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ISBN: (纸本)9787512126831

关键词： 工程水文学   编程   教学方法  

摘要： 工程水文学中很多手工计算方法繁复费时,学生普遍感觉深奥难懂。为解决这个问题,提出与编程计算相结合的教学方法,并论证该教学方法的必要性和实施办法,讨论实施中会遇到的问题和解决方法,使学生能掌握该门课程的知识点,并提高学生动手解决实际问题的能力。

关键词： 水文与水资源工程   水文学原理   课程教学   教学研究  

摘要： 水文学原理课程是水文与水资源工程专业重要的专业基础课,该课程的教学质量将直接影响学生后续课程如水文预报、水文水利计算的学习,同时也直接影响学生专业素质的提高。针对高校水文学原理课程教学实践中存在的主要问题,文章从知识内容体系、理论与实践性教学、教学方法和教学资源、教师和学生等方面对课程教学效果的改善进行了探索,对水文学原理课程教学质量的提高提出了一些思考。

关键词： DRILLING & boring   CRETACEOUS stratigraphic geology  

摘要： This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers.

关键词： Poyang Lake Project   Environmental Fluid Dynamics Code (EFDC) model   Hydrological impact   Wintering bird   Flow velocity  

摘要： Dams have great hydrological impacts on the river system. Poyang Lake, the largest freshwater lake in China, has experienced severe drought over the past decade since the operation of the Three Georges Dam. The Jiangxi Province Government proposed to build a 2.8-km-wide dam with sluice gates across the narrowest part of the channel that links Poyang Lake and Yangtze River, called the Poyang Lake Project (PLP), to solve the problem of drought. The proposal caused concerns about the negative effect of increased water level on wintering birds' habitat and water quality. But so far, little scientific data have been provided to evaluate the hydrological impacts of the PLP. The aim of this study is to investigate the hydrological impacts of the PLP using a two-dimensional Environmental Fluid Dynamics Code (EFDC) model based on the latest regulation scheme, which will be helpful to evaluate the advantages and disadvantages of the building of PLP. The model was calibrated and verified by comparing model predictions with observed data. A typical dry season between 2006 and 2007 was used as the period to simulate the scenarios with and without the PLP. Simulated results from the EFDC model showed that the increase of water depth mainly occurred in the water channel in the north part of Poyang Lake with the regulated water level set at 10-11 m, and the increased water depth in two national nature reserves was less than 0.1 m, which has little effect on wintering birds' habitat. However, the benefit of the PLP was limited with this regulated water level and the increased water storage was less than 6.2 x 10(8) m(3). The increased water storage would double when the lowest water level was set at 12 m, and the bird habitat was still little affected. The existing regulated water level reduced the flow velocity in the northern part of Poyang Lake by approximately 50% and the effect became smaller with distance far away from the PLP. The slowdown of flow velocity would increase the

关键词： nuclear waste disposal   Clay   Bentonite   THMC   Modeling   High temperature  

摘要： One of the most important design variables for a geological nuclear waste repository is the temperature limit up to which the engineered barrier system (EBS) and the natural geologic environment can be exposed. Up to now, almost all design concepts that involve bentonite-backfilled emplacement tunnels have chosen a maximum allowable temperature of about 100 degrees C. Such a choice is largely based on the consideration that in clay-based materials illitization and the associated mechanical changes in the bentonite (and perhaps the clay host rock) could affect the barrier attributes of the EBS. However, existing experimental and modeling studies on the occurrence of illitization and related performance impacts are not conclusive, in part because the relevant couplings between the thermal, hydrological, chemical, and mechanical (THMC) processes have not been fully represented in the models. This paper presents a fully coupled THMC simulation of a nuclear waste repository in a clay formation with a bentonite-backfilled EBS for 1000 years. Two scenarios were simulated for comparison: a case in which the temperature in the bentonite near the waste canister can reach about 200 degrees C and a case in which the temperature in the bentonite near the waste canister peaks at about 100 degrees C. The model simulations demonstrate some degree of illitization in both the bentonite buffer and the surrounding clay formation. Other chemical alterations include the dissolution of K-feldspar and calcite, and precipitation of quartz, chlorite, and kaolinite. In general, illitization in the bentonite and the clay formation is enhanced at higher temperature. However, the quantity of illitization is affected by many chemical factors and therefore varies a great deal. The most important chemical factors are the concentration of K in the pore water as well as the abundance and dissolution rate of K-feldspar;less important ones are the concentration of sodium and the quartz precipitation ra

关键词： 分年级教学   工程水文学   水利计算   知识树   方案  

摘要： 水文水利计算涵盖水文计算和水利计算两大部分,涉及的信息量大、知识点繁琐。作为我校的专业基础课,不同的专业将在不同的年级开设。本文在介绍水文水利计算课程特点之后,根据笔者多年教学经验,着重对分年级的教学方案进行探讨,以期做到因材施教,不断提高教学质量,提升学生的听课效果。

关键词： Simulation   SWAT model   SUFI-2   Uncertainty analysis   Engineering projects   KRB  

摘要： Limited water supply is one of the major restrictions in development and agricultural activities in numerous countries, especially in arid and semi-arid regions. Wetlands are constantly affected by anthropogenic factors such as engineering projects and landscaping. Therefore, simulation of hydrologic processes and modeling the factors involved are important. In this study, Soil and Water Assessment Tool (SWAT) was used to simulate the hydrologic process in the Karkheh River Basin (KRB) in southwest Iran and to evaluate the impacts of engineering projects on its wetland (Al Hawizeh) located in the Iran-Iraq border. Calibration, validation, and uncertainty analysis were performed using Sequential Uncertainty Fitting Ver. 2 (SUFI2), which is one of the program interfaces with SWAT, in the Package SWAT Calibration Uncertainty Programs (SWAT-CUP). To assess the goodness of calibration and validation, four measures were applied: (i) percentage of data bracketed by 95% prediction uncertainty or P-factor (95PPU) calculated at 2.5% and 97.5% intervals of the simulated variables, (ii) R-factor, which is the ratio of average thickness of the PPU, (iii) Nash-Sutcliffe coefficient (NSE), and (iv) determination of coefficient (R-2). Stream flows from four gauge stations combined with 14 synoptic stations were used for calibration (1987-1990) and validation (1991-1994). The P-factor values for these stations ranged from 0.64 to 0.84 and from 0.65 to 0.79 for calibration and validation, respectively. These results showed reasonable accuracy according to literature. NSE values were also acceptable, ranging from 0.52 to 0.8 and from 0.62 to 0.72 for calibration and validation, respectively. R-2 values were also within an acceptable range. The calibration and validation results were then used to simulate two watershed scenarios (with and without a dam). In addition, annual flow volumes (AFVs) for two downstream stations (Hamidiyeh and Pay e Pol) were computed. AFV is defined as the vo

关键词： 工程水文学   时间序列   突变检验   Mann-Kendall法   样本熵   复杂度   湘江流域  

摘要： 传统的突变检验方法 Mann-Kendall法主要基于线性和概率统计理论,对于高度复杂和非线性的水文时间序列检测能力不足。采用基于非线性动力学参数的样本熵方法,结合滑动技术和滑动移除技术,利用湘江流域1961~2009年多个气象站点日降雨资料和控制站湘潭站日径流资料,对降雨和径流时间序列进行突变检验。结果表明：日尺度降雨和径流时间序列样本熵值最小,复杂度最低,可预测性最高;径流分别在1966年、1983年、1992年以及2002年发生突变,降雨在1966年、1987年以及2002年发生突变;滑动样本熵与滑动移除样本熵相结合不仅能有效地识别突变,更能发现突变前后时间序列的动力学变化特征。