吉林省特大干旱灾害对粮食的影响及其对策

本文通过分析我省历史发生的特大干旱灾害事件，论述了不同时期特大干旱对粮食产量的严重影响。提出了21世纪特大干旱的研究与对策。     

安徽省旱涝急转规律的认识与研究

旱涝急转是指某一地区或某一流域发生较长时间干旱时，突遇集中强降雨，引发山洪暴发、河水陡涨．客水入侵、内水难以及时外排的一种自然现象。旱涝急转极易造成人员伤亡、水库垮坝等重大经济损失。在防汛抗旱中，安徽省要充分认识旱涝急转的危害性，加强应急管理，具体包括思想上保持高度的警觉，加快防汛抗旱工程体系和预测预警体系建设，有效应对旱涝急转。     

全球气候变暖对水资源的影响

全球气候变暖加剧了干旱、洪涝、台风等自然灾害的发生，是目前各国政府和社会公众普遍关注的热点问题。根据有关资料对气候变暖研究进展情况作相关介绍，可供参考。     

中国的主要水问题及水文学的机遇

从水资源开发利用与保护、水旱灾害防治等方面论述中国当前存在的主要水问题：水危机和水浪费同时存在、水污染日趋严重、防洪减灾任重道远、生态环境破坏严重、全球气候变暖产生不利影响；进而论述水文学研究面临的新课题：水文现象的不确定性、人类活动对水文的影响、水位频率计算、水资源开发利用的最佳效应、水资源供需分析、农业节水灌溉机理及水旱灾害的防治，并指出必须加强对这些新课题的研究     

旱情预报技术进展与展望

受全球气候变化影响和人类活动的加剧,干旱灾害发生频次增加且强度增大,严重威胁着我国的粮食安全和水安全。准确及时的旱情预报,对于制定科学有效的干旱应对策略、减少灾害造成的损失具有重大意义。从基于数理统计模型的预报技术和基于物理机制模型的预报技术两方面入手,梳理回顾了国内外研究进展,揭示了当前预报技术所存在的问题,并提出针对性的解决方案。未来研究应注重提高干旱监测数据的质量、突破核心关键技术、构建全国旱情预报业务化系统,为抗旱减灾事业提供强有力的科技支撑。     

基于SPI的辽宁省庄河市近35年干旱演变特性研究

庄河市是辽南地区的重要水源地,分析其干旱演变特性有利于该地区水资源的合理开发与利用,对于防旱减灾、合理布局产业结构具有重要的现实意义。本文根据庄河市1984年1月1日至2018年12月31日的逐日降水数据计算了1个月、3个月、6个月、12个月共4个不同时间尺度下的标准化降水指数(SPI),并基于SPI对该地区近35年的年际与季节干旱演变特征进行了分析。结果表明:在年际变化方面,庄河市的SPI在2000年以前波动幅度较小,说明该地区的降水在时间上分布较为均匀;但自2000年以来,SPI序列出现较大的波峰与波谷,说明降雨的分布不均匀性有所增强;SPI的时间序列趋势线斜率为负值,说明该地区整体上呈现偏旱趋势,因此其水资源压力不断增大。在季节演变特征方面,夏季干旱和秋季干旱呈现增强趋势;秋旱的发生频率最高,而夏旱的出现频率最低。本研究结果可为庄河地区的抗旱减灾与水资源规划提供科学依据。     

A Novel DUF569 Gene Is a Positive Regulator of the Drought Stress Response in Arabidopsis

In the last two decades, global environmental change has increased abiotic stress on plants and severely affected crops. For example, drought stress is a serious abiotic stress that rapidly and substantially alters the morphological, physiological, and molecular responses of plants. In Arabidopsis, several drought-responsive genes have been identified; however, the underlying molecular mechanism of drought tolerance in plants remains largely unclear. Here, we report that the “domain of unknown function” novel gene DUF569 (AT1G69890) positively regulates drought stress in Arabidopsis. The Arabidopsis loss-of-function mutant atduf569 showed significant sensitivity to drought stress, i.e., severe wilting at the rosette-leaf stage after water was withheld for 3 days. Importantly, the mutant plant did not recover after rewatering, unlike wild-type (WT) plants. In addition, atduf569 plants showed significantly lower abscisic acid accumulation under optimal and drought-stress conditions, as well as significantly higher electrolyte leakage when compared with WT Col-0 plants. Spectrophotometric analyses also indicated a significantly lower accumulation of polyphenols, flavonoids, carotenoids, and chlorophylls in atduf569 mutant plants. Overall, our results suggest that novel DUF569 is a positive regulator of the response to drought in Arabidopsis.     

Genome-Wide Analysis of the Late Embryogenesis Abundant (LEA) and Abscisic Acid-, Stress-, and Ripening-Induced (ASR) Gene Superfamily from Canavalia rosea and Their Roles in Salinity/Alkaline and Drought Tolerance

Canavalia rosea (bay bean), distributing in coastal areas or islands in tropical and subtropical regions, is an extremophile halophyte with good adaptability to seawater and drought. Late embryogenesis abundant (LEA) proteins typically accumulate in response to various abiotic stresses, including dehydration, salinity, high temperature, and cold, or during the late stage of seed development. Abscisic acid-, stress-, and ripening-induced (ASR) genes are stress and developmentally regulated plant-specific genes. In this study, we reported the first comprehensive survey of the LEA and ASR gene superfamily in C. rosea. A total of 84 CrLEAs and three CrASRs were identified in C. rosea and classified into nine groups. All CrLEAs and CrASRs harbored the conserved motif for their family proteins. Our results revealed that the CrLEA genes were widely distributed in different chromosomes, and all of the CrLEA/CrASR genes showed wide expression features in different tissues in C. rosea plants. Additionally, we introduced 10 genes from different groups into yeast to assess the functions of the CrLEAs/CrASRs. These results contribute to our understanding of LEA/ASR genes from halophytes and provide robust candidate genes for functional investigations in plant species adapted to extreme environments.     

Chemical and Isotopic Tracer Evaluation of Water Mixing and Evaporation in a Dammed Texas River During Drought

The interaction between drought and river regulation is monitored to better understand river flow mixing, evaporation and surface‐groundwater exchange in changing regional climates and in increasingly regulated waterways. This study compared Brazos River stable isotope (δ¹⁸O and δD) and electrical conductivity values with reservoir, creek and aquifer samples in the Brazos watershed, the largest watershed in Texas. The combination of tributaries, rainfall and the Brazos River Alluvium Aquifer, on the one hand, and the Lake Whitney reservoir, on the other hand, represent endmembers of dilute run‐off water and evaporated saline water, respectively. A simple isotope mixing model that uses monthly river discharge, Lake Whitney discharge, historical monthly precipitation δ¹⁸O and pan evaporation accurately reconstructs river δ¹⁸O (±0.5‰ on average). Data and isotope balance modelling support continued evaporation of ¹⁸O‐enriched Lake Whitney water as it flows downstream, although the most evaporation took place in Lake Whitney. The difference between river and precipitation δ¹⁸O, or Δ¹⁸O_RIV‐_PPT, here a measurement of degree of evaporation, ranged from ?0.1‰ for a small creek, to 1.7‰ for the Brazos River, to at least 2.7‰ in Lake Whitney. This study indicates that drought in regulated rivers may enhance reservoir discharge dominance in river flows during peak drought conditions when combined run‐off and baseflow dominance would be expected in a similar undammed river. Copyright © 2016 John Wiley & Sons, Ltd.