Mapping and ranking global mortality,affected population and GDP loss risks for multiple climatic hazards

Coping with extreme climate events and its related climatic disasters caused by climate change has become a global issue and drew wide attention from scientists, policy-makers and public. This paper calculated the expected annual multiple climatic hazards intensity index based on the results of nine climatic hazards including tropical cyclone, flood, landslide, storm surge, sand-dust storm, drought, heat wave, cold wave and wildfire. Then a vulnerability model involving the coping capacity indicator with mortality rate, affected population rate and GDP loss rate, was developed to estimate the expected annual affected population, mortality and GDP loss risks. The results showed that: countries with the highest risks are also the countries with large population or GDP. To substantially reduce the global total climatic hazards risks, these countries should reduce the exposure and improving the governance of integrated climatic risk; Without considering the total exposure, countries with the high mortality rate, affected population rate or GDP loss rate, which also have higher or lower coping capacity, such as the Philippines, Bangladesh and Vietnam, are the hotspots of the planning and strategy making for the climatic disaster risk reduction and should focus on promoting the coping capacity.     

The Predictability of Ocean Environments that Contributed to the 2020/21 Extreme Cold Events in China:2020/21 La Niña and 2020 Arctic Sea Ice Loss

Several consecutive extreme cold events impacted China during the first half of winter 2020/21,breaking the low-temperature records in many cities.How to make accurate climate predictions of extreme cold events is still an urgent issue.The synergistic effect of the warm Arctic and cold tropical Pacific has been demonstrated to intensify the intrusions of cold air from polar regions into middle-high latitudes,further influencing the cold conditions in China.However,climate models failed to predict these two ocean environments at expected lead times.Most seasonal climate forecasts only predicted the 2020/21 La Ni?a after the signal had already become apparent and significantly underestimated the observed Arctic sea ice loss in autumn 2020 with a 1-2 month advancement.In this work,the corresponding physical factors that may help improve the accuracy of seasonal climate predictions are further explored.For the 2020/21 La Ni?a prediction,through sensitivity experiments involving different atmospheric-oceanic initial conditions,the predominant southeasterly wind anomalies over the equatorial Pacific in spring of 2020 are diagnosed to play an irreplaceable role in triggering this cold event.A reasonable inclusion of atmospheric surface winds into the initialization will help the model predict La Ni?a development from the early spring of 2020.For predicting the Arctic sea ice loss in autumn 2020,an anomalously cyclonic circulation from the central Arctic Ocean predicted by the model,which swept abnormally hot air over Siberia into the Arctic Ocean,is recognized as an important contributor to successfully predicting the minimum Arctic sea ice extent.     

Predicting unit plot soil loss in Sicily,south Italy

Predicting soil loss is necessary to establish soil conservation measures. Variability of soil and hydrological parameters complicates mathematical simulation of soil erosion processes. Methods for predicting unit plot soil loss in Sicily were developed by using 5 years of data from replicated plots. At first, the variability of the soil water content, runoff, and unit plot soil loss values collected at fixed dates or after an erosive event was investigated. The applicability of the Universal Soil Loss Equation (USLE) was then tested. Finally, a method to predict event soil loss was developed. Measurement variability decreased as the mean increased above a threshold value but it was low also for low values of the measured variable. The mean soil loss predicted by the USLE was lower than the measured value by 48%. The annual values of the soil erodibility factor varied by seven times whereas the mean monthly values varied between 1% and 244% of the mean annual value. The event unit plot soil loss was directly proportional to an erosivity index equal to , being Q_RR_e the runoff ratio times the single storm erosion index. It was concluded that a relatively low number of replicates of the variable of interest may be collected to estimate the mean for both high and particularly low values of the variable. The USLE with the mean annual soil erodibility factor may be applied to estimate the order of magnitude of the mean soil loss but it is not usable to estimate soil loss at shorter temporal scales. The relationship for estimating the event soil loss is a modified version of the USLE‐M, given that it includes an exponent for the Q_RR_e term. Copyright © 2007 John Wiley & Sons, Ltd.     

非饱和带全剖面尿素态氮迁移转化规律分析

尿素是农田常用氮肥,本文通过实验室土柱试验,利用HYDRUS-1D建立非饱和带尿素态氮迁移转化模型,并对大沽河地下水源地夏玉米生长季节内水氮运移过程进行模拟,分析灌溉农业条件下非饱和带全剖面中氮迁移转化和深层淋溶规律。结果表明:(1)常规施肥条件下,尿素态氮水解达97.09%,仅有0.01%能够淋溶至地下水;(2)硝态氮更易淋溶至地下水,硝态氮淋失量与灌溉量和施肥量呈正相关,与灌溉强度呈负相关,不同施肥方式下淋失量表现为深施>灌施>表施;(3)根系吸氮量与灌溉量和施肥量呈正相关,与灌溉强度呈负相关,不同施肥方式下吸氮量表现为灌施>深施>表施,不同管理策略下玉米氮素利用率为20%~50%;(4)常规条件下土壤储氮量>玉米氮素利用率>氮淋溶量>气态氮损失。本研究对量化氮迁移转化过程、定量评价氮损失、预测地下水氮污染具有重要意义。     

基于条件模拟的DEM误差曲面实现研究

为了抑制采样点中粗差对数字高程模型(digital elevation model,DEM)建模的影响,以较高精度的多面函数(multi-quadric,MQ)为基函数,由改进Huber损失函数和权重惩罚项组成目标函数,发展了MQ抗差插值算法(MQ-H)。通过优化MQ-H目标函数,采样点权重计算最终转换为方程组求解。以数学曲面为研究对象,将MQ-H计算结果与传统MQ及最小绝对偏差MQ(MQ-L)进行比较,结果表明:当采样误差服从正态分布时,MQ-H计算精度与传统MQ相当,而远高于MQ-L;当采样误差服从拉普拉斯分布时,MQ-H计算精度略高于MQ-L及传统MQ;当采样点被粗差污染时,MQ-H计算精度远高于传统MQ及MQ-L。在实例分析中,以无人遥测飞艇立体像对获取的地面离散高程点为基础数据,基于MQ-H构建测区DEM,并将计算结果与传统插值算法,如反距离加权(inverse distance weighting,IDW)、普通克里金(ordinary Kriging,OK)和专业DEM插值软件ANUDEM(Australian National University DEM)进行比较,结果表明,传统插值方法在不同程度上受采样点中异常值或偶然误差影响,而MQ-H受异常值影响较小,且能准确捕捉到地形细节信息。     

Determination of fractional energy loss of waves in nearshore waters using an improved high-order Boussinesq-type model

Fractional energy losses of waves due to wave breaking when passing over a submerged bar are studied systematically using a modified numerical code that is based on the high-order Boussinesq-type equations.The model is first tested by the additional experimental data,and the model's capability of simulating the wave transformation over both gentle slope and steep slope is demonstrated.Then,the model's breaking index is replaced and tested.The new breaking index,which is optimized from the several breaking i...     

二次损失下一般的回归系数线性估计的容许性

本文研究线性模型中一般的回归系数的估计问题,用统计决策函数理论中容许性准则,讨论了线性估计的优良性,通过将一般的非可估回归系数转化成可估的情形,得到了一个线性估计在线性估计类中是容许估计的充分必要条件。     

冀中坳陷前第三系岩溶发育规律及其控制因素

冀中坳陷自蓟县纪杨庄运动以来经历了七次较大规模的构造运动,伴随发育有七期岩溶,但只有最晚的发生于印支—燕山运动的第Ⅶ期岩溶被较多保存下来,它可划分出三个次级岩溶期。从中元古界长城系高于庄组到下古生界奥陶系峰峰组,潜山碳酸盐岩的溶蚀作用发生在多个层位,尤其是蓟县系白云岩和奥陶系灰岩岩溶现象普遍。纵向上可统计出第Ⅶ期岩溶中的全部三期次级岩溶,岩溶层位主要为蓟县系雾迷山组、寒武系及奥陶系。钻井中泥浆漏失现象普遍,其中单井泥浆漏失量最大的层位是雾迷山组,其次是奥陶系,寒武系相对最小。冀中坳陷岩溶的总体展布特征表现为水平岩溶带距古地表的深度由凹陷向凸起变大,而水平岩溶带的厚度总体呈现由凹陷向凸起减小的趋势。构造运动、多层系碳酸盐岩的发育以及多套烃源岩的生烃演化,是影响冀中坳陷岩溶发育的三个主要控制因素。     

2020年中国大陆地震灾害损失述评

本文在统计分析2020年中国5.0级以上地震目录的基础上,结合有关省（自治区、直辖市）地震局地震灾害损失评估资料,总结2020年中国大陆地震灾害情况和主要特点。总体全年地震灾害程度较轻,但小震致灾致亡的现象突出。将1991—2020年中国大陆地震灾害相应数据和特性进行比较,得到中国大陆致灾地震频次、伤亡情况和经济损失变化趋势。     

The Demarcation Point from E-AGB Stars to TP-AGB Stars in HR Diagram for Medium-mass Stars

Via a study of the evolutionary tracks of 3∼10 M stars on the Hertzsprung-Russell diagram, the variations of the energy, density, temperature at the peak of helium-shell burning, ratio of surface luminosity of helium shell to stellar surface luminosity as well as the stellar radius are analyzed. Then the demarcation point of medium-mass stars in the evolution from early AGB stars to thermally pulsing AGB stars on the HR diagram is determined, and for 119 carbon stars our analysis agrees rather well with observation. At the same time the following is suggested. After arriving at this demarcation point in stellar evolution, in the formula of the loss of stellar wind material it is probably needed to introduce a quantity which is not concerned with the surface luminosity, but it dominates the formation of super stellar wind. On this basis and via the analysis of the structure and evolution of 5 M stars as well as the rate of mass loss of stellar wind, it is found that the effect of turbulent pressure on the mass loss of stellar wind in the stage of thermally pulsing AGB stars is rather great, hence the turbulent pressure of thermally pulsing AGB stars cannot be overlooked. Furthermore, the physical factors which possibly affect the matter loss of the stellar winds of thermally pulsing AGB stars are suggested.