Runoff variations in the Luanhe River Basin during 1956-2002

The decrease of runoff in the Luanhe river basin, which caused water crisis in Tian-jin for several times, was investigated using discharge data covering the period 1956-2002. The data from the differential integral curves of the annual runoff indicate that the decreasing point began in 1979 in the six sub-basins. The decrease of runoff in the Luanhe river basin resulted from the combination of climate effects and human activities, in which the latter plays an important role. This can be illustrated by noting that after 1979 the runoff generated by similar precipitation decreased under the condition that the total precipitation did not decrease in the entire basin. As a result, the annual runoff of the Luanhe river basin after 1979 decreased by about 6.46×10^8 m^3 each year. To analyze the runoff characteristics, it is inadequate to seek the runoff trends only and the identification of cyclical component of the runoff as accurate as possible is necessary. From the natural annual runoff discharge time series, we can see the annual runoff fluctuates around the long-term average. Analyzed by VRL （Variable Record Length） method, the main periods of 3, 5-6, 7, 9, 16-20 and 37-39 years were found. The last decade causing water crisis was the driest period in the history, and this condition will last several years from trend analysis and power spectrum analysis. So finding new water sources is urgent to solve water crisis in Tianjin city, and the South-North Water Transfer is a feasible option.

Sediment transport in the Luanhe River delta:grain size trend analysis

Sediment grain size in the deltaic environment of the Luanhe River(LR),Liaoning,China,contains sediment transport pathway information useful in elucidating the shoreline change and fluvialmarine interaction.In this study,we utilized numerical partitioning of the sedimentary components and geostatistical grain size trend analysis(GSTA)to define the sediment transport pattern in the Luanhe River delta(LRD)and interpolated the sediment transport pattern using content changes of end numbers(EM).EM1(the mean grain size 7.12Ф,fine silt),EM2(2.37Ф,fine sand),and EM3(1.27Ф,medium sand)components were identified by the numerical partitioning by GSTA.Kriging interpolation method was used to interpolate the parameters of the grain size for the regular grid,and the interpolation radius was 0.015 decimal degree.We chose 0.09 decimal degree as the characteristic distance for GSTA in the semivariogram model using the geostatistical method.The FB(-)case(finer,better sorted and more negatively skewed)was adopted in GSTA for its satisfaction in the Global Moran’s I test.The result of the GSTA shows that the sediments in the south barriers(SBs)were transported to the southwest of the study area.The sediments in the north,in the SE direction of sediment transport trend from the river mouth,indicated that the sediments in the north of the study area were transported from the LR to the northern beaches,and to the south and east of the study area.The sediment transport trend that simplified by GSTA as the FB(-)case was approved by the content changes of sedimentary components(i.e.EM1,EM2,and EM3).In addition,the turbulent jet diffusion pattern indicated that the coarse sediments(EM3)were delivered by LR during the flood season,and the EM2 and EM1 were from wave and tide,respectively.

Analysis of spatio-temporal evolution of droughts in Luanhe River Basin using different drought indices

Based on the monthly precipitation and air temperature from 1960 to 1989 in the Luanhe River Basin, the standardized precipitation evapotranspiration index （SPEI） and standardized precipitation index （SPI） at three- and six-month time scales and the self-calibrating Palmer drought severity index （sc-PDSI） were calculated to evaluate droughts in the study area. Temporal variations of the drought severity from 1960 to 1989 were analyzed and compared based on the results of different drought indices, and some typical drought events were identified. Spatial distributions of the drought severity according to the indices were also plotted and investigated. The results reveal the following： the performances of different drought indices are closely associated with the drought duration and the dominant factors of droughts; the SPEI is more accurate than the SPI when both evaporation and precipitation play important roles in drought events; the drought severity shown by the sc-PDSI is generally milder than the actual drought severity from 1960 to 1989; and the evolution of the droughts is usually delayed according to the scPDSI. This study provides valuable references for building drought early warning and mitigation systems in the Luanhe River Basin.

Environmental and ecological water requirement of river system: a case study of Haihe-Luanhe river system

In order to reduce the environmental and ecological problems induced by water resources development and utilization, this paper proposes a concept of environmental and ecological water requirement. It is defined as the minimum water amount to be consumed by the natural water bodies to conserve its environmental and ecological functions. Based on the definition, the methods on calculating the amount of environmental and ecological water requirement are determined. In the case study on Haihe-Luanhe river system, the water requirement is divided into three parts, i.e., the basic in-stream flow, water requirement for sediment transfer and water consumption by evaporation of the lakes or everglades. The results of the calculation show that the environmental and ecological water requirement in the river system is about 124×108 m3, including 57×108 m3 for basic in-stream flow, 63×108 m3 for sediment transfer and 4×108 m3 for net evaporation loss of lakes. The total amount of environmental and ecological water requirement accounts for 54% of the amount of runoff (228×108 m3). However, it should be realized that the amount of environmental and ecological water requirement must be more than that we have calculated. According to this result, we consider that the rational utilization rate of the runoff in the river systems must not be more than 40%. Since the current utilization rate of the river system, which is over 80%, has been far beyond the limitation, the problems of environment and ecology are quite serious. It is imperative to control and adjust water development and utilization to eliminate the existing problems and to avoid the potential ecological or environmental crisis.

Changes of groundwater flow field of Luanhe River Delta under the human activities and its impact on the ecological environment in the past 30 years

The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone.It enjoys rapid economic and social development while suffering relatively water scarcity.The overexploitation of groundwater in the Luanhe River Delta in recent years has caused the continuous drop of groundwater level and serious environmental and geological problems.This study systematically analyzes the evolution characteristics of the population,economy,and groundwater exploitation in the Luanhe River Delta and summarizes the change patterns of the groundwater flow regime in different aquifers in the Luanhe River Delta according to previous water resource assessment data as well as the latest groundwater survey results.Through comparison of major source/sink terms and groundwater resources,the study reveals the impacts of human activities on the groundwater resources and ecological environment in the study area over the past 30 years from 1990 to 2020.The results are as follows.The average annual drop rate of shallow groundwater and the deep groundwater in the centers of depression cones is 0.4 m and 1.64 m,respectively in the Luanhe River Delta in the past 30 years.The depression cones of shallow and deep groundwater in the study area cover an area of 545.32 km^(2)and 548.79 km^(2),respectively,accounting for more than 10%of the total area of the Luanhe River Delta.Overexploitation of groundwater has further aggravated land subsidence.As a result,two large-scale subsidence centers have formed,with a maximum subsidence rate of up to 120 mm/a.The drop of groundwater level has induced some ecological problems in the Luanhe River Delta area,such as the zero flow and water quality deterioration of rivers and continuous shrinkage of natural wetlands and water.Meanwhile,the proportion of natural wetland area to the total wetland area has been decreased from 99%to 8%and the water area from 1776 km^(2)to 263 km^(2).These results will provide data for groundwater overexploitation control,land subsidence prevention,and ecological restoration in plains and provide services for water resources management and national land space planning.

Water Purification Capacity of Four Kinds of Aquatic Plants in the Upper Reaches of Luanhe River

Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic plants and their configurations showed purification effects for total nitrogen(TN), nitrate nitrogen(NO_3^-), total phosphorus(TP), orthophosphate(PO_4^(3-)) and chemical oxygen demand(COD) in water body, and the purification effects of aquatic plant configurations were better than those of single ones. Regression analysis was conducted for dynamics of various water quality indicators. The removal rates of TN and COD within 50 d by the combination of L. salicaria and I. wilsonii were 73.83% and 77.4%, respectively, with the best purification effect; the removal rate of NO_3^- within 20 d by the combination of S. validus and I. wilsonii was 89.41%; and the combination of S. validus and I. wilsonii showed the best removal effect for TP and PO43-, of which the 50-d removal rates were 88.98% and 92.39%, respectively. Reasonable choice of local aquatic plants and their optimal combinations can be applied in the improvement of water quality of rivers.

土地利用结构与景观格局对黎河水质的影响

黎河是引滦入津工程的唯一连接通道,探究土地利用结构与景观格局对黎河水质的影响,可为合理优化流域土地资源、保护流域水质安全提供参考。2022年3月至6月选取了12个水质监测点采集水样,并检测了化学需氧量(COD)、氨氮(NH_(4)^(+)-N)、总磷(TP)、溶解氧(DO)和高锰酸盐指数(COD_(Mn))等5个水质指标。基于遥感数据和土地利用数据,利用GIS软件生成4种空间尺度的圆形缓冲区域,提取了不同空间尺度的景观格局指数,采用相关分析和冗余分析(RDA),探讨了土地利用结构与景观格局对水质的影响。结果表明:(1)黎河水质整体较好,总体达到Ⅱ类标准,但仍存在超标水质,其中输水期水质明显好于非输水期;多数点位COD、TP值超过Ⅱ类水质标准限值,其余水质指标年均浓度均达到Ⅱ类以内水质标准;(2)不同尺度缓冲半径内占地类型均以林地、耕地、建设用地为主,建设用地、水域面积比例的增加可导致水质的恶化,林地、草地增加可对水质起到提升作用;(3)不同空间尺度缓冲区景观格局指数对水质具有较好的解释度,500 m半径缓冲区景观格局对水质的解释能力最强,解释度达59.8%,其次为1000 m尺度(56.0%)。因此,要加强500 m半径缓冲区尺度土地利用的优化,严格控制流域建设用地、水域面积的增加。

滦河流域TRMM卫星降水数据适用性研究

利用滦河流域8个雨量站点2003—2019年实测降水资料,对TRMM卫星降水数据在滦河流域的适用性进行了评估。结果表明,TRMM降水量与实测降水量具有一致的年内分布规律和时空分布特征。在年、季、月时间尺度上,TRMM降水量具有较高的精度,普遍高于实测值,7月存在低估现象;夏秋季降水精度较高,冬季略差;7—10月精度较高,12月—次年2月精度较差。空间上,TRMM降水量精度随着海拔的降低而增加,在流域中上游TRMM降水量高估,沿海地区略微低估,乐亭站、秦皇岛站存在低估现象。

渤海曹妃甸海域表层沉积物常量元素特征及其对源区风化特征的指示意义

通过对渤海曹妃甸海域的161个表层沉积物样品和环渤海湾主要河流的30个表层沉积物样品进行常量元素测试,研究常量元素组合特征及其影响因素,并运用化学蚀变指数(CIA),探讨沉积物风化特征及其物源指示意义。结果表明,曹妃甸附近海域表层沉积物常量元素氧化物组分以SiO_(2)和Al_(2)O_(3)为主,Si、Al、Fe、K、Mg、P、Ti 7种元素“粒度效应”显著,受沉积物粒径影响,除Si外,其他6种元素在研究区基本呈现南高北低、西高东低的分布格局。元素Ca、Na受物源的影响显著,Mn的分布与氧化还原条件相关。风化程度研究表明,曹妃甸海域砂粒级和粉砂粒级沉积物CIA分别为48.4和57.2,CIA与沉积物粒径呈正相关性,与周边水系沉积物同处于初级风化阶段,其源岩成分接近二长花岗岩。地形和气候差异是影响滦河水系和海河水系沉积物风化程度差异不可忽视的重要因素。

基于下垫面变化的月径流模型在滦河中游武烈河、柳河典型子流域的应用

随着气候变化与人类活动的推进,研究基于下垫面变化的月径流模型尤为重要。在对当前主流月径流模型进行总结评估的基础上,结合模型应用过程中所反映的实际问题,对所涉及的关键技术进行了深入研究、改进和整合,并结合研究区水文特性,建立了一个能够综合考虑下垫面变化的月径流水文模型。实例应用表明,模型具有定量识别下垫面变化过程的能力,采用10年分段方法进行下垫面变化过程的识别是可行的,有利于消除水文过程的随机性及模型误差带来的波动性;模型在水资源评价方面可以较方便地进行还原或还现处理,定量分析出下垫面变化对水资源的影响。研究结果对于深入了解流域下垫面变化条件下的径流变化规律及未来不同气候情景下径流效应具有重要的理论意义和现实价值。

滦河流域防洪形势分析及应对策略研究

滦河流域是海河流域三大水系之一,历史上多次发生流域性大洪水。在对滦河流域现状水库、堤防防洪能力分析的基础上,系统梳理了潘家口水库调度,潵河洪水防御,潘家口、大黑汀、桃林口水库联合调度,防洪小埝防守,超标准洪水应对等防御重点,研究提出加强水文监测预报预警、强化水库群联合调度、加强河道治理、完善超标准洪水避险转移和安置预案等应对策略。

河北丰宁抽水蓄能电站水情自动测报系统越冬实践

河北丰宁抽水蓄能电站水情自动测报系统所在区域冬季温度极低,为了保障电站正常、安全运行,对水情自动系统在冬季寒冷条件下运行情况进行了测试,观察、统计了极寒条件下系统各遥测站的电压与通畅率,分析测试期间上、下水库的逐日最低气温过程、遥测站电压过程以及气温对遥测站电压的影响。结果表明:丰宁水情测报系统能够适应该地区冬季的严寒条件,测试期间水情数据报送及时、准确,遥测站平均通畅率达到98.8%,能够为丰宁抽水蓄能电站平稳运行提供水情信息保障。

数字孪生滦河工程“四预”平台建设研究

针对滦河历史洪水灾害频发情况,为提升滦河水灾害防御能力,实施数字孪生滦河工程“四预”平台建设。结合滦河流域洪水特点,基于数字孪生、数字映射、大数据、云计算、物联网等先进技术,以三维数字孪生场景为数据底板,水文计算模型为算力,提升流域防洪“四预”能力为目标,开发“四预”平台和滦河智慧“四预”大屏,实现历史演变、实时监控、趋势研判3个不同时间维度的功能递进展示。“四预”平台包含信息化基础设施、数字孪生平台、业务系统3个层级,通过构建流域洪水“天空地”一体化监测体系,共享补充流域下垫面、数字地形、影响区域经济社会等数据,形成流域防洪数字孪生场景,开展超前模拟仿真推演,实现洪水预报、预警、预演、预案功能。数字孪生滦河工程“四预”平台建设完成后,将滦河流域“七一三”洪水的水文监测和工程调度资料输入系统进行验证,计算成果可靠,可为滦河流域防洪安全提供有力保障。

Analysis Hierarchy Process Model for Plain River Reach Health Assessment of the Luanhe River

In light of the ecological health problem occurring between the plain river reach between Daheiting and the estuary of the Luanhe River, three first-level indicators （river physical characteristic, eco-hydrological characteristic and socio-economic features） and corresponding fifteen second-level indicators such as river natural connectivity, water quantity, etc., were employed to establish the analysis hierarchy process （AHP） model. After fitting the AHP model with the data of 2005, the results show that the overall plain river reach health assessment score is 0.698 and the ecology is basically healthy. Moreover, construction of the Panjiakou Reservoir on the river mainstream destroyed the river natural morphologies, and finally contributed to the relatively low scores： 0 and 0.5 for river natural connectivity and river curve degree, respectively. It implicates that measures such as construction of ecological river course and reservoir dispatching should be taken into account in further restoration projects of the Luanhe River.

滦河水系马口鱼胚胎及仔鱼发育观察

为了解滦河水系马口鱼(Opsariichthys bidens)胚胎和仔鱼发育情况,对其胚胎和仔鱼发育开展了系统观察。结果显示:马口鱼卵圆球形,颜色黄或深黄,沉性,卵径1.2~1.4 mm,吸水后卵径1.4~1.6 mm。孵化水温19~22℃的条件下,经历胚盘形成期、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和出膜期7个阶段,历时50 h 46 min孵化出膜,所需积温1054.90℃·h。培育水温22~25℃条件下,仔鱼1日龄平均全长为(6.03±0.24)mm,2日龄时眼中布满黑色素,3日龄胸鳍出现,4日龄鳔出现,至5日龄时卵黄囊完全消耗,17日龄全长(14.55±0.40)mm,各鳍发育完全。其早期发育阶段(1—17日龄)的生长特性符合:y=0.0145 x 2+0.2627 x+6.0443(R 2=0.9933)。

滦河下游河水及沿岸地下水水化学特征及其形成作用

了解地表水和沿岸地下水的水化学特征及其形成作用,对地下水水资源保护和可持续开发利用具有重要意义。在系统采集滦河河水及沿岸地下水的基础上,运用描述性统计、相关性分析、阴阳离子三角图、Gibbs图、离子比例系数等方法对水样的离子特征和水化学类型的形成作用进行了分析。研究结果表明:(1)从出山口到入海口,浅层地下水化学类型由HCO3型过渡到HCO3·SO4(SO4·HCO3)型,再逐渐转变为Cl·HCO3型,而阳离子则由Ca(Ca·Mg)向Na·Ca(Na)型转化。(2)浅层地下水化学的形成受地形地貌以及地质结构的控制,在山间盆地和冲洪积扇,溶滤作用是控制地下水水化学变化的主要作用,向下游随着含水介质颗粒变细,地下水径流速度变缓,溶滤作用减弱,蒸发浓缩作用逐渐增强,从出山口到入海口,河水和地下水的钠吸附比(SAR)不断增大,说明溶滤作用逐渐被阳离子交替吸附作用代替。(3)河水的水化学类型主要为HCO3·SO4-Ca·Mg(SO4·HCO3-Ca·Mg)型。水化学形成以蒸发浓缩作用为主,同时受河床中的碳酸盐矿物和硅铝酸盐矿物溶滤作用的影响,在冲积海积平原可能存在蒸发盐岩的溶解。

渤海湾北部底质沉积物中黏土矿物组成与物源研究

采用X射线衍射物相分析,对渤海湾北部166个表层沉积物样品和A435柱状样中的23个沉积物样品的主要黏土矿物含量组成进行分析。研究结果表明:渤海湾表层沉积物黏土矿物中伊利石(53.0%)含量最高,其次为蒙脱石(27.9%)、绿泥石(9.9%)和高岭石(9.2%),黏土矿物组合为伊利石-蒙脱石-绿泥石-高岭石型。渤海湾北部表层沉积物可分成3个沉积区,分别代表不同的沉积物来源:北部沿岸为滦河-海河物源区;中部和东部为黄河-海河物源区;西部沿岸为海河物源区。渤海湾北部表层沉积物黏土矿物分布和组合特征显示了渤海湾环流对海河、黄河和滦河来源物质的搬运和扩散作用。A435柱状样各黏土矿物含量在100cm以上层段具有很大的波动性,推测主要为黄河在1048—1128年和1128—1855年的改道事件的影响。

臭氧—活性炭深度处理滦河水的试验研究

对滦河水进行 O_3—GAC 工艺深度处理中试研究表明：O_3—GAC 能在较长时间内保持对水中有机物的去除，COD_(Mn)的平均去除率为60.19%；TOC 的平均去除率为64%；UV_(254)的平均去除率为70.41%；NH_3-N 的平均去除率为53.83%；对水中的浊度和色度都有明显的去除效果，尤其臭氧化对改善难生物降解有机物的可生化性有十分显著的作用；O_3—GAC 能有效地去除饮用水中的有害、有毒物质，提高饮用水的安全性。

滦河流域土地利用/覆被变化的水文响应

以滦河流域为研究区,利用1985和2000年土地利用数据,结合SWAT分布式水文模型定量评价了流域土地利用/覆被变化的水文效应,并分析了流域地表径流变化与主要景观类型的响应关系。结果表明:SWAT(Soil and Water Assessment Tool)模型可以较好地模拟滦河流域的月流量过程,在研究区具有较好的适用性;1985—2000年流域林地向草地和耕地的转变导致流域年均地表径流和总径流量分别增加了12.6%和5.1%;并使得流域年均地表径流变化空间差异显著,整体呈增加趋势,且主要受到林地变化的影响,而在三道河子以上集水区地表径流的变化则主要受到耕地景观的影响。合理规划土地利用格局,对于流域水资源可持续利用具有重要意义。

滦河流域沉积物中重金属分布特征及风险评价

沉积物作为重金属污染物的源和汇,对水环境有着至关重要的影响。为了全面了解滦河沉积物中重金属污染现状,采用电感耦合等离子体质谱法对滦河干支流沉积物中重金属含量进行了测定,分析了其空间分布,并采用潜在生态危害指数法对滦河沉积物进行了评价。结果表明:滦河沉积物中Cr、Ni、Cu、Zn、Cd和Pb的平均含量分别为60.40、26.15、48.07、76.42、0.30、25.55 mg/kg,其中Cu和Cd含量高于中国水系沉积物背景值。滦河干流的重金属含量空间分布自上游往下游呈逐渐增加趋势。潜在生态危害指数评价结果表明:不同重金属污染对滦河流域生态风险构成的危害由强至弱依次为:Cd>Cu>Pb>Cr>Zn,其中Cu、Pb、Cr和Zn为低生态危害等级,Cd以中等生态危害等级为主。总体上,滦河沉积物重金属处于中等生态危害等级,干流大黑汀水库和支流瀑河宽域处于强生态危害等级。