论文: Wen Yeqiang, Shang Songhao, Yang Jian. Optimization of irrigation scheduling for spring wheat with mulching and limited irrigation water in an arid climate . Agricultural Water Management, 2017, 192: 33-44. doi: 10.1016/j.agwat.2017.06.023 . 全文下载(2017.8.30前有效): https://authors.elsevier.com/a/1VMmw1M27RZA3I 摘要:Combining mulch and irrigation scheduling may lead to an increase of crop yield and water use efficiency (WUE = crop yield/evapotranspiration) with limited irrigation water, especially in arid regions. Based on 2 years’ field experiments with ten irrigation-mulching treatments of spring wheat ( Triticum aestivum L.) in the Shiyang River Basin Experiment Station in Gansu Province of Northwest China, a simulation-based optimization model for deficit irrigation scheduling of plastic mulching spring wheat was used to analyze optimal irrigation scheduling for different deficit irrigation scenarios. Results revealed that mulching may increase maximum grain yield without water stress by 0.4–0.6 t ha −1 in different years and WUE by 0.2–0.3 kg m −3 for different irrigation amounts compared with no mulching. Yield of plastic mulching spring wheat was more sensitive to water stress in the early and development growth stages with an increase of cumulative crop water sensitive index (CCWSI) by 42%, and less sensitive to water stress in the mid and late growth stages with a reduction of CCWSI by 24%. For a relative wet year, when irrigation water is only applied once, it should be at the mid to end of booting growth stage. Two irrigations should be applied at the beginning of booting and heading growth stages. The irrigation date can be extended to the beginning of jointing and grain formation growth stages with more water available for irrigation. For a normal or a dry year, the first irrigation should be applied 5–8 days earlier than the wet year. The highest WUE of 3.6 kg m −3 was achieved with 180 mm of irrigation applied twice for mulching in a wet year. Combining mulch and optimal deficit irrigation scheduling is an effective way to increase crop yield and WUE in arid regions.
研究发现西北干旱区高海拔地区增湿更加明显 姚俊强 气候变化的海拔依赖性是一个尚无定论的命题,核心问题是不同海拔高度的增幅问题。研究表明高海拔地区气候变暖比以前更快,“第三极”青藏高原的气候经历了持续且更显著的变暖,表现出明显的增暖海拔依赖性。高海拔地区快速变暖会加剧山区水循环,水汽和降水变化首当其冲。 西北干旱区山盆结构突出,高海拔地区降水变化对区域水资源有决定性作用。研究发现近 50 年干旱区降水变化趋势与海拔有明显的正相关,相关系数为 0.49 ( p0.001 ),但在不同海拔梯度和不同降水等级存在差异。在 1500m 以上,降水增加趋势最明显,增幅为 13mm/10a ,两者相关为 0.68 ( p0.001 ),但在 1500m 以下相关不大,而 1500m 为山区的分界线。以 500m 为海拔变化梯度,发现 1500-2000m 梯度增湿最明显,为 27mm/10a (相关为 0.66 , p0.001 ),其次是 500m 以下,为 25 mm/10a (相关为 0.65 , p0.001 ),但 500-1500m 之间关系不显著,这主要与该区域城市和绿洲分布有关。城市化加剧人为气溶胶排放,在城市热岛效应下增加降水,而绿洲农田灌溉也会通过改变区域水循环增加降水。因此,干旱区有明显的增湿海拔依赖性特征。在季节上,春季和秋季的增湿海拔依赖性明显,而夏季在 90 年代之后明显。 形成机制主要包括:1.山区水汽的增加;2.山区变暖加剧水循环。 增湿海拔依赖性有利有弊,对干旱区来说,总体上利大于弊。有利的方面,高海拔地区降水增多,增加山区固态冰川和积雪的积累,储备干旱区的潜在水资源量。但同时,研究发现山区降水更加极端化,山区降水量增多在很大程度上与降水极值态的变化有关。会引起气象灾害和衍生灾害,加剧山洪、滑坡、泥石流等灾害的频率和强度,对绿洲城市和草场有很大潜在影响。 存在的主要问题是高海拔地区气象观测稀缺 ( 世界上超过 4000m 的站点非常稀少 ) ,且观测规范不统一。积极呼吁加强对全球高山地区气候要素的严格监测。 文章发表在国际期刊 Global and Planetary Change上。 Yao J Q, Yang Q, Mao W Y, Zhao Y, Xu X B.Precipitation trend – Elevation relationship in arid regions of the China, Global and Planetary Change , 2016(143):1-9. doi:10.1016/j.gloplacha.2016.05.007. GPC--2016--Precipitation trend–Elevation relationship in arid regions of the China.pdf
Reynolds, J. F., et al. (2007). Global Desertification: Building a Science for Dryland Development. Science 316(5826): 847-851. 在这个千年里,全球的干旱区面临着大量问题,这些问题在研究、管理和政策方面提出了强硬的挑战。但是,干旱区发展的近期进展连同全球变化和可持续科学的综合管理方法建议我们关注土地退化、贫穷、生物多样性保护以及对能够面对乐观主义复兴的25亿人口的文化保护。我们综述了关于干旱区生态系统功能和当地居民生计系统的最新经验,引进了一个新的综合框架-干旱区发展范例(Drylands Development Paradigm)。DDP,由一套在政策和管理行动上发展的、经得起考验的工具支撑,通过鉴别和整合那些对研究、管理和政策发展重要的因子来帮助探索沙漠化和干旱区发展的内在复杂性。
论文链接: http://www.tcsae.org/nygcxb/ch/reader/view_abstract.aspx?file_no=20132014flag=1 全文下载: http://www.tcsae.org/nygcxb/ch/reader/create_pdf.aspx?file_no=20132014flag=1journal_id=nygcxbyear_id=2013 蒋磊,杨雨亭,尚松浩. 基于遥感蒸发模型的干旱区灌区灌溉效率评价. 农业工程学报, 2013, 29(20): 95-101 基于遥感蒸发模型的干旱区灌区灌溉效率评价 Evaluation on irrigation efficiency of irrigation district in arid region based on evapotranspiration estimated from remote sensing data 投稿时间: 2013-06-26 最后修改时间: 2013-09-11 中文关键词 : 灌溉,遥感,蒸发,灌溉水有效利用系数,灌溉效率评价,灌区,干旱区 英文关键词 : irrigation remote sensing evapotranspiration coefficient of irrigation water effective utilization irrigation efficiency assessment irrigation district arid region 基金项目 : 国家科技支撑计划项目(2011BAD25B05),国家自然科学基金项目(51279077) 作者 单位 蒋 磊 清华大学水沙科学与水利水电工程国家重点实验室,北京 100084 杨雨亭 清华大学水沙科学与水利水电工程国家重点实验室,北京 100084 尚松浩 清华大学水沙科学与水利水电工程国家重点实验室,北京 100084 中文摘要 : 为评价干旱区灌区的灌溉效率,该文以作物生长期灌溉地的蒸散发扣除降水量作为灌溉水的有效利用量,将灌溉水有效利用量与灌溉净引水量(总引水量减去退、排水量)的比值定义为灌溉水有效利用系数。利用遥感蒸散发模型可以较为准确地估算灌溉地蒸散发,从而可以避免传统灌溉水利用系数评估中难以准确估算通过灌溉到达作物根系层水量的问题。以河套灌区为研究对象,利用遥感蒸散发模型(surface energy balance algorithm for land,SEBAL)计算了区域内灌溉地作物生育期的蒸散发量,并结合降水量与净引水量的观测资料,对节水改造以来(2000-2010年)河套灌区灌溉水有效利用系数进行了分析和评价。结果表明,灌溉水有效利用系数近年来有增加趋势,同时灌溉水有效利用系数随降水量和净引水量的减小而增大,减少供水对灌溉水有效利用系数的影响要大于灌区节水改造工程的影响。另一方面,在灌区净引水量减少的情况下,灌溉地蒸发量能够维持在较稳定的水平,反映了近年来灌区节水改造的效果较好。 英文摘要 : Abstract: To evaluate the irrigation efficiency of irrigation districts in arid regions where crop growth relies heavily on irrigation, a new evaluation indicator, coefficient of irrigation water effective utilization, was proposed. The difference of evapotranspiration and precipitation in irrigated land during the crop growing season was considered as the effective use of irrigation water, and the ratio of effective use of irrigation water and net water diversion to the irrigation district was defined as the coefficient of irrigation water effective utilization (ηe). With the development of a remote sensing evapotranspiration technique in recent decades, spatial and temporal variations of evapotranspiration can be estimated with acceptable precision. Then ηe can easily be estimated from evapotranspiration and measured precipitation and net water diversion, which can avoid the difficulties of accurate measurement or simulation of irrigation water stored in the crop root zone in a traditional irrigation water use efficiency evaluation. A case study in the Hetao irrigation district in North China was carried out to estimate the coefficient of irrigation water effective utilization throughout the period 2000-2010 based on remote sensing evapotranspiration data calculated by the SEBAL (Surface Energy Balance Algorithm for Land) model, meteorological data, and water diversion data. Results indicated that ηe tends to increase with the implementation of water-saving irrigation projects. ηe varied from 0.547 to 0.715 during 2000―2010 and ηe decreased with precipitation and net water diversion. The correlation coefficients between ηe and precipitation, and ηe and net water diversion were -0.32 and -0.57, respectively. Moreover, ηe was estimated under different precipitation and water diversion schemes after water-saving irrigation projects. Results indicated that the reduction of water diversion had a greater effect than the water-saving irrigation projects on ηe. However, water consumption in irrigated land kept at a relatively stable level although water diversion tended to decrease in recent years, which showed the good performance of water-saving irrigation projects.