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1.
华南地区香蕉、荔枝寒害的气候风险区划   总被引:7,自引:3,他引:4  
基于华南地区(广东、广西、福建)224个气象站点1951—2006年气候资料和香蕉、荔枝历史灾情资料,采用日最低气温≤5.0 ℃、持续日数≥3 d寒害过程的积寒和表征香蕉、荔枝年度寒害的气候致灾风险信息,构建了基于气候变化背景下的寒害综合气候风险指标,编制了香蕉、荔枝寒害等级风险概率地理分布图和气候风险区划图,并评述了香蕉、荔枝寒害气候风险的区域分异规律.结果表明:随着气候变暖,研究区香蕉、荔枝抗寒性降低,寒害致灾风险增加;香蕉、荔枝寒害各等级气候风险概率均呈纬向分布.基于综合气候风险指数的大小将香蕉、荔枝寒害划分为高、中、低3个气候风险区,这为农业结构布局的调整提供了重要依据.  相似文献   

2.
海南岛橡胶(Hevea brasiliensis)寒害风险区划   总被引:2,自引:0,他引:2  
寒害是海南岛橡胶面临的主要气象灾害之一,开展橡胶寒害风险区划能够有效提高海南岛橡胶寒害防御能力。根据海南岛1964—2016年的气象资料和1988—2016年橡胶种植面积、产量、社会经济等数据,通过构建橡胶寒害指数和台风灾害指数,实现了橡胶寒害减产率的分离,基于风险形成的机理,选择橡胶寒害的致灾因子危险性、孕灾环境敏感性、承灾体脆弱性和防灾减灾能力4个因子,建立海南岛橡胶寒害风险评估模型,计算橡胶寒害风险指数,并按自然断点法划分为5个风险等级。结果表明:海南岛橡胶寒害风险总体呈现西北部和中部较高,其他沿海地区较低的特征;西北部临高风险最高,其次为中部五指山地区;西南部东方、乐东沿海地区,以及北部海口、文昌风险最低;南部三亚和陵水无寒害风险。  相似文献   

3.
华南地区龙眼寒害灾损风险评估   总被引:2,自引:0,他引:2  
基于华南地区64个基本气象站1961—2012年逐日气象资料,采用公认的龙眼寒害灾害指标,结合农业气象灾害风险研究的方法与模拟技术,并考虑龙眼寒害灾损减产风险在不同生育期(花芽生理期、花芽形态分化期、休眠期)之间的差别,对1961—2012年华南地区龙眼不同发育时段的寒害灾损最大风险进行定量评估与分析.结果表明: 在花芽生理期,各地区龙眼受灾最严重的是轻度寒害,其次为重度寒害,最后为中度寒害;不同寒害致灾等级对各地龙眼造成的危害程度不同,在轻度寒害威胁下,龙眼受灾轻重次序为福建、广东和海南、广西,中度寒害威胁下,龙眼受灾轻重次序为海南、广东和广西、福建,重度寒害威胁下,龙眼受灾轻重次序为海南、广东和广西、福建.在花芽形态分化期,各地区龙眼受灾最严重的是轻度寒害,其次为重度寒害,最后为中度寒害;该时段内不同寒害致灾等级对各地龙眼造成的危害程度相似,龙眼受灾轻重次序均为海南、广东和广西、福建.在休眠期,各地区龙眼寒害受灾最严重的是轻度寒害,其次为重度寒害,最后为中度寒害;该时段内不同寒害致灾等级对各地龙眼造成的危害程度不完全相同,轻度和重度寒害威胁下,各地龙眼受灾轻重次序为海南、广东和广西、福建,中度寒害威胁下,海南和广西龙眼受灾最轻,其次为广东,福建受灾最严重.同一寒害致灾等级下,不同发育时段龙眼寒害灾损减产最大风险指数差异显著:轻度寒害威胁下,各地区龙眼在花芽生理期受到危害最重,其次为花芽形态分化期,休眠期危害最轻;中度和重度寒害威胁下,各地区龙眼在花芽生理期受到危害最重,其次为休眠期,花芽形态分化期危害最轻.  相似文献   

4.
寒害是广东省继洪涝、台风之后的第三大灾害性天气,预测寒害重现期对科学防寒减灾具有实际意义.本研究基于广东省86个县(市)气象站1961-2015年冬季(12月-翌年2月)逐日气象资料,以积寒指数为寒害指标,采用Gumble分布、Weibull分布、对数正态分布和Pearson-Ⅲ型分布4个模型对各站寒害极值进行概率分布拟合,并检验筛选最优模型,计算不同重现期的寒害极值.结果表明: 广东省86个县(市)气象站中,有77个站适用Pearson-Ⅲ型分布,8个站适用对数正态分布,1个站用Gumble分布拟合最佳,Weibull分布函数不适用于广东寒害极值分布的拟合.根据各站最优拟合分布函数,预测广东86个站点10、25、50和100年寒害重现期,其相对误差均较小(≤6%);其多年一遇的积寒极值呈明显的纬向分布特征,表现为北多南少,与寒害发生过程中最低气温、平均气温、降温幅度等分布特征一致.研究成果可为广东相关行业科学防寒提供依据.  相似文献   

5.
江淮地区小麦涝渍灾害风险评估与区划   总被引:5,自引:1,他引:4  
基于灾害风险分析理论,根据历年气候资料,小麦生长发育、种植面积和产量资料,对江淮地区各县小麦涝渍脆弱性、自然气候风险、灾损风险和抗灾能力等方面进行分析评估,建立了包括涝渍脆弱度、气候风险指数、灾损风险指数、涝渍综合风险评估系数等不同的涝渍风险表征模型,并构建了涝渍综合风险评估系数作为区划指标,对江淮地区小麦涝渍灾害风险进行了空间区域划分。结果表明:涝渍脆弱度、气候风险指数、灾损风险指数和抗灾力系数4个因子的组合,可以较好地反映江淮地区小麦涝渍风险特征;按照高、较高、中和低4个等级对小麦涝渍综合风险进行了区划;安徽省江淮南部为高风险区;沿淮中部以及江淮中部南部、沿洪泽湖区域为涝渍较高风险区;河南省33°N以南区域、以及安徽、江苏省淮北中部区域为涝渍中风险区;33°N以北地区为涝渍低风险区。  相似文献   

6.
利用海南省18个站点1998—2011年的逐日气象资料、冬种瓜菜的产量和面积资料,基于3—4月降水量、无雨日数、连续无雨日数、最长连续无雨日数对春季干旱的综合影响,采用主成分分析法构建春季干旱综合指数,建立春季干旱等级指标。通过减产率分离得到春季干旱导致的瓜菜(西瓜Citrullus lanatus、豇豆Vigna unguiculata、辣椒Capsicum annuum、丝瓜Luffa cylindrica)灾损,综合考虑致灾、孕灾、灾损、防灾能力进行瓜菜春季干旱灾害的综合风险分析与区划。结果表明:瓜菜春季干旱致灾风险指数呈现东西高、中间低的分布,且不同春季干旱等级风险概率分布存在着明显的地区差异;春季干旱孕灾环境指数以海南中部的五指山为中心向四周逐渐减小;4种瓜菜的灾损风险和防灾能力分布地域差异显著;集成致灾、孕灾、灾损、防灾能力得到的干旱综合风险,4种瓜菜的高风险区均主要分布在海南的西部和南部部分地区,低风险区在海南的中部和东部部分地区。  相似文献   

7.
吉林省农业气象干旱灾害的风险分析及区划   总被引:4,自引:0,他引:4  
利用1961-2010年吉林省50个站气候观测资料、1981-2010年干旱灾情和农业经济资料,基于灾害风险系统分析理论、农田水分平衡法和综合灾害风险指数法,在分析干旱对吉林省农业影响致灾因子危险性、孕灾环境敏感性、承灾体脆弱性和防旱减灾能力的基础上,应用加权综合法得到不同单元的综合风险度指数;基于GIS技术,开展了干旱对吉林省农业影响的风险区划.结果表明:致灾因子危险性的高值区分布在西部的白城和松原大部分地区,孕灾环境敏感性的高值区分布在白城地区、松原地区、四平地区北部和通化地区南部,承灾体脆弱性的高值区主要分布在经济较发达的松原大部分地区、长春大部分地区、四平地区等,防旱减灾能力的高值区分布在松原、长春、四平、吉林和通化市区及其周边地区.考虑各因子的综合风险度,干旱对吉林省农业影响的风险可分为高风险、次高风险、中等风险、次低风险和低风险5个等级,其中,高、次高风险主要分布在吉林省中西部的白城、松原、长春和四平地区.  相似文献   

8.
1961-2017年环渤海地区气象干旱时空特征及致灾危险性评估   总被引:1,自引:0,他引:1  
王晓利  张春艳  侯西勇 《生态学报》2019,39(13):4647-4659
基于1961-2017年环渤海地区60个地面气象站点的逐日气温和降水资料,计算了各站点逐日气象干旱综合指数(Meteorological drought Composite Index,MCI),统计近57年各站点的气象干旱过程,并进一步分析了环渤海地区各季节气象干旱的时空变化特征及致灾危险性等级分布。结果表明:(1)环渤海地区春季干旱覆盖范围和持续日数呈下降趋势,但干旱强度有所增加,夏、秋两季干旱覆盖范围和持续日数呈上升趋势,而干旱强度有所减少,冬季干旱覆盖范围和干旱强度均呈增加状态,干旱持续日数有所下降。(2)春季干旱覆盖范围、干旱持续日数、干旱强度以及干旱发生频率均居四季之首,干旱状况最严重,夏、秋季次之,冬季最轻。(3)各季节干旱强度和干旱发生频率的高值区主要分布在辽宁西北部、河北中南部以及山东大部分地区,低值区主要位于辽宁东部地区。(4)各季节干旱致灾危险性等级总体呈西高东低、南高北低的分布特征,其中,河北中南部气象干旱的致灾危险性较高,辽宁东部的较低;春旱致灾危险性总体较高,夏、秋季次之,冬季最低。  相似文献   

9.
基于GIS技术的吉林省生态灾害风险评价   总被引:6,自引:0,他引:6  
基于自然灾害风险形成原理,综合考虑吉林省自然和社会经济现状,从致灾因子的危险性、承灾体的暴露性和脆弱性及防灾减灾能力4个方面选取指标,利用自然灾害风险指数法、加权综合评价法及层次分析法构建生态灾害风险评价模型,评价了各风险因子的贡献率,并运用GIS技术生成吉林省生态灾害风险区划图.评价结果对于正确认识吉林省的生态环境风险水平,有针对性地确定生态恢复与管理决策都有重要意义.  相似文献   

10.
香蕉寒害研究现状及展望   总被引:1,自引:0,他引:1  
我国绝大部分香蕉种植区域属于香蕉非最适宜种植区,容易受到冬春寒流的侵袭而造成重大经济损失。寒害已成为制约我国香蕉产业健康发展的主要灾害之一。对香蕉寒害症状和类型、香蕉抗寒生理生化研究、防寒措施、抗寒相关基因的挖掘等方面进行了综述,简述了香蕉寒害研究存在的问题和发展现状,以期对香蕉寒害的基础研究及生产应用提供参考。  相似文献   

11.
《环境昆虫学报》2014,(5):790-804
综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生(宾主共栖和异种共栖)、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌(原生动物、细菌、真菌和放线菌)和外生菌(蚁巢伞菌等)间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用(如纤维素酶)及今后研究物种间的协同进化提供了基础资料。  相似文献   

12.
New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn2NPSCH2CH2Sa(P-Sa) (Bn = benzyl, 4), Bn2NPSCHCHSa(CH2)3CaH2(P-Sa)(Ca-Sa) (6) and Bn2NP(4-XC6H4OMe)2 (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)2] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl2Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the νCO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The 1JPRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the 1JPSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh3. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh3.  相似文献   

13.
Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.  相似文献   

14.
The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.  相似文献   

15.
To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.  相似文献   

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18.
The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE2, PGD2, PGF, TXB2 and 6-keto-PGF. In all types studied PGE2 and TXB2 were the major products formed. The identification of PGE2 and TXB2 was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.  相似文献   

19.
Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.  相似文献   

20.
In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.  相似文献   

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