环境变化对河北省水资源量的影响

分析了气候变化、地下水超采、地表径流及粮食产量变化等方面对水资源的影响，结论认为，在新一轮水资源评价中，要充分考虑环境变化对水资源量的影响，加强地下水位大埋深条件下地表产流量、地下水补给量以及作物产量水平提高对水资源影响的实验研究，以提高新一轮水资源评价成果的精度。     

The contribution of shallow groundwater by safflower (Carthamus tinctorius L.) under high water table conditions, with and without supplementary irrigation

Lysimetric experiments were conducted to determine the contribution made by groundwater to the overall water requirements of safflower (Carthamus tinctorius L.). The plants were grown in 24 columns, each having a diameter of 0.40 m and packed with silty clay soil. The four replicate randomized complete block factorial experiments were carried out using different treatment combinations. Six treatments were applied during each experiment by maintaining groundwater, with an EC of 1 dS m^?1, at three different water table levels (0.6, 0.8 and 1.10 m) with and without supplementary irrigation. The uptake of groundwater as a part of crop evapotranspiration was measured by taking daily readings of the water levels found in Mariotte tubes. The supplementary irrigation requirement for each treatment was applied by adding water (EC of 1 dS m^?1). The average percentage contribution from groundwater for the treatments (with and without supplementary irrigation under water table levels of 0.6, 0.8 and 1.10 m) were found to be 65, 59, 38% and 72, 70, 47% of the average annual safflower water requirement (6,466 m³ ha^?1). The increase in groundwater depths under supplementary irrigation treatments from 0.6 to 0.80 and 1.10 m caused seed and oil yield reductions of (7, 23.10%) and (48.23, 65.40%), respectively.     

Assessing the groundwater dynamics and impacts of water saving in the Hetao Irrigation District, Yellow River basin

Water resources allocated to the agricultural sector in the Yellow River basin are being reduced due to severe water scarcity and increased demand by the non-agricultural sectors. In large-scale irrigation districts, the application of water-saving practices, e.g., improving the canal system, using water-saving irrigation technology and adjusting cropping patterns, is required for the sustainable agricultural development and the river basin environmental equilibrium. Adopting water-saving practices leads to lowering the groundwater table and to controlling salinity impacts related to excessive irrigation. However, assessing the effects of water-saving practices on the groundwater system requires further investigation. The Jiefangzha Irrigation Scheme of the Hetao Irrigation District is used as a case study for analyzing the temporal and spatial dynamics of the groundwater table. A lumped parameter groundwater balance model has been developed with this purpose and to assess impacts of various water-saving practices. The model was calibrated with monthly datasets relative to the non-frozen periods of 1997-1999 and validated with datasets from 2000 to 2002. Results indicate that canal seepage and deep percolation account for respectively 48% and 44% of the annual groundwater recharge. Groundwater discharge by direct evaporation and plant roots uptake represents 82% of the total annual groundwater discharge. After validation, the model was applied to assess the impacts of various canal and farm irrigation water-saving practices. It was observed that improvements in the canal system (e.g., canal lining, upgrading the hydraulic regulation and control structures, improving delivery schedules) might lower the groundwater table by 0.28-0.48 m, depending upon the level of implementation of these measures. Higher declines of the groundwater table are predicted when water-saving technologies are applied at both the canal and the farm systems. That decline of the water table favours salinity control and reduces capillary rise, thus reducing the groundwater evaporation and uptake by plant roots; that reduction may attain 128 mm. However, predictions may change depending on the way how water-saving measures are applied, which may be different of assumptions made; therefore, there is the need to perform a follow-up of the interventions in order to update predictions. Results indicate the need for appropriate research leading to improved irrigation management when the decline of the groundwater level will reduce groundwater contribution to vegetation growth.     

关于农业节水灌溉改革创新的建议

农业节水灌溉应做好的工作:采取工程的、农业的和管理的综合节水措施,降低腾发耗水量,提高农作物水分生产率和灌溉水利用系数;流域和灌区要地表水与地下水联合开发利用,统一管理,改变"近水者先用水"的现状,做到水资源均衡配置,可持续利用;井渠结合,排灌统筹,提高水资源利用率,综合防治旱涝盐碱;实行灌排区自主管理制度,实现可持续发展目标;开展科学研究,明确不同地区节水灌溉的发展方向和技术措施.     

Could deficit irrigation be a sustainable practice for quinoa (Chenopodium quinoa Willd.) in the Southern Bolivian Altiplano?

The application of deficit irrigation (DI) to stabilize yield and to increase water productivity of quinoa (Chenopodium quinoa Willd.) raises questions in the arid Southern Altiplano of Bolivia where water resources are limited and often saline. Rainfed quinoa and quinoa with irrigation restricted to the flowering and early grain filling were studied during the growing seasons of 2005–2006 and 2006–2007 in a location with (Irpani) and without (Mejillones) water contribution from a shallow water table. It was found that the effect of additional irrigation was only significant above a basic fulfillment of crop water requirements of around 55%. Below this threshold, yields, total water use efficiency (TWUE) and marginal irrigation water use efficiency (MIWUE) of quinoa with DI were low. Capillary rise (CR) from groundwater was assessed using the one-dimensional UPFLOW model. The contribution of water from capillary rise in the region of Irpani ranges from 8 to 25% of seasonal crop evapotranspiration (ET_c) of quinoa, depending mostly on the depth of the groundwater table and the amount of rainfall during the rainy season. DI with poor quality water and cultivation of crops in fields with a shallow saline groundwater table pose a serious threat for sustainable quinoa farming. To assess the impact of saline water resources, soil salinity and required leaching were simulated by combining the soil water and salt balance model BUDGET with UPFLOW. The results indicate that irrigation of quinoa with saline water and/or CR from a saline shallow water table might, already after 1 year, result in significant salt accumulation in the root zone in the arid Southern Altiplano. A farming system with only 1 year fallow is often insufficient to leach sufficient salts out of the root zone. In case the number of fallow years cannot be increased, leaching by means of an important irrigation application before sowing is an alternative. Although potentially beneficial, DI of quinoa in arid regions such as the Southern Bolivian Altiplano should be considered with precaution.     

CPSP模型在华北井灌区农业水管理中的应用

为研究不同农业水管理措施对区域水平衡的影响,选择北京市大兴区为华北井灌区代表性研究区,以CPsP模型为技术支持,研究了提高灌溉水利用率、采用亏缺灌溉、改善农业种植结构及利用区外水源等不同水管理措施影响下区域水平衡、区域耗水、区域取水及用水指标的变化规律.结果表明,在资源型缺水区域,提高灌溉水利用率、采用非充分灌溉及改善农业种植结构在一定程度上能缓解区域水资源紧缺的压力,特别是采用非充分灌溉及改善作物种植结构能显著减少区域取水及耗水总量,并能减少地表水及地下水的补给量中回归水所占比例,在缓解区域水资源紧缺压力的同时也降低了区域水质遭受回归水污染风险.另外,在未来情景中,因经济快速发展及人口持续增长,工业及居民生活用水量增加,区域水资源供需矛盾将会加剧,为确保区域水资源良性循环,势必采取积极有效的水资源管理模式.     

Combining hydrological modeling and GIS approaches to determine the spatial distribution of groundwater recharge in an arid irrigation scheme

Accurate quantification of the rate of groundwater (GW) recharge, a pre-requisite for the sustainable management of GW resources, needs to capture complex processes, such as the upward flow of water under shallow GW conditions, which are often disregarded when estimating recharge at a larger scale. This paper provides (1) a method to determine GW recharge at the field level, (2) a consequent procedure for up-scaling these findings from field to irrigation scheme level and (3) an assessment of the impacts of improved irrigation efficiency on the rate of GW recharge. The study is based on field data from the 2007 growing season in a Water Users Association (WUA Shomakhulum) in Khorezm district of Uzbekistan, Central Asia, an arid region that is characterized by a predominance of cotton, wheat and rice under irrigation. Previous qualitative studies in the region reported irrigation water supplies far above the crop water requirements, which cause GW recharge. A field water balance model was adapted to the local irrigation scheme; recharge was considered to be a fraction of the irrigation water losses, determined as the difference between net and gross irrigation requirements. Capillary rise contribution from shallow GW levels was determined with the HYDRUS-1D model. Six hydrological response units (HRUs) were created based on GW levels and soil texture using GIS and remote sensing techniques. Recharge calculated at the field level was up-scaled first to these HRUs and then to the whole WUA. To quantify the impact of improved irrigation efficiency on recharge rates, four improved irrigation efficiency scenarios were developed. The area under cotton had the second highest recharge (895 mm) in the peak irrigation period, after rice with 2,514 mm. But with a low area share of rice in the WUA of <1 %, rice impacted the total recharge only marginally. Due to the higher recharge rates of cotton, which is grown on about 40 % of the cropped area, HRUs with a higher share of cotton showed higher recharge (9.6 mm day^?1 during August) than those with a lower share of cotton (4.4 mm day^?1). The high recharge rates in the cotton fields were caused by its water requirements and the special treatment given to this crop by water management planners due to its strategic importance in the country. The scenario simulations showed that seasonal recharge under improved irrigation efficiency could potentially be reduced from 4 mm day^?1 (business-as-usual scenario) to 1.4 mm day^?1 (scenario with maximum achievable efficiency). The combination of field-level modeling/monitoring and GIS approaches improved recharge estimates because spatial variability was accounted for, which can assist water managers to assess the impact of improved irrigation efficiencies on groundwater recharge. This impact assessment enables managers to identify options for a recharge policy, which is an important component of integrated management of surface and groundwater resources.     

基于两阶段优化配置模型的济南泉域补给区灌溉水源置换研究

目前全球地下水能保持持续平衡的地区日趋减少,不合理农业灌溉成为很多地区地下水系统恶化的主要因素之一。济南市历城区地下水用于农业灌溉是当地地下水位下降的重要因素,对于济南泉域、白泉泉域喷涌有直接影响。针对研究区农业用水特点和水生态文明建设水源置换的要求,建立两阶段优化配置模型,将灌溉用水配置分为2个阶段,阶段一,以生态、节水和经济效益为目标,引入单位脉冲响应系数约束地下水利用量,实现区域地下水与地表水的合理配置;阶段二,以作物最大产量为目标,进行作物生育阶段水量配置和种植结构调整。结果表明,采取两阶段优化算法与用水结构调整后,可以有效减少地下水利用量,2011—2014年平均地表水与地下水用水结构由原来的3∶7调整为5.2∶4.8,较好地实现地下水源置换目标,同时地下水位计算值较实际年分别增加0.31、1.12、1.55和3.38 m,对保证泉域持续喷涌具有重要作用。     

浅埋区地下水--土壤水资源动态过程及其调控

分析了冬小麦生长期地下水-地下水资源量动态过程和地下水、土壤水分变化特征.结果表明,在地下水浅埋区地下水对土壤水的补给为农田蒸散的重要的水分来源,现行的灌溉制度不考虑这一作用,过多的灌溉量不仅会消弱地下术对土壤水的补给,而且多余的土壤水分还会下渗补给地下水,造成水资源的无效损失和动力能源的损耗.为了提高作物水分利用效率,提出了相应的地下水-土壤水资源调控措施.     

Analysis on groundwater table drawdown by land use and the quest for sustainable water use in the Hebei Plain in China

Increased water use in the Hebei Plain during the last decades has caused serious groundwater level decline and many geological problems which have become the biggest threat to social–economic sustainability. Thus, to determine the factors resulting in the groundwater decline and to develop a practical plan for long-term groundwater use appear to be necessary in this region. In this paper, a water balance model is used in conjunction with regression techniques to estimate the groundwater recharge coefficient and the specific yield (defined as the ratio of the volume of water that a saturated rock or soil will release by gravity drainage to the volume of rock or soil) and the groundwater withdrawn by different water use sectors and the corresponding drop in the water-table are analyzed. The decline in water-table by different crops and water economic benefit of crops are discussed in detail in order to suggest sustainable use of groundwater resources in the Hebei Plain. Finally, sample policy scenarios are developed to show how groundwater in the Hebei Plain could be used in a sustainable manner. In our study, it is found that agriculture is the major consumer of groundwater, with about 85% of the total groundwater withdrawals, and groundwater depletion is mainly caused by agricultural water use. Production of winter wheat exerts a great negative influence on the groundwater system. Winter wheat is the most water consuming crop and result in significant decline of groundwater table. Water economic benefit of winter wheat is lower than that of other crops and withdrawing winter wheat sown area is rational option to make sustainable use of groundwater. With far-sighted and regional planning, the limited water resource can be used sustainably to generate maximum social benefits. This paper will provide information necessary for land-use planning in a severe water shortage region where farmland is mainly irrigated by groundwater.     

农田水量调控与水管理研究

针对80年代骊为华北平原地下水位的持续下降问题，选择河北省雄县胜利灌区为水资源平衡调控研究区，对水管理现状、存在问题、以及水量供需状况进行了分析。根据地下水动态规律、渠床入渗率分布、地表水引用量在年内的分配、研究区农业用水和地下水的回灌要求，提出水量调控措施。结合田间农业节水研究，提出以提高用水效率为目标的不管理改进措施。     

河套灌区井渠结合地下水数值模拟及均衡分析

建立了河套灌区三维地下水数值模型,用2006-2013年灌区实测地下水埋深资料对模型进行率定和验证,并在规划的井渠结合区内,设置3种不同井灌区灌溉定额和3种秋浇频率,组合共9种井渠结合节水情景,分别分析了9种节水情景下的地下水动态变化.结果表明:井渠结合后全灌区地下水埋深范围为1.863~2.029 m,较现状条件增加0.084~0.250 m;不同灌域结合区井渠结合后地下水埋深差别很大,解放闸结合区地下水埋深最大,为2.308~2.803 m,永济结合区地下水埋深最小,为2.079~2.455 m;井渠结合后,入渗补给量减少2.01×10⁸ ~3.63×10⁸ m³/a,潜水蒸发量减少1.69×10⁸ ~3.03×10⁸ m³/a.     

Life Cycle Assessment of biomass production in a Mediterranean greenhouse using different water sources: Groundwater, treated wastewater and desalinated seawater

An experimental biomass crop of Nicotiana tabacum was grown over a nine-month period inside a greenhouse situated in Almería, south-eastern Spain. Two irrigation methods corresponding to treated urban wastewater and groundwater, were arranged. No significant differences were observed in the total biomass produced on the treated wastewater and groundwater plots, which ranged from 17 to 28 kg m⁻², depending on plant density. Environmental Life Cycle Assessment (LCA) was applied in order to gain knowledge of the potential impacts of using either treated wastewater, groundwater, or desalinated water for irrigation. The LCA study included all the processes involved in agricultural production up to the final plant cutting. Since desalinated water was not actually used in the experiment, the experimental data from tobacco irrigated with groundwater was used in the LCA. Impact categories included were: global warming; acidification; water eutrophication; primary energy use; as well as aquatic and terrestrial ecotoxicity. Special attention was put on the ecotoxicity of emerging and priority pollutants in treated wastewater, as well as on soil quality impacts, namely soil organic carbon deficit and soil salinisation. The results show that using desalinated water leads to higher environmental impacts in several impact categories, including global warming, energy use, soil quality, and aquatic ecotoxicity. As an example, primary energy use increases by 80% and 50% as compared to using treated wastewater and groundwater, respectively. On the other hand, wastewater pollutants in irrigation water may involve a relevant contribution to terrestrial ecotoxicity. For this reason, the impact score of the wastewater-irrigated crop is 23% and 35% higher as compared to the crop using desalinated water and groundwater, respectively.     

Effect of shallow groundwater table on crop water requirements and crop yields

Due to the increasing demand for food and fiber by its ever-increasing population, the pressure on fresh water resources of Pakistan is increasing. Optimum utilization of surface and groundwater resources has become extremely important to fill the gap between water demand and supply. At Lahore, Pakistan 18 lysimeters, each 3.05 m × 3.05 m × 6.1 m deep were constructed to investigate the effect of shallow water tables on crop water requirements. The lysimeters were connected to bottles with Marriotte siphons to maintain the water tables at the desired levels and tensiometers were installed to measure soil water potential. The crops studied included wheat, sugarcane, maize, sorghum, berseem and sunflower. The results of these studies showed that the contribution of groundwater in meeting the crop water requirements varied with the water-table depth. With the water table at 0.5 m depth, wheat met its entire water requirement from the groundwater and sunflower absorbed more than 80% of its required water from groundwater. Maize and sorghum were found to be waterlogging sensitive crops whose yields were reduced with higher water table. However, maximum sugarcane yield was obtained with the water table at or below 2.0 m depth. Generally, the water-table depth of 1.5–2.0 m was found to be optimum for all the crops studied. In areas where the water table is shallow, the present system of irrigation supplies and water allowance needs adjustments to avoid over irrigation and in-efficient use of water.     

地下水埋深对冬麦田土壤水分及产量的影响

通过6种地下水位控制处理和对照(自然地下水位)冬小麦试验,探讨了不同地下水埋深对冬麦田土壤水分季节变化规律和垂直变化规律、地下水-土壤水界面水分转化量变化过程以及对冬麦田田间土壤水分平衡的影响。结果表明,地下水埋深对冬麦田0～60cm土壤水分动态有着明显的影响。地下水埋深越浅,麦田表层和主要根层土壤储水量季节变化越强烈,地下水对土壤水分的补给量越大,冬小麦全生育期耗水量也随着增加;土壤排水量大小与灌溉量和降雨量大小有关。地下水位埋深越深,灌溉和降水后的土壤开始排水日期越滞后;无论地下水埋深深浅,冬麦田累计地下水补给量变化规律可分为4个阶段,即稳定增长期、缓慢增长期、快速增长期和趋于稳定期;地下水埋深1.5m时冬小麦产量最高,地下水位太深或太浅产量均下降。水分利用率最高值出现在地下水埋深1.0m的处理。地下水位在1.0m以下时,水分利用效率随地下水深度加深和灌水量增加而减少。     

Water saving and economic impacts of land leveling: the case study of cotton production in Tajikistan

Water conservation is essential to prevent salinity and land degradation in Central Asia. Therefore, field-testing and evaluation of water conservation methods, i.e. laser land leveling in new farming systems of Central Asia is important task. This in mind the International Water Management Institute (IWMI) and its regional partner on IWRM FV (IWRM FV project – Integrated Water Resources Management in Ferghana Valley project is funded by Swiss Development Cooperation (SDC) and conducted jointly with IWMI and Scientific Information Center of Interstate Coordination Water Commission (SIC ICWC) in the Ferghana Valley of Central Asia) project SIC ICWC have conducted 3 year study of impacts of the Laser leveled land leveling on water use, productivity and crop yields in northern Tajikistan. The major research question was laser land leveling an effective water saving tool in the new context of land use and ownership on smaller private plots. Can farmers afford the costs of laser land leveling and how economically viable is it? These research questions were studied in 5 ha laser leveled and neighboring non-leveled (control) fields for 2004–2006. The results showed that laser land leveling can reduce the water application rate in 2004 by 593 M³/ha, in 2005 by 1509 M³/ha and in 2006 by 333 M³/ha in comparison with the unleveled field, located in the similar agro-ecological conditions. The deep percolation was 8% lower and run off 24% less than in non-leveled field. The average annual net income from the laser field was 22% higher than that from the control field. The gross margin from the laser-leveled field were 16. 88 and 171% higher compared to that from the control field for 2004, 2005 and 2006, and on average was 92% higher. In spite of these positive results, there are hindrances on wide application of laser land leveling in Tajikistan. These are absence of initial capital of farmers and scattered land location.     

Shallow groundwater use by Safflower (Carthamus tinctorius L.) in a semi-arid region

Two-year lysimeter experiments were conducted to determine groundwater contributions by safflower (Carthamus tinctorius L.) crop. The plants were grown in twenty columns each with a diameter of 0.40 m packed with Silty Clay soil. The experiments were carried out in a complete randomized blocks design with four replicates. In each experiment, five treatments were applied by maintaining groundwater salinity to a control treatment with EC 1 dS/m, while the groundwater salinity of the other treatments was 2, 5, 8 and 10 dS/m, and 0.8 m water table level, respectively. The use of groundwater as a part of crop evapotranspiration was characterized by using daily measurements of the water level in Mariotte tubes. The extra magnitude of irrigation water requirement for each treatment was applied by water with EC of 1 dS/m. The results of experiments showed that for different control treatments with 1 dS/m, 2, 5, 8 and 10 dS/m, the groundwater contributions were achieved as 59, 51, 38, 32 and 19% of the total plant water requirements, respectively.     

平原井灌区地下水多年调节配水模型及其应用

华北平原纯井灌区水资源严重不足。限水灌溉是保持地下水平衡、农业可持续发展的必要条件,通过对作物耗水规律及地下水动态规律的分析,在保持地下水多年平衡的前提下,不追求个别年份高产,以多年粮食总产量最高为目标,提出了地下水均衡开采的调节配水模型,并采用非线性规划理论对该模型进行了论证。应用该模型可计算出不同水文年地下水开采量及各作物灌溉定额,进而计算灌溉制度,可广泛应用于纯井灌区的井灌工程的规划设计。     

山西晋中井渠结合灌溉水资源综合平衡分析与模拟

在对灌区水资源系统进行概化分析基础上,建立了区域水量平衡方程、区域地下水平衡方程,利用实测与调查资料对平衡方程各要素进行了分析计算,并对现状条件下及节水灌溉实施后二种情况不同水平年水资源进行了模拟分析。计算结果表明,在现状种植结构、灌溉条件、产量水平下,项目区中等干旱年缺水量达到710万m~3,缺水形势相当严峻。实施各种节水措施后,项目区水资源量在多年平均及现状引水条件下基本上能满足用水需求,但需保证节水资金的投入。     

A GIS-based approach for up-scaling capillary rise from field to system level under soil–crop–groundwater mix

Capillary rise represents an often neglected fraction of the water budget that contributes to crop water demand in situations of shallow groundwater levels. Such a situation is typical in irrigated areas of Central Asia where water from capillary rise is exploited by farmers to meet production targets in Uzbekistan under uncertain water supply. This leads to higher water inputs than needed and creates a vicious cycle of salinization that ultimately degrades the agricultural land. In this study, capillary rise is quantified at different spatial scales in the Shomakhulum Water Users Association (WUA), situated in the southwest of Khorezm, Uzbekistan. The mathematical model HYDRUS-1D was used to compute the capillary rise at field level for three major crops (cotton, wheat and vegetables) on six different hydrological response units (HRUs). These six HRUs having homogenous groundwater levels (1–2 m beneath the soil surface) and soil texture were created using GIS and remote-sensing techniques. Capillary rise from these HRU was then up-scaled to WUA level using a simple aggregation approach. The groundwater levels simulated by FEFLOW-3D model for these HRUs in a parallel study under four improved irrigation efficiency scenarios (S-A: current irrigation efficiency or business-as-usual, S-B: improved conveyance efficiency, S-C: increased application efficiency and S-D: improved conveyance and application efficiency) were then introduced into HYDRUS-1D to quantify the impact of improved efficiencies on the capillary rise contribution. Results show that the HRUs with shallow groundwater-silt loam (S-SL), medium groundwater-silt loam (M-SL) and deep groundwater-silty clay loam (D-SCL) have capillary rise contribution of 28, 23 and 16 % of the cotton water requirements, 12, 5 and 0 % of the vegetable water requirements and 9, 6 and 0 % for the wheat water requirements, respectively. Results of the scenarios for the whole WUA show that the maximum capillary rise contribution (19 %) to the average of all crops in the WUA was for the S-A scenario, which reduced to 17, 11 and 9 % for S-B, S-C and S-D, respectively. Therefore, it is recommended that before any surface water intervention or drainage re-design, water managers should be informed about the impacts on groundwater hydrology and hence should adopt appropriate strategies.