Modern state of the Small (Northern) Aral Sea fauna

The Aral Sea is a terminal lake lying within the deserts of Central Asia in Kazakhstan and Uzbekistan, draining the Amu Darya and Syr Darya rivers. Before the 1960s, it was a large brackish water lake with an average salinity of 10.3 g L^?1. The anthropogenic regression and salinization of the Aral Sea at that time resulted from increasing water withdrawals from the Amu Darya and Syr Darya for irrigation purposes. The salinization resulted in the disappearance of most of its invertebrates and all freshwater fish. As a result of the water level decrease, the Aral Sea divided into a northern Small Aral and a southern Large Aral at the end of the 1980s, with the two having different hydrological regimes. After construction the first Kokaral Dam in 1992, the water level of the Small Aral Sea increased by >1 m, with a gradual decline in the salinity beginning. To date, the Small Aral has again become brackish. Its average salinity reached 5.3 g L^?1 by April–May 2013, with the highest salinity of 9.9 g L^?1 in Butakov Bay, whereas the salinity was very low at 1.2–2.0 g L^?1 in the estuary zone of the Syr Darya. There is an ongoing process of restoration of the former biodiversity, with many fresh water and brackish water invertebrate species reappearing due to the decreasing salinity. Freshwater fish species (bream, roach, carp, asp, zander, wels, etc.) returned into the Small Aral from the Syr Darya River and lakes in its lower reaches where they survived. Fisheries are recovering and catches are growing. Continuing salinity decreases, however, may cause decreases in the numbers, or even disappearance, of marine and halophilic invertebrate species. This study summarizes the results of studies of the Small Aral zooplankton, zoobenthos and ichthyofauna carried out in the spring of 2013. An historical review of changes in the Aral Sea and its fauna also is presented.     

The Aral Sea and the Dead Sea: Disparate lakes with similar histories

In spite of significant differences in their sizes, depths, salinity and other properties, the Aral Sea and the Dead Sea share many features, as illustrated by a comparison of the histories of both water bodies. Fifteenth and early sixteenth century maps, based on the ‘Geography’ of Ptolemy, contain both lakes. The first successful limnological surveys of the lakes were made in the same year 1848, when Alexey Butakov explored the Aral Sea and William Lynch mapped the Dead Sea. Paintings and drawings by Taras Shevchenko (Aral Sea) and David Roberts (Dead Sea) document the landscapes around the lakes in the first half of the 19th century. The water balance of both lakes has been strongly negative in the past decades, leading to a decreased water surface area and volume for both lakes, their increased salinity and deterioration of their local infrastructures. Complex and expensive mitigation schemes have been proposed for both lakes, based on the import of large quantities of water from distant sources via canals or pipelines (i.e. Siberian rivers or Caspian Sea to supply water to the Aral Sea, Mediterranean Sea or Red Sea, to be connected with the Dead Sea). Less dramatic solutions to improve the local situations already have resulted in improved water quality in the Aral Sea, and partial restoration of its fisheries. In contrast, the Dead Sea remains much too saline to support higher forms of life. Nevertheless, a biblical prophecy predicts that even this most hypersaline of all lakes will eventually be teeming with fish of many kinds.     

A systems approach to validating the water vision of the Aral Sea Basin

Abstract:

The governments of the Aral Sea Basin countries, in cooperation with international organizations (UNESCO and World Bank) came up with a “water vision “for the region until 2025. The landlocked Aral Sea has been suffering from an imbalance in water evaporation, and, water inflow from its two main sources — Amu Darya and Syr Darya rivers, when the planners in the former Soviet Union from the 1960s diverted the river waters for irrigation. The irrigated area has increased from the 1960s by two‐thirds to 7 million hectares and the population by three‐fold to 50 million in the basin countries. Consequently the inflow to the Aral Sea from these two rivers decreased from 55 km³ in 1960 to a few km³ during the 1980s and 1990s. This has resulted in one of the worst man‐made ecological disasters of the century. In this paper, we examine different scenarios to achieve the vision goals and whether it is indeed feasible. Using IWMI basin‐oriented water accounting principles, we have shown that significant amount of water is being wasted in the region. Our analysis concludes that though not all the vision goals are likely to be met over the next 25 years, the inflow into the Aral Sea can be increased to over 20 km³ through better management and use of water resources.     

The past,present, and future Aral Sea

The Aral Sea, a once vast brackish terminal lake in the heart of Central Asia, has been rapidly drying since the 1960s. It had separated into four separate waterbodies by September 2009. The maximum water level decline was more than 26 m, whereas the lake surface area decreased 88% and the water volume 92%. The lake salinity increased by more than 20‐fold. Prior to the modern recession, the Aral Sea experienced a number of water level declines and subsequent recoveries over the last 10 millennia. The main causative factor until the 1960s was the periodic westward diversion of the Amu Dar’ya, the main influent river, towards the Caspian Sea by both natural and human forces. The post‐1960 recession, however, was overwhelmingly the result of unsustainable irrigation development. The lake’s modern recession has caused a broad range of severe negative ecological, economic and human welfare problems. To restore the Aral Sea to its 1960s’ size and ecological condition would be very difficult, if not impossible, in the foreseeable future. The plight of the Aral Sea, however, is far from hopeless. Partial restoration of portions of the lake is still feasible. A project to raise the Small (northern) Sea was completed in Fall 2005, raising its water level by 2 m, and lowering its salinity to a level not much higher than the early 1960 levels. Its ecological recovery has been dramatic, and a new project to improve further the Small Aral was recently announced. Improving the Large (southern) lake would be much more difficult and expensive. A project to save the deep Western Basin partially is technically feasible, however, and should be given careful evaluation. It is important to repair and preserve what is left of the deltas of the two tributary rivers, Syr Dar’ya and Amu Dar’ya, as these two rivers are of great ecological and economic value, and act as biological refugia for endemic species of the Aral Sea.     

钱塘江河口生态环境变化及对策

为保障钱塘江河口地区社会经济和生态环境的稳定,科学推进治理工作,分析探讨了钱塘江河口地区生态环境的状况及其影响因子。结果表明:大规模实施"全线缩窄"治理方案以来,河口地区生态环境发生了新的变化,洪水、潮汐作用进一步增强;水资源需求不断增长,开发利用程度加大,跨流域配水量增加,水环境污染加剧;主槽摆动趋于平缓,河床冲淤幅度减小,河势趋于稳定;滩涂湿地资源总量减少,生态服务功能受到限制;水生生物物种减少,生物多样性有下降趋势。针对上述问题,提出了加强流域水资源管理、推进水环境治理、科学围垦和淤垦平衡、统一推进河口生态规划建设等意见和建议。     

冬、夏季北黄海悬浮物分布特征

利用国家908专项ST02区块(北黄海)水体专项调查2007年夏、冬资料,应用浊度观测资料对悬浮物质量浓度进行线性拟合,得到较好的反演结果。在北黄海海域选取了具有代表性的9个断面,利用反演的悬浮物质量浓度,综合温度、盐度等水文要素,辅以冬、夏季山东半岛沿岸流、北黄海冷水团和黄海暖流的季节变化特征,着重分析了冬、夏季北黄海悬浮物分布特征、形成原因以及季节变化。研究结果表明,冬、夏山东半岛北部沿岸、成山头海域和老铁山水道以及旅顺湾附近海域始终为高悬浮物浓度区,呈现出近岸高,离岸低,底层高,表层低的态势。夏季,水体垂向层结显著,受北黄海冷水团以及沿岸流的作用,老铁山水道附近及山东半岛北部沿岸的高悬浮物浓度值区基本不能进入北黄海,只能沿岸分布,并且由于海底底质为粘土质以及沿岸流的共同作用,成山头附近海域悬浮物浓度值很高,但基本为局地再悬浮,没有向外输送的趋势。冬季受强劲东北风的影响,水体垂向混合均匀,悬浮物浓度值比夏季高得多,悬浮物的分布受黄海暖流、沿岸流以及地形的影响,特别是成山头附近海域,存在一个显著的高悬浮物浓度值区,并具有向南输送的特征。     

黄海和东海的环流数值模拟研究

本文从海洋三维原始动力学方程出发,考虑真实地形及(1/4)°×(1/4)°的水平网格,同时考虑黑潮和潮流,数值模拟黄海和东海的环流系统,主要结论是:1)模拟调和常数与分布于该区的81个台站的实测调和常数相比,日分潮振幅和位相的平均绝对误差分别为1.7cm和5.2°,半日分潮M_2振幅和位相的平均绝对误差分别为4.1cm和3.7°;2)模拟的黑潮路径与长期观测结果相吻合;3)黑潮进入研究区域后,一分支从台湾东北部分离出来后进入东海,影响可达29°N,这与海洋普查的调查结果以及文献中的结果一致;4)黑潮的一个分支北上形成对马暖流的一部分,且对马暖流是多源的,对马暖流通过对马海峡进入日本海,同时模拟结果显示一支由日本海进入研究区域的海流,后者需进一步调查和研究;5)黄海表层流主要沿南下方向,在近底层。中国和朝鲜的沿岸流为南下,黄海底层海盆由一顺时针方向的环流控制着,在中国成山头以外的北黄海底层,存在一较弱的逆时针环流。     

中型山区河流水电站下游的鱼类生态需水量计算

为更好地对河流水电开发后的鱼类进行保护,探讨中型山区河流水电站下游的鱼类生态需水量计算.参照大型河流鱼类水力生境参数标准,根据中型山区河流的特点,得到中型山区河流鱼类水力生境参数的参考标准.选取有代表性的四川中型山区河流杂谷脑河进行鱼类生境原型观测,原型观测结果证实了该参考标准能够满足杂谷脑河鱼类对生境的实际需求.基于所得到的参考标准,应用生态水力学法对杂谷脑河红叶二级、理县以及甘堡3座电站减水河段的鱼类生态需水量进行计算分析,得到3座电站的生态需水量推荐值.通过分析可知,所得到的生态需水量推荐值占年均天然流量以及设计引用流量的比例都不高,在3座电站的运行实践中,具有可操作性.     

水污染防治中国有渔场征占的补偿安置方式探析

随着我国水环境治理和水生态保护力度的不断加强,湖泊水污染防治中征占国有渔场的情况日益增多。然而,在此领域的补偿安置活动却面临着补偿标准不合理、补偿款分配矛盾、叠加转制改革过程中的利益纠纷,以及渔业职工生计恢复与持续发展困难等问题。以湖北省国有NH渔场补偿安置活动为例,分析总结了征占国有渔场采用“贫困、风险和重建”模式（Impoverishment, Risk and Reconstruction Model,简称IRR模式）的实践经验,结果表明,政府应当明确渔场渔业职工的合法权益和补偿属性、完善征占国有渔场的法规和政策、合理确定补偿标准及资金分配使用办法、结合国有渔场转制改革保障职工权益,以及采用多样化安置方式等策略,以化解当前面临的补偿安置难题。     

潮白河试验性生态补水期间问题及对策

2021年春季,潮白河首次实施试验性生态补水,实现了潮白河自1999年以来北京境内首次全线通水,生态补水有效回补了地下水,改善了生态环境.但由于河道常年断流,多年未过水,此次补水对水工建筑物和涉河工程造成一定影响,如局部堤防严重渗水、溯源冲刷导致建筑物受损、多处跨河工程受严重冲刷.梳理了补水期间出现的问题,分析了出险原因,并从河道规划、河道治理、涉河工程保护及应急抢险等方面提出对策和建议.     

长江流域大型水利工程与鱼类资源救护

为解决长江流域的洪涝灾害和开发利用水资源，在长江的干支流已建成一些水利工程，还有许多工程包括三峡水利枢纽正在建设或规划之中。研究认为,这些工程在为长江流域带来巨大的经济和社会效益的同时，也会对长江流域的水环境尤其是鱼类资源产生很大影响。简述了长江流域各类大型水利工程对长江鱼类资源的影响，分析长江流域鱼类资源变化与流域梯级开发的关系及鱼类资源救护措施。     

鄱阳湖流域水资源生态安全状况及承载力分析EI北大核心CSCD

为系统评估鄱阳湖流域水资源生态安全状况,基于水资源生态足迹模型计算了流域所在地市水资源生态足迹和水生态承载力,并通过水资源生态盈余和生态赤字、万元GDP水资源生态足迹及水资源生态经济协调指数评估了水资源生态压力状况。结果表明:研究区内农业用水是产生水资源生态足迹的主要类型,宜春市是产生水资源生态足迹最多的地区;各市均处于生态盈余状态,但多数地区水生态承载力有所降低;在产生水资源生态足迹的因素中,应重点关注农业用水和水污染因素;研究区万元GDP水资源生态足迹逐年降低,萍乡市和吉安市水资源的生态经济协调性下降。各市应以绿色发展为目标,注意水资源消耗强度,通过建立健全农业水价形成机制、持续加强水环境治理等措施,保障水资源的可持续利用。     

Integrated Water Resources Management in the Republic of Uzbekistan

Abstract

The Uzbek socio-economic structure is characterized by the transition from a centrally-planned to a market-orientated economy, with a shifting from agricultural production to industrial development. However, the agricultural sector continues to play a significant role in a general economy of the country. The major water sector strategy is to decrease the dependence of agricultural production on climate by introducing advanced irrigation techniques and water saving methods to achieve future sustainable socio-economic development and environmental protection. Water management policy should be flexible enough to adapt to new demands. The regulation of consumption through demand management tools, such as appropriate pricing policies, has recently received greater attention in Uzbekistan. The main thesis of this paper is that allocation of water resources cannot be separated from ecological and economic considerations. The establishment of development objectives and the identification of constraints are also discussed. In the coming years, special attention will need to be paid to the control of water pollution and land salinization, water resources conservation, and acknowledging that actions to increase water productivity are as important as finding additional sources of water.     

鱼类产卵敏感期河流生态流速的分区分类阈值研究

敏感生态流量目标的合理制定是生态流量管理的重难点问题。针对目前敏感生态流量目标制定中存在的计算方法繁杂、关键参数缺乏等问题,本文以鱼类产卵期为重点,提出了分区分类河流敏感期生态流速和生态流量核算方法,制定了不同区域(东北、黄淮海、西南、长江中下游和东南沿海)、不同类型(按集水面积、山区河段和平原河段等划分)河流敏感期生态流速阈值。结果显示,全部分区分类推荐流速平均值为0.66 m/s,其中山区大站平均值为0.94 m/s、山区小站平均值为0.62 m/s、平原大站平均值为0.63 m/s、平原小站平均值为0.46 m/s。基于阈值核算了全国217个鱼类产卵生境保护河段的敏感期生态流量目标,并结合部分断面湿周法结果对阈值合理性与适应性进行了验证,验证结果表明相关阈值和方法适应于不同类型、不同规模河流,可为我国现阶段河流敏感生态流量管控提供参考。     

生态流域建设理念与发展模式探讨

建设生态流域、协调流域生态环境保护与社会经济发展间的关系已成为当前流域研究的重点.对生态流域的概念及内涵进行了探讨,阐述了生态城市和生态乡村建设示范的规划目标,提出开展生态流域建设应重点开展流域分区与保护、城市群发展规划、生态产业规划、人工系统结构与功能调整四个方面的研究,以流域人工系统物质流和能量流的生态化为核心,深...     

生态沟渠对水稻不同生长期降雨径流氮磷的拦截效应研究

农田养分的大量流失已成为农业面源污染的主要来源之一,研究生态沟渠对稻田降雨径流氮磷拦截效应具有重要意义。针对水稻不同生长期内的降雨以及降雨的不同时段下生态沟渠对稻田径流氮磷的动态拦截效应研究缺乏的现状,本文选取太湖西岸何家浜流域典型农田作为研究对象,将该流域的自然排水沟渠改造为生态沟渠。研究了生态沟渠对水稻不同生长期内的3场降雨径流的氮磷去除效果。研究结果表明:(1)在3场不同强度的降雨过程中,生态沟渠对TN(总氮)的平均去除率为31.4%,TP(总磷)的平均去除率为40.8%;(2)生态沟渠对降雨径流不同形态氮磷的去除率大小为NH4+-N(氨氮)PN(颗粒态氮)NO3--N(硝态氮),PP(颗粒态磷)DP(溶解态磷),且PN和PP的去除率随沟渠径流量的增大而呈现下降趋势;(3)生态沟渠底泥总氮、总磷浓度在水稻的生长周期内呈现先增加后降低的趋势,说明生态沟渠具有一定的自净能力,对氮磷的拦截去除具有可持续性。     

基于黄河鲤栖息地水文-生态响应关系的黄河下游生态流量研究

本研究采用野外生物监测、栖息地同步观测和实验室控制实验等技术手段,应用生物学、鱼类生态学、生态水力学、水文学等多学科理论,基于河流栖息地模拟法,研究了黄河下游指示物种黄河鲤生态学特性及其栖息生境与流速、水深、水温等水文水环境因子之间的关系,将径流条件与目标物种不同生长阶段生物学信息相结合,建立了代表物种繁殖期、越冬期栖息地适宜度指数,构建了黄河下游重点河段河流栖息地模型,建立了指示物种栖息地状况与河川径流条件定量响应关系,提出黄河下游花园口和利津断面繁殖期最小生态流量为300 m³/s和100 m³/s、适宜生态流量为600～700 m³/s和190～250 m³/s。该研究在水生生物习性及其与河川径流响应关系方面实现突破,解决了黄河生态需水研究中关键技术问题。     

太子河流域不同生态分区的水生态承载力年内变化研究

为实现太子河流域水生态系统的分区、分期保护,并达到太子河流域的水生态环境与社会经济协调发展的目标,采用系统动力学和隶属度相结合的方法,从分析流域的人口、社会经济、水资源、水环境、水生态系统之间的相互关系入手,考虑到各分区之间的水流、水质交替关系,建立了基于水生态分区的太子河流域水生态承载力大系统动力学仿真模型和量化模型。对其8个水生态分区的水生态承载力指标的年内变化情况进行模拟,并量化各分区12个月的水生态承载力值,最终确定各水生态分区的水生态承载力最小值出现的月份,为更好的实施流域可持续发展战略提供科学依据。     

天津北大港水库渔业生态环境调查与评价

运用熵权模糊综合评价法和浮游生物多样性指数及优势种等方法,分析评价了天津北大港水库2013年5月、7月和9月的检测数据。结果表明:北大港水库2013年5、7和9月的水质都属于Ⅳ类水,浮游生物多样性指数较高,但是优势种中已出现耐污种类。北大港水库的水质评价结果和浮游生物分析结果都表明其已处于富营养化状态。最后针对这一结果提出了改善建议。