有限供水条件下水库和田间配水整合优化调度

针对多水源多作物灌区,研究有限供水条件下灌区优化配水问题。模型中既考虑水库优化调度,又考虑田间优化配水。模型思路:根据灌区水土资源分布状况,将全灌区划分为多个子区,每个子区种植有若干种作物。如果把每个子区每种作物所在的田块看作一个土壤水库,则可采用水库群调度的方法研究这类灌区优化配水问题,文中采用的是优化控制方法。为了证明模型的正确性,同时建立了3个模型。模型1:既不考虑水库优化调度又不考虑田间优化配水;模型2:只考虑水库优化调度;模型3:只考虑田间优化配水。实例计算表明,整合调度模型能产生较多的效益(特别在干旱年份),优化控制方法计算性能良好。     

线性规划在灌区用水管理中的应用

采用流速仪测量渠道流量的灌区,在其测流及水量计算过程中,由于测验断面或人为因素,不可避免地存在着一定误差,有时出现上游测站水量小于下站水量或站间计算配水量明显偏大、偏小等不合理现象.应用线性规划理论中的修正单纯形法,提出水量平差模型,对不合理的测站水量进行修正,以提高配水统计和配水调度的精度.通过在位山灌区的实际运用,取得了明显效果,灌区配水调度也因此实现了由经验定性决策向科学定量决策的过渡,提高了用水管理水平.     

Estimates of uncertainty in the prediction of past climatic variables

Fitting a regression line to a set of measurements to investigate the relationship between a proxy estimate of past climate and known climatic parameters is a routine procedure. It is generally accepted that the higher the correlation between parameters, the more reliable the reconstruction. However, there is a lack of published work upon what correlation is the minimum acceptable value. Simulated data was used to demonstrate that the relationship between proxy values and the climatic data are adversely affected by falling correlation, to the point where, in a training set consisting of 100 pairs of temperature and tree-ring proxies, the mean 95% confidence interval width for the reconstructed temperature exceeds the total range of temperatures in the training set at or below r = 0.65. This correlation is typical of that used in many climate-proxy reconstructions, and it suggests that understanding of past climate variability may be somewhat constrained.     

Surface irrigation performance of date palms under water scarcity in arid irrigated lands

In this paper, a study on the performance of surface irrigation of date palms in a Tunisian arid area (Douz oasis) is presented. The study is conducted in 16 plots with various sizes and soil textures over a 4-year period (2012–2015). In the first step, an assessment of total water requirements of the date palms is carried out. Then, the surface irrigation performance is analyzed using three indicators, i.e., the relative water supply (RWS) indicator, the uniformity index of water distribution (D _U ), and the water application efficiency (E _a ). Finally, the irrigation management problems are identified. The results indicate that in the arid Tunisian Saharan oases, the soil texture, plot size, and farmers’ practices (especially irrigation duration) have significant effects on surface irrigation performance. The average annual net irrigation requirements of date palms are about 2400 mm. The RWS increases from 1.8 in the smaller plots (0.5 ha) to 3.6 in the largest plots (2.5 ha), implying that the increase in the plot size requires an excessive water supply. D _U decreases from 80.7 in the 0.5 ha plots to 65.4 in the 2.5 ha plots; however, no significant difference in the E _a is observed. The results show that the soil texture has no influence on the RWS and D _U , but the E _a is significantly higher in the loamy-sand soils (46.7%) compared to the sandy soils (36.3%). Overall, RWS indicator is higher than 1 (RWS?=?2.6) implying excessive irrigation supply to the system. Although D _U is relatively uniform (>?60%), E _a is relatively low (<?50%) indicating that the current irrigation management is inefficient. These findings have a paramount importance for improving irrigation water management in the Tunisian Saharan oases.     

沟底膜孔灌水条件下土壤水入渗规律的数值模拟

以土壤水动力学原理为基础,研究了沟底膜孔灌水条件下土壤水分运动规律,建立了二维入渗模型。对模型检验表明,试验实测数据与模型计算值吻合较好,说明所建立的模型是可行的。     

Eustatic and climatic controls on the development of the Wahiba Sand Sea, Sultanate of Oman

Aeolian sand sea accumulations can serve as valuable archives of climate change in continental environments. The Wahiba Sand Sea is situated at the northern margin of the area presently affected by Indian Summer Monsoon Circulation and it records environmental changes associated with this major climatic boundary over the last 160 000 years. The internal stratigraphy and evolution of the sand sea is investigated using a combination of outcrop, borehole, seismic and luminescence data. Proximity to the Indian Ocean means that the sand sea succession shows the influence of sea level changes on the sedimentary architecture and composition of the dune deposits. During the last two glacial periods, low global sea level was associated with a high input of bioclastic grains, reflecting the significance of subaerially exposed shelf areas as one of the main sources of aeolian sediment. The onset of aeolian sediment transport and deposition was related to the breakdown of stabilizing vegetation during arid periods that equate with sea level lowstands. The preservation of aeolian sediments by the formation of supersurfaces and associated palaeosoils took place during times of increased wetness and elevated groundwater tables. This interplay of constructive and destructive periods greatly influenced the sedimentary architecture. Oscillations of wet and dry periods between 160 000 and 130 000 years and 120 000–105 000 years ago are attributed to the evolution of a wet aeolian system. Younger periods of aeolian deposition around and after the last glacial maximum were characterized by dry aeolian conditions. No soil horizons developed during these times.     

冻结作用下考虑补水层影响的水分迁移试验

冻融协同淋洗修复污染土壤的过程中,为了提高淋洗效率,须使土体在冻结过程中吸收更多的水分或淋洗液。因此,通过室内大尺寸单向冻结水分迁移试验,开展了开放系统下温度梯度、冻结速率及补水方式对水分迁移的影响研究。试验结果表明：冻结过程中土中水分迁移与温度梯度的变化速率有关,变化速率越大水分迁移量越大;可以通过边界温度控制冻结锋面推移速度进而影响土中水分的迁移,当冻结锋面推移速度为0.5 cm·d^-1左右时,补水速率最大;距离冻结锋面越近水分迁移量越大,当距离冻结锋面10 cm左右时,水分迁移量开始增大,可通过在土体中添加多层补水层的方式让土体吸收更多的水分;有外界水源的补给下土体含水量整体增加,但上层土体含水量增加较多,下层土体含水量增加较少。     

气候变化下贵州省水资源安全空间评价及敏感性分析

探讨气候变化下水资源安全的时空演变规律,对喀斯特地区水资源安全的保障有着重要意义。文章采用GA-BP神经网络模型,研究了贵州省水资源安全的空间分异特征,并分析其对气候要素变化的敏感性。结果表明：（1）研究区水资源安全有较强的空间异质性。2001－2015年,黔南的水资源安全一直是全省最差的地区,贵阳的水资源安全改善最为明显,变化幅度最小的是安顺;（2）当变动率相同时,年平均降雨量的变动对水资源安全的影响最大,其增加10%时水资源安全指数上升0.95%,单位地表水资源量变动的影响其次,单位地下水资源量变动的影响最小;（3）对年平均降雨量变化最为敏感的地区是遵义、毕节、六盘水和黔西南。研究结果可为贵州省水资源的调控和开发提供参考。     

系统动力学-多目标规划整合模型在秦皇岛市水资源规划中的应用

应用系统动力学-多目标规划整合模型对秦皇岛市城市水资源利用结构进行了优化研究,首先预测秦皇岛市在以1999年为基准年,不进行结构调整状态下的总体发展趋势,从中获取有关水资源的供需信息,然后进行水资源利用结构分析,找出存在的问题,据此进行城市总体结构和水资源利用结构的优化研究,获得了秦皇岛市区水资源利用规划方案;将所得规划结果输入系统动力学模型,对规划方案实施后的社会、经济和环境后果进行了合理预测.     

微咸水膜下滴灌对温室乳瓜产量及品质的影响特性研究

本文采用正交试验,研究了防渗技术、微咸水利用方式对温室膜下滴灌乳瓜产量及品质的影响。结果表明,一定矿化度的微咸水灌溉会增加作物土壤根系层含盐量和阻碍作物根系吸水,在灌溉方式和灌水定额一定的情况下,虽然全塑料薄膜防渗保水效果强于四周塑料薄膜+底部粘土防渗,但是四周塑料薄膜+底部粘土防渗透气性好,土壤呼吸作用强,在高温时可以及时调节土壤温度,并有利于乳瓜根部呼吸和生长,使其光合速率升高,有助于乳瓜水分和干物质积累,从而获得增产。     

Risk and uncertainty analysis in the planning stages of a risk decision-making process

Natural disaster risk, a long-time concern in the insurance industry, is increasingly recognized as a present danger in the business strategies of risk control and enterprise management agencies. Floods and earthquakes can cause massive loss of life and infrastructure, resulting in business interruption and heavy casualties. Many of the short-term developmental strategies employed throughout the world have only served to exacerbate the impact of natural disasters. Therefore, this study presents a review of formal methods that are commonly used in risk and uncertainty analysis in planning and concludes with a critical assessment of the advantages and disadvantages of the different priority setting methods. Our focus is a preliminary proposal for developing an efficient probabilistic approach to facilitate design optimization that involves probabilistic constraints.     

MIS在水资源管理中的应用

MIS(Management Information System),管理信息系统)是一个正常中文Windows工作环境下,能进行信息的收集、传递、存储、加工、维护和使用的计算机人机对话系统.主要功能是:利用过去的数据预测未来、利用信息和模型辅助企业进行决策.根据MIS和计算机辅助管理的基本原理和功能.笔者利用Visual foxpro 5.0等计算机编程语言开发出一套适用于水资源管理部门的《水资源管理信息系统》计算机应用软件,解决了水资源管理部门在水资源管理工作中运用MIS实现计算机辅助决策和信息管理的问题. 1 系统组成 由水资源管理和取水许可管理两大子系统组…     

气候变化下长江中下游水稻灌溉需水量时空变化特征

选择长江中下游单季中稻为研究对象,结合45个气象站1961~2010年逐日气象资料,基于统计降尺度模型(SDSM),生成HadCM3气候模式A2和B2两种情景下各站点参考作物腾发量和降水数据。基于联合国粮食及农业组织(FAO)推荐的作物系数法,并考虑有效性降雨和不同地区深层渗漏量,分析历史和未来的水稻灌溉需水时空变化特征。结果表明:过去50年,除了太湖流域以外的长江中下游大部分区域的参考作物腾发量和水稻需水量都呈显著下降趋势,而显著下降的水稻灌溉需水量主要位于鄱阳湖流域;未来两种情景下,参考作物腾发量、水稻需水量和水稻灌溉需水量均值都呈下降趋势,但水稻灌溉需水量降幅最小;水稻需水量和水稻灌溉需水量在长江中下游地区的变化趋势具有明显的空间异质性,水稻需水量大幅减少的区域由太湖流域向汉江和洞庭湖流域扩展。未来水稻灌溉需水量减少的区域主要分布在太湖流域、汉江流域东部和洞庭湖流域北部,并随时间推移呈扩大趋势。     

Simulation analysis of domestic water demand and its future uncertainty in water scarce areas

This paper demonstrates a practical simulation approach to analyze domestic water demand and its future uncertainty in water scarce areas through a case study of Beijing, China. Analytic models and a forecasting model were constructed using statistic and econometric regression approaches. The analytic models were used to analyze the interrelationships between domestic water demand and some socio-economic factors of Beijing. The forecasting model was applied to predict domestic water demand from 2009 to 2015, and this model was validated by comparing the prediction values with the observations. Scenario analysis was applied to simulate uncertainty and risks in domestic water demand in the future. The simulation results proved that domestic water demand will increase from 13.9×10⁸ m³ to 16.7×10⁸ m³ from 2009 to 2015. Three more sustainable strategies were also found through scenario analysis. The simulation and modeling approaches and results would be very supportive for water decision makers in allocating water efficiently and making sustainable water strategies.     

地下开采条件下水资源流失机理与环境影响研究

通过剖析因地下采动造成阜新矿区自然村民井断水现象，对地下开采条件下水资源流失与恶化机理进行了分析研究。结果表明，即使采空区和受影响区处于不同的水文地质单元，因采动对隔水构造的破坏而形成地下水径流通道-空巷和裂隙，从而为水的流失创造了水文地质条件；地下水经过长时间聚集和物化作用发生水质恶化，失去使用价值。废弃关闭矿井水的资源化与利用问题，对水资源缺乏和煤炭资源枯竭、经济转型矿区具有现实的经济与社会意义。应该研究因抽取矿井水而引起的相关环境影响与灾害问题，防止出现二次破坏。     

The petrogenetic association of carbonatite and alkaline magmatism: constraints from the Masfut-Rawda Ridge, Northern Oman Mountains

Summary ?A new occurrence of carbonatites associated with intrusive ijolite and syenite has been discovered within the Hawasina Complex underlying the Semail Ophiolite Complex at the southern part of the Rawda-Masfut ridge, Northern Oman Mountains. The carbonatites occur as dikes and sills with lengths of several hundreds of meters and range in composition from calciocarbonatites to ferruginous calciocarbonatites. The carbonatites intruded the ijolite and the associated radiolarian cherts of the Early Cretaceous Sid’r Formation. The close spatial association of carbonatite, ijolite, syenite and radiolarian cherts along with geological, petrographical and geochemical data indicates that these rocks are of intra-oceanic origin. Petrological and field relationships between the carbonatite and associated alkaline silicate intrusives from the Masfut area are consistent with the carbonatites being generated as derivative magmas through liquid immiscibility. They appear to represent magmas related to the volcanism associated with regional crustal extension that preceded the genesis of the Semail Ophiolite. Received April 19, 2001; revised version accepted February 18, 2002     

气候变暖背景下极端气候对青海祁连山水文水资源的影响

利用青海祁连山区极端气候要素和青海湖、哈拉湖及主要河流的水文资料,研究表明：冷夜日数（10%）呈显著减少趋势,暖夜日数（90%）呈显著增加趋势;年大风日数显著减少;年降水量21世纪初增加趋势最为显著并发生突变,降水量增加幅度中西段大于东段;≥ 5 mm、≥ 10 mm、≥ 25 mm年降水日数呈显著增加趋势,进入21世纪后更为明显,而≥ 0.1 mm年降水日数呈减少趋势;年平均大风日数与湖泊水位、河流流量变化呈负相关,大风天气的减少,可以缓解湖面和土壤因蒸发而导致的水分损失,对植被的改善可增加径流的产生,流入湖泊的流量增加;降水量与湖泊水位、河流流量呈正相关,受21世纪降水量增加的影响青海湖水位逐年上升,共上升1.67 m,达到20世纪70年代末的水位,中西部主要河流流量近几年也达到最大值,而东段流量增加不明显;祁连山区≥ 5 mm、≥ 10 mm、≥ 25 mm年平均降水量与湖泊、河流流量变化呈正相关,各量级年降水量对湖泊水位、河流流量的增加贡献显著。     

Urban water supply planning and management in Nigeria

The gap between water need and supply has widened steadily in Nigeria's urban centres despite continuous efforts made to develop the nation's vast surface and groundwater resources. Less than 0.5% of the total water resource potential has been developed for consumption, and the per capita water supply for all uses is only 61 litres per day. Acute water shortages afflict the inhabitants of the towns and cities. The bulk of available water supplies is unmetered; where metered, ridiculously low rates are changed. Thus, there is a great need for management policy that aims at financial viability and economic efficiency. More realistic water rates should be charged in order to raise the much-needed revenue to meet increasing production and distribution costs.