

总量控制规划中允许排放量的平权分配

对总量控制规划中公平合理分配各污染源允许排放量的意义以及现有平权分配方法中存在的问题进行分析。阐明了允许排放量平权分配的原则,提出了平权分配污染源允许排放量的Ｂ值法。剖析了分析平权后剩余环境容量的必要性,并提出了相应的解决方法。     

泥浆含砂量对泥水盾构泥浆成膜性能影响的试验研究

为在高渗透砂卵石地层泥水盾构施工中确保开挖面稳定、保证施工安全,泥浆顺利成膜至关重要.依托京张高铁清华园隧道工程,采用自行设计的泥浆渗透试验装置,配制6种不同含砂量的泥浆,在与实际地层渗透系数相似的试验地层中进行渗透试验.对泥浆在渗透过程中的成膜类型、成膜质量、渗透深度、滤失量、闭气性能等相关指标进行分析,得到适用于高...     

转型期耕地数量动态变化及最佳非农转化量的实证研究——以江苏省为例

伴随着我国经济的快速发展和城市化进程的加快，对土地资源的需求量急剧上升，作为土地中的精华——耕地资源也在农业部门和经济建设之间面临着如何分配的矛盾。如何确保耕地资源在粮食安全和经济发展间的优化配置已经成为一个迫切需要解决的问题。本文试图通过对江苏省耕地数量的变动态势进行分析，并运用区域容许耕地转换量化模型（MAC）来确定江苏省可以允许转换的耕地的最优数量，借此来确定区域耕地保护的底线及调控指标，为城市化进程中区域耕地资源的优化配置提供一种依据和解决思路。     

模拟及河道实验浮床水芹根系生长及生物量分配对比研究

为了对比研究浮床植物水芹菜在模拟及野外河道实验中根系生长及生物量分配的差异性,探索水芹浮床模拟实验与实际应用中的差异性,我们在实验河道边放置水箱,通过抽取河水到水箱中设置水芹浮床水箱模拟实验,并且与河道中水芹浮床实验作对比。结果发现:河道和水箱中植物根系指标除了平均根直径外其他指标随着水芹的生长以指数方式增长,平均根直径随着水芹的生长以指数方式下降;在根系总长度、根系总表面积、根系分叉数、根系交叠数方面,水箱中的水芹显著大于河道中的水芹(p0.05);水箱浮床水芹根系指标的增长速度大于地上部分的增长速度,河道中水芹地上部分增长速度要大于地下部分;水芹冠根比随时间的变化呈现出先下降后上升趋势,水箱中水芹冠根比的变化速率更小。水箱中的水芹受到了营养条件的限制,用模拟水芹浮床来研究其净化效率时,在一定程度上(与实际应用相比)高估了河道水芹浮床根系部分的作用。     

The role of body size in early mating behavior in a simultaneous hermaphrodite, <Emphasis Type="Italic">Chelidonura sandrana</Emphasis>

Intraspecific variation in mating behavior is widespread among simultaneous hermaphrodites but its underlying sources remain largely unexplored. In the sea slug Chelidonura sandrana, most matings are reciprocal. However, despite non-conditional sperm exchange and potential polygamy-mediated benefits, 30% of matings end after unilateral insemination. To resolve this apparent inconsistency, we here investigated the effect of body size on the frequency of reciprocal matings by testing the following two hypotheses. First, sex-allocation theory predicts that the likelihood of reciprocity depends on the size difference between mating partners. Second, if both sex functions temporally differ in reaching maturity, reciprocal matings should be more frequent with increasing absolute body size of the smaller partner. The likelihood of reciprocity increased with body size of the smaller partner. Moreover, smaller individuals acted more often as males among unilateral matings. These findings suggest that the ability to donate sperm develops prior to female functionality in C. sandrana.     

Female-biased sex allocation of offspring by an <Emphasis Type="Italic">Apodemus</Emphasis> mouse in an unstable environment

We investigated the effects of population fluctuation on the offspring’s sex allocation by a weakly polygynous mouse, Apodemus argenteus, for 3 years. In acorn-poor seasons, heavier mothers invested more in sons, and lighter mothers invested more in daughters. In acorn-rich seasons, heavier mothers invested more in daughters, and lighter mothers invested more in sons. Maternal body condition and litter size affected the sex allocation. Furthermore, there was a maternal investment trade-off between a son’s birth mass and the number of daughters. Based upon the effect of population fluctuation on the lifetime reproductive success of each sex, we proposed the new “safe bet hypothesis”. This hypothesis predicts that frequent and unpredictable change in female distribution, which is often caused by abrupt fall in food condition, favors female-biased maternal investment to offspring by polygynous mammals and is applicable to many small mammals inhabiting in unstable environments.