The annual mean sketches and climatological variability of the volume and heat transports through the inter-basin passages:A study based on 1 400-year spin up of MOM4p1

The annual mean volume and heat transport sketches through the inter-basin passages and transoceanic sections have been constructed based on 1400-year spin up results of the MOM4p 1. The spin up starts from a state of rest, driven by the monthly climatological mean force from the NOAAWorld Ocean Atlas （1994）. The volume transport sketch reveals the northward transport throughout the Pacific and southward transport at all latitudes in the Atlantic. The annual mean strength of the Pacific-Arctic-Atlantic through flow is 0.63x106 m3/s in the Bering Strait. The majority of the northward volume transport in the southern Pacific turns into the Indonesian through flow （ITF） and joins the Indian Ocean equatorial current, which subse- quently flows out southward from the Mozambique Channel, with its majority superimposed on the Ant- arctic Circumpolar Current （ACC）. This anti-cyclonic circulation around Australia has a strength of 11 x 106 ms /s according to the model-produced result. The atmospheric fresh water transport, known as P-E^R （pre- cipitation minus evaporation plus runoff）, constructs a complement to the horizontal volume transport of the ocean. The annual mean heat transport sketch exhibits a northward heat transport in the Atlantic and poleward heat transport in the global ocean. The surface heat flux acts as a complement to the horizontal heat transport of the ocean. The climatological volume transports describe the most important features through the inter-basin passages and in the associated basins, including： the positive P-E＋R in the Arctic substantially strengthening the East Greenland Current in summer; semiannual variability of the volume transport in the Drake Passage and the southern Atlantic-Indian Ocean passage; and annual transport vari- ability of the ITF intensifying in the boreal summer. The climatological heat transports show heat storage in July and heat deficit in January in the Arctic; heat storage in January and heat deficit in July in the Antarctic circumpolar current regime （ACCR）; and intensified heat transport of the iTF in July. The volume transport of the ITF is synchronous with the volume transport through the southern Indo-Pacific sections, but the year-long southward heat transport of the ITF is out of phase with the heat transport through the equatorial Pacific, which is northward before May and southward after May. This clarifies the majority of the ITF origi- natinR from the southern Pacific Ocean.

Analysis of Asynchronism-Synchronism of Regional Precipitation in Inter-Basin Water Transfer Areas

The local characteristics of multi-dimensional modeling method of multivariate copula. A new modeling remedy this defect. Different types of copula distribution random variables are seldom considered in the general method, called pair-copula construction, is introduced to functions are allowed to be introduced in this method. Correspondingly, the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time. In the analysis of asynchronism-synchronism of regional precipitation in WED inter- basin water transfer areas, the pair-copula construction method is compared with the general modeling method of mul- tivariate copula. The results show that the local dependence structure would exist among hydrologic variables even in three-dimensional cases. In this situation, the general modeling method of multivariate copula would face difficulties in fitting distribution. However, the pair-copula construction method could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions. Moreover, the compensation ca- pacity of water resources is strong in different hydrological areas of WED water transfer project. The asynchronous frequency of wetness and dryness is 69.64% and the favorable frequency for water transfer is 46.15%.

Modeling for Inter-Basin Groundwater Transfer Identification: The Case of Upper Rift Valley Lakes and Awash River Basins of Ethiopia

Groundwater movement beneath watershed divide is one component of the hydrological cycle that is typically ignored due to difficulty in analysis. Numerical ground-water models, like TAGSAC, have been used extensively for predicting aquifer responses to external stresses. In this paper TAGSAC code was developed to identify the inter-basin groundwater transfer (IBGWT) between upper Awash River basin (UARB) and upper rift valley lakes basin (URVLB) of Ethiopia. For the identification three steady state groundwater models (for UARB, URVLB and for the two combined basins) were first created and calibrated for the 926 inventoried wells. The first two models are conceptualized by considering the watershed divide between the two basins as no-flow. The third model avoids the surface water divide which justifies IBGWT. The calibration of these three models was made by changing the recharge and hydrogeologic parameters of the basins. The goodness of fit indicators (GoFIs) obtained was better for the combined model than the model that describes the URVLB. Furthermore, the hydraulic head distribution obtained from the combined model clearly indicates that there is a groundwater flow that doesn’t respect the surface water divide. The most obvious effect of IBGWT observed in these two basins is that it diminishes surface water discharge from URVLB, and enhances discharge in the UARB. Moreover, the result of this study indicates potential for internal and cross contamination of the two adjacent groundwater.

Inter-Basin Groundwater Transfer and Multiple Approach Recharge Estimation of the Upper Awash Aquifer System

Multiple approaches have been used to estimate groundwater recharge in the Upper Awash river basin. The amount of recharge reaching the Upper Awash aquifer system from the Blue Nile sub-basins is also estimated. Water Balance, Chloride Mass Balance and HYDRUS 1D infiltration model are used to estimate recharge. A total of 29 sites were selected for the HYDRUS 1D multiple “at point” recharge simulations. Base Flow Separation (BFS) methods, using both River Analysis Package software Version 3.0.3 and Excel-based Time Plot program are also used as a proxy for recharge. Besides, overlay analysis in Processing MODFLOW, ArcGIS, and SURFER environments has been done to thoroughly consider spatial heterogeneity between any two point estimates and appreciate the effect of lineament density, topography, slope and major urbanized land on pattern of spatial distribution of recharge. Because of differences inherent in the assumptions and datasets used, the various methods employed give wide range of differences in recharge estimates. Recharge estimated for the Upper Awash basin ranges from 51.5 mm/year to 157 mm/year and for the two southern left-bank sub-basins of the Middle Blue Nile basin (Mugher and Jema) ranges from 86 mm/year to 239 mm/year. Consequently, annual average volumetric recharge in the Upper Awash and annual groundwater flux from portion of the Blue Nile sub basins to the Upper Awash aquifer system are estimated to be 983 Mm3 and 365 Mm3 respectively. The significant flux joining the Upper Awash groundwater system from part of the Middle Blue Nile basin, which is almost 37% of the total annual recharge to the Upper Awash basin makes this part of the Middle Blue Nile basin an important recharge zone for the Upper Awash groundwater. Estimating recharge using integrated approaches was found to be useful to identify range of plausible recharge rates in the two basins. Besides, the new methodological approach of superimposing recharge governing factors on interpolation of point recharge estimates helps to produce physical based spatial distribution of recharge.

Alleviating Water Scarcity in the Central Rift Valley Lakes through an Inter-Basin Water Transfer, Ethiopia

Demand for fresh water, as one of the major natural resources, is increasing rapidly with increasing development and environmental degradation. The continued abstraction of water from Lake Ziway and its main feeder rivers Meki and Katar for irrigation indicates that the water demand may soon exceed the supply. To illustrate disparities in spatial distribution of water resources, the Upper Awash sub-basin, which shares a water-divide with the CRVL sub-basin, has large flow volumes particularly in the rainy season and suffers with seasonal flooding. The rationale behind regaining the water in CRVL relies on this non-uniform spatial distribution of fresh water, calling for a balance between water surplus and deficit regions. For this reason, Inter Basin Water Transfer (IBWT) is suggested as a viable option to augment utilizable water resources of the Upper Awash sub-basin to reduce the significant pressure on the water supply of the rapidly developing urban and irrigation areas in the CRVL sub-basin. A water evaluation and planning (WEAP) model was used to quantify the amount of surplus water in the donor basin, when examining the hydrological dynamics of the basins. Furthermore, optimal flow diversion scenarios were generated by maintaining two baseline scenario constraints. The estimated surplus water in the rainy season is expected to contribute 18 million cubic meters (mcm), 88 mcm and 192 mcm in months June, July and August respectively under average conditions. The optimal amount of diverted water could potentially stabilize the environmental degradation of Lake Ziway and Lake Abijata by compensating for development-driven abstraction and surface water evaporation respectively.

Inter-basin water transfer-supply model and risk analysis with consideration of rainfall forecast information

This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast information from the global forecast system (GFS), the actual diversion amount can be determined according to the inter-basin water transfer rules with the decision tree method; secondly, the reservoir supply operation system is used to distribute water resource of the inter-basin water transfer reservoir; finally, the integrated risk assessment model is built by selecting the reliability of water transfer, the reliability (water shortage risk), the resiliency and the vulnerability of water supply as risk analysis indexes. The case study shows that the inter-basin water transfer-supply model with rainfall forecast information considered can reduce the comprehensive risk and improve the utilization efficiency of water resource, as compared with conventional and optimal water distribution models.

Multi-reservoir joint operating rule in inter-basin water transfer-supply project

The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir.In this study,a joint operating rule is proposed for the purpose of solving such complex operation problem.This rule is composed of a set of sub-rules,including hedging rule curves of virtual aggregation reservoir(i.e.equivalent reservoir)and other individual reservoirs,water-transfer rule curves of each individual reservoir,as well as some of important assisted rules.These assisted rules refer to allocation models for water transfer-supply.In the proposed rule,an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand(i.e.aggregation method).Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system(i.e.decomposition method).And these models are integrated with a set of influence factors such as hydrologic characteristics,reservoir storage or vacant storage,regulating ability,water-supply pressure,and so on.The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release.Finally,the proposed rule is applied to the North-line IBWTS Project in Liaoning Province,China.The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs.Thus it can improve the utilization efficiency of water resources in system.

Financing Model Decision of Inter-basin Water Transfer Projects

Inter-basin Water Transfer Projects require the appropriate financing model to attract large amounts of social investment.Therefore,financing model decision becomes the key of engineering construction.In three aspects,such as the subject,the object and the target of the financing model,Grey Target Model is established in this paper.First,the complex financing mode decision problems of Inter-basin Water Transfer Projects are decomposed by using hierarchical decomposition method.Then Analytical Hierarchy Process(AHP) method is used to calculate the comprehensive weight of evaluation index.Experts' opinions financing model are transformed into the evaluation matrix based on the Dephi method.The Weighted Grey Target Model is used to calculate the approaching degree of financing model and assists financing mode decision.In addition,this paper takes the water diversion project from the Han to the Wei River of Shaanxi Province as a verification example for the model.For other water diversion projects,the evaluation results are also reliable and provide theoretical references for the financing model decision of Inter-basin Water Transfer Projects.

南水北调西线工程水源区可调水量“十问”

南水北调西线工程是我国“四横三纵”国家水网主骨架尚待建设的最后一环,而水源区可调水量是西线工程规划论证面临的焦点和难点问题。本文从水资源本底条件与演变趋势,生态环境与经济社会发展需水,调蓄水库与输水工程规模,调水对水源区及其下游水资源开发利用、水生态环境、水力发电、航运等方面影响的角度,提出了与水源区可调水量相关的10个问题;以长江上游分布式水文模型为基础,建立了南水北调西线工程水源区可调水量模拟分析模型,力图系统、定量地回答所提问题。本文的主要研究结论有:在仅考虑满足水源区河道内外生态环境和经济社会需水的前提下,“上线+下线”组合方案多年平均可调水量为1.59×10^(10)m^(3),“完全下线”方案在建设岗托水库进行联调时,多年平均可调水量将达到1.74×10^(10)m^(3);在综合考虑调水对水源区水平衡、水力发电和航运影响及其可接受程度后,南水北调西线水源区可调水量为1.22×10^(10)~1.26×10^(10)m^(3)。长远来看,应谋划西南片区水网与国家水网主骨架、“大动脉”的连接与融合,在减小南水北调西线工程调水影响的同时,提高南水北调西线工程的整体供水能力以及对气候变化等外部条件的适应性。

基于马斯京根法的区间洪水推求方法

针对马斯京根法的蓄量系数K和楔蓄系数X在流域上游有水库控制时难以通过实测资料率定的问题,通过建立K、X与河道水力特征间的关系估算K、X,并采用马斯京根法将上游来水演算到下游,用下游洪水扣除上游演算到下游的洪水得到区间洪水。沭河流域青峰岭水库、小仕阳水库至莒县区间洪水的实例推求结果表明:基于马斯京根法的区间洪水推求方法与新安江模型法推求的区间洪水过程差别较小,但前者进行参数估计时可考虑不同来水河段水力特征的差异。

Assessment of rehabilitation strategies for lakes affected by anthropogenic and climatic changes: A case study of the Urmia Lake, Iran

Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a.

黄河流域生态保护府际协作网络结构及其影响因素

黄河流域府际协作网络的建立能够为实现流域生态保护高质量发展提供现实依据。以黄河流域地方政府间有关生态保护的1 263份府际协议为样本,从社会网络视角可视化呈现黄河流域生态保护府际协作结构,以整体指标和中心度刻画府际协作网络特征,并通过二次指派程序(QAP)回归探析地理邻近性、经济发展水平、行政隶属关系、行政层级差异、合作组织网络、行政领导关系、生态保护水平7个变量对府际协作关系建立的影响。研究发现:黄河流域府际协作网络紧密,但整体网络密度仍处于较低水平;黄河流域府际协作网络呈复合式结构特征,具体表现为三角结构、星型结构、网状型结构等;河南省处于府际协作网络的核心位置,对周边地区的辐射带动作用明显;地理邻近性、经济发展水平、行政层级差异、行政领导关系和生态保护水平是当前黄河流域生态保护府际协作的主要驱动因素。

桑托斯盆地盐下孤立碳酸盐台地沉积建造与深水大油田

针对桑托斯被动陆缘盆地深水盐下碳酸盐岩储层分布特征及大油田成藏规律不清的难题,综合利用地质、地震及岩心等数据资料,通过早白垩世原型盆地与岩相古地理恢复重建,提出盐下碳酸盐岩沉积建造受控于坳间断隆型和坳中断凸型两类孤立台地。坳间断隆型孤立台地分布于现今盐下坳间隆起带上,建造于早期陆内和陆间裂谷两个原型阶段继承性发育的单断式和双断式垒式断块上,早白垩世陆内裂谷晚期沉积的ITP组介壳灰岩和陆间裂谷早期沉积的BVE组微生物灰岩为连续建造;坳中断凸型孤立台地分布于现今盐下坳陷带中,建造于早期陆内裂谷原型阶段火山岩建隆所形成的凸起带上,发育BVE组微生物灰岩。两类孤立台地灰岩所形成礁滩体均具有储层厚度大、物性好的特点。结合盐下已发现大油田解剖,发现两类台地均可形成大型构造-岩性复合圈闭,周缘为优质湖相和潟湖相烃源岩环绕,上覆为巨厚的优质蒸发盐岩盖层高效封堵,形成了“下生中储上盖”式最佳生储盖组合关系,油气富集程度高。已发现大油田均为具有统一压力系统的底水块状油田,且均处于充满状态。未来勘探重点目标是西部隆起带和东部隆起带南段上的坳间断隆型孤立台地及中央坳陷带中的坳中断凸型孤立台地。该项研究成果为在桑托斯被动陆缘盆地超前选区选带、新项目评价及中标区块探区勘探部署提供了重要依据,也为今后在全球被动大陆边缘盆地深水勘探战略选区提供借鉴。

引汉济渭工程初期调水风险特征研究

为解决引汉济渭工程运行中调水风险因素与特征规律识别不全面的问题,以工程运行初期为研究对象,采用专家调查法识别工程主要调水风险因素并确定风险组合类型,再建立危险度模型,分析单一风险因素的稳定性和风险组合危险度的特征规律。研究结果表明:变异系数越大则风险因素稳定性越差,其中管理失误风险因素最不稳定,其值高达0.998;水源不足、需水量增加两类风险因素叠加后风险组合的危险度更高;风险组合的危险度与风险因素数量之间没有明显的正向关系。研究成果补充了引汉济渭工程调水风险特征研究的不足,为制定针对性风险减控和管理策略提供技术支撑。

跨流域调水工程“用户枢纽”群联合优化调配

针对跨流域调水工程运行中存在枢纽群调水与用户群需水不匹配的问题,构建了兼顾水源区枢纽工程运行关键指标和受水区用户侧多目标需求的“用户-枢纽”群联合优化调配模型,用户侧量化了受水区水资源、生态环境、社会经济子系统间函数关系,嵌套于供水子系统的水量配置模型中,枢纽侧考虑水源区枢纽侧调水、发电、能耗等多重效益目标,确保最大化实现用户侧需水过程和枢纽侧调水过程的匹配。将模型应用于陕西省引汉济渭调水工程联合调配模拟,结果表明:联合优化调配模型可提高跨流域调水工程的整体运行效率,灵活调控“用户枢纽”群的需水与运行需求;水量联合优化调配后,各用户缺水率约为7%,经济效益提升了3.6%,水库群基本完成了调水任务,电站群发电量超过5.43亿kW·h,库空率约为8%,降低了系统缺水风险。

南水北调中线工程年度正常输水调度方案分析

为提高南水北调中线工程水资源调度效率,切实提升水安全保障水平,以南水北调中线工程年度正常输水调度方案为例,针对线路长、交叉建筑物多、运行工况复杂、无在线调蓄水库、输水调度技术难度大等问题,以水量平衡为基础,明确正常输水调度技术要求,提出一系列科学有效的调度措施和优化策略,为类似长距离调水工程调水方案编制提供参考。

新型储水储能模式在引沅补资方案中的初步探索

跨流域调水需要水源工程和能量驱动,而汛期超额洪水及电力系统弃能需要寻找出路。文章以引沅补资方案为例,提出了一种新的储水储能模式,实现了调水蓄洪储能。在为调水工程找到能量来源、促进清洁能源消纳的同时,实现了洪水的资源化利用,使生态调水工程得以良性运行。方案的提出,为跨流域水资源配置和电网储能建设提供了新思路。

1981—2023年雅鲁藏布江流域大气饱和水汽压差变化及影响因素

饱和水汽压差(vapor pressure deficit,VPD)可反映大气对水分的需求,厘清VPD时空变化特征有助于了解区域大气干湿程度对气候变化的响应。基于近43年(1981—2023年)雅鲁藏布江流域(简称雅江流域)34个气象站点逐月日照时数、平均气温、平均最高气温、平均最低气温、降水量(P_(r))、相对湿度、水汽压和平均风速等资料,采用线性倾向估计、R/S分析、Mann-Kendall法、Morlet小波分析和逐步回归等方法,分析近43年雅江流域VPD时空变化特征及影响因子。结果表明:(1)雅江流域年、季VPD总体上呈东西部低、中部高分布特征;月际变化呈双峰型,第1、2峰值分别在6、10月,1月最小;VPD夏季最大,春季次之,冬季最小。(2)年VPD以0.030 kPa/(10 a)的速率显著增加,主要表现在夏秋季,尤其近23年(2001—2023年)增速明显。年、季VPD在21世纪前10年中后期发生了突变,且未来持续增大的可能性很高。20世纪80和90年代年、季VPD均偏低,以90年代最明显;21世纪前10年因夏、冬两季VPD偏高,年VPD偏高;21世纪10年代年、季VPD均偏高,主要表现在夏、秋两季。VPD在春、夏、秋3季都存在3~4 a显著周期,冬季有2~3 a周期,年VPD无显著周期。(3)四季和年VPD与地理因子的线性关系不显著,但存在极显著的二次曲线关系。(4)年、季平均气温升高是致使VPD增加的主导因子;2004年以后,年平均气温、水汽压对VPD贡献率有所降低,P_(r)的作用明显增大。

西藏改则地区拉果错蛇绿岩地球化学特征及成因

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