Spatiotemporal Characteristics of Droughts and Floods in Shandong Province,China and Their Relationship with Food Loss

Mastering the pattern of food loss caused by droughts and floods aids in planning the layout of agricultural production,determining the scale of drought and flood control projects,and reducing food loss.The Standardized Precipitation Evapotranspiration Index is calculated using monthly meteorological data from 1984 to 2020 in Shandong Province of China and is used to identify the province’s drought and flood characteristics.Then,food losses due to droughts and floods are estimated separately from disaster loss data.Finally,the relationship between drought/flood-related factors and food losses is quantified using methods such as the Pearson correlation coefficient and linear regression.The results show that:1)there is a trend of aridity in Shandong Province,and the drought characteristic variables are increasing yearly while flood duration and severity are decreasing.2)The food losses caused by droughts in Shandong Province are more than those caused by floods,and the area where droughts and floods occur frequently is located in Linyi City.3)The impact of precipitation on food loss due to drought/flood is significant,followed by potential evapotranspiration and temperature.4)The relationship between drought and flood conditions and food losses can be precisely quantified.The accumulated drought duration of one month led to 1.939×10^(4)t of grain loss,and an increase in cumulative flood duration of one month resulted in1.134×10^(4)t of grain loss.If the cumulative drought severity and average drought peak increased by one unit,food loss due to drought will increase by 1.562×10^(4)t and 1.511×10^(6)t,respectively.If the cumulative flood severity and average flood peak increase by one unit,food loss will increase by 8.470×103t and 1.034×10^(6)t,respectively.

Dryness-wetness change and regional differentiation of flood-drought disasters in Guangdong during 1480-1940AD

Based on the historical records of the drought and flood disasters during 1480-1940AD, this paper reconstructs the sequences of wetness index （WI） and drought and flood disasters. We find a good identical relationship between the fluctuation of WI sequence and the δ^18O record of the GISP2 ice core in Greenland, which shows an apparent monsoonal disposal pattern of moisture and temperature. By applying the Morlet Wavelet Transform Method to deal with the data, several apparent periodicities, such as 7-8a, 11-15a, 20-23a and ca 50a, are revealed, among which some can be attributed to the solar forcing. Based on results of Cluster Analysis of dry-wet changes, we resume the regional differentiation pattern of flood-drought disasters all over Guangdong during different climatic intervals in the LIA and, find the western and northern parts of Guangdong have undergone drastic changes in drought-flood regional differentiation, but the eastern part is relatively stable, and the area of the Pearl River Delta shows stable condition of more flood disasters.

Yellow River Valley flood and drought disaster：spatial－temporal distribution prediction and early－warning

By means of analysing the historical data of flood-drought grade series in the past 2000 years(A.D.0-1900),especially in the last 5000 years (1470-1900) , this paper revealed the spatial-temporaldistribution features of severe flood and drought in Yellow River Valley. Statistical methods of varianceanalysis, probability transition and the principles of scale correspondence were employed tocomprehensively predicate 90's tendency of severe flood and drought in the Yellow River Valley. In addi-tion, this paper pointed out the possible breaching dikes, sectors and the flooding ranges by future's se-vere flood, meanwhile estimating the associated economic losses and impact to environment.

Characteristics and Variations of the East Asian Monsoon System and Its Impacts on Climate Disasters in China

Recent advances in studies of the structural characteristics and temporal-spatial variations of the East Asian monsoon （EAM） system and the impact of this system on severe climate disasters in China are reviewed. Previous studies have improved our understanding of the basic characteristics of horizontal and vertical structures and the annual cycle of the EAM system and the water vapor transports in the EAM region. Many studies have shown that the EAM system is a relatively independent subsystem of the Asian- Australian monsoon system, and that there exists an obvious quasi-biennial oscillation with a meridional tripole pattern distribution in the interannual variations of the EAM system. Further analyses of the basic physical processes, both internal and external, that influence the variability of the EAM system indicate that the EAM system may be viewed as an atmosphere-ocean-land coupled system, referred to the EAM climate system in this paper. Further, the paper discusses how the interaction and relationships among various components of this system can be described through the East Asia Pacific （EAP） teleconnection pattern and the teleconnection pattern of meridional upper-tropospheric wind anomalies along the westerly jet over East Asia. Such reasoning suggests that the occurrence of severe floods in the Yangtze and Hualhe River valleys and prolonged droughts in North China are linked, respectively~ to the background interannual and interdecadal variability of the EAM climate system. Besides, outstanding scientific issues related to the EAM system and its impact on climate disasters in China are also discussed.

A Relationship between Solar Activity and Frequency of Natural Disasters in China

The relationship between the length of the solar cycle, a good indicator of long-term change in solar activity, and natural disasters (drought, flood, and strong earthquakes) in China during the last 108 yearsis analyzed. The results suggest that the length of solar cycle may be a useful indicator for drought/flood and strong earthquakes. When the solar activity strengthens, we see the length of the solar cycle shorten and more floods occur in South China and frequent strong earthquakes happen in the Tibetan Plateau, but the droughts in East China as well as the strong earthquakes in Taiwan and at the western boundary of China are very few. The opposite frequencies occur when the solar activity weakens. The current study indicates that the solar activity may play an important role in the climate extremes and behavior in the lithosphere.

The Analysis on the Temporal and Spatial Variation of Strong Precipitation Caused Flood and Agricultural Disaster Loss in Huaihe River Basin of Anhui Province during Meiyu Period of 2007

[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.

The Impact of Climate Change Induced Extreme Events on Agriculture and Food Security: A Review on Nigeria

The study of the climate change and the effects of climate change induced extreme events on food security are fundamental for the sustainable development of agriculture globally. Climatic factors are the primary important factors affecting agricultural production. Furthermore, the world is now experiencing more frequent and intense droughts and floods in many agricultural regions which damage and at times destroy crops. The effects of climatic change on agriculture have triggered significant trend of research during the last decade globally in order to unfold the solutions to climate change induced extreme events on agriculture. Several studies have been conducted on effects of extreme events such as droughts and flooding induced by climate change on agriculture and food security. These effects include changes in crop and livestock yields as well as the economic consequences of these potential yield changes globally. Therefore, this study reviews the effects of extreme events, including floods and drought, caused by climate change on agriculture and food security with focus on Nigeria in particular. For the study, literatures were identified for review through a comprehensive search by using electronic and non-electronic databases to identify researches conducted on effects on climate change and extreme events on agricultural productivity. From the review, it shows that extreme events such as droughts and floods impact agriculture and food security. In order to mitigate the effects of climate change especially droughts and floods, on agricultural productivity, there is an urgent need to intensity efforts and researches on climate change to mitigate and adapt to the occurrences of these extreme events when necessary in Nigeria. Several mitigation and adaptation measures need to be implemented to mitigate the effects of extreme events on agricultural productivity and food security. These measures include practicing climate-smart agriculture, construction and improvement of drainage networks to effectively dispose of flood water in order to reduce the risks of flooding in urban agriculture and drought-resistant varieties of crops should be cultivated.

The Recurrence of Natural Disasters in Jowhar, Middle Shabelle Region, Somalia: The Causes and Impacts

Natural disasters usually involve a phenomenon with consequences that exceed the response capabilities of local communities and have a significant impact on the region’s socioeconomic development. Droughts, floods, and hurricanes are all natural disasters that jeopardize the environment and the lives of Somalis. Severe floods have devastated the south and central parts of the country multiple times, destroying infrastructure and homes and killing many vulnerable people. Droughts in the south and central parts of the country, particularly in the Middle Shebelle region, have killed a number of children and mothers. It also had a negative influence on crops and cattle. Objective of this study is to know the recurrence of Natural Disasters in Jowhar, Middle Shabelle region, Somalia: The Causes and Impacts. The Somali people are completely aware of natural disasters such as droughts and floods, and they are self-sufficient in dealing with the consequences of these disasters. Furthermore, the Somali government has not fully created environmental laws to protect and conserve the environment, and the majority of laws, rules, acts, and regulations are not used or administered effectively. We also found that the Somali government is not yet financially prepared to deal with these crises, and that there are no strategic plans in the central government or even state administrations to prevent or at least control these disasters from causing extreme harm to the community and the environment.

ENVIRONMENTAL FEATURES AND WATERENVIRONMENTAL PROBLEMS IN THE CONTIGUOUSREGION OF JIANGSU,SHANGDONG,HENANAND ANHUI PROVINCES

Owing to intensive human activities and the floods of the Huaihe River in historic peiod, the contiguous region of Jiangsu, Shandong, Henan and Anhui provinces is suffering from a variety of environmental problems and naturaldisasters, of which water pollution and drought-flood disasters are most observable. Considering the special location andenvironmental status of the contiguous region, advices are proposed in the paper: perfecting trans-regional managementssystem of water environment incorporating basin management agencies in local government activities; strengthening cooperation of two agencies: water conservancy agency and environment protection agency; enhancing integrated control ofwater pollution and flood-drought disasters; taking the interests of the whole river into acount and paying attention to bothstorage and drainage; broadening sources of water supply and inceasing water delivery; controlling pollutant discharge,developing water saving production system.

近53 a辽河流域旱涝灾害的时空特征

针对气候变化背景下辽河流域旱涝事件的频繁发生,以国家气象中心提供的地面降水日值数据集V3.0为基础数据,采用Z指数法表征旱涝事件,并应用集合经验模态分解法(EEMD)分析了辽河流域1968—2020年逐年、逐生长季的旱涝事件分布特征及其周期性规律,结果表明:(1)辽河流域近53 a中发生旱涝事件的灾害年份约占总时间序列的2/3以上,集中发生于上世纪80、90年代中后期及本世纪00年代.(2)近53 a中,重度干旱或洪涝事件均以流域东南部的河流下游及入海口区域最为严重,流域东南部的旱涝程度反差最为强烈.(3)对于辽河流域范围的旱涝事件来说,周期特征以短时高频振荡为主,年代际尺度的波动对于周期规律的贡献率相对较低.

北斗导航卫星系统在水利行业的应用与展望

北斗导航卫星系统是我国重要的时空基础设施,建设以来已经广泛应用于社会经济多个领域。智慧水利是新阶段水利高质量发展的最显著标志和6条实施路径之一,北斗导航卫星系统为智慧水利提供了强大的技术支撑,为数字孪生水利建设提供了重要的时空基准和高精度的位置及通信服务。从北斗导航卫星系统的功能视角,选择水利工程变形监测、水利巡检、水文监测数据传输等典型应用场景,分析了北斗导航卫星系统的应用现状;同时,还讨论了北斗遥感技术在水位监测、土壤水分反演和大气水汽反演等方面的应用情况;最后,展望了北斗系统在水利领域的发展趋势,指出其应用场景和领域将持续拓展、应用规模将不断增长,以及与新技术融合应用将不断增强,随着北斗导航卫星系统技术的持续创新和应用范围的进一步扩大,北斗导航卫星系统在未来水利行业中将发挥越来越重要的作用,它将成为加快水利新质生产力、推动水利高质量发展的重要推力。

为以中国式现代化全面推进强国建设、民族复兴伟业提供有力的水安全保障

今年3月22日是第三十二届“世界水日”,第三十七届“中国水周”宣传活动同步开启。联合国确定今年“世界水日”主题为“以水促和平”。我国纪念今年“世界水日”“中国水周”的活动主题是“精打细算用好水资源,从严从细管好水资源”。水是生存之本、生产之要、生态之基。2014年3月,习近平总书记主持召开中央财经领导小组第五次会议,研究水安全问题,提出“节水优先、空间均衡、系统治理、两手发力”的治水思路,这为系统解决我国水灾害水资源水生态水环境等新老水问题、保障国家水安全提供了根本遵循和行动指南,在中华民族治水史上具有重要里程碑意义。

海河“23·7”流域性特大洪水防御启示与对策——以永定河为例

在极端天气常态化的背景下,流域应具有承受、化解和抵御洪涝和干旱灾害的韧性。分析了海河“23·7”流域性特大洪水的特点,在此基础上,阐述了此次洪水过程中永定河流域综合治理各项措施发挥的作用、存在的问题,按照建设韧性流域的要求,对提升永定河流域防洪能力提出建议。

东江流域控制性水工程联合调度策略与机制探讨

近年,东江流域旱涝事件并存,防洪与供水安全形势严峻,三大水库和干流梯级电站是东江流域水旱灾害防御中的重要水利工程。收集流域水工程多年运行经验、案例、数据,综述东江流域控制性水工程联合调度在管理体制、防洪调度、水量调度等方面的研究、实践现状,通过数学模型、统计等方法,对现状调度体制与机制中存在的问题进行分析。从管理、技术、研究等角度提出建议与对策。

乡村河道治理对极端天气下洪涝灾害的影响分析:以豫北乡村为例

【目的】随着近年来强降雨引发洪涝灾害问题的日益突出,为深入探索乡村河道治理对极端天气下发生洪涝灾害的内在影响,进一步提高乡村地区河道治理水平,加强保障乡村—城市区域整体生产运行安全及人民生命财产安全能力,【方法】以豫北乡村为例,基于诸多业界专家学者的研究成果,通过对乡村河道的实地走访调查,对现有乡村河道老化、侵占等现状及问题进行了统计、总结归纳与研究分析,并对乡村区域实例进行了不同等级的降水计算分析。【结果】结果显示:乡村河道治理工作对极端天气所致洪涝灾害风险具有重要影响、乡村河道治理工作的现状存在诸多问题、乡村河道改造具有迫切性和必要性。【结论】针对调研数据统计分析,总结归纳了乡村河道治理存在的以违规侵占土地为主的6方面问题,结合降水计算结果,发现:现有状况下的乡村河网不足以面对极端变化天气下引发的洪涝风险,需持续提升新时期的河湖管理水平,加强应对极端变化天气引发洪涝灾害的应急能力。基于此,针对乡村河道治理问题给出了对应的6点对策建议。

1981—2018年吉林省玉米水分盈亏及旱涝时空分布

吉林省作为我国玉米主产区和重要的商品粮基地,明确吉林省玉米水分盈亏指数及旱涝灾害的时空分布特征,有助于提高农业生产的稳定性和抗灾能力。该文采用吉林省逐日气象站点数据,通过计算月尺度下的潜在蒸散量,构建水分盈亏指数来分析吉林省潜在蒸散量和旱涝灾害的时空分布特征,运用趋势分析法和小波分析法来探究水分盈亏指数的趋势性及周期性变化。结果表明:多年平均潜在蒸散量和各月份平均潜在蒸散量均有由西北至东南逐渐递减的趋势,5—9月潜在蒸散量分别占生长周期内总平均潜在蒸散量的26.3%、24.5%、21.1%、16.8%和11.3%。5月和9月发生中旱及以上频率大于50%的地区主要位于白城市西部,四平市西部和长春市中部地区。8月和9月中涝及以上频率高值区位于吉林省东部及东南部地区。

湖南省水旱灾害风险管理系统设计与应用

为满足湖南省水旱灾害防御实际需求,有效支撑防汛抗旱指挥决策,设计开发了湖南省水旱灾害风险管理系统。该系统包括综合信息、普查成果、实时分析、动态展示4个模块,覆盖水旱灾害风险管理业务的主要环节,具备基础数据查询、流域联合调度、洪水过程预演、灾害损失统计、风险及时评估等功能,对水旱灾害防御的实时化、可视化、精细化管理,以及防汛抗旱决策服务能力的提升有良好助益。

广东省水旱灾害风险普查成果微服务共享应用平台建设

水旱灾害风险普查项目产生了丰富的成果,为了最大化发挥项目成果的社会效益和推动“一数一源、一源多用”的成果管理,研发了成果微服务共享应用台。平台以项目成果为核心进行了多源数据的统一可视化集成管理与微服务发布,构建了成果知识库,研发了成果应用分析与模型计算服务,实现了区域与流域的多维度在线化综合分析,提供了横向面向厅各业务平台,纵向面向市县各级业务系统的普查成果数据接口和应用服务接口,实现了成果接口服务共享,推进全省的水旱灾害防御相关工作。

近57年来El Nino/La Nina事件对鄂尔多斯高原东缘气候的影响

根据1955年～2011年期间发生的El Nino／LaNina事件和鄂尔多斯高原东缘3个站点（兴县，绥德和榆林）的气象资料，利用统计分析的方法研究了1955年以来该区的降水量、温度、旱涝灾害与El Nino／LaNina事件之间的关系，揭示了El Nino／LaNina事件对鄂尔多斯高原东缘气候的影响.结果表明，鄂尔多斯高原东缘近57年降水量呈减少趋势而气温呈升高的趋势；厄尔尼诺年降水量比正常年平均降水量少87.6mm，年平均气温比正常年高0.2℃；拉尼娜年降水量比正常年均降水量少22.3mm，年平均气温比正常年低0.1℃，且其年降水量递减率和增温率略高于全国.厄尔尼诺事件对鄂尔多斯高原东缘降水量减少的影响和气温上升的影响要大于拉尼娜事件对鄂尔多斯高原东缘的影响.由小波分析可知，鄂尔多斯高原东缘降水变化在30a尺度内存在2a、8a、20a、27a的变化周期，而气温变化在30a尺度内存在3a、5a,7a、29a的变化周期.El Nino／LaNina事件对该区的旱涝灾害影响显著，旱灾年份出现厄尔尼诺的概率为63％，出现拉尼娜的概率为25％，厄尔尼诺年易于发生旱灾.

基于机器学习的湖南省干旱灾害风险评价研究

旱灾是制约农业发展的主要因素,为提高湖南省应对干旱灾害的能力,基于机器学习构建湖南省农业旱灾风险评价模型,探究湖南省农业干旱危害的时空分布特征。结果显示:湖南省农业旱灾综合风险由西向东减小,整体风险处于中低等级,波动小且稳定性好。旱灾受灾率与农业旱灾综合风险分布相一致。采用Pearson检验,将旱灾综合风险与绝收率、受灾率进行对比发现,湖南省农业旱灾综合风险与绝收率和受灾率存在显著相关性,证明本研究旱灾风险评价模型的有效性。