提高南四湖上级湖正常蓄水位的可行性研究

南四湖是中国北方最大的淡水湖泊,形状狭长,流域面积31700km2.南四湖多年平均弃水量为15.5亿m3,其中上级湖通过二级坝闸弃水量10.2亿m3.为提高南四湖供水量,根据翔实可靠的水文实测资料,动态分析结合静态分析,研究提高南四湖上级湖正常蓄水位的合理性.     

水面蒸发对南水北调江苏段调水效率的影响

为了掌握南水北调东线江苏境内工程输水河道和调蓄湖库水面蒸发损失水量,及其所造成的泵站机组损失功率,了解水面蒸发对工程调水效率的影响,分析比较了适用于工程所在地区的水面蒸发量计算模型和计算公式,计算了工程沿线输水河道和调蓄湖库的水面蒸发量,分析了工程水面蒸发量的时间和空间分布特征.通过积分,计算了水面蒸发造成的各梯级泵站的流量损失和输入功率损失,求解并分析了水面蒸发对整个江苏段工程调水效率的影响.结果表明：工程沿线水面年蒸发量自南向北、西北方向逐渐递增;蒸发量夏季最高,冬季最低;全线平均水面年蒸发量为862.2 mm.洪泽湖、骆马湖、白马湖和输水河道蒸发损失水量分别占总蒸发损失水量的77.7%,13.3%,3.6%和5.4%,蒸发损失水量约占源头泵站抽水量的17.46%,使工程平均调水效率降低10.33%.调水工程可以考虑采用管道输水,从而避免蒸发损失.     

新疆开孔河灌区灌溉面积控制红线的确定

从保护湖泊生态、控制水资源过度开发的角度出发，以水资源可利用量和博斯腾湖合理水位作为社会经济发展的控制上限，通过分析新疆开孔河灌区现状和2015年的水资源开发利用潜力，并将各业用水户与地表水、地下水供水水源一一对应，按照优先考虑高保证率、后考虑低保证率的供水次序，在满足了生活、工业等行业的用水需求后反推农业的可供水量，最后结合当地的灌溉水平，采用供需分析计算手段，针对每个分区的具体情况确定出灌溉面积发展的适宜规模。     

2000—2014年中国粮食主产区植被水分利用效率时空演变特征研究

【目的】实现在气候变化背景下对粮食产区农业水资源的优化配置和水分的高效利用。【方法】利用Python、ArcGIS软件和MODIS遥感估算的MOD17和MOD16数据产品,研究了中国粮食主产区(东北、内蒙古、华北、南部)2000—2014年植被生态系统水分利用效率(water use efficiency,WUE)的时空分布规律。【结果】①年WUE(以碳计,下同)整体呈上升趋势,增速为0.013 g/(mm·m2·a)(P<0.01),2个转折点分别出现在2003、2010年;②年内WUE的变化主要呈M型的双峰模式,峰值出现在4—5月、9—10月,而季节尺度上WUE的变化具有显著差异;③不同时间尺度的WUE空间分布上具有明显的异质性;④2000—2014年来全区年WUE整体呈上升趋势,其中呈上升趋势的面积占84.01%,但上升幅度以轻度、中度为主;⑤各季WUE整体呈上升趋势,但是不同季节WUE发生上升的区域位置、面积和显著性的大小都不同。【结论】在气候变化背景下,2000—2014年中国粮食主产区植被生态系统WUE呈上升趋势,且年内呈M型的双峰结构,季节和空间尺度上的分布具有显著差异。     

Seasonal and land use impacts on the nitrate budget and export of a mesoscale catchment in Southern Portugal

Stream nitrate nitrogen exports are an important indicator of agricultural impacts on aquatic health in catchments. Quantitative assessment of factors and processes affecting stream nitrate loadings is complex because of the large number of causal factors and processes, such as weather and rainfall, catchment hydrological behavior, soils, land use practices and biogeochemical processes. An eco-hydrological catchment modeling approach, using the SWAT model driven by detailed field data, was used to analyze the nitrate export and the components of the nitrogen budget of the 352 km² upper Roxo river catchment in Southern Portugal. A detailed eight-year record (2001–2008) of the monitoring of weather, reservoir inflow, stream biogeochemistry, soils, in-stream and groundwater quality, and fertilizer application was used to calibrate and validate the streamflow and nitrate loadings obtained by the model. Results indicated a strong seasonal variation in nitrate exports, closely related to temperature and rainfall. Monthly nitrate loadings varied from 0.02 to 2.48 kg N ha⁻¹ during summer and between 0.03 and 14 kg N ha⁻¹ during late autumn and winter. Stream nitrate values, ranging from 1.5 to 16.5 mg N L⁻¹, were strongly related to extreme rainfall occurrences and wet periods. Detailed analysis of nitrate budget components at the sub-catchment level enabled evaluation of the impacts of the various processes affecting the nitrate nitrogen pool of the catchment. Besides high fertilizer inputs for annual crops, it was shown that biological nitrogen fixation and wet deposition by rainfall should be accounted for in input balances. Where denitrification naturally reduces nitrate levels in soils, streams and the reservoir, the largest contribution to stream nitrate originates from leached soil nitrate reappearing in groundwater baseflow, compared with less than 2% from direct surface runoff during high rainfall events. A fertilizer reduction scenario was effectively implemented to evaluate remedial nitrate control policies in accordance with the European Nitrate and Water Framework Directives. Agricultural practices and seasonal weather fluctuations were the main reasons for temporal variations in nitrate export via small streams to the main reservoir.     

Optimal irrigation efficiency for maximum plant productivity and minimum water loss

Castilla-La Mancha in Central Spain is a semi-arid area of extremely high interannual and seasonal rainfall variability. Average annual rainfall for the catchment of the Upper Guadiana using data from 60 rain gauges for October 1956–September 1991 varied from a minimum of 326 mm in October 1982–October 1983 to a maximum of 642 mm in October 1968–September 1969. The mean annual rainfall for the period was 495 mm with a coefficient of variation for annual rainfall of 26.4%. In addition to this the spatial variability of rainfall is particularly high. For example total annual rainfall varied from 200 to 1200 mm for the hydrological year October 1968–September 1969 over a distance of only 50 km. The mean annual rainfall for all 60 stations for the period 1956–1991 was 460 mm with a coefficient for spatial variation of 15%. Dryland farming which relies on these uncertain precipitation inputs is a high risk activity [Tarjuelo, J.M., de Juan, J.A., Valiente, M., Garcia, P., 1996. Agric. Water Manage. 31, 145–163] and over recent decades intensive irrigation has increased dramatically in order that precipitation inputs can be supplemented as required thereby allowing more stable agricultural productivity. The paper uses a coupled hydrology and vegetation growth model – PATTERN [Mulligan, M., 1996. Modelling hydrology and vegetation change in a degraded semi-arid environment. PhD. Thesis, University of London] to explore the relationship between irrigation and productivity for different soils typical of the Upper Guadiana catchment. Analysis of the model results shows that irrigation efficiency is highly sensitive to both soil texture and irrigation volume. Optimally efficient irrigation in terms of water losses occurs at the lowest volumes of applications. Fine grained soils are better suited to irrigation than coarse grained soils as losses to recharge are minimised. Coarse grained soils have large recharge losses and irrigation is also more sensitive to small changes in texture for coarser soils. Irrigation losses through recharge are also very sensitive to the interannual and spatial variability of rainfall.     

内蒙古乌梁素海污染源调查研究

内蒙古乌梁素海已成为我国寒旱区富营养化最为严重的湖泊,为弄清乌梁素海所面临的污染负荷情况,在大量实测数据和调查数据的基础上,对乌梁素海的污染源进行了详细的计算分析。结果表明:乌梁素海的污染源主要来自3个方面,分别是农田排水、工业废水和生活污染。其中,农业排水中总磷对乌梁素海的贡献率超过了30%,总氮的贡献率接近50%,COD的贡献率达到了65%。可见,农田排水对乌梁素海污染负荷的贡献率最大。为乌梁素海源头治理提供了一定的参考依据。     

乌梁素海水环境容量分析

【目的】研究乌梁素海的水环境容量特征和探索水环境容量与入湖水质水量间的响应关系。【方法】采用零维模型分别计算并分析了乌梁素海冰封期与非冰封期的水环境容量,基于水文实际条件,分析入湖水量对出口断面污染物质量浓度的影响。【结果】冰封期湖泊的自净容量小于非冰封期时的自净容量,且冰封期的氮和有机物污染物的环境容量远小于非冰封期。【结论】非冰封期引入的黄河水和农田退水会导致湖泊氮磷水环境容量下降。有机物污染物的水环境稀释容量会因为黄河引水增加。     

乌梁素海水环境综合评价

从湖泊水环境理论出发,以灌区的草型湖泊乌梁素海为研究对象,用基于监测样本信息的主成分分析确定权重的模糊综合评价方法,从水质、富营养状况和水生生态3方面对2006-2008年6月份乌梁素海各功能区水环境指标的均值进行综合评价,定量地评价出各功能区的水质级别。综合评价的结果为:农业用水区的水质为4.416级,景观娱乐用水区的水质为3.635级,渔业用水区的水质3.122级,混合区的水质4.762级,得出乌梁素海大部分水体已处于富营养状态。     

基于水文水动力模型的浦阳江流域洪水情景模拟

浦阳江流域地形复杂,包括山丘、盆地和平原.中游诸暨盆地是人口主要聚集地,受上游山区洪水和下游钱塘江潮位顶托影响,洪涝灾害形势严峻.为解决上述问题,本文对流域上游山区采用新安江水文模型模拟降雨径流过程,对下游盆地区采用IFMS一、二维水动力模型模拟水流运动,并以水文模型的计算结果作为水动力模型的边界条件进行水文水动力模型...     

基于结构-参数同步优化的河湖水位模型及应用

为解决河湖水位支持向量回归(SVR)模型输入变量选择问题,提出了基于进化算法的模型结构-参数同步优化方法.该方法可应对复杂河湖交汇水系输入变量搜索空间的高维特性,减小源自模型结构及参数不确定性的模型误差.将提出方法应用于洞庭湖城陵矶站和荆江陈二口站水位建模,结果显示:提出方法可准确反映不同影响因素对水位预测的作用大小,城陵矶水位预测最主要的外部变量为长江来水和湘江来水,陈二口水位预测则为枝城站和马家店水位;该方法可充分发掘SVR潜力,2个站点的水位模型均取得了理想精度(R² > 0.998);提出方法采用的n折交叉验证方式可有效避免模型过拟合问题.综上,提出的SVR模型结构-参数同步优化方法适用于河流湖泊,特别是复杂河湖交汇水系的水位建模.     

涪江流域径流量变化及对武引灌区引水的影响

研究运用涪江武都引水枢纽段1984-2010年的年径流量和月径流量资料分析流域径流量变化规律,并结合2005-2010年武引灌区实际引水情况分析流域径流量变化对灌区引水的影响。根据研究,涪江武都引水枢纽段具有年径流量线性下降、年代际平均径流量下降、年径流量丰枯波动等特征,而未来灌区需水总量将大幅增加,将对灌区引水总量产生影响;涪江发生枯水的月份与灌区灌溉用水时间的吻合,加剧了灌区供用水的矛盾,将对灌区引水时间产生影响。因此,应采取积极的措施应对径流量的变化,使武都引水工程更好地为灌区工农业生产服务。     

变化环境下的龙川江流域水循环要素响应与趋势

根据实测资料,分析了1950年以来龙川江流域气温、降水、水面蒸发和径流等水循环要素的变化情况.结果表明受全球升温的影响,龙川江流域气温和降水量均为较明显的升高和增加趋势,年径流量呈现为非常微弱的减少趋势,而年蒸发量则表现为非常明显的减少趋势.从年代际来看,气温在20世纪80年代以前是偏冷期,80年代以来为偏暖期;蒸发量...     

Fate and risks of potentially toxic elements in wastewater-fed food production systems—the examples of Cambodia and Vietnam

Non-treated wastewater is used for irrigation of aquatic food production systems in the peri-urban areas of the major cities in Southeast Asia. This paper complement the knowledge on agricultural soil-based crops irrigated with low quality water, by reviewing the research findings on the wastewater-fed aquatic productions with special focus on heavy metals and other potentially toxic elements (PTEs) in the production systems of Hanoi in Vietnam and Phnom Penh in Cambodia. In Hanoi, sediments in the wastewater exposed rivers of Hanoi were reported to be polluted with PTEs, in particular with Cadmium (Cd). The river sediment had a high retention capacity for PTEs which seems to prevent the transport of PTEs to the wastewater-fed production systems. In Phnom Penh, domestic and industrial wastewater is pumped into the Cheung Ek Lake located south of the city. A major part of the water spinach (Ipomoea aquatica Forssk.) consumed in the city is produced in the lake. The concentrations of some PTEs were elevated at the wastewater inlets to the lake compared to concentrations at the lake outlet and at the control site. Water spinach is by far the major vegetable produced in the wastewater-fed systems in Hanoi and Phnom Penh, but did only contain PTEs in concentrations within or slightly above the concentration range observed for water spinach grown in agricultural soil not exposed to wastewater. PTE concentration in fish grown in wastewater-fed systems in Hanoi and Phnom were low. However, mean PTE concentrations in liver and skin of some fish were high. Consumption of muscle tissue from fish produced in wastewater-fed systems in Hanoi and Phnom Penh resulted in an estimated intake of PTEs amounting to less than 9% of the tolerable intake. It was concluded, that the PTE concentrations in fish and water spinach from Hanoi and Cheung Ek Lake in Phnom Penh constituted low food safety risks for consumers.     

喷灌条件下土壤水分入渗的数学模拟

采用摇臂式喷头喷灌时,地表处于蒸发和入渗的交替变化过程。在室内模拟了单喷头喷洒时土壤水分的运移过程。试验结果显示,当上边界条件同时考虑蒸发和喷灌时,模拟的土壤水分分布与用平均喷灌强度模拟的结果相比更接近于实测的土壤水分,但是2种情况模拟的土壤水分分布区域一致。水量平衡计算显示,随着喷灌时间的增加,2种方法模拟的土壤含水量相差较小,逐渐接近实测值。     

Economic analysis of water harvesting in a mountainous watershed in India

Water management is an essential feature of any project related with overall development of agriculture. The Soan river catchment in the northwest Himalayas, is fed only by rainwater. Hence, a strategy of rainfed agriculture needs to be developed through water conservation and storage techniques. The Soan is an important river from a soil erosion and water management point of view and detailed economic analysis is needed for any proposal to be implemented in the field. The present study was undertaken to propose an economic analysis of water harvesting structures for the Soan catchment. The purpose of the investigation is to control erosion and conserve water to meet the requirements of supplemental and pre-sowing irrigation for major cereal crops in the area and to maximise agricultural productivity. Benefit/cost ratios ranging from 0.41 to 1.33 are obtained for water harvesting structures of different sizes with estimated life of 25 and 40 years respectively, by taking into account different crop return from maize and wheat.     

基于主成分分析法的洞庭湖水质评价研究

水质问题日益成为影响人类社会发展的重大问题,因而对水质评价研究至关重要;根据对洞庭湖的监测断面的评价指标体系进行主成分分析,得出各个断面的主成分得分以及综合得分,对各断面的污染程度进行排名。结果表明,污染较严重的断面有:万子湖、东洞庭湖、坡头、目平湖、洞庭湖出口以及樟树港;污染一般的断面有:岳阳楼、横岭湖、沙河口、漉角以及南嘴;污染较轻的断面有:虞公庙、小河嘴以及万家嘴。     

洞庭湖烂泥湖水系洪涝灾害风险评估与应对措施

近年来,洪涝灾害是全球发生频繁、危害最严重的气象灾害之一,国内不少学者开始对洪涝灾害进行研究,目前对于洞庭湖区洪涝灾害风险的研究较少.采用综合评价法建立模型对洞庭湖区烂泥湖水系洪涝灾害风险进行评估并提出应对策略,结果表明:新泉寺闸内水位和滞涝水面率的不同导致暴雨对烂泥湖水系的影响程度也不同.同时采取提高滞涝水面率和降低...     

基于三标度法的可变模糊集模型在湖泊水质评价中应用

针对湖泊水质评价中存在模糊性的特征,应用可变模糊集理论建立湖泊水质评价模型.该模型以相对差异函数为基础,充分考虑评价指标的"优"与"劣"两方面,更具合理性.利用可变模糊集方法对杭州西湖、青海湖、巢湖以及滇池的水质进行评价,并对样本进行排序.在指标权重的确定上选取三标度法,使评分更符合决策者的习惯.实例表明该模型简单方便、有效可行,能较好地应用于生产实际.     

岩溶流域典型农业区水体氢氧同位素的空间异质性及形成机制

分别于平水期和枯水期采集了花溪河流域典型农业区地表水和地下水样品。利用氢氧同位素示踪技术,结合土地利用类型对研究区不同水体的补给来源、季节变化及主要影响过程进行了分析,并对不同水体氢氧同位素值进行了空间插值分析,同时对其形成机制进行了分析,阐明了不同土地利用类型影响下的主要水文过程。结果表明:(1)研究区不同水体的主要补给来源为当地大气降水,月亮湖水库受蒸发作用影响明显,地表水和地下水的δD和δ~(18)O整体上呈现平水期高于枯水期的特征。(2)地下水的δD和δ~(18)O在枯水期与平水期均呈现明显的空间分异性特征,西部水田/水库集中区富集,东部旱地集中区贫化,土地利用对研究区环境水文过程影响明显。该研究结果有助于了解不同土地利用方式下地表水对地下水的影响,为流域管理提供科学依据。