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.

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.

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.

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.

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.

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.

Spatio-temporal evolution of drought and flood disaster chains in Baoji area from 1368 to 1911

Based on the collation and statistical analysis of flood and drought information in Baoji area from 1368 to 1911, and in the context of climate change, we investigated the spatio-temporal evolution characteristics of drought and flood disaster chains in this area during the Ming and Qing dynasties using the methods of moving average, cumulative anomaly and wavelet analysis. The results are as follows:(1) We found a total of 297 drought and flood events from 1368 to 1911 in Baoji. Among these events, droughts and floods occurred separately 191 and 106 times, which accounted for 64.31% and 35.69% of the total events, respectively.(2) We observed distinct characteristics of flood and drought events in Baoji in different phases. The climate was relatively dry from 1368 to 1644. A fluctuant climate phase with both floods and droughts occurred from 1645 to 1804. The climate was relatively wet from 1805 to 1911. Moreover, we observed a pattern of alternating dry and wet periods from 1368 to 1911. In addition, 3 oscillation periods of drought and flood events occurred around 70 a, 110 a and 170 a, which corresponded to sunspot cycles.(3) We also observed an obvious spatial difference in drought and flood events in Baoji. The northern and eastern parts of Weihe River basin were regions with both frequent droughts and floods.(4) The sequential appearance of drought and flood disaster chains in Baoji from 1368 to 1911 was in response to global climate change. Since the 1760s, global climatic deterioration has frequently led to extreme drought and flood events.

Role of land-atmosphere coupling in summer droughts and floods over eastern China for the 1998 and 1999 cases

Droughts and floods are the two most costly climate disasters over China.However,our ability to predict droughts and floods is limited by poor understanding of the atmospheric response to long memory climate drivers such as sea surface temperature and soil moisture.In this study,we investigate soil moisture feedbacks on summer droughts and floods over eastern China for the1998 and 1999 cases using the Weather Research and Forecasting(WRF)model simulations.Soil moisture climatology,derived from a 20-year-long control run,is used to replace soil moisture evolution in uncoupled simulations for 1998 and 1999 summers.Eastern China experienced severe floods during the summer of 1998,while 1999 summer is characterized by a"southern flood and northern drought"pattern.The WRF model generally simulates relatively well the droughts and floods in the two summers.It is found that land-atmosphere coupling contributes substantially to both droughts and floods over northern China while it plays a relatively small role in precipitation anomalies over southern China.Our findings suggest that soil moisture memory help contribute skill to seasonal prediction of droughts and floods over northern China.

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。

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。

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.

民俗文化视域下的云南兴蒙蒙古族之旱涝灾害应对考察

云南兴蒙蒙古族是杞麓湖滨农耕文化的重要创造者之一。元明清以来,随着当地蒙古族的农业开发,杞麓湖西畔的蒙古族聚居地逐渐成为滇中的重要粮仓,然而,严重的水旱灾害常常给当地农业生产带来巨大的破坏。兴蒙蒙古族的民俗文化应对主要包括生活经验的传承、自然崇拜的祈愿和日常生活的禁忌,这些旱涝灾害的民俗文化应对一方面能较好地使民众意识活动脱离对特定事件因果的沉浸,调节当地群众的消极情绪,提升安全感,成为居民情感的疏导口;另一方面,浸润人民群众生存智慧的灾害经验总结和应对是当地蒙古族经历代传承留存的民俗文化精髓。

我国水旱灾害防御应对

洪旱灾害是我国自然灾害中损失最为严重的灾害。中华人民共和国成立以来,历经70余年的建设,已逐步形成较为完备的工程体系和非工程体系相结合的水旱灾害防御体系,水旱灾害防御能力达到国际中等水平。在近年来海河“23·7”流域性特大洪水、2022年长江流域干旱等水旱灾害防御应对中,已建的工程体系和非工程体系发挥了重要作用。近年来因洪涝灾害死亡人口、因洪涝直接经济损失占当年GDP的比值呈明显下降趋势,水旱灾害防御成效显著。受全球气候变化和人类活动影响,我国水旱灾害呈现趋多、趋频、趋强、趋广的趋势,为应对更为极端和反常的水旱灾害,文章提出了构建水旱灾害防御矩阵、完善水旱灾害防御工程体系、建设数字孪生流域、完善法律法规及管理体制机制等思路构想。

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。

川渝高温热浪与暴雨旱涝演变特征及适应策略研究

为加深对川渝地区多灾种综合影响的理解,提升灾害综合风险防范能力,基于长时序观测数据,利用线性拟合、Pettitt检验、小波时频分解等方法,分析了1961~2022年川渝热浪与暴雨的时空演变特征,并针对耦合影响区提出适应性策略。结果表明:(1)近60 a来川渝总体高温热浪趋强趋长趋频,且不同时长高温热浪的区域差异性特征显著。川南经济区、川东北经济区至重庆市9 d及以上高温热浪的发生频次显著增多,成都平原经济区西部3~8 d高温热浪频次显著增多,自1990年代初期以来,盆西变化尤为明显。(2)川渝暴雨灾害变化也存在显著的区域差异。成都平原经济区西部、川南经济区暴雨日数显著减少、强度降低,川东北经济区至重庆市的暴雨日数增加、强度增强。(3)对高温干旱复合与旱涝急转事件的分析表明,盆东至重庆市旱涝急转自1980年代中期以来显著增加,盆南高温干旱复合事件自2000年代初以来显著增加。(4)成都平原经济区应着重关注高温热浪频发对超大城市脆弱人群及能源供给的冲击;川南经济区需关注持续性高温热浪叠加干旱给工业、农业带来的不利影响;川东北经济区在充分考虑高温热浪和暴雨灾害单独影响的同时,也应进一步综合考虑区域内旱涝急转给农业及重点项目带来的不利影响。

着力提升现代条件下的防灾减灾能力和水平——《加快构建水旱灾害防御工作体系的实施意见》解读

深入贯彻落实习近平总书记关于防汛抗旱工作重要指示精神,按照党的二十届三中全会决策部署,水利部办公厅印发了《加快构建水旱灾害防御工作体系的实施意见》,指导各级水利部门加快构建责任落实、决策支持、调度指挥“三位一体”的水旱灾害防御工作体系。解读了《实施意见》编制背景与重要意义、主要内容和特点及责任落实、决策支持、调度指挥三大方面的内涵,并提出《实施意见》印发后的落实安排,推动水旱灾害防御工作体系落地见效。