金沙江下游水库拦沙效应研究

随着众多水库建成运用,水库拦沙成为了金沙江下游减沙的主要原因。1956—2021年金沙江干流及下游支流共修建10万m^(3)以上的水库504座,总库容为687.63亿m^(3)。水库运用后,金沙江下游年径流量不存在明显变化,而年输沙量显著减小。金沙江下游出口含沙量在1998年、2013年以后大幅减小,1956—1997年平均含沙量为1.75 kg/m^(3),1998—2012年平均含沙量减小为1.22 kg/m^(3),2013—2021年平均含沙量减小为0.01 kg/m^(3)。采用双累积曲线法及水库拦沙率公式,分析水库拦沙与水土保持工程对金沙江下游减沙贡献度,结果表明:金沙江下游减沙主要由水库拦沙造成,其中1998—2012年金沙江下游年均减沙0.97亿t,水库拦沙的减沙贡献度为0.67,水土保持工程等措施的减沙贡献度为0.33;2013—2021年下游年均减沙2.43亿t,水库拦沙贡献度为0.97,水土保持工程等措施减沙贡献度为0.03。

水库水温分布结构识别的高斯过程机器学习方法

利用高斯过程机器学习模型建立水库水温垂直分布结构类型与其复杂影响因素之间的非线性映射关系,提出一种基于高斯过程机器学习的水库水温垂直分布结构类型的模式识别方法。工程实例应用表明,该方法具有模型参数自适应确定、容易实现且识别精度高等优点。

漫湾水电站水库水温分布观测与数学模型计算研究

近年来建设的高坝大库越来越多,下泄低温水的影响日趋严重,对水库下泄低温水的影响和减缓措施的研究应给予关注和不断加强。本文是对已投入运行的漫湾水电站库区的水温结构进行研究。通过2004年2月对漫湾水库进行水温分布现场观测,并辅以三维数值模型计算,获得了较详细的水温分布成果。研究结果表明,漫湾水库的水温结构既不属于典型分层型又不属于完全混合型,应属于局部分层型或过渡型。该成果对于流域梯级水电开发对水环境的影响研究,具有一定的代表性,可用于类比分析研究与漫湾水库条件类似的其它水电站。

泥沙异重流影响下的水库垂向水温分布预测模拟

水库水体异重流的变化是影响水库水温分布最为关键的因素之一。本文以黄河上游刘家峡水库为例,建立考虑泥沙异重流影响的三维水库水温模型,利用已有水库水温分布监测数据对模型进行验证。在考虑有无泥沙异重流影响的条件下,对水库汛期库区垂向水温分布进行预测和比较。模拟结果显示,在不考虑来流含沙时,库区垂向水温分布始终为典型分层型,按实际含沙来流计算时,库区垂向水温分布随着水沙量增大而呈现从分层型转化为混合型分布的变化,泥沙异重流是造成夏季水库水温成混合型的主要原因,只有考虑泥沙异重流的影响才能正确预测多沙河流上水库水温的变化规律。

煤矿分布式地下水库渗流场分析及优化调度

煤炭规模化开采势必产生扰动裂隙场,进而破坏地下水系统,并产生大量矿井水,导致矿井突涌水风险。为了保障煤矿生产安全,并将矿井水储存在井下供生产和生活使用,提出了煤矿地下水库理论框架和技术体系。煤矿地下水库建设的关键难题是库容(或储水量)的评估与控制,即将矿井水储存在采空区后,如何保障不断增加的矿井水不会危及到后续煤炭开采活动。基于此,提出了在煤矿区建设多个地下水库,通过管道将多个地下水库相互连接起来形成相互连通的分布式地下水库,并可在多个水库间进行水量联合调度的技术思路。其优势是可以通过水库间的水量调度保证每个水库中的矿井水在安全库容范围,特别是可以使威胁现有采区的地下水库储水量得到有效控制,防止水害发生。以某煤矿分布式地下水库建设为例,根据矿井开采区的地质资料,计算不同高程区域的储水能力,确定分布式地下水库的库容-水位曲线;在此基础上,建立分布式地下水库的地下水数值模拟模型,预测矿区的涌水量;并针对矿区的涌水量,结合地表水资源,按照水量供求关系,进行矿区水资源的优化调度,使得矿区涌水得到合理和高效利用。

我国水库淤损情势分析

基于全国第一次水利普查水库资料,分析了我国水库时空分布特征,我国现有10万m^(3)以上的水库约9.8万座,总库容约9323亿m^(3),其中小型水库数量占全国的95.22%,大型水库库容占全国的80.43%,我国水库数量和库容在1950年以后快速增加。在掌握全国水库分布的基础上,收集了我国6702座水库淤积资料,其中约90%的水库淤积资料年份统计到2016—2018年,水库资料涵盖了七大流域和内陆所有省份。其中,大型水库131座,库容约2143亿m^(3);中型水库580座,库容约155亿m^(3);小型水库5991座,库容约44亿m^(3);分别占本次统计总库容的91.5%、6.6%和1.9%。根据收集的资料分析得到:我国水库平均淤损率为11.27%,各流域水库淤损率差别较大,其中黄河流域水库淤损率为36.76%,长江流域水库淤损率为4.25%,水库淤损率随水库运行时间增加整体呈上升趋势;我国水库年均淤损率为0.41%~0.49%,其中黄河流域水库年均淤损率最高,为1.39%,长江流域水库年均淤损率为0.25%,水库年均淤损率随水库运行时间增加而减小。在此基础上,采用模糊数学均值聚类方法对水库进行了分类,根据水库淤损率大于38%、14%~38%、小于14%将水库分为严重淤积、中度淤积和轻度淤积三类。根据年均淤损率大于1.5%、0.5%~1.5%、小于0.5%将水库分为淤积速率较快、淤积速率中等和淤积较慢三类。研究成果可为科学开展淤损水库功能恢复提供基础数据和技术支撑。

湖南省水库与干旱情势空间匹配关系研究

根据湖南省地质、地形等条件,以县域为单元将湖南省划分为9个区域,对省内14000多座各类型水库开展空间统计,分析了水库空间分布规律,并采用SPI-3指数法计算得到4-9月重旱及以上干旱频率的空间分布,对比研究了水库分布与干旱的空间匹配关系。结果表明:湖南省水库分布具有明显的空间分异特征,丘陵区水库数量密度一般要大于山地区,但受大型水库不足的影响,库容密度一般要小于山地区。洞庭湖平原腹地水库密度极低,而外围岗地区则拥有全省最大的水库分布密度。不同分区水库供水能力与人口、耕地的匹配关系也有很大差异。湘东南罗霄-南岭山地区单位面积兴利库容和人均兴利库容最大分别可达54397.32 m^(3)/hm^(2)和3286.53 m^(3),而在湘中南岩溶丘陵区、洞庭湖区等地区则分别不大于3450 m^(3)/hm^(2)和210 m^(3)。湖南省水库的空间分异特征主要受地质、地形等地理条件控制,山地区水库规模大、数量少,而丘陵区水库小、数量多。总体上看,湖南省水库供水能力与干旱的空间分布存在明显的失衡错位,如衡邵盆地不仅年均降雨量少、重旱频率高,而且水库供水能力也处于全省较低水平,再加上岩溶区“保水难”的特性,该区成为省内干旱情势最为严重的地区。

小浪底水库垂向二维水温数值模拟研究

采用垂向二维水动力水温数学模型,研究模拟小浪底水库水温分布结构及年内变化规律。结果表明:小浪底水库库尾水深小,水温呈等温分布;坝前水深较大,会出现水温分层情况,具体表现为:4—6月坝前水温呈稳定分层结构,7—11月坝前水温呈等温分布,12月—次年3月坝前水温处于逆温结构。

水库水温结构划分的模糊回归预测模型及其应用

根据水库水温垂直结构分布的模糊性特点,应用多目标模糊模式识别和回归分析理论,研究了水库水温垂直分布类型的模糊识别回归预测方法,实例分析表明该方法是有效的。

神东矿区采区式煤矿地下水库系统设计研究

我国西部生态系统脆弱,煤炭开采中水资源的保护与利用意义重大,结合神东矿区20多年煤矿地下水库的技术探索和工程实践,提出了以“导储用”为核心的煤矿地下水库理论框架和技术体系。基于神东矿区30余座煤矿地下水库建设经验,研究了采区式煤矿地下水库系统设计理念,构建了采区水库及巷道布置、坝体设计、水库库容计算、管路设计、相关硐室及设备布置和安全监控系统组成的设计体系,总结了各系统设计的核心技术,对采区式煤矿地下水库设计的推广有重要的意义。

神东矿区煤炭开采水资源保护利用技术与应用

针对神东矿区矿井水外排蒸发损失的问题,分析了以往保水采煤方法的不足,系统研究了矿区水文地质条件,提出了矿区三类水(近地表土壤水、第四系松散层孔隙水和基岩裂隙水)概念。在此基础上,神东矿区通过开展一系列水资源保护和利用技术研究,掌握了矿区煤炭现代开采地下水的运移规律,相继研发了采空区储水设施、煤矿地下水库和煤矿分布式地下水库的水资源保护和利用技术,形成了以煤矿地下水库为核心的矿区水资源保护和利用技术,并通过技术提升,建成了大柳塔矿分布式地下水库示范工程,实现了矿井水井下循环利用。现场工程应用表明,神东矿区煤矿地下水库安全稳定运行,提供了矿区95%以上用水,有效保障了矿区的可持续发展,为我国西部地区煤炭开采水资源保护利用技开辟了新的技术途径。

Spatio-temporal distribution of phytoplankton in the Danjiangkou Reservoir, a water source area for the South-to-North Water Diversion Project (Middle Route), China

One of the water source areas of the South-to-North Water Diversion Project is the Danjiangkou Reservoir （DJKR）. To understand seasonal variation in phytoplankton composition, abundance and distribution in the DJKR area before water diversion, as well as to estimate potential risks of water quality after water diversion, we conducted an investigation on phytoplankton in the DJKR from August 2008 to May 2009. The investigation included 10 sampling sites, each with four depths of 0.5, 5, 10, and 20 m. In this study, 117 taxa belonging to 76 genera were identified, consisting of diatoms （39 taxa）, green algae （47 taxa）, blue-green algae （19 taxa）, and others （12 taxa）. Annual average phytoplankton abundance was 2.01×10^6 ind./L, and the highest value was 14.72 ×10^6 ind/L （at site 3 in August 2008）. Phytoplankton abundance in front of the Danjiangkou Dam （DJKD） was higher than that of the Danjiang Reservoir Basin. Phytoplankton distribution showed a vertical declining trend from 0.5 m to 20 m at most sites in August 2008 （especially at sites of 1, 2, 4 and 10）, but no distinct pattern in other sampling months. In December 2008 and March 2009, Stephanodiseus sp. was the most abundant species, amounting to 55.23% and 72.34%, respectively. We propose that high abundance ofStephanodiscus sp. may have contributed greatly to the frequent occurrence of Stephanodiscus sp. blooms in middle-low reaches of the Hanjiang River during the early spring of 2009. In comparison with previous studies conducted from 1992 to 2006, annual average phytoplankton density, green algae and blue-green algae species, as well as major nutrient concentrations increased, while phytoplankton diversity indices declined. This indicates a gradual decline in water quality. More research should be conducted and countermeasures taken to prevent further deterioration of water quality in the DJKR.

Spatial and seasonal distribution of macroinvertebrates in high altitude reservoir (Beyler Reservoir, Turkey)

A highland reservoir in the West Black Sea region of Turkey which belongs to the Mediterranean climatic zone was examined.Both littoral and profundal zones were sampled from October 2009 to September 2010,to determine taxonomic composition,biodiversity and abundance of benthic invertebrates as well as the seasonal variation of these measures.A total of 35 taxa were identified,of which 12 belong to Chironomidae and 10 to Oligochaeta groups.The highest diversity and abundance of benthic macroinvertebrates were found at the littoral stations.Macroinvertebrates showed significant positive correlations with water temperature and NO_2 and NO_3 concentrations,and negative correlation with dissolved oxygen.

Reservoir Inflow Estimation Using Remote Sensing, GIS and Geosimulation

RS （remote sensing） applications to hydrological problem solving have successfully transitioned from being experimental to operational in the last couple of years, and information gathered through these technologies can facilitate water resource procedures. Patterns from RS imagery can be translated into a deterministic distribution of input data over a wide area on a pixel-by-pixel basis. This paper presents the implementation of different methodologies of integrating satellite-derived information from RS, and GIS （geographic information system） visualization and simulation capabilities in improving hydrologic estimation processes.

Intensive Observation of Reservoirinduced Seismicity and Preliminary Analysis on the Causes of Earthquakes in the Three Gorges Reservoir Area,Yangtze River

In accordance with the requirements of the National Key Technology R＆D Program of the 11th ＂Five-year Plan＂, a densified seismic network consisting of 26 seismic stations was established at the Three Gorges Reservoir area in the section of Hubei Province in March 2009 （21 short-period seismographs, 5 broadband digital seismographs）. From March to December, 2009, a total of 2,995 ML -0. 8 - 2. 9 earthquakes were detected during the trial impounding of the Three Gorges Reservoir （ water level rose from 145 m to 172.8m）. Using the double difference earthquake location algorithm, 2,837 earthquakes were precisely re-located. The results show that the pattern of small local earthquake swarms in the Three Gorges Reservoir area took on a linear distribution or mass-like cluster distribution, the mass-like clusters of events were generally within a distance of 5 km from waterfront, and the linear distribution of the earthquakes could be extended to a distance of 16 km away from the waterfront. In the Hubei section of the Three Gorges Reservoir, earthquakes were mainly concentrated in the northern end of the Xiannvshan and Jiuwanxi faults near the Xiangxihe River, and along the banks of the Yangtze River at the west of Xietan township and the Shenlongxi area on the northern bank in the Badong region, with focal depths less than 10km, and 4km in average. Earthquake frequency in the reservoir region had a positive correlation with reservoir water level fluctuations, indicating that the seismicity belongs to reservoir induced earthquakes. Along the Shenlong River in the reservoir area, earthquakes showed three linear distributions in the northern Badong county, and distributed according to Karst distribution. There are underground rivers in the carbonate strata. When the reservoir was impounded, water permeated into the underground rivers, thus inducing earthquakes. Earthquakes in the areas on the crossriver segment of Xiannvshan fault, the Jiuwanxi fault and at the areas west of Xietan, Shazhen and Xizhen, may be related to the softening of discontinuities, such as the Nukou fault, the Xiannvshan fault, or the bedding joints, which would lead to failure of rock masses, thus, inducing earthquakes. However, convincing conclusions about the triggering mechanism still need further study. Additionally, near the areas south of Wenhua and Yanglin of Zigui county and at Rangkou town east of Badong county, mininginduced earthquakes occurred at the mines nearby, and on the shores of the reservoir are some collapse earthquakes.

Gillnet Selectivity and Length at Maturity of Nile Tilapia （Oreochromis niloticus L.） in a Tropical Reservoir （Amerti： Ethiopia）

The selectivity of gillnets for Oreochromis niloticus in Amerti reservoir （9°63′ N, 37°23′ E） was determined from gillnets with four mesh sizes （60, 80, 100 and 120 mm）. Four selectivity models （a normal model assuming fixed spread, a normal model assuming that spread is proportional to mesh size, a lognormal model and a gamma model） were fitted to the data by using the share each length＇s catch total （SELECT） method. A total of 657 specimens of Oreochromis niloticus were caught （12.0-35.5 cm total length, TD. The sizes at first sexual maturity were 21.5 cm TL and 18.9 cm TL, respectively, for male and female Oreochromis niloticus. The lognormal selectivity curve provided the best fit to the data according to model deviance estimates with optimum selectivity of 16.66, 22.26, 27.78 and 33.38 cm TL for the 60, 80, 100 and 120 mm mesh sizes, respectively.

Quantitative and Qualitative Analysis of Groundwater in Aguanaval and Chupaderos Aquifers （Mexico）

Adequate regional groundwater assessment studies are essential for the correct groundwater management by policy/decision makers; increased use of groundwater resources and drought have led to concern about the future availability of groundwater to meet domestic, agricultural, industrial, and environmental needs. Deep understanding of spatial and temporal water table dynamics together with transport processes is required. This paper gathers historical geological, hidrological and chemical information for quantitative and qualitative as well as spatial and temporal evolution of groundwater for Aguanaval and Chupaderos aquifers, both surrounding Calera aquifer in Mexico. Historical databases were employed to determine temporal trends of water levels and values were projected for years 2010, 2030 and 2050. Potential recharge sites were also identified through water level-topography correlation. The water quality analysis was completed by obtaining, through geostatistics, spatial distributions for bicarbonate, chloride, sulfate, total dissolved solids, temperature, and sodium, employing databases generated in recent sampling campaigns. This analysis provided additional elements to help understand the functioning of groundwater in studied aquifers. Finally, results were compared with permissible values established in the Mexican norm.

Applied research of correspondence analysis method in waste tailings reservoir heavy metal pollution monitoring points optimization

In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points and monitoring factors in thegraphic on the same factor axis can clearly express the intrinsic link between pollutantsand monitoring points and distribution characteristics.To determine the main monitoringpoint and the main monitoring indicators can reduce and optimize the number of monitoringpoints under the premise of ensuring the typical and representative of monitoring data.Using the correlation of pollutants can reduce the number of monitoring indicators and improvethe effectiveness of data collection.

A Distributed Soil Erosion and Sediment Transport Sub-model in Non-point Source Pollution and Its Application in Guishui Watershed

官厅水库妫水地区土壤侵蚀较为严重。为控制妫水地区的土壤流失非点源污染,本文建立了一个参数较少、便于应用的分布式土壤侵蚀和泥沙输移子模型。该模型由USLE模型和泥沙输移模型组成。首先,本研究确定了USLE中各因子的计算公式,用该模型计算土壤流失。然后,将流域概化为河网,利用曾提出的应用于经Laplace变换和逆变换求得的一维水质迁移转化方程的解中的面积汇污系数和S曲线之间的关系,推导得到了分布式泥沙输移模型。最后,从妫水河流域土壤图、土地利用图中提取地理信息,以DEM为依据,研究了该模型在妫水河流域的应用。结果表明,该模型不仅可用于研究非点源泥沙污染,而且可用于研究流域内土壤侵蚀的空间分布,为实现农业最佳管理提供科学依据。妫水流域土壤流失主要来自坡度较大、地表植被覆盖差的丘陵和山地,控制土壤流失应该将重点放在该流域内的丘陵和山地上。

Modeling study of residence time and water age in Dahuofang Reservoir in China

Understanding the dynamics of water renewal in a reservoir is essential when the transport and fate of dissolved substances are evaluated.A three-dimensional hydrodynamic model was implemented to compute average residence time and water age in Dahuofang Reservoir in China.The model was verified for a one-year time period in 2006.A simulation reproduced intra-annual variation of mixing represented by the fall/winter mixing and the spring/summer stratification.The simulated variation of vertical thermal structures also matched observation.The spatially varying average residence times and age distribution were investigated through a series of numerical experiments using a passively dissolved and conservative tracer as a surrogate.Residence time estimations yield a broad range of values depending on the position.The average residence time for a tracer placed at the head of the reservoir under high-,mean-,and low flow conditions was found to be about 125,236 and 521 days,respectively.The age simulation reveals that the age distribution is a function of the freshwater discharge.In the vertical direction,the age of the surface layers is larger than that of the bottom layers and the age difference between the surface and bottom layers decreases further downstream.The density-induced circulation plays an important role in the circulation in the reservoir,and can generate vertical age distribution in the reservoir.These findings provide useful information for understanding the transport process in Dahuofang Reservoir that can be used to assist the water quality management of the reservoir.