Climate change vulnerability assessment in the new urban planning process in Tanzania

Climate change vulnerability assessment is an essential tool for identifying regions that are most susceptible to the impacts of climate change and designing effective adaptation actions that can reduce vulnerability and enhance long-term resilience of these regions.This study explored a framework for climate change vulnerability assessment in the new urban planning process in Jangwani Ward,Tanzania.Specifically,taking flood as an example,this study highlighted the steps and methods for climate change vulnerability assessment in the new urban planning process.In the study area,95 households were selected and interviewed through purposeful sampling.Additionally,10 respondents(4 females and 6 males)were interviewed for Focus Group Discussion(FGD),and 3 respondents(1 female and 2 males)were selected for Key Informant Interviews(KII)at the Ministry of Lands,Housing and Human Settlements Development.This study indicated that climate change vulnerability assessment framework involves the assessment of climatic hazards,risk elements,and adaptive capacity,and the determination of vulnerability levels.The average hazard risk rating of flood was 2.3.Socioeconomic and livelihood activities and physical infrastructures both had the average risk element rating of 3.0,and ecosystems had the average risk element rating of 2.9.Adaptive capacity ratings of knowledge,technology,economy or finance,and institution were 1.6,1.9,1.4,and 2.2,respectively.The vulnerability levels of socioeconomic and livelihood activities and physical infrastructure were very high(4.0).Ecosystems had a high vulnerability level(3.8)to flood.The very high vulnerability level of socioeconomic and livelihood activities was driven by high exposure and sensitivity to risk elements and low adaptive capacity.The study recommends adoption of the new urban planning process including preparation,planning,implementation,and monitoring-evaluation-review phases that integrates climate change vulnerability assessment in all phases.

Sediment Provenance and Climate Changes Since the Middle Pleistocene in the Yingqiong Continental Slope of the South China Sea

The age,grain size compositions and major elemental compositions for sediments in core YQ1 from the Yingqiong continental slope in the South China Sea was determined in this paper.It is noted that the periodically cyclic change of sedimentation rates occurred in the Yingqiong continental slope in the South China Sea.During the interglacial periods,the sedimentation rates were high,while the sedimentation rates exhibited low values during the glacial periods.During Marine Isotope Stage 1(MIS1),the sedimentary rate could reach about 800 cm kyr-1 and during the MIS6 this area is characterized by the lowest sedimentary rate,which is lower than 3 cm kyr-1.According to the R-mode factor analysis of the major element data,three factors F1(Al2O3,Fe2O3,TiO2 and K2O),F2(MgO and MnO)and F3(Na2O and P2O5)were obtained,which shows that vertical change of the major elemental concentrations in the core was mainly controlled by the nearby terrestrial inputs and the early diagenesis,while the effect of volcanic and biogenous inputs was less.The obvious glacial-interglacial cyclic features are presented in the changes of the typical terrestrial element ratios contained in factor F1,which reflects the impact of glacial-interglacial climatic cycle on the evolution of the East Asian monsoon.This indicates that the major element ratios in terrestrial sediments are significant indicators of regional climate changes.

About A New Complex Method of Climates Reconstruction and Forecasting of Climate Changes in the Future

This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorological data, and data about of solar activity expressed in numbers of W （Wolf）. Here we present the results of investigation of sediments of the 2nd Fomich River terrace, Taymyr Peninsula, Russia. The formation of the peat bog started 10500 ± 140 years BP and continued during the entire Holocene. The pollen analysis of the sediment samples of the 2nd Fomich River terrace and the analysis of surface samples from a larch forest, typical of this region, reveals two phytochrones： both climatically preconditioned--tundra phytochrone （I1-4） and forest phytochrone （Ⅱ1-4）. The techniques of reconstruction and forecasting of basic elements of climate are presented and discussed in details.

WEATHERING AND CLIMATE CHANGE SINCE 1820 AD IN HOH XIL, QINGHAI-XIZANG PLATEAU, CHINA——EVIDENCE FROM ELEMENT GEOCHEMISTRY OF LAKE SEDIMENTS OF GULUG CO LAKE

Element geochemistry of lake sediments has been widely used to detect climate change because element composition and ratios can reflect the weathering degree in the source area. Given the element composition of lake sediments from Gulug Co Lake, Hoh Xil, Qinghai-Xizang Plateau, chemical index of alteration (CIA), index of composition variability (ICV) and other element ratios have been used to establish the weathering sequence of this area since 1820 AD. The weathering is so weak that the element composition change is more sensitive to climate change and autochthonous processes. From 1820 to 1984 AD, there were two drier periods with a wetter interval from 1870 to 1945 AD. After 1984 the weather showed a tendency of becoming wet.

变化环境下汉江流域水循环要素响应规律

汉江是长江第一大支流,也是南水北调中线工程和引汉济渭工程的水源地,具有重要的战略地位,科学评估气候变化和人类活动等变化环境下其水循环的响应,对流域水资源的可持续利用和制定适宜的管理政策有着重要意义。本文以汉江流域为研究区域构建了校准后的VIC分布式水文模型,随后基于降尺度后的全球气候模式数据和不同时期土地覆盖遥感数据设置不同情景的模拟,全面分析变化环境下流域水循环要素响应规律,并量化了气候变化和土地利用对径流变化的贡献率。结果表明:不同气候变化情景下,年均降水中上游增加显著,年内降水更加集中于夏秋季节丰水期,各月实际蒸散发整体增加且年内分布更加均匀化;丹江口入库流量和流域出口断面流量在RCP8.5情景呈显著增加趋势,流域年内枯水期流量减少,丰水期流量全年占比最大增加了8.51%,未来月流量更加集中于丰水期,发生干旱和洪涝灾害的概率将会增加。汉江流域的部分稀树草原和有林地在21世纪以来转化为郁闭度更高的落叶阔叶林,土地利用的变化没有使得流量的年际变化趋势有较大改变,但使得流量整体降低了。不同时期气候变化和土地利用对丹江口入库流量变化的贡献率分别为80%~88%和12%~20%,对流域出口断面流量变化的贡献率分别为72%~88%和12%~28%,气候变化是汉江流域径流变化的主要驱动力。

黄河源区典型流域水文要素演变及其对气候变化的响应

以黄河源区白河流域为研究对象,采用Mann-Kendall方法分析水文要素的演变特征,利用RCCC-WBM水量平衡模型(monthly water balance model developed by research center for climate change)模拟探究流域生态水文要素对气候变化的敏感性。结果表明:1981-2020年白河流域气温增加趋势显著,气温递升率为0.45℃/(10 a),潜在蒸散发年际变化不明显,而降水和径流呈现先减少后增加的阶段性变化特征;RCCC-WBM水量平衡模型对白河流域具有较好的月尺度径流模拟效果,率定期和验证期的纳什效率系数(Nash-Sutcliffe efficiency coefficient,ENS)分别为0.69和0.62;在假定的气候变化情景下,降水量增加40%且气温变化-4~4℃时对应的径流量变化范围为20.2%~84.4%,实际蒸散发量为1.4%~51.0%,即随着降水量的增多,流域气温和蒸散发变化对径流的影响越来越显著。研究结果可为黄河源区的水循环演变规律的揭示提供参考。

气候变化下长江黄河源区水循环变化及生态效应

长江黄河源区对中国的生态安全和区域发展有重要影响。当下该区域正在经历气候变化,受其影响源区的关键水循环要素也发生改变。气候变化和水循环要素变化下源区的生态出现了何种变化、水土涵养现状如何已成为普遍关注的问题。通过文献综述,总结梳理了气候变化下长江黄河源区关键水循环要素的基本变化情况及其产生的生态效应。研究结果表明:长江黄河源区气温升高显著,降水变化趋势存在区域差异;冰川积雪消融增加,冻土消融加剧;不同区域径流量变化趋势存在差异;源区植被覆盖度总体呈现上升趋势;沼泽草甸湿地和高寒泥炭湿地出现退化,而湖泊数量增多,面积增加显著;在多因子的综合作用下,源区河流输沙量平稳或是下降,水土涵养状况稳定或有所改善。未来气候变化的不确定性对源区生态的压力仍然存在,植被和湿地有退化风险;反映源区水土涵养状况的河流输沙系统驱动机制还不够明晰,相关研究还较少,与之相关的研究亟待进一步展开。

Probabilistic analysis of embankment slope stability in frozen ground regions based on random finite element method

Prediction on the coupled thermal-hydraulic fields of embankment and cutting slopes is essential to the assessment on evolution of melting zone and natural permafrost table, which is usually a key factor for permafrost embankment design in frozen ground regions. The prediction may be further complicated due to the inherent uncertainties of material properties. Hence, stochastic analyses should be conducted. Firstly, Karhunen-Loeve expansion is applied to attain the random fields for hydraulic and thermal conductions. Next, the mixed-form modified Richards equation for mass transfer （i.e., mass equation） and the heat transport equation for heat transient flow in a variably saturated frozen soil are combined into one equation with temperature unknown. Furthermore, the finite element formulation for the coupled thermal-hydraulic fields is derived. Based on the random fields, the stochastic finite element analyses on stability of embankment are carried out. Numerical results show that stochastic analyses of embankment stability may provide a more rational picture for the distribution of factors of safety （FOS）, which is definitely useful for embankment design in frozen ground regions.

Paleoclimatic evolution indicated by major geochemical elements from aeolian sediments on the east of Qinghai Lake

As the largest inland lake of China, along with its unique landscape and geographical location, Qinghai Lake has got much atten- tion of the scientists for a long time. The precursors have done substantive researches by using the lake sediment, which deepen our tmderstanding of the climate changes in this region. Although sand dunes and loess sediment are widely distributed around the lake, so far the researches on geochemical elements from aeolian sediment have been less reported. In this paper, we selected a typical aeolian profile on the east of Qinghai Lake. Based on systematic sampling and analysis of seven major geochemical ele- ments, combined with OSL dating and previous researches, this paper discusses climate changes in the Qinghai Lake area since 12.5 ka B.P.. Our conclusions are： （1） Before 12.5 ka B.P., the climate in this region was dry, cold, and accompanied by strong wind-sand activities. （2） During 12.5-11.9 ka B.P., the climate became warm and wet. However, there was an abrupt climate cooling event during 12.2-11.9 ka B.P., which likely corresponded to the Younger Dryas event. （3） During 11.9 8.0 ka B.P., the climate fluctuated greatly and frequently from warm to cold, and three cooling events occurred. （4） During 8.0-2.6 ka B.P., the climate was warm and humid. （5） Since 2.6 ka B.P., similar to the modem climate, the climate was mainly dry and cold.

Paleo-sedimentary environmental restoration and its significance of Chang 7 Member of Triassic Yanchang Formation in Ordos Basin,NW China

Paleo-sedimentary environment of Chang 7 Member of Upper Triassic Yanchang Formation in Ordos Basin, including the paleoclimate, paleo-salinity and paleo-redox conditions were restored through geochemical elements analysis of 289 samples collected from the outcrop sections around and wells drilled in the basin and using a series of identification indexes of paleo-climate, paleo-salinity and paleo-redox conditions, such as CaO/MgO?Al2 O3, Sr/Cu, Rb/Sr, Rb/K2 O, Th/U, V/(V+Ni), the content of element B tested from the mudstone. Comprehensive analysis shows that in sedimentary period of the Chang 7, the paleo-climate was warm temperate to subtropical climate with temperature higher than 15 ?C, the water body was continental brackish water to freshwater, and the sediments were deposited under strong reduction conditions. Suitable temperature, extensively deep lake basin and strongly reductive paleo-sedimentary environment led to the blooming, enrichment and preservation of organic matter in the submember Chang 73. As a result, a set of high-quality source rock was formed, laying material foundation for large-scale accumulation of shale oil.

Holocene climatic change reconstructed from trace elements of an aeolian deposit in the southeastern Mu Us Desert, northern China

In semi-arid and arid desert regions of northern China, aeolian deposits document the framework variation of an Asian monsoon during the late Quaternary. However, there is still a lack of detailed data pertaining to Holocene Asian monsoonal variation especial in the modern Asian summer monsoonal boundary belt. In this study, we reconstructed Holocene millennial-scale climatic changes in the Mu Us Desert, northern China, through systematic analysis of the variation of trace elements(324 samples) in different lithological units of the palaeosol-aeolian sand deposit, in combination with14 C and OSL chronology. Statistical results, correlation and clustering analysis indicate that the high content of 11 trace elements(V, Y, Cr, Nb, P, Mn, Cu, Zr, As, Ni and Rb, represented by P) and lower Sr content corresponding to periods of palaeosol development, marked increase of vegetation, weathering degree, and enhanced Asian summer monsoonal strength. In contrast, their opposed variation are coincident with accumulated aeolian sand layers, implying weaker summer monsoons and less geochemical weathering and degraded vegetation. These associations can be considered as signaling regional humid and dry changes of the Holocene environment. Accordingly, relatively arid conditions dominated the region before 7.2 ka, and there was an optimal humid climate in 7.2-4.6 ka. Afterwards, the climate became obviously dry, accompanied with several cycles of relatively wet and dry, such as relatively wet intervals around 4.1-3.7 ka, 3.5-3.3 ka and 2.5 ka. In addition, six millennial-scale dry events were recorded, and these events were consistent with weaker Asian summer monsoonal intervals in low latitudes, declined palaeosol development and precipitation in middle latitudes, as well as increased winter monsoon and periodic ice-rafting events in high latitudes of the Northern Hemisphere, within limits of accuracy of existing dating ages. This possibly suggests a noteworthy synchronism between millennial-scale climatic changes in this region and on a global scale.

庚子年牛膝木瓜汤应用探析

五运六气是古人研究的气化运行的规律,其核心理念是天人相应。2020年为庚子年,亦是同天符之年[中运之气太商(金)与在泉之气阳明燥金相和],燥火太过伤及肝木,则为肝虚、肺燥之证。牛膝木瓜汤出自《三因司天方》五运时气民病证治篇,是治疗六庚年岁金太过之主方。文章撷取牟淑敏教授应用牛膝木瓜汤的2则典型医案,即“脱发案”和“目赤肿痛案”,并对其病因、用药进行了深入剖析,以阐述五运六气理论在临床中的应用思路。

末次冰期东海嵊山岛黄土元素地球化学特征及其古气候意义

以东部季风区浙江省舟山群岛嵊山岛黄土沉积为研究对象,在光释光测年基础上,探讨黄土沉积的元素地球化学等特征并揭示其记录的古气候意义。光释光年代结果显示,嵊山岛黄土堆积于末次冰期时期。黄土中地球化学成分以SiO_(2)、Al_(2)O_(3)和Fe_(2)O_(3)为主,占比90.22%,与黄土高原洛川剖面中黄土层和古土壤层以及镇江下蜀黄土样品相比,嵊山岛黄土常量元素中的铝、铁元素表现为相对富集,钙、钠和钾元素相对亏损,化学蚀变指数CIA为85.1。从东部嵊山岛到西北黄土高原洛川,不同区域黄土风化强度差异显著,总体表现为:嵊山岛黄土>镇江下蜀黄土>陆源页岩>洛川古土壤>洛川黄土>上陆壳(UCC)。嵊山岛黄土沉积剖面磁化率平均值为70.9×10^(-8)m^(3)/kg,磁化率随剖面深度变化明显。结合磁化率指标,嵊山岛黄土地球化学记录揭示了末次冰期间冰阶时期气候大体呈现由暖湿至冷干再至暖湿的波动特征,这与会宁黄土、下蜀黄土等所反映的MIS3时段气候变化情况具有一致性。嵊山岛黄土沉积记录末次冰期间冰阶时期气候特征也与全球气候变化具有一致性。

水葱和香蒲叶经济性状对模拟增温和CO_(2)浓度倍增的响应

气候变化是国际社会共同关注的环境问题,植物对气候变化的响应反映了植物应对气候变化的生长和生存策略。叶经济性状与植物对资源的获取、利用和储存直接相关,并且受到温度条件和CO_(2)浓度的显著影响。该文采用人工环境控制系统封顶式生长室研究广布湿地植物水葱(Scirpus validus)和香蒲(Typha orientalis)的叶经济性状对模拟增温(现行环境温度+2℃)和CO_(2)浓度倍增(增至850μmol·mol^(-1))的响应。结果表明:(1)增温处理下,水葱净光合速率、氮含量和磷含量显著降低,但其胞间CO_(2)浓度和比叶重显著增加;CO_(2)浓度倍增处理下,水葱胞间CO_(2)浓度和净光合速率均显著降低,但比叶重显著增加。(2)增温处理下香蒲的比叶重显著增加,而氮含量和磷含量显著降低;香蒲的光合参数、氮含量和磷含量在CO_(2)浓度倍增处理下均显著降低,而比叶重显著增加。(3)水葱的比叶重、氮含量、磷含量、净光合速率、气孔导度、胞间CO_(2)浓度与主成分分析的两个环境变量相关;而香蒲的经济性状均与两个环境变量相关,表明这些经济性状在香蒲响应增温和CO_(2)浓度变化过程中发挥重要作用。(4)除碳含量外,水葱和香蒲的其他经济性状参数包括净光合速率、气孔导度、蒸腾速率、胞间CO_(2)浓度、氮含量、磷含量和比叶重均在响应增温和CO_(2)浓度倍增过程中发挥重要作用。总体而言,该研究结果反映了水葱和香蒲在功能性状上对增温和CO_(2)浓度倍增的响应策略。两种植物的光合能力和养分含量在两种处理下虽然均受到显著的抑制作用,但是其抗逆能力升高,表明增温和CO_(2)浓度升高不利于水葱和香蒲的生长。

不同土壤水分下元素化学计量对微生物多样性的塑造特征

土壤元素化学计量特征在塑造微生物多样性方面起着至关重要的作用,而元素化学计量受到土壤含水量的影响。为探究不同土壤水分条件下,有机碳(OC)、全氮(TN)、全磷(TP)及其元素化学计量特征(C?N、C?P和N?P)如何影响土壤微生物多样性,在浙江省20 hm^(2)亚热带森林动态监测样地内共采集1 287份土壤样品。利用Illumina高通量测序技术测定了土壤细菌和真菌的群落组成,并结合土壤理化性质,分析了不同土壤水分下元素和元素化学计量与微生物群落的关系。结果表明,土壤水分能改变元素化学计量特征,进而塑造细菌和真菌群落的多样性。其中,(1)土壤水分显著影响微生物群落的α多样性。相较于高土壤水分,在低土壤水分下,细菌和真菌群落的α多样性分别显著提高了0.830%和2.62%。(2)细菌和真菌的主要门类对土壤水分表现出差异化响应。相较于低土壤水分,高土壤水分显著提高了细菌5个门类和真菌2个门类的相对丰度;并且显著降低了细菌7个门类和真菌2个门类的相对丰度。(3)土壤元素含量和元素化学计量特征与土壤水分呈显著正相关关系。(4)元素化学计量C?N、C?P和N?P与微生物多样性呈显著负相关关系,其相关性不受土壤含水量的影响。综上所述,土壤元素化学计量塑造微生物多样性,且土壤水分的高低并不改变其整体变化趋势。该研究验证了土壤水分对元素化学计量的影响,有助于提高微生物多样性如何响应全球气候变暖引起的土壤水分变化的理解。

森林土壤有机碳的影响因子及其研究进展

森林是陆地生态系统的重要组成部分,是大气温室气体的重要源与汇,在区域和全球碳循环中发挥着关键作用。森林土壤有机碳作为土壤碳库重要组成部分,其积累和分解的变化直接影响陆地生态系统的碳贮藏。了解森林土壤有机碳的影响因子可为全面理解土壤有机碳的特征及其关键控制因素提供帮助。为此,本文综述了气候变化(温度、降水、CO_(2)浓度)、自然调控因素(植被类型、土壤理化性质)、人为调控因素(土地利用方式、施肥、林火)对森林土壤有机碳的影响,并提出了相关的研究展望。

古尔班通古特沙漠南缘全新世沉积微量元素特征及古环境意义

选取古尔班通古特沙漠南缘风积-冲积地层剖面,基于光释光测年建立剖面年代标尺,以微量元素丰度及其比值变化为主要代用指标,结合沉积相和粒度特征,揭示沙漠南缘全新世沉积环境和气候演变过程。结果表明:约11.11~10 ka,各微量元素含量处于低值,反映气候转暖、冰川消融、河流汇入沙漠,但化学风化较弱;约10~6 ka,湖沼沉积发育,各微量元素含量升高,反映该时段化学风化较强,暖湿气候交替偏凉偏干波动;约6 ka至今,各微量元素含量随席状风沙与泥质荒漠交互沉积呈明显波动变化,反映暖湿气候交替偏冷波动。研究区沉积环境和气候演变的阶段性特点,反映了全新世北半球夏季太阳辐射和西风环流的强度变化。此外,天山冰川消融和北大西洋冷事件引发的大气波动也对区域沉积环境变化产生重要影响。

基于“天人相应”理论探析冠心病的中医时间医学内涵

《黄帝内经》中提出“天人合一”理念,人体的阴阳、气血随外界的昼夜节律、年节律、子午流注、五运六气等呈现周期样变化,是中医时间医学的主要内容。基于冠心病患者的病因病机探析阴阳、气血、六淫邪气等方面在昼夜及四时的变化情况,冠心病患者病情变化呈四时节律冬季、夏季加重,日节律夜间及上午多发,年节律火运太过与水运太过之年、阳明燥金司天之年、少阴君火在泉之年发病人数最多,时支午时、未时发病人数最多。根据冠心病患者病情的时间节律选择适合的时间治疗可显著提高治疗疗效。

五运六气与高血压病、肾性高血压的研究进展

高血压病是临床常见的多发病、慢性病,同时高血压也是慢性肾脏病最常见的并发症之一。现代医学对高血压的治疗主要是对症降压,但需终身服药,且由此引发的合并症、不良反应较多,致残、致死率高。五运六气理论是中医学天人合一思想的理论基础和主要载体,是古人研究天时气候变化规律以及其对人体生命影响的科学。现代相关研究运用五运六气理论治疗高血压病,临床取得显著疗效。本文就五运六气与高血压病、肾性高血压的研究进展做一综述。