Quantitative relationship between surface sedimentary diatoms and water depth in North-Central Bohai Bay,China

To study the quantitative relationship between surface sedimentary diatoms and water depth,67 surface samples were collected for diatom analysis on eight profiles with water depth variation from the muddy intertidal zone to the shallow sea area in North-Central Bohai Bay,China.The results showed that the distribution of diatoms changed significantly in response to the change in water depth.Furthermore,the quantitative relationship between the distribution of dominant diatom species,their assemblages,and the water depth was established.The water depth optima for seven dominant species such as Cyclotella striata/stylorum,Paralia sulcata,and Coscinodiscus perforatus and the water depth indication range of seven diatom assemblages were obtained in the study area above the water depth(elevation)of-10 m.The quantitative relationship between surface sedimentary diatoms and water depth provides a proxy index for diatom-paleo-water depth reconstruction in the strata in Bohai Bay,China.

Validation of the Relationship between Precipitable Water and Surface Vapor Pressure by Means of Reanalysis Data

By means of ERA-40, JRA-25, NCEP/NCAR and NCEP/DOE reanalysis data, empirical relations between precipitable water and surface vapor pressure in spatial and temporal scale were calculated. The reliabilities of precipitable water from reanalysis data were validated based on comparing different W-e empirical relations of various reanalysis data, in order to provide basis and reference for reasonable application. The results showed that W-e empirical relation of ERA-40 was closest to that of sounding data in China, and precipitable water from ERA-40 was the most credible. The worldwide comparison among W-e empirical relations of four reanalysis data showed that there was little difference in annual mean W-e empirical relations in the middle latitudes and great differences in low and high latitudes. Seasonal mean W-e empirical relations in the middle latitudes of the northern Hemisphere had little difference in spring, autumn and winter, but great difference in summer. Therefore, the reliabilities of precipitable water from reanalysis data in spring, autumn and winter in the middle latitudes of the northern hemisphere were higher than other areas and seasons. W-e empirical relations of NCEP/NCAR and NCEP/DOE had good stability in different years, while there was poor stability in ERA-40 and JRA-25.

The new multistage water adsorption model of Longmaxi Formation shale considering the spatial configuration relationship between organic matter and clay minerals

The water adsorption by shale significantly affects shale gas content and its seepage capacity.However,the mechanism of water adsorption by shale is still unclear due to its strong heterogeneity and complicated pore structure.The relationship between the adsorbed water content at different relative humidities(RHs)and shale compositions,as well as shale pore structure and the spatial configuration relationship between organic matter(OM)and clay minerals,was investigated to clarify the controlling factors and mechanisms of water adsorption by Longmaxi Formation shale from the Southern Sichuan Basin in China.Consequently,the water adsorption process could be generally divided into three different stages from 0%RH to 99%RH.Furthermore,the Johnston’s clay mine ral interlayer pore structure model(JCM),the Freundlich model(FM)and the Dubinin-Astakhov model(DAM)were tested to fit the three water adsorption stages from low RH to high RH,respectively.The fitting results of the JCM and FM at lower RHs were far from good,while the fitting results of DAM at higher RHs were acceptable.Accordingly,two revised models(LRHM and MRHM)considering the spatial configuration relationship between OM and clay minerals were proposed for the two stages with lower RHs,and performed better fitting results indicating the pronounced effect of the spatial configuration relationship between OM and clay minerals on the water adsorption process of Longmaxi Formation shale.The outcomes of this study will contribute to clarifying the water distribution characteristics in the pore network of shale samples with variable water contents.

Relationship between the Water Body Chlorophylla and Water Quality Factors of Wetlands Baiguishan Reservoir

[Objective] The aim was to explore the relationship between water body Chlorophyll-a and water quality factors of wetlands Baiguishan reservoir.[Method] Chlorophyll-a and water quality factors of water quality of Wetlands BaiGuishan Reservoir was studied,the analysis of the relationship on water quality of Wetlands Baiguishan Reservoir was made by use of trophic status indices and SPSS17.0 statistical analysis.[Result] Total phosphorus was an important factor of influence Chlorophyll-a in reservoir,water body had slight eutrophication phenomenon in reservoir of July to October in 2010.[Conclusion] Comprehensive management should be strengthened so as to improve the water quality of Baiguishan wetland.

Combined effect of bicarbonate and water in photosynthetic oxygen evolution and carbon neutrality

Carbon neutrality is widely concerned and highly valued by many countries.Biosphere has always maintained the balance between oxidized organic substances and assimilated organic matter,resulting in netzero carbon dioxide(CO_(2)) emissions and maintaining its own carbon neutrality.Nature has set a good example for human beings to coordinate oxygen(O_(2)) balance and CO_(2)balance,and achieve carbon neutrality.How does photosynthetic oxygen evolution initiate carbon and water neutrality?My synthesis shows that photo system Ⅱ functions as carbonic anhydrase to catalyze the reaction of CO_(2)hydration under physiological conditions,and CO_(2)hydration coupled with chemical equilibrium,H^(+)+HCO_(3)^(-)→1/2O_(2)+2e^(-)+2H^(+)+CO_(2),occurs in a photosystem Ⅱ corecomplex.Meanwhile,I focused on the revisiting of four classical heavy oxygen(O^(18)) labeling experiments and found that bicarbonate can promote photo synthetic oxygen evolution,and that photo synthetic oxygen evolution can alternately come from bicarbonate and water,not only water.Bicarbonate photolysis and water photolysis account for half of the photo synthetic oxygen evolution respectively,which can well explain the bicarbonate effect,Dole effect and plants’ environmental adaptability.Photosynthetic oxygen evolution initiated the journey of water metabolism and carbon metabolism in nature,which led to the coupling as 1:1(mol/mol) stoichiometric relationship between the reduction of CO_(2)and oxidation of organic carbon,coordinated the evolution of the atmosphere,hydrosphere,lithosphere and biosphere,and realized "carbon neutrality" in the whole Earth system.

Relative Abundance and the Relationships between Aniline,Phenol and Catechol Degraders in Fresh Water

Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.

区域水平衡及失衡程度度量方法

区域水平衡量化及诊断是水网工程建设优化和水资源均衡调控的基础,对提升水安全保障能力、支撑经济社会稳定发展、实现人水和谐具有重要意义。本文从空间、时间、结构、过程、总量五个维度解构了区域人水系统的四大平衡,即反映水收入项和支出项定量关系的水收支平衡、体现经济社会供水量与需水量匹配关系的经济社会供需水平衡、结合经济社会-生态系统发展与用水定量关系的经济社会与生态用水平衡、表征人水系统发展状态的人水关系和谐平衡,并提出相应的水平衡度量方法。多角度解析了区域水平衡的失衡状态,提出四大平衡的失衡程度度量方法及区域水平衡的失衡程度综合度量方法。以沁河流域为实例应用和检验了上述方法,结果表明:提出的度量方法具有科学性和适用性,能够应用于区域水平衡研究实践;2019年沁河流域水平衡的失衡度为0.327,处于蓄水量减少、水资源短缺、生态端亏水、水系统受损的中度失衡状态,后续应注重人类涉水行为的管控。研究成果可为区域水平衡评估与调控提供理论支撑,服务国家或区域水平衡策略制定和水网工程规划。

基于系统结构的水利高质量发展内涵与结构解析

准确把握水利高质量发展内涵,是实施新时代水利发展战略的重要前提。通过系统梳理高质量发展和水利发展的研究进展,基于系统观,分析了水利高质量发展的基本概念体系和核心要义;基于系统结构及系统优化视角,构建了由水利高质量发展目标、发展途径、发展条件三要素组成的水利高质量发展系统的关系结构。结果表明:水利高质量发展既是水利系统优化的发展理念,也是实现系统治水的发展措施;将水利高质量发展目标解析为水旱灾害防御安全、水资源供给安全、水生态保护安全和水环境保护安全保障以及高质量水利共享;五大新发展理念内化于水利高质量发展系统的关系结构之中,其中水资源禀赋和绿色发展是前提基础和约束条件,开放是其外在环境条件和内在体现,水利科技创新、水资源优化配置、水资源集约节约利用、水利系统现代化管理、水利基础设施建设和水安全系统功能协调是发展的重要优化途径,高质量水安全保障与满足人民需求的高质量水利共享是发展目标的核心内容。基于系统结构及系统优化问题视角深入剖析水利高质量发展的系统结构及其内在关系,可进一步深化对水利高质量发展的内涵认识,为区域水利高质量发展综合定量评价奠定基础。

水土保持生态建设下的黄土高原典型流域水沙响应

为探讨黄土高原多沙粗沙区流域水沙关系演变特征及其对水土流失治理的响应,以黄河中游无定河流域为研究对象,综合采用水沙关系曲线、数理统计等多种方法,系统分析1956—2019年间无定河流域水沙关系多时间尺度演变特征及其与水土流失治理的协同响应。研究结果表明:1)研究时段内,无定河流域年径流及年输沙量呈锐减趋势(P<0.05),且均在1970年左右发生减少突变;2)流域水沙关系在年际和场次洪水尺度上均发生深刻变化。2010年以后,暴雨频发导致流域内侵蚀物源头供应明显增加,流域河道泥沙输送能力小幅提高;3)水土保持措施实施对流域水沙锐减影响较大。2000年前后在相似降雨条件下,单位降雨量径流量和单位降雨量输沙量较20世纪70年代减少47%和62%。水土保持措施面积增加与流域径流输沙减少呈现较好的一致性,流域水土流失治理在提高黄河多沙粗沙区流域下垫面抗侵蚀能力等方面发挥重要作用。研究结果可为科学认知区域水土流失治理成效及入黄泥沙锐减成因提供参考。

考虑水土互馈关系的区域水土资源联合优化配置

针对水土资源空间不匹配、水资源总量不足及土地资源利用程度不高等问题,以二元水循环理论为基础,构建考虑水土互馈关系的区域水土资源联合优化配置模型。该模型包括产水模块、水土联合配置模块和土地模拟模块,以GDP最大和基于生态绿当量的区域植被覆盖率(EGE-RVC)最高为目标函数,并提出了一种耦合约束法、逐次逼近法和非线性规划的三层嵌套算法进行求解。以河南省洛阳市为例对模型和方法进行验证,结果表明,洛阳市可利用水量增加了4463万m^(3),GDP提高了12.5%,EGE-RVC增加了2.6%,各用地类型缺水率不同程度下降。研究成果能够为区域水土资源优化配置研究提供新的思路和技术参考。

面向新质生产力发展需求的国家水网建设关键内容及研究展望

为推动国家水网建设稳步迈入新质生产力发展的新征程,在理解水利新质生产力内涵及发展需求的基础上,从高科技、高效能、高质量、绿色4个维度出发,系统梳理国家水网建设需要把握的关键内容,分析有代表性的研究实例,并在此基础上进一步对国家水网未来研究进行展望,包括研发国家水网模拟器大科学装置、物理水网和虚拟水网协同建设、支撑人与自然和谐共生的现代化建设、科学处理人水关系4个方面,以期为面向新质生产力发展的国家水网建设提供参考。

水资源刚性约束制度研究框架与展望

实行水资源刚性约束制度是当前水资源管理制度领域的重大改革措施,也是推动相关国家战略实施、实现人水和谐共生的必然举措。梳理了水资源刚性约束制度的提出背景与历程,分析了水资源刚性约束制度的概念内涵,从指导思想、理论基础、技术支撑、战略目标、研究内容和关键问题等6个方面构建了水资源刚性约束制度研究框架,从理论研究、技术研究、实践研究等3个方面对未来研究进行了展望,以期为水资源刚性约束制度相关研究提供理论和实践参考。

经济社会与生态用水平衡计算规则与方法

从平衡的概念出发,针对经济社会与生态用水竞争问题,提出了经济社会与生态用水平衡的概念,并论述了其内涵及特性;构建了经济社会与生态用水平衡计算规则框架,包括遵循四大规律、基于六大理论、考虑六大因素、符合三大准则;提出了经济社会与生态用水平衡的计算思路,包括资料处理、量化计算、结果检验3个步骤,并给出了其计算方法和计算结果表征方式。以2019年沁河流域为例,量化了流域经济社会与生态用水平衡;在求解一次平衡点以及经济社会用水刚性约束、生态用水刚性约束、综合效益刚性约束条件下平衡结果的基础上,综合考虑六大因素以及总需水量与水资源总量关系,确定了沁河流域经济社会与生态用水平衡点,即经济社会用水与生态用水的比例为0.71∶0.29。

人水关系学的基本方程及模型构建

人水关系是人类与自然界关系中最重要的关系之一,人水关系学是研究人水关系的一门新交叉学科,构建其基本方程和模型是深入研究人水关系的核心内容之一。基于前期研究工作和不同学科成果梳理,提出了人水系统“四大过程”(水循环过程、物质循环过程、生物过程、人文过程),总结给出了“四大过程”的基本方程及其耦合与计算方法,提出了考虑“四大过程”的分布式人水关系模型构建框架与人水关系模拟器的构建设想,并介绍了沁河流域分布式人水关系模型应用研究实例。人水系统“四大过程”是表征人水关系的重要基础,其基本方程是研究人水关系学的基础方程,由基本方程耦合构建的模型是模拟人水关系问题的重要工具,可为进一步完善人水关系学奠定基础,为深入研究人水关系模型提供思路。

基于典型计量统计的农业灌溉地下水用水量评估

【目的】利用现有计量统计机井数据准确评估典型地区灌溉农业地下水实际用水量。【方法】基于唐山市不同种植结构典型井灌区地下水计量统计数据,通过典型区域实地调查,结合降水量、农业种植结构、统计年鉴等数据,绘制不同种植结构下降水量与灌溉定额的关系曲线,评估2010年唐山地下水实际用水量。【结果】①水浇地、水田的灌溉定额与降水量的关系曲线分别为y=1.167×10^(7)x^(-1.2773)、y=378796x^(-0.6366),拟合R^(2)分别为0.8990、0.8833。②唐山市2010年降水量条件下不同种植结构作物灌溉定额表现为水田灌溉定额(5763~7649 m^(3)/hm^(2))>大棚灌溉定额(4950 m^(3)/hm^(2))>水浇地灌溉定额(2633~4647 m^(3)/hm^(2))。③唐山市2010年灌溉农业地下水实际开采量评估结果为13.08亿m^(3),与《唐山市水资源公报》数据相差9.42%。【结论】水田灌溉定额要大于大棚和水浇地,利用计量统计数据评估得到的农业地下水开采量可在一定程度上评估北方地区农业地下水实际开采量。

水资源集对系统中的对立关系分析

水资源集对系统中同一项和对立项构成的对立关系是水资源集对分析辩证思维的集中体现,是构建集对系统联系数的基石。通过五种常见对立关系类型的概念解析与其应用之间对应关系的分析,以及面向五类对立关系的水资源集对系统差异项不确定性分析,在对立关系复杂、深刻的涵义方面取得了一些新的认识:在水资源集对系统中常见的反比型、互斥型、正负型、互补型和虚实型对立关系可分别由模糊、随机、涨落、分配和存在型不确定性对应产生并进行分析计算;在集对系统中最基本的对立关系是反比型、互斥型对立关系,对应的模糊性、随机性是事件发生的内容性质、事件发生的结果数量方面的不确定性;差异项不确定性的变化是导致联系数中同异反三类关系变化的原因,是“一分为三”辩证思维的一种典型展开,反映了量变到质变的转化规律;在差异项表征的五类不确定性中最常见的是模糊不确定性,模糊不确定性变量的运算可通过随机模拟技术转化为随机不确定性变量的运算。模糊和随机的不确定性分析分别注重物理内涵解析和数学定量计算,这反映了水资源集对分析学科属于计算思维领域,对进一步推动模糊水文学、随机水文学、水资源集对分析、结构水资源学等学科发展无疑具有明显的启发作用和指导意义。

黄河流域(甘肃段)水资源与其他自然资源耦合协调关系研究

本文基于黄河流域(甘肃段)2009、2012、2015、2018、2021年57个县级行政区面板数据,利用耦合协调度模型测算并分析了水资源与耕地、园地、林地、草地、湿地的耦合协调关系及时空演变规律。结果表明:①研究期内黄河流域(甘肃段)水资源与耕地、园地、林地、草地、湿地的两两耦合协调关系呈不同发展规律与空间分异特征。总体上,水资源与草地、耕地、园地的耦合协调度相对较高,与林地、湿地的耦合协调度相对较低。②水资源与耕园林草湿整体上呈耦合、协调发展趋势,在空间上呈东北低、西南高的分布特征,在时间变化上未有明显波动。③研究时段内未出现明显的高耦合-高协调演化趋势,表明黄河流域(甘肃段)各类自然资源空间分布和数量分布不均衡,未来应重视设计差异化的自然资源协调发展路径,引导各类自然资源向更有序、协调的方向发展。

构建和谐水城关系的多维度思考

水城关系是影响城市兴衰变迁的重要因素。近年来,随着全球城市化加速及气候变暖,极端气候所引起的雨洪灾害日益频繁,构建和谐水城关系成为保障城市安全健康和可持续发展的关键。主要梳理河南省在构建和谐水城关系方面面临的突出问题,并从水安全、水保护、水治理、水资源利用以及水文化传承等方面提出构建和谐水城关系的相关对策。

水资源节约集约利用理论体系与应用实践

水资源节约集约利用是促进全社会节约用水、保障国家水安全、促进生态文明建设、助力高质量发展的重要举措。通过梳理水资源节约集约利用的提出背景及历程,深入剖析水资源节约集约利用的概念内涵,提出了水资源节约集约利用理论体系框架,包括基础理论、符合原则与研究内容。重点分析了水资源节约集约利用理论在节水型社会建设、水利高质量发展、人与自然和谐共生以及水资源刚性约束制度建设中的应用实践,旨在为我国现代水资源利用提供理论支撑和实践指导。

从流域视角探讨文化遗产保护

目前,文化遗产保护工作多在行政区划的框架内开展。然而现有的行政区划管理逻辑与人类文明和遗产形成的源起逻辑是大相径庭的。众所周知,早期人类依水而居,流域成为孕育人类文明的载体和城乡演变的见证。可以说,人水关系在人地关系中是最本质、经典且持久的。文章从流域视角切入,探讨文化遗产保护所呈现的“自然-人文”耦合的系统性特征,提出多尺度协调保护与系统性网络构建、跨学科整合与数据同化技术应用、与动态环境变化适应性响应策略等保护思路,并分析“黄-运-长”流域共同体中的两组人水互动模式的典型案例,从文化遗产的本质出发,为其保护与发展提供一个可持续的综合框架,以回应构建文化遗产大保护格局的时代要求。