Climate Characteristics in Three Gorges Reservoir Area after Water Storage and Its Impact on the Production Potential

Based on the meteorological data from 33 stations of Three Gorges Reservoir from 1960 to 2008,climate yield of rice,corn and winter wheat and the changes of climatic potential productivity after water storage in Three Gorges Reservoir were calculated by the dynamic statistic model of crop growth.The results showed that the temperature in Three Gorges Reservoir was fluctuant decreased before late 1980s,and warmed rapidly after the late 1980s.The precipitation had little change before the late 1990s and had a slight decrease after the late 1990s.Sunshine hours were more in 1960s and 1970s,and then it changed little after 1980s.After water storage,the temperature increased in Three Gorges Reservoir as a whole.The precipitation decreased in the south of Three Gorges Reservoir,while it increased in the northwest of Three Gorges Reservoir.The sunshine hours were reduced except that in the vicinity of Dianjiang.After water storage,climatic potential productivity of rice decreased in the northwest and the northeast,while it increased in the south of Three Gorges Reservoir.The climatic potential productivity of corn decreased in the northeast and the southwest,but increased in the rest of Three Gorges Reservoir.The climatic potential productivity of winter wheat increased almost in total.

Study on the Reservoir Water Quality Change Rule in Northern China

Water quality index of reservoir source water were tracked during three years in a north frigid area,the effect on supplied water quality was also studied.Based on the analysis of the monitoring data during the same season,the reservoir source water had typical and seasonal variation characteristics that was divided into four periods including the icebound period,spring period(or peach blossom period),stable period in summer and autumn and winter period.The icebound period was charactered by the typical low temperature and turbidity,pH and oxygen consumption decreased gradually showed that the gradually anaerobic trend existed in the reservoir.In May as the reservoir completely thawed,upstream water inflow and the total pollutant in the reservoir gradually increased,but the bottom of reservoir bottom was stable in the anaerobic state temporarily.The state completely disappeared,various index increased significantly in the middle of July.The water had high chroma characteristics,chroma and turbidity increased significantly in the summer and autumn(7-11months),but stability of water quality was poor because of rainfall.The reservoir gradually froze after the middle of November and the flow of water decreased.The peak of chroma appeared a month later than the water temperature.Due to the water turbidity was low,and the floc was small and light,the conventional water purification process design based on removal of turbidity achieved removal of chroma through a lot dosing of coagulant.

Revision of Water Function Division and Countermeasures for Water Resources Protection in Jiangjin District of Chongqing City in China

According to the current situation and development planning of water resources in Jiangjin District of Three Gorge Reservoir Area at the upper reaches of Yangtze River,by combining with social needs,through the survey on pollution source and analysis of water quality,based on the Report of Water Function Division of Jiangjin District(2005) ,the adjustment and revision have been conducted on water function divisions,and corresponding protection targets and countermeasures for water resources have been proposed,so that the water function division can comply with the development situation of Jiangjin District,providing a reliable reference for the protection and reasonable utilization of water resources,enhancing the unified and effective supervision of water resources,promoting the sustainable use of water resources in Jiangjin District,and ensuring the sustainable development of regional society and environment.

小型水库报废实施--以遂昌县高垄峡水库为例

随着国民经济发展和产业结构调整,新的区域经济发展规划会带来国土空间规划调整,从而导致区域内部分水库报废。以遂昌县高垄峡水库为例,介绍小型水库报废的实施过程,分析报废适用条件、国土空间规划、水域面积、政策处理等方面的问题并提出相关建议,可为因社会经济发展需要而报废的小型水库提供借鉴和参考。

Estimation of Small Reservoir Sedimentation in Semi-Arid Southern Zimbabwe

Small surface reservoirs play an important role of providing ready and convenient source of water for various uses in semi-arid areas which are characterized by erratic and low rainfall. Lack of current data on reservoir capacity loss due to sedimentation is one of the challenges to the sustainable management of surface reservoirs. The study investigated the capacity loss due to sedimentation from 2000-2012, and estimated the trap efficiency of the Mutangi reservoir which is located in semi-arid Chivi, Southern of Zimbabwe. Hydrographic surveys, grab sampling and water depth-capacity methods were used to determine the capacity of the dam as of 2012. To compute capacity loss from 2000 to 2012, the 2000 and 2012 dam capacities were compared whilst the trap efficiency of the reservoir was determined using a set of empirical models that relates trap efficiency to the capacity-watershed area ratio and capacity-inflow ratio. The results show that Mutangi reservoir has a trap efficiency of 95% - 98% (av = 96.4%) and has lost 37% of its capacity due to sedimentation in 12 years (2000 and 2012). Rates of sedimentation were 8539 t·yr-1, 9110?t·yr-1 and 8265 t·yr-1 for the hydrographic survey, grab sampling and water depth-capacity method respectively, and the little difference in these figures demonstrates that any method can be used to determine sedimentation rates. The area specific sediment yield (ASY) ranged from 14 - 15.5 t·ha-1·yr-1 (av = 14.956 t·ha-1·yr-1). At the current rate of sedimentation the projected dead level of the reservoir will be lost to sedimentation in 8 years while the useful life of the reservoir is estimated to be 30 years. Capacity loss due to sedimentation is further complicating the already strained water scarcity situation in semi-arid areas and management decisions should be made based on the current sedimentation rates estimated by different methods. These results imply that management practices that reduce erosion, hence sedimentation in these small reservoirs should be practiced in order to prolong their lifespan.

三峡库区黑石板滑坡的变形特征和涌浪预测

三峡库区水位波动易于导致库岸滑坡失稳进而形成涌浪灾害。以三峡库区黑石板滑坡为研究对象,基于近5年的监测数据分析:三峡库区黑石板滑坡为动水压力型滑坡,降雨只在库水位下降时和低水位波动期对滑坡的变形有一定的助推作用,其他时间对滑坡变形影响并不大。通过分析累积位移曲线中的6次阶跃变形,确定了库水位下降至165 m时为滑坡阶跃变形的启动阈值,并以此作为滑坡最危险情况下所对应的库水位高度,将其设置为数值模拟的初始水位高度。运用FLOW-3D软件进行了涌浪计算及预测:在165 m水位时,滑坡入水的最大速度为19.4 m/s,涌浪产生的最大波高为24.9 m,最大爬高为42.21 m。预测结果表明,黑石板滑坡破坏后引发的涌浪将会淹没水田坝乡沿岸部分区域,毁坏入乡主干道,这将严重影响后续对水田坝乡的救援工作。该研究为三峡库区库岸滑坡涌浪的风险管理提供科学依据,具有一定的工程实践意义。

1987—2022年新安江水库(千岛湖)水面面积时空变化及其与水位、蓄水量的响应关系

水面面积、水位、蓄水量是水库水资源管理的重要基础数据,遥感是湖库水体提取、水位和蓄水量估算的重要技术手段。由于不同水体提取方法的适用性差异、测高卫星数据的有限时间覆盖度和开源数据集的时空分辨率不足等原因,湖库水面面积、水位、蓄水量的长时序、高频率时空变化监测仍存在一定挑战。本研究以新安江水库为研究区,结合多源遥感、气象、水文和土地利用等数据,基于Google Earth Engine云平台,运用水体指数法,分析1987—2022年新安江水库水面面积时空变化特征,构建水位—水面面积、水位—蓄水量和水面面积—蓄水量响应关系,探究水面面积时空变化成因。结果表明:(1)Landsat 5、Landsat 8和哨兵2号数据的最佳水体提取指数分别为AWEIsh和GNDWI,F1-score分别为91.93%、91.03%和93.14%。相比于开放数据集GSWED(32.61%)、JRC GSW(76.17%)和ReaLSAT(69.76%),基于最优水体指数的水体提取结果具有最高的F1-score(91.26%);(2)时间上,1987—2022年新安江水库水面面积呈显著上升趋势(R^(2)=0.20,P=0.01),总体增长速率为0.96 km^(2)/a;空间上,永久性水体(淹没频率大于75%)面积占比为73.44%,主要分布在湖心等水体开阔区域;季节性水体(淹没频率>25%且≤75%)面积占比为10.17%,主要分布在湖汊区域;(3)三次多项式函数可以较好地模拟新安江水库水位—水面面积、水位—蓄水量和水面面积—蓄水量的响应关系;(4)千岛湖流域上游降水和人类活动导致的土地利用变化是影响新安江水库水面面积动态变化的主要因素。

水位变动下三峡库区堆积层滑坡失稳机制研究

库区堆积层滑坡失稳的地质灾害越来越得到广大学者的关注,水位变动是诱发滑坡失稳的重要原因之一。以三峡库区二道河滑坡为研究对象,基于非饱和流⁃固耦合数值方法,根据实际工程的水位波动情况设计了四种水位变动工况,运用仿真计算软件FLAC3D探讨库区滑坡的渗流特性、位移响应、塑性破坏及稳定性演变规律,并深入研究其失稳机制。研究结果表明:三峡库区二道河滑坡为典型的动水压力滞后型滑坡,水位上升期和低水位恒定期对滑坡有利,高水位恒定期和水位下降期对滑坡不利;随着水位的变动,安全系数的变化呈现出急剧增加、快速下降、急剧降低、缓慢回升四个阶段;水位快速下降会引起滑体部位产生位移突变,应重视滑坡前缘的防护及加固。研究成果可为堆积层滑坡失稳机制分析及滑坡治理提供科学依据。

以确保“一泓清水永续北上” 引领南水北调中线水源区水土保持高质量发展

丹江口库区及上游是南水北调中线水源区(以下简称“水源区”),其水土保持高质量发展是保障“一泓清水永续北上”的重要支撑。文章针对水源区水土流失现状和特点,总结了丹江口库区及上游水土保持重点防治工程(以下简称“丹治”工程)实施以来的水土保持成效,分析了水土保持面临的新形势和新要求,梳理了水土保持存在的短板和不足,研究提出了引领丹江口库区及上游水土保持高质量发展的对策举措,为各级政府加强南水北调中线水源区水土保持治理管理提供参考。

基于突变理论和模糊数学的湖库型水源地风险评价

为科学评估湖库型水源地风险评价等级,以茂名市电白区罗坑水库水源地为例,从水要素、管理要素、社会经济要素3方面构建了湖库型水源地风险评价指标体系,并确定各指标的评价标准,基于突变理论和模糊数学构建了风险评价模型。结果表明:水源地风险等级与水源地建设投入关系密切。自2018年罗坑水库水源地划为饮用水水源地以来,随着水源地建设投入的加大和保护力度的增强,水源地风险逐渐降低。2018-2022年,罗坑水库水源地风险评价等级依次为较高风险、较高风险、中风险、较低风险、较低风险;尽管现在罗坑水库风险较低,但后续罗坑水库仍需加大投入力度,提高水源地管理、监控和应急水平、进一步降低风险等级。

全球深水区富烃凹陷形成机理

进入21世纪以来,深水区已经成为全球常规油气储量增长的主要领域,目前处于发现期的早期,勘探潜力巨大。截至目前,全球深水区已发现的探明油气地质储量在10×10^(8)t以上的巨型、大型富油气盆地(群)共17个,其形成条件是影响/制约深水油气勘探的关键科学问题。基于对全球深水区已发现油气田分布和形成条件的综合研究,首次提出了控制深水巨型、大型富油气盆地(群)形成的“四广”成藏特征,即广烃源、广优储、广强盖、广圈闭。全球海洋深水区油气勘探存在两大领域:已证实的巨型、大型富油气盆地(群)的新领域和潜在的巨型、大型富油气盆地(群)。已证实的巨型、大型富油气盆地(群)的新领域主要包括盆地的超深水区、深层隐蔽圈闭及浅层隐蔽圈闭,是今后主要勘探领域,如大西洋陆缘盆地盐下深层、东非陆缘侏罗—白垩系碎屑岩与碳酸盐岩、南海北部深水区深层潜山、巴伦支海三叠系、东地中海盐下白垩系碎屑岩及侏罗系生物礁、澳大利亚西北陆架波拿巴盆地深层石炭—二叠系等,勘探程度低,是近期深水勘探的主攻方向。潜在的巨型、大型富油气盆地(群)资源潜力大,当前这些盆地或已钻井有油气发现、或没有钻井且勘探程度低,与已证实的巨型、大型富油气盆地(群)经历了类似的构造演化过程,油气地质条件相似,是未来深水油气勘探新的增长点。

小浪底水库水体时空变化特征与驱动因素分析

以2018-2021年Sentinel-2遥感影像为数据源,利用Google Earth Engine (GEE)云平台研究小浪底水库月尺度水体面积的时空变化。结果表明,2018-2021年小浪底水库水体面积月际变化波动较大,每年均呈先降后升的趋势,具有显著的季节性变化规律,夏季汛期防洪降低库容,冬季蓄水增加库容保证生产生活用水;小浪底库区存在约85.29 km2的永久性水体,占总面积的34.84%,出现水陆变化的区域集中于水库边缘区域;气温、降水是水体变化的驱动因素,水体面积与月平均气温、月降水量呈负相关关系。研究结果表明,以GEE云平台为基础的连续时间序列、大范围水体动态变化监测存在可行性。

丹江口水库水源区地下水环境调查与评价

丹江口库区是南水北调中线工程的核心水源区,为了持续抓好输水沿线区和受水区的污染防治和生态环境保护工作,运用综合评价分析方法,对水源区的地下水环境进行调查和采样分析。结果表明:①丹江口水库水源区共有20个潜在污染源,其中生活垃圾场共12个,尾矿库共4个,闭坑矿洞废水4个。②126组地下水样品中,Ⅲ类水占比最高,为30%,其次为Ⅱ类水和Ⅳ类水,均占比24.5%,Ⅴ类水占比19%,Ⅰ类水占比最低,仅为2%;重度污染的Ⅴ类水有24组,主要分布在郧阳区和竹山县,郧阳区主要超标指标为硝酸盐、铝等,竹山县主要超标元素为锌;中度污染的Ⅳ类水有31组,主要分布在房县和丹江口市,房县主要超标元素为铁,丹江口市主要超标指标为硝酸盐。③地下水中超标率较高的指标为铁(18.0%)、硝酸盐(12.5%)、铝(11.7%)和锌(10.9%)。研究结果可为该区域生态环境保护提供基础支撑。

埕岛东区水淹油藏加密水平井合理生产压差研究

埕岛油田东区馆上段Ng4^(2)层油藏历经多年注水开发,已形成较强水淹,在井区调整加密水平井大幅提高产能的开发需求下,既要保证油井较高的产能和采油速度,又要在平台寿命期内合理控制含水上升达到较高的采收率,需要优化合理的生产压差。通过建立埕岛东区的油藏物理模型,设立六种不同生产压差分别模拟评价含水率变化特征、产液量变化特征、采出程度变化特征,并开展综合开发效果评价。结果显示,在埕岛海上平台开发寿命周期内最优生产压差为1.2 MPa,并在251GB-P1、251GB-P2等井的矿场实践中取得了较好的开发效果。研究认为,在水淹油藏通过优化生产压差实现提升产油量、提高采油速度和最终采出程度的目的是可行的。

基于长时序稠密遥感数据分析黄河流域大中型湖库水域面积动态变化特征

黄河流域在我国经济社会发展和生态安全中具有重要地位。但从全流域的角度,基于长时序稠密遥感数据对黄河流域大中型湖库开展的研究却较少。本文基于MODIS 8天合成数据,提取了2000—2020年黄河流域大中型湖库长时序的水域信息,分析其时空变化特征,结果表明:从月际变化看,3—5月为水域面积第一个快速增长时期,6—10月为第二个增长时期,在10月达到最大值,10月之后逐渐下降,至次年2月达到最小值;从年际变化看,近20年上、中、下游湖库水域面积均呈现增长趋势,其中上游地区对全流域面积增长的贡献度最大,中游次之;湖库水域空间分布不均衡,上、中、下游近20年湖库水域面积平均占比分别为69.27%、25.02%、5.72%。

适应水位变化的三峡库区消落带碳汇提升设计及效益评估

【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带生态系统并提升碳汇能力的技术框架,选取位于三峡库区腹心的大浪坝消落带开展实证研究。运用CASA模型测算修复前后大浪坝消落带的净初级生产力(net primary productivity,NPP),基于植被生物量数据计算修复后大浪坝消落带与未修复对照组内不同高程带的碳汇能力,评估林塘碳汇系统的可持续效益。【结果】修复后大浪坝消落带的碳汇能力随时间推移明显提升,NPP由2012年的154.4 g C·m^(2)·a^(-1)增长至2016年的182.5 g C·m^(2)·a^(-1);各高程带的碳汇能力均显著高于对照组,并呈现出随海拔降低而减弱的趋势,170~175 m高程带碳汇能力达到1.827 kg C/m^(2),160~165 m高程带碳汇能力仅为0.830 kg C/m^(2)。林塘系统增强了生态系统的适应性和复原力,形成了适应水位变化的立体固碳模式并有效提升了碳汇效率。【结论】林塘碳汇系统是应对三峡库区复杂水位变化和长时间深水淹没挑战的适应性探索,显示出景观优化、生物多样性、经济效益与碳汇协同耦合的关键特征。研究成果能够为中国大型工程型水库消落带的治理及碳增汇提供科学依据与可复制推广的创新技术模式。

三峡库区不同种植制度的坡地水土流失特征

剖析农业种植制度对库区水土流失的季节性影响,有助于深刻认识库区农业区域水土流失发生规律。基于2018—2021年共4年期间中国科学院三峡库区水土保持与环境研究站自有粮油作物、蔬菜作物、柑橘果园、灌草撂荒4种种植制度小区的水土流失监测数据的整理分析,结果表明:库区4—8月降雨量占全年降雨量的60.4%~75.8%,年内中雨发生频率最高,占73.63%,大雨次之,占19.78%,暴雨频率最低,占6.59%。4种种植制度小区中,柑橘果园的平均径流深、土壤侵蚀强度都最大,表明柑橘果园是该区域重要的水土流失源地。蔬菜作物和粮油作物是库区坡耕地的主要农作物,地块耕作频繁,易于发生水土流失,但不同种植制度下的作物生长周期、田间管理措施存在明显差异,对植被覆盖度、土壤紧实度产生显著影响,进而影响地表径流发生和土壤侵蚀过程。因此,对于三峡库区侵蚀性降雨年内分布不均和不同种植制度田间耕作管理、植被覆盖的季节性差异,应有针对性地采取防治措施,以有效保护农业土壤资源。

Effects of the dispatch modes of the Three Gorges Reservoir on the water regimes in the Dongting Lake area in typical years

Based on the field-survey prototype hydrology data in typical years, the effect during the running periods of different dispatch modes of the Three Gorges Reservoir on the water regimes in Dongting Lake area is comparatively analyzed. The results are shown as follows. （1） The influence periods are from 25 May to 10 June, from 1 July to 31 August, from 15 September to 31 October and from December to the next April, among which the influence of the water-supplement dispatch in the dry season is not very sensitive. （2） During the period under the pre-discharge dispatch, the runoff volume slightly increases as well as both the average water level and the highest water level rise in the usual year. While in the wet and dry years, the average increase in the runoff volume is 40.25×1 08 m3 and the average rises of the average water level and the highest water level are both 1.06 m. （3） As for the flood-storage dispatch, the flood volume increases slightly, in the dry and wet years, the flood volume, the average water level and the highest water level averagely reduce by 444.02×108 m3, 2.64 m and 1.42 m respectively. （4） Under the water-storage dispatch, the runoff volume slightly in- creases and the water level heightens in a sort in the usual year. And in the dry and wet years the average decreases in the runoff volume, the average water leve/and the highest water levels are respectively 185.27×108 m3, 3.13 m and 2.14 m. （5） During the period under the water-supplement dispatch, the runoff volume, the average water level and the highest water levels averagely decline by 337.7×108 m3, 1.89 m and 2.39 m respectively in the usual and wet years. However, in the dry year, the runoff volume increases as well as the average and highest water levels slightly go up.

农村供水工程中生物慢滤净水工艺数字孪生实践

在新形势下,国家大力推进数字孪生技术在农村供水工程管理中的应用。我国西南丘陵山区农民居住较为分散,水源多样,生物慢滤技术因其构造简单、对水质适应性强而被广泛应用,但在日常运行过程中存在维护不及时、无法准确判断出水是否达标等问题,对供水安全构成威胁。生物慢滤技术实施数字孪生建设,通过在关键节点安装监控设备,监测供水过程的浊度、滤速和水质等参数,监测数据由无线遥感终端汇集至数据分析系统,对超出阈值的实时数据发出报警,通知管水员实地检查。三峡库区秭归县水田坝乡工程实践结果表明,农村供水工程进行智慧化改造能够改变人工现地管理传统方式,减轻了管水员的工作压力,供水水质得到保障。从实践的效果来看,生物慢滤净水工艺数字孪生是农村供水工程智慧化供水的一次有益尝试。

岩溶库区不同植被类型土壤碳、氮及其组分特征-以贵阳市花溪水库为例

在贵阳市花溪水库附近选择3种植被类型(草地、灌丛、竹林)作为研究对象,探究3种植被类型下不同土层中土壤碳、氮含量及其不同活性组分的特征。结果表明:植被对碳、氮及其组分(除铵态氮外)影响显著,随植被类型变化(草地→灌丛→竹林)有机碳及其各活性组分含量逐渐增加,A层>B层;竹林中有机碳含量为36.16 g·kg^(-1)、29.68 g·kg^(-1),明显高于草地中的20.48 g·kg^(-1)、18.24 g·kg^(-1);草地中微生物碳含量仅占竹林的54%及49%,水溶性碳在有机碳中的比例最小(0.04%~0.11%),其次是微生物量碳;微生物量氮所占比例最少,仅占全氮中的0.02%~0.20%,随植被变化(草地→灌丛→竹林)微生物量氮含量逐渐增加,硝态氮含量逐渐降低,铵态氮的含量远高于硝态氮的含量,微生物量氮与碱解氮的含量随土层加深含量降低,全氮含量增加。土壤的C/N在8.49~21.52之间,在A层中表现为草地<灌丛<竹林,A层>B层。因此,植被类型对岩溶地区的土壤质量及附近水域均会产生影响,在岩溶水源涵养区,竹林及灌丛更有利于保持水土及附近水域的水质,草地不适合作为岩溶地区生态修复的植被类型。