国那里引黄灌区走出困境途径探讨

1 基本情况 国那里引黄灌区位于济宁市梁山县境内,始建于1967年,灌区总控制面积366km~2,其中东平湖滞洪区占灌区总面积的71％,设计灌溉面积2.07万hm~2,其中:自流灌溉面积1.19万hm~2,提水灌溉面积8746.6hm~2,为当地农业生产发挥了巨大作用。但由于灌区工程标准低,配套较差,已有工程老化失修严重。另外,原有灌区管理体制已很不适应新形势发展需要,使灌区陷入困境。     

浅谈陈垓引黄灌区节水续建工程

陈垓引黄灌区位于梁山县境内，始建于1959年，控制面积544.2km^2，设计灌溉面积2.81万hm^2，涉及粱山县10处乡镇，总人口45.36万人。该灌区融自流、提水、井灌补源、引黄补湖于一体，是山东省大型引黄灌区之一，为灌区及南四湖地区的工农业发展作出了突出贡献。历经多年运行，灌区设施退化老化严     

用好国债资金搞好灌区改造

淮涟灌区位于江苏省淮安市淮阴区、涟水县境内,涉及26个乡镇,总人口57万人,灌区总控制面积860km~2,原有耕地面积85.43万亩,设计灌溉面积76.97万亩,现有耕地面积79.93万亩,现状有效灌溉面积55.94万亩,是淮安市重要的商品粮生产基地。经过40多年的运行,灌区内工程老化失修严重,灌溉水利用系数较低,水资源浪费严重,许多建筑物已不能适应工     

陈垓引黄灌区续建配套项目地方配套资金筹措浅析

陈垓引黄灌区位于济宁市梁山县境内,是山东省大型引黄灌区之一。始建于1959年,控制面积544.2km~2,设计灌溉面积2.81万hm~2。由于灌区在亏本情况下运行多年,维修及改造资金缺口较大,且许多工程标准低、质量差、老化退化严重,远不能适应当前工农业经济发展的需要。为改变灌区工程设施及用水管理状况,推动灌区可持续发展,2000年4月,水     

混凝土衬砌渠道施工中应注意的问题

1工程概况信阳市石山口灌区位于罗山县的中北部,与信阳市南湾灌区毗邻,灌区工程兴建于1976年,1978年正式开灌。设计灌溉面积2.06万hm2(其中自流灌溉面积1.56hm2,提灌面积0.50万hm2)。灌溉范围涉及罗山县境内的8个乡(镇),72个行政村,灌区总人口28万人。灌区的建成,大大地改善了当地的农业生产和农民生活条件,促进了当地农村经济的发展。但由于工程建设     

渭河流域大中灌区水资源开发利用存在问题及对策

1 灌区概况 我省渭河流域有宝鸡峡、泾惠渠、交口抽渭等10万亩以上的大中型灌区21个,设施灌溉面积1214.72万亩,占全省设施灌溉面积的54％。这一区域南依秦岭,北界北山,西起宝鸡,、东到撞关,东西长约360km,南北宽约30～80km,土地总面积5.54万km2,占全省总土地面积的26.9％。灌区地势为南北高中间低,西部高东部低,海拔     

海河流域中型灌区发展对策与建议

<正>一、海河流域中型灌区概况1.基本情况截至2017年,海河流域有中型灌区449处,设计灌溉面积2 867.74万亩(1亩=1/15 hm~2,下同),有效灌溉面积2 145.97万亩,占海河流域有效灌溉面积1.13亿亩的19%。近3年平均实灌面积1 563.17万亩,占有效灌溉面积的73%。海河流域共有重点中型灌区195     

南湾灌区工程效益衰减的思考

一、灌区概况南湾灌区是信阳市最早建成的大型灌区之一,1959年开始兴建,1960年部分开灌,至1966年全部建成通水。灌区工程由平桥渠首枢纽、南北2条干渠(长144km),28条支渠(长225km)、565条斗渠(长698km)、44座提灌站、2条排水干沟(长10km)、6条支沟(长113km)等组成。灌溉平桥区、上天梯管理区、罗山、息县、正阳3县2区的24个乡镇,受益人口80.2万人。灌区总土地面积1548hm~2,设计灌溉面积7.49万hm~2。目前有效灌溉面积4.93万hm~2。     

河南省三义寨引黄灌区骨干工程管理

一、基本情况河南省三义寨引黄灌区是1958年兴建的大型灌区,灌区当时涉及河南、山东两省的开封、商丘及菏泽3个地区的18个县(市),渠首闸设计过水能力为520m~3/s,设计灌溉面积132万hm~2,在工程尚未形成灌排体系的情况下,于1958年明15日放水蓄灌,引起地下水位普遍升高,导致大面积次生盐碱化,被迫于1961年停灌。后经1974年和1990年2次改造后,渠首闸目前过水能力为150m~3/s。灌区缩为河南省的豫东地区。河南省计委以豫计经规[1992]1943号文批复:建设新三义寨引黄灌溉工程,总干渠设计流量为107m~3/s,灌溉面积22．67万hm~2。灌区包括开封、商丘两市的9个县(区),总土地面积43．43万hm~2,总耕地面积27．00万hm~2。     

浅析引黄灌溉的经济效益

淮河流域引黄灌区到目前为止已有大小灌区15处,共有农业人口382万人,耕地767万亩,设计灌溉面积748万亩,有效灌溉面积251万亩,淤改面积215万亩,抗旱补源面积约700万亩。引黄灌区位于淮河流域北部,河南、山东两省沿黄市,县。西起京汉铁路,东至东平湖,涉及河南省郑州市、开封市、中牟县、尉氏县、通许县、杞县、民权县、兰考县等;山东省菏泽地区的东明县、菏泽市、鄄城县、郓城县、梁山县等。送水补源到商丘地区,菏泽     

Feeding Ecology of Lake Whitefish in Lake Huron

We determined diet composition, feeding strategy, prey size, and effects of prey type on food weight and energy in stomachs for lake whitefish Coregonus clupeaformis in Lake Huron during 2002–04. Age-0 lake whitefish (73–149 mm TL) ate mainly large-bodied cladoceran zooplankton in the summer (July–mid September). Medium lake whitefish (≤ 350 mm TL excluding age-0) generally ate softbodied macroinvertebrates, especially Chironomidae larvae and pupae, in the spring (mid May-June). Zooplankton, if eaten, were generally most important in the summer. Molluscs were generally a minor part of medium lake whitefish diets. Large lake whitefish (> 350 mm) mainly ate molluscs, particularly quagga mussels (Dreissena bugensis), despite geographic differences in mussel abundance. Large-bodied crustaceans (Diporeia spp., Mysis relicta, Isopoda) were a minor part of large lake whitefish diets. Lake whitefish demonstrated a flexible feeding strategy, with individual specialization on some prey and generalized feeding on others. The size of benthic prey (Diporeia spp., Chironomidae, and Dreissena spp.) eaten increased with fish size and influenced the energetic value of prey for medium and large lake whitefish. The type of prey eaten affected the food and energy intake differently for each size class of lake whitefish. Age-0 lake whitefish that ate mainly zooplankton had more food and energy in stomachs than fish eating shelled prey or other macroinvertebrates. On the other hand, food weight in stomachs did not differ across prey groups for medium fish, but energy in stomachs was lowest for fish that ate shelled prey. For large lake whitefish, there was no difference in food weight or energy in stomachs for different prey groups.     

洪泽湖混合流数值模拟

本文通过构造一个二维开边界数值模式，对不同风情及出入湖流量组合情况下的洪泽湖混合流流态进行模拟研究，探讨其混合流特征。     

Maturity Schedules of Lake Trout in Lake Michigan

We determined maturity schedules of male and female lake trout (Salvelinus namaycush) in Lake Michigan from nearshore populations and from an offshore population on Sheboygan Reef, which is located in midlake. Gill nets and bottom trawls were used to catch lake trout in fall 1994 and 1995 from two nearshore sites and Sheboygan Reef. Each lake trout was judged immature or mature, based on visual examination of gonads. Probit analysis, coupled with relative potency testing, revealed that age-at-maturity and length-at-maturity were similar at the two nearshore sites, but that lake trout from the nearshore sites matured at a significantly earlier age than lake trout from Sheboygan Reef. However, length at maturity for the nearshore populations was nearly identical to that for the offshore population, suggesting that rate of lake trout maturation in Lake Michigan was governed by growth rather than age. Half of the lake trout males reached maturity at a total length of 580 mm, whereas half of the females were mature at a length of about 640 mm. Over half of nearshore males were mature by age 5, and over half the nearshore females matured by age 6. Due to a slower growth rate, maturity was delayed by 2 years on Sheboygan Reef compared with the nearshore populations. Documentation of this delay in maturation may be useful in deciding stocking allocations for lake trout rehabilitation in Lake Michigan.     

Potential Strategies for Recovery of Lake Whitefish and Lake Herring Stocks in Eastern Lake Erie

Lake Erie sustained large populations of ciscoes (Salmonidae: Coregoninae) 120 years ago. By the end of the 19^th century, abundance of lake whitefish (Coregonus clupeaformis) had declined drastically. By 1925, the lake herring (a cisco) population (Coregonus artedii) had collapsed, although a limited lake herring fishery persisted in the eastern basin until the 1950s. In the latter part of the 20^th century, the composition of the fish community changed as oligotrophication proceeded. Since 1984, a limited recovery of lake whitefish has occurred, however no recovery was evident for lake herring. Current ecological conditions in Lake Erie probably will not inhibit recovery of the coregonine species. Recovery of walleye (Sander vitreus) and efforts to rehabilitate the native lake trout (Salvelinus namaycush) in Lake Erie will probably assist recovery because these piscivores reduce populations of alewife (Alosa psuedoharengus) and rainbow smelt (Osmerus mordax), which inhibit reproductive success of coregonines. Although there are considerable spawning substrates available to coregonine species in eastern Lake Erie, eggs and fry would probably be displaced by storm surge from most shoals. Site selection for stocking or seeding of eggs should consider the reproductive life cycle of the stocked fish and suitable protection from storm events. Two potential sites in the eastern basin have been identified. Recommended management rocedures, including commercial fisheries, are suggested to assist in recovery. Stocking in the eastern basin of Lake Erie is recommended for both species, as conditions are adequate and the native spawning population in the eastern basin is low. For lake herring, consideration should be given to match ecophenotypes as much as possible. Egg seeding is recommended. Egg seeding of lake whitefish should be considered initially, with fingerling or yearling stocking suggested if unsuccessful. Spawning stocks of whitefish in the western basin of Lake Erie could be utilized.     

Nitrogen dry deposition to Lake Superior and Lake Michigan

Nitrate (NO₃^?) levels in Lake Superior have increased from historic levels of about 5?μM to its current concentration of about 25?μM. The atmosphere makes a substantial contribution to the nitrogen budgets for Lake Superior and Lake Michigan. This study provides a more well-defined estimate of nitrogen dry deposition rates derived from the measurement of over-water concentrations, and in situ meteorological measurements, which were input into the Resistance Model. We obtained a nitrogen dry deposition rate of [(3.41?±?2.26)?×?10⁷?kg?N/yr; (5.90?±?3.91)?kg?N/ha/yr] over Lake Michigan, and [(1.54?±?1.06)?×?10⁷?kg?N/yr; (1.87?±?1.27)?kg?N/ha/yr] over Lake Superior. Nitric acid (HNO₃), which originates from the combustion of fossil fuels, contributes 84% of the total nitrogen dry deposition to Lake Michigan; and 66% to Lake Superior. Ammonia (NH₃), which originates from agricultural activities and gasoline combustion, is the second highest contributor of nitrogen dry deposition to both lakes: contributing 13% to Lake Michigan and 32% to Lake Superior. The nitrogen dry deposition is approximately 68% of the nitrogen wet deposition over Lake Superior, and approximately 80% of wet deposition over Lake Michigan. The over-water dry deposition velocity of HNO₃ and NH₃ were also evaluated. We obtained morning deposition velocities of 0.099?cm/s for NH₃ and 0.095?cm/s for HNO₃; and afternoon values of 0.137?cm/s for NH₃ and 0.132?cm/s for HNO₃. Another key finding is that the atmospheric concentrations of nitrogen compounds near Lake Michigan and Lake Superior have decreased since 2003.     

太湖梅梁湾、贡湖套网格风生流数值模拟

对太湖梅梁湖、贡湖湖流进行套网格数值模拟。根据1998年8月太湖富营养化水质监测水文物理资料,绘制出梅梁湖、贡湖各站点位置分布图和其流速大小和方向。模拟计算与实测结果吻合较好,证明其套网格数值模型的建立是合理和有效的。分析结果表明,太湖各水域流速相差很大,近岸区域流速高于远岸区域,存在明显的近岸流。但流速值不大,即梅梁湖、贡湖和大太湖的水体交换量不大,通过流场分布可初步判断污染物质在水体中的扩散与迁移情况。     

Spatial Patterns in PCB Concentrations of Lake Michigan Lake Trout

Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.     

GPS?RTK?技术在青海湖容积测量中的应用

随着? GPS?的快速发展,RTK?测量技术也日益成熟,并逐步在测绘中得到应用.分析? GPS? RTK?技术在第一次水利普查青海湖容积测量中的应用,就? GPS? RTK?技术在水下地形测量中数据处理方法和野外测量优势进行探讨.在青海湖容积测量中的应用说明,RTK?技术改变了水下地形测量的作业模式,真正实现高精度、高效率,减轻了劳动强度,经过不断发展和完善,RTK?技术将改变测绘领域其他如控制测量、纵横断面测量、施工放样等的手段.     

Lake trout in northern Lake Huron spawn on submerged drumlins

Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.     

魏源湖赋

荆楚古邑,宝庆隆中。乙卯降魔,治水劈山,扼河兴湖,名弘魏源。彰群贤壮志,汗青碧湖;酬先哲宏愿,水映金潭。登高远眺,雪峰逶迤,资水蜿蜒;凌空俯瞰,黛镜平铺,翡玉精嵌。南北隽秀,西洋江、小沙江,江湖连环;东西妖娆,白马山、九龙山,山峦迭嶂。高州温泉,闻名遐迩,荷田钟乳,玲珑剔透,