Irrigation Water Demand Model as a Comparative Tool for Assessing Effects of Land Use Changes for Agricultural Crops in Fraser Valley, Canada

Available water for human needs and agriculture is a growing global concern. Agriculture uses approximately 70% of global freshwater, mainly for irrigation. The Lower Fraser Valley (LFV), British Columbia, is one of the most productive agricultural regions in Canada, supporting livestock production and a wide variety of crops. Water scarcity is a growing concern that threatens the long-term productivity, sustainability, and economic viability of the LFV’s agriculture. We used the BC Agriculture Water Demand Model as a tool to determine how crop choice, irrigation system, and land-use changes can affect predicted water requirements under these different conditions, which can aid stakeholders to formulate better management decisions. We conducted a comparative assessment of the irrigation water demand of seven major commercial crops, by distinct soil management groups, at nineteen representative sites, that use both sprinkler vs drip irrigation. Drip irrigation was consistently more water-efficient than sprinkler irrigation for all crops. Of the major commercial crops assessed, raspberries were the most efficient in irrigation water demand, while forage and pasture had the highest calculated irrigation water demand. Significant reductions in total irrigation water demand (up to 57%) can be made by switching irrigation systems and/or crops. This assessment can aid LFV growers in their land-use choices and could contribute to the selection of water management decisions and agricultural policies.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

Application of WEAP Simulation Model to Hengshui City Water Planning

Like many river basins in China, water resources in the Fudong Pai River are almost fully allocated. This paper seeks to assess and evaluate water resource problems using water evaluation and planning (WEAP) model via its application to Hengshui Basin of Fudong Pai River. This model allows the simulation and analysis of various water allocation scenarios and, above all, scenarios of users' behavior. Water demand management is one of the options discussed in detail. Simulations are proposed for diverse climatic situations from dry years to normal years and results are discussed. Within the limits of data availability, it appears that most water users are not able to meet all their requirements from the river, and that even the ecological reserve will not be fully met during certain years. But the adoption of water demand management procedures offers opportunities for remedying this situation during normal hydrological years. However, it appears that demand management alone will not suffice during dry years. Nevertheless, the ease of use of the model and its user-friendly interfaces make it particularly useful for discussions and dialogue on water resources management among stakeholders.

Assessment of Point and Nonpoint Sources Pollution in Songhua River Basin,Northeast China by Using Revised Water Quality Model

Individual participation of pollutants in the pollution load should be estimated even if roughly for the appropriate environmental management of a river basin.It is difficult to identify the sources and to quantify the load, especially in modeling nonpoint source.In this study a revised model was established by integrating point and nonpoint sources into one-dimensional Streeter-Phelps(S-P) model on the basis of real-time hydrologic data and surface water quality monitoring data in the Jilin Reach of the Songhua River Basin.Chemical oxygen demand(COD) and ammonia nitrogen(NH 3-N) loads were estimated.Results showed that COD loads of point source and nonpoint source were 134 958 t/yr and 86 209 t/yr, accounting for 61.02% and 38.98% of total loads, respectively.NH 3-N loads of point source and nonpoint source were 16 739 t/yr and 14 272 t/yr, accounting for 53.98% and 46.02%, respectively.Point source pollution was stronger than nonpoint source pollution in the study area at present.The water quality of upstream was better than that of downstream of the rivers and cities.It is indispensable to treat industrial wastewater and municipal sewage out of point sources, to adopt the best management practices to control diffuse pollutants from agricultural land and urban surface runoff in improving water quality of the Songhua River Basin.The revised S-P model can be successfully used to identify pollution source and quantify point source and nonpoint source loads by calibrating and validating.

高质量发展视角下新阶段水利人才队伍建设机制研究

新阶段水利高质量发展亟须与之相适配的人才队伍,专业技术人才是推动新阶段水利高质量发展的骨干力量。从高质量发展视角出发,基于人力资本理论,搭建跨边界专业技术人才池,集聚并储备行业发展所需的关键人才,并从引进、培养、使用、评价、流动、激励全链条创新人才发展模式。基于灰色模型预测了人才需求特点,结合人力资本理论构建了跨边界人才池的开发机制和实施路径。结果表明:水利人才分布的空间异质性问题将持续存在,集聚并储备行业关键人才需要构建跨边界人才池;应通过内部培养和外部引进双轮驱动等措施满足行业人才需求,创新人才发展模式,从而在强化宏观调控的基础上实现人才的统筹调配、跨界蓄用与动态共享。

饶河流域水源涵养服务供需演变及驱动因素

[目的]探究流域水源涵养服务供需的时空分异特征及主要驱动因素,为流域水资源管理和优化配置及生态安全与保护提供科学依据和参考。[方法]以饶河流域为研究区,基于InVEST模型和多源数据定量评估研究区水源涵养服务供给、需求,根据供需指数得到水源涵养服务供需匹配空间关系,利用地理探测器进一步探究水源涵养服务供需关系空间异质性的主要驱动因素。[结果]①2005—2020年水源涵养服务供给和需求量均呈现先增后减的趋势,不同土地利用类型的水源涵养能力具有显著差异,其中林地和草地水源涵养能力明显高于耕地和城乡工矿用地;②水源涵养服务供给和需求空间分布具有明显的空间异质性和不匹配特征,水源涵养供需匹配赤字区主要分布在西部鄱阳县、万年县、乐平市、昌江区和珠山区,盈余区分布在北部浮梁县、东部婺源县、德兴市和弋阳县;③自然因素中年潜在蒸散发、高程和林地覆盖率是影响水源涵养服务供需关系的主要因素,同时,城乡工矿用地和耕地覆盖率等人为因素起主导作用,自然因素和人为因素交互作用,加剧水源涵养服务供需失衡。[结论]饶河流域水源涵养服务供需关系优化存在挑战,未来应在该地区加快建立生态补偿机制,优化林地水源涵养功能,提高水源涵养服务供给,提升水资源利用效率,进一步实现区域水源涵养服务供需平衡,促进生态系统与社会经济系统协调发展。

基于定额法和GM(1,1)模型对河南省2030年需水量的预测与情景分析

采用定额法和GM(1,1)模型对河南省2030年的需水量进行预测,并设计了保持现状型、经济发展型、节水型和综合发展型四个发展情景进行分析。结果表明:四种情境下的需水量分别为253.7亿m^(3)、278.5亿m^(3)、220.2亿m^(3)和260.7亿m^(3);农业灌溉用水占全省用水量近55%,提升农业灌溉水的利用效率对改善全省的水资源利用效率有巨大作用,同时,调整产业结构也可以提高水资源利用率;综合考虑四种发展情景,河南省未来的发展趋势应向综合发展型社会靠拢,使经济、环境和社会协同发展;需水量受人口数量、生产总值、产业结构等多种因素的协同影响。

近红外光谱的水体污染指标COD定量预测模型

针对传统化学需氧量(chemical oxygen demand, COD)检测存在检测成本高、耗时、易造成二次污染,以及现有检测模型泛化性较差等不足,难以满足水环境实时监测需求的问题,提出基于近红外光谱技术的COD快速无损定量预测模型.实验结果表明,本模型在污水COD光谱数据集上的预测性能,相较于传统机器学习算法和现有其他深度学习算法更优.测试的决定系数(R^(2))和均方根误差(E_(RMS))分别达到0.992 1和27.47 mg·L^(-1),模型卷积层的输出特征可解释性强,能有效表征关键波长点.该预测模型为实际水体COD含量快速检测提供一种新的方法.

Numerical simulation of water quality in Yangtze Estuary

In order to monitor water quality in the Yangtze Estuary, water samples were collected and field observation of current and velocity stratification was carried out using a shipboard acoustic Doppler current profiler （ADCP）. Results of two representative variables, the temporal and spatial variation of new point source sewage discharge as manifested by chemical oxygen demand （COD） and the initial water quality distribution as manifested by dissolved oxygen （DO）, were obtained by application of the Environmental Fluid Dynamics Code （EFDC） with solutions for hydrodynamics during tides. The numerical results were compared with field data, and the field data provided verification of numerical application： this numerical model is an effective tool for water quality simulation. For point source discharge, COD concentration was simulated with an initial value in the river of zero. The simulated increments and distribution of COD in the water show acceptable agreement with field data. The concentration of DO is much higher in the North Branch than in the South Branch due to consumption of oxygen in the South Branch resulting from discharge of sewage from Shanghai. The DO concentration is greater in the surface layer than in the bottom layer. The DO concentration is low in areas with a depth of less than 20 m, and high in areas between the 20-m and 30-m isobaths. It is concluded that the numerical model is valuable in simulation of water quality in the case of specific point source pollutant discharge. The EFDC model is also of satisfactory accuracy in water quality simulation of the Yangtze Estuary.

气候与种植结构变化对温室气体排放及灌溉需水的影响

针对气候变化和种植结构调整对黄淮海地区农业生产作用不明晰的问题,基于反硝化分解模型(Denitrification-decomposition, DNDC),采用情景分析法评估了气候与种植结构变化对黄淮海地区农业温室气体(CO_(2)、CH_(4)和N_(2)O)排放和灌溉需水量的影响。结果表明:从1995年到2015年,研究区气候向暖湿化方向发展,其中年均最高温度无显著变化,年均最低温度上升0.7℃,年降水量增长46.5 mm;1995年研究区玉米、小麦和水稻种植面积分别约为7.9×10^(6)、1.4×10^(7)、2.9×10^(6)hm^(2);2015年3种作物种植面积均增大,而水稻、小麦种植比例减小。气候变化影响下,黄淮海地区农业温室气体排放增加,灌溉需水量小幅减小。与1995年相比,2015年CO_(2)、CH_(4)、N_(2)O排放强度分别增长至3 730.5、443.2、5.9 kg/hm^(2),增幅分别为4.7%、0.8%、26.2%,灌溉需水量减小为499.3 mm,减幅为6.6%。种植结构调整改变温室气体排放和灌溉需水量,黄淮海地区种植结构演变使CO_(2)、CH_(4)、N_(2)O排放总量增加至9.9×10^(7)、1.4×10^(6)、1.3×10^(5)t,分别增加13.8%、8.6%、13.3%,同时,玉米作为高耗水作物,部分地区灌溉需水量随其种植比例的增大而增大。研究结果可为黄淮海地区未来农业节水减排政策的制定提供理论依据。

基于GWAS模型的武安市水资源优化配置

为缓解河北武安市水资源供需不平衡的突出矛盾,立足水资源精细化管理的需求,构建了武安市GWAS(general water allocation and simulation)模型,并开展规划年(2025年与2030年)不同情景下武安市各乡镇水资源优化配置研究。结果表明:2025年和2030年,平水情景(P=50%)下模型优化配置水量基本可以满足各乡镇水量需求,枯水情景(P=75%)下各乡镇存在不同程度的缺水情况;全市普遍农业缺水,2025年平枯情景农业缺水率分别为6.45%和44.11%,2030年平枯情景农业缺水率分别为5.05%和42.47%;优化后的供水结构改善效果显著,地下水供水量占比在各规划年平枯情景下均有所下降。

基于水质水量耦合模型的湟水西宁市段生态流量计算及模拟分析

考虑未来枯水期湟水生态流量、水质将面临不稳定达标风险,提出量化计算与数值模拟相结合的方法确定满足水质水量目标的湟水西宁市段生态流量。基于实测流量、断面、污染源等现状调查及分析,采用不同频率最枯月平均值法、改进年内同频率展布法、生态水力半径法3种方法计算了湟水西宁市段生态流量,并与Tennant法的计算结果进行合理性分析比较。利用MIKE11水动力和水质模块构建了水质水量耦合模型,利用率定后的模型,以COD、NH3-N作为主要污染物指标,通过模拟不同生态流量下泄过程,分析了3种计算方法对应的下泄方案对湟水西宁市段水质的影响,优选出合理的生态流量的下泄方案,得出了满足水质水量需求的湟水西宁市段生态流量,为湟水西宁市段的水生态保护及区域水资源配置方案提供理论支撑。

基于SWAT模型的图们江流域蓝绿水资源供需平衡分析

随着经济快速发展和工农业各类用水量大幅增加,对河流的开发程度随之加强,流域水资源可持续利用受到不利影响。从蓝绿水视角出发,基于SWAT模型量化了图们江流域2015—2020年不同时间尺度下的蓝绿水资源并探讨了研究区水资源供需平衡情况。结果表明:研究时段内流域蓝绿水资源均具有明显的季节特征,年均蓝绿水资源量为117.16亿m^(3),其中蓝水资源量30.14亿m^(3),绿水资源量87.02亿m^(3),绿水占水资源量的74.27%。以年为尺度,蓝水资源供需评估指数>1,可利用蓝水资源量基本不能满足其需求量,降水少的年份蓝水资源供需矛盾突出,而绿水资源可以达到供需平衡,其供需评估指数集中在0.1—0.2之间。在月尺度分析中研究区蓝水供需评估指数出现极端值的频率较高,表明该地区蓝水供需不平衡,尤其是可利用蓝水资源一般在每年的7—8月才较为丰富,而蓝水需求用水集中分布于作物生长期,导致蓝水供应与蓝水需求在时间分配上不均衡,且在实际水资源分配中忽略了生态用水;月尺度绿水供需评估指数集中在0.1—0.4之间,有明显的季节变化特征,整体上绿水资源供需平衡安全性较高。

基于3S的小开河灌区农业灌溉需水量预测研究

土壤含水率的空间分布是影响农业灌溉决策的关键因素。采用3S技术对灌区的土壤含水率空间分布进行探索,以土壤含水率为预报对象,结合作物生长情况和气象预报,以田间水量平衡方程为理论基础,利用土壤含水率预测灌区农业灌溉需水量。结果表明:小开河灌区5月下旬的预测需水量为621.77万m^(3),与灌区的统计数据一致,基于3S的灌区农业灌溉需水量预测技术可实现灌区的精准灌溉。

河南省卫河流域蓄滞洪区水资源供需情势分析

为明晰河南省卫河流域蓄滞洪区水资源供需情势,构建最小二乘法与灰色预测模型相结合的组合模型,预测2025年、2035年该区域的需水量与供水量,并对其开展供需平衡分析。结果表明:河南省卫河流域蓄滞洪区2025年50%、75%保证率的农业需水量占比分别为68%、73%,2035年50%、75%保证率的农业需水量占比分别为61%、67%,农业需水量在总需水量中占比较大;2025年、2035年研究区均处于缺水状态。建议研究区落实最严格水资源管理制度,合理利用南水北调水,加强雨洪水资源利用,逐步改善水资源供需不平衡状态。

江西省水稻需水量预报与网络发布系统开发

为了促进江西省灌区技术现代化及灌溉用水管理现代化的发展,为实时灌溉决策提供较为精确和及时的作物需水量预报数据支持,开发了江西省逐日水稻需水量预报与网络发布系统。系统通过关系型数据管理系统MySQL来获取水稻需水量预报模型计算所需的参数及基本信息,分别使用率定了的Hargreaves-Samani(HS)模型、Blaney-Criddle(BC)模型、McCloud(MC)模型和作物系数来预测江西省未来7天26个气象站点的作物腾发量ETc值。用户可登陆网址查询任意站点、任意水稻生长阶段、任意模型预报的ETc数值,页面简洁,易于操作。总体而言,率定后的4种模型均具有较高的预报精度,可用于全省的水稻需水量预报,为灌溉决策和节约灌溉用水提供科学依据。

高架绿植智能灌溉系统架构及智能模型研究

随着物联网和人工智能技术的迅猛发展,现有的灌溉模式已经无法满足实际运维的需要。笔者针对应用现状,设计了在定时灌溉基础上高架绿植智能灌溉系统。系统首先使用物联网系统实现电磁阀控制系统的统一管理和控制,破除了原来的信息孤岛问题,避免定时定量灌溉造成的水资源浪费。其次系统还引入Transformer框架,构建基于历史灌溉数据和天气预报数据的电磁阀控制路段的花箱需水量预测模型,真正实现基于定时灌溉模式的按需灌溉。

数值模拟在岩溶湿地需水量计算中的应用

为进行岩溶湿地生态修复,采用数值模拟的方式进行湿地需水量计算。以会仙湿地为研究对象,在多年平均水位的条件下,采用Mike21模型进行了湿地需水量和补水方案的二维数值模拟。通过建立良丰站与会仙湿地内部水位相关关系,得出湿地多年平均水位为148.86 m。在此水位条件下,计算得出湿地的生态需水量和环境需水量分别为386.51万m^(3)和367.20万m^(3),总体需水量为386.51万m^(3)。通过地表水系分析,确定了会仙河—古桂柳运河的补水路径,以5m^(3)/s的流量进行补水,模拟结果显示,补水后湿地水面率在正常范围内。

阅海湖生态环境需水研究

[目的]探明银川市阅海湖生态环境需水量,满足其生态系统稳定不退化所需要消耗的水资源总量。[方法]于2019年对阅海湖进行水样采集,测定总氮(TN)、总磷(TP)、化学需氧量(COD Cr)和高锰酸盐指数(COD_(Mn))4个主要水质污染物指标,通过建立水质-水量耦合模型,采用功能法计算分析阅海湖水体最小、适宜和最大生态环境需水量。[结果]阅海湖水质保持现状所需引水量由污染物指标TP、COD Cr和COD_(Mn)决定,达到地表水水质标准Ⅲ类水时所需引水量由污染物指标COD Cr决定;阅海湖生态环境需水量划分为3个部分,分别为水体基本需水量、水体生态环境改善需水量、岸边带植被及景观娱乐需水量,水体基本需水量和生态环境改善需水量占阅海湖总需水量的绝大部分,通过计算可知,水体生态环境最小需水量为14.64×10^(6) m^(3),适宜需水量为24.76×10^(6) m^(3),最大需水量为50.98×10^(6) m^(3)。[结论]阅海湖水体水质已受到污染,含磷营养盐和有机物污染正在成为阅海湖水质的基本制约因素,应严格限制流入湖区地表水体污染物含量,并实现多渠道补水以免湖泊生态情况进一步恶化。