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1.
The forests of southeastern Africa are vulnerable to damage imposed by tropical cyclones operating in the South Indian Ocean. We undertook a geographical analysis to determine the relative vulnerability of forests given tropical cyclones recorded during the 1959–2008 storm seasons. From this analysis, eastern coastal forests of Madagascar seem to be the most vulnerable, although return intervals for severe storms vary along the eastern coast, and are shorter (about 10 years) through the central portion of the country. Therefore, the central lowland to upper montane rainforests on the eastern coast seem to be more vulnerable to damage from tropical cyclones than others in the area. While not as extensive, western coastal forests of Madagascar are also as vulnerable in part due to the recurvature of storms in the Mozambique Channel. Though the coastal forests of Mozambique are all nearly equal in terms of vulnerability, the return interval for severe storms to this area is highly variable. The inland Miombo forests of southeast Africa are less vulnerable to damage from tropical cyclones; however, portions of western Mozambique and Zimbabwe have experienced strong tropical storms in the last 50 years. A number of caveats and limitations associated with the data and analyses are noted. Given the broad scale of the study, the relative vulnerability and the return intervals for severe storms should be considered general representations of these phenomena for the southeastern African coast and the island of Madagascar. 相似文献
2.
This study explores two different tropical cyclone rainfall (TCR) problems: first, the identification of areas where TCR is highly concentrated and, second, the contribution of tropical cyclones (TCs) to the climatology of Puerto Rico for the period 1970–2010. A total of 86 storms within a 500-km radius of Puerto Rico were analyzed. Daily and monthly rainfall data from 32 weather stations were used to generate interpolated surfaces. Two geostatistical interpolation techniques were implemented: ordinary kriging and ordinary cokriging. Results show that rainfall from most TCs tends to be clustered in the eastern, southeastern, and central regions of the island, with a decrease in values toward the west. TCs closer to Puerto Rico (≤230 km) and embedded in high moisture environments (≥44.5 mm) exhibited the highest rainfall values, with most concentrated in the high elevation areas of the southeastern region of the island. Months with the largest TC contributions to rainfall (20–30%) were August and September, while the lowest contributions were found in June and November. For August, stations in the southern and eastern portions of the island had TCR contributions of >20%, with some stations in the southern coastal plains exhibiting 30%. 相似文献
3.
基于热带气旋时间、路径、强度数据和中国728个气象站点1951~2014年日降水数据,分析了年和季节极端降水广义极值（GEV）分布函数特征及受热带气旋的影响。通过检查年和各季节极端降水的非一致性,发现具有变异点或显著时间趋势的站点占总站点数的比例较低。仅考虑满足一致性的站点,年和各季节极端降水GEV分布上尾部在全国大部分区域表现出厚尾特征,且不具有上边界。总体来看北方厚尾特征重于南方,秋季和冬季明显高于年和夏季。年极端降水厚尾特征受到不同季节极端降水机制的混合影响。而且,热带气旋对中国沿海区域极端降水有重要影响,往往引发大量级极端降水。东南沿海地区最大10场极端降水由热带气旋引发的比例达到60%以上。因此热带气旋趋向于增加沿海区域年极端降水GEV分布形状参数的大小,并控制着曲线上尾部的形状。 相似文献
4.
Julie A. Silva 《The Professional geographer》2013,65(2):174-189
This study uses a mixed methodology to investigate the relationship between agricultural trade and socioeconomic inequality in Mozambique at multiple geographical scales. The quantitative analysis examines all rural regions of the country and a nationally representative sample of rural households, whereas the qualitative analysis focuses primarily on two case study villages. Research findings suggest that social and geographical context greatly influence the relationships between agricultural trade and regional inequality. Trade-related effects on economic inequality—and the social status of traders—vary across Mozambican regions. Results suggest that trade increases inequality in regions where traders have low social status, but reduces inequality in areas where they have high social status. These findings suggest that social and economic factors work together to shape landscapes of inequality. 相似文献
5.
影响蔬菜周年均衡供应的原因是多方面的，不利的天气气候影响是主要原因之一。广西以广州市为例，剖析了影响蔬菜年供应的原因，并提出缩短淡季实现周年均衡供应的对策。 相似文献
6.
The southeastern United States is routinely hit by tropical cyclones (TC). As TC track inland and dissipate their inland impacts can be substantial. This study examined the spatial patterns of societal impacts associated with tornadoes and high winds with 31 inland-moving TC that made landfall from 1985 to 2008. Hourly weather information was collected from all available first-order weather stations affected by each storm, as well as tropical cyclone preliminary reports issued from the National Hurricane Center. Societal impacts were identified through selected newspapers across the region and the National Climatic Data Center’s Storm Data. Geographic Information System (GIS) software was employed to make geometric measurements of the distance and direction of the impacts relative to storm center. From these measurements, the spatial distribution of the societal and meteorological impacts was plotted relative to the track (e.g., left vs. right) and location (forward vs. rear sector) of the cyclone center. Various tropical cyclone attributes, including size, strength, and forward speed of movement were then related to the occurrence of different impacts and their location relative to the cyclone track. The majority of tropical cyclone tornado and high wind impacts occur in the right-forward sector of the tropical cyclone. However, many TC produce impacts that occur in other sectors far from the center of circulation. These abnormalities are associated in many cases with interactions between the tropical cyclone circulation, topography, peripheral dry air, and extratropical synoptic weather features. 相似文献
7.
8.
江苏省区域经济极化及其动力机制定量分析 总被引：67，自引：3，他引：64
在分析国内外区域经济极化研究进展的基础上,引用最近的国外区域经济极化有关研究方法,以人均国内生产总值 (GDP) 为测度区域经济极化的变量指标,定量评价改革开放以来江苏省区域经济差异与极化的总体水平与变化特征,并发现：随着区域经济差异的扩大,区域极化明显增强,其主要影响因素是区域发展策略、乡村工业化和外商直接投资 (FDI)。分析结果表明：自上而下的动力因子是影响江苏省区域经济极化的最主要方面。在空间上,江苏省区域经济极化明显表现为南北区域的分化与城乡分化两个方面。 相似文献
9.
This paper examines how double exposure to economic and environmental stressors – and the interaction between the two – affect smallholder farmers in Mozambique's Limpopo River Basin. Studying two case study villages we find that people, in general, are resilient to environmental stressors. However, most households show less resilience to the socioeconomic stressors and shocks that have been introduced or intensified by economic globalisation. Our findings indicate that economic change brought about by structural adjustment policies pressures rural people to alter their approach to farming, which makes it more difficult for them to respond to environmental change. For example, smallholder farmers find it difficult to make a transition to commercial farming within the Limpopo Basin, in part because farming techniques that are well adapted to managing environmental variability in the region – such as seeding many small plots – are not well suited to the economies of scale needed for profitable commercial agriculture. People use a variety of strategies to cope with interactive environmental and economic stressors and shocks, but many face considerable constraints to profitably exploiting market-based opportunities. We conclude that economic stressors and shocks may now be causing small-scale agriculture to be less well adapted to ecological and climate variability, making smallholders more vulnerable to future climate change. Some local level policy interventions, including those that support and build on local environmental knowledge, could assist rural agricultural societies in adapting to future environmental change in the context of economic globalisation. 相似文献
10.
Werner Nel Alexia Hauptfleisch Paul D. Sumner Ravindra Boojhawon Soonil D. D. V. Rughooputh Kumar R. Dhurmea 《自然地理学》2016,37(3-4):264-275
Mauritius is a volcanic island with a raised interior where extreme rainfall events dominate rainfall erosivity. Intra-event characteristics of the 120 highest erosive events at six selected locations between 2004 and 2008 were analyzed to provide the first detailed intra-storm data for a tropical island environment. On Mauritius, spatial variation is evident in the characteristics of extreme erosive rainfall recorded at the stations, with a noticeable increase in rainfall depth, duration, kinetic energy, and erosivity of extreme events with altitude. Extreme events in the raised interior (central plateau) show high variability of peak intensity over time as well as a higher percentage of events in which the greatest intensity occurs in the latter part of the event. Intra-event distribution of rainfall in the interior of the island shows that rainfall there has a higher potential to exceed infiltration rates as well as the ability to generate high peak runoff rates and cause substantial soil loss. The study suggests that even though within-event rainfall characteristics are complex, they have implications for soil erosion risk, and that, in tropical island environments, the within-storm distribution of rainfall should be incorporated in soil-loss modeling. 相似文献
11.
The 2005 Atlantic hurricane season was unprecedented in terms of storm activity in the United States, Mexico, Central America and Caribbean. Given the impacts of hurricanes Katrina and Rita, the Honduran Mosquitia sparked little attention despite being hit by two hurricanes and a tropical storm in 2005. This article recounts the history of these storms in the Afro-Caribbean community of Batalla, drawing from public weather advisories and testimony of local residents obtained through participatory research. We contextualise this local history with results from the first paleotempestological study undertaken in the Mosquitia to shed light on long-term risk of catastrophic storms in the region and to demonstrate the value of integrating these two research approaches. Our findings contribute to recent ethnographic research on hazards by describing how a coastal people understand and respond to tropical cyclones and how landscape change influences the vulnerability of a coastal area. Although residents have not witnessed a storm as intense as those documented in the paleotempestological record, their knowledge and perceptions show how tropical cyclones can be disasters while leaving behind no sedimentary records. The paleotempestological evidence, however, reminds us that catastrophic hurricanes have struck the Mosquitia in the past and will do so again in the future. Understanding the interactions between contemporary human perceptions and responses and long-term hurricane risk provides insight for emergency managers and local stakeholders to better prepare for such a catastrophic event. 相似文献
12.
我国热带气旋潜在影响力指数分析 总被引：6，自引：0，他引：6
利用热带气旋路径资料和灾情资料,综合考虑热带气旋的频数、强度、范围以及持续时间,建立热带气旋潜在影响力指数,分析了1949-2009 年我国热带气旋的潜在影响力的空间格局和年际变化特征,并以0608 号超强台风“桑美”为例分析了该指数与灾害损失、过程极大风速、过程雨量的关系。研究结果表明：1949-2009 年间,我国的热带气旋的潜在影响力呈现出弱减少的趋势,这种趋势并不显著,但各阶段性的趋势比较明显;近20 年来,我国海南、广东、广西等华南沿海受热带气旋潜在影响力在下降,而浙江、福建、台湾等东南沿海省份受热带气旋潜在影响力在上升;潜在影响力指数最高的区域主要分布在台湾、海南、广东沿海、福建沿海以及浙江南部沿海等地;TCPI 与灾害损失、过程极大风速、过程降水量等有较好的相关性,并都通过了0.01 的显著性检验。 相似文献
13.
Gregory E. Faiers Barry D. Keim Katherine K. Hirschboeck 《The Professional geographer》1994,46(2):156-163
This research classifies extreme three-hour and 24-hour rainfall events in Louisiana by synoptic weather types (Frontal, Gulf Tropical Disturbance, and Air Mass). These classes were used to analyze differences in frequencies and intensities of extreme rainfall. Significant differences were found in the storm frequencies by weather type. However, no significant differences were detected in rainfall intensities between weather types during either duration. These findings have a bearing on statistical procedures associated with estimating storm probabilities in the region. 相似文献
14.
Mekonnen A. Degefu Woldeamlak Bewket 《Geografiska Annaler: Series A, Physical Geography》2015,97(2):395-414
The objective of this paper is to evaluate trends and spatial patterns of drought incidence across the Omo‐Ghibe River Basin using monthly rainfall data from eight stations for the period 1972–2007. It also aims to estimate the probability of drought episodes for a 100‐year period. Drought indices were generated using the Standard Precipitation Index (SPI) computed at 3‐, 6‐, 12‐ and 24‐month time‐steps for three intensity classes: moderate, severe and extreme drought events. The Mann–Kendall's trend test and Sen's slope estimator were employed to detect temporal changes. The results show complex spatial patterns on the frequency and magnitude of drought events across the study area for all timescales and intensity classes. However, the total number of drought events for the three intensity classes for all timescales were larger in the southern lowlands, where there exists a serious water scarcity for the rain‐fed pastoral system, than in the northeastern part (around Wolaita Sodo area). In contrast to this, the longest and most extreme (SPI < ?4.0) drought events for all timescales were observed at Wolaita Sodo station. In a 100‐year period one could expect 57–69 drought events with 3 months' duration, 19–34 events with 6 months' duration, 9–16 events with 12 months' duration and 5–9 events with 24 months' duration. The SPI values show negative rainfall anomalies in the 1980s while positive anomalies have occurred in the 1990s and 2000s, which implies tendency towards decreasing drought events. The Mann–Kendall's trend test for the 12‐ and 24‐month timescales and for seasonal events also confirms this general trend. 相似文献
15.
中国登陆热带气旋与太平洋海表温度的关系 总被引：16，自引：0，他引：16
根据1951～2000年中国登陆热带气旋与厄尔尼诺年、拉尼娜年的关系分析,得到了一些重要认识：(1) 在厄尔尼诺年,中国登陆热带气旋数偏少;(2) 厄尔尼诺事件强度越大,中国登陆热带气旋数越少;(3) 厄尔尼诺事件的结束时间若超过5月1日,那么次年中国登陆热带气旋数偏少;(4) 中国登陆热带气旋数的特多年主要集中在拉尼娜年;(5) 在拉尼娜次年,中国登陆热带气旋数偏少;(6) 中国登陆热带气旋强度越大,在厄尔尼诺年出现机会越少;(7) 在厄尔尼诺年,中国初旋偏迟,终旋偏早。同时对其机理进行了探讨。 相似文献
16.
广西百色大王岭原始森林风景区气候条件分析 总被引：2，自引：0，他引：2
采用广西百色大王岭原始森林景区1976～1991年平均资料及2005-2008年该地自动气象监测站资料对景区旅游气象条件进行统计分析,结果表明：风景区气温适中,年温差振幅小,夏、冬温差5℃,夏季少有35℃以上的高温,年舒适指数等级在-1～1的最佳舒适期长达9个月;影响景区旅游活动的主要气象灾害有强降雨、寒害等。 相似文献
17.
Tropical cyclone,a high energy destructive meteorological system with heavy rainfall and gale triggered massive landslides and windstorms,poses a significant threat to coastal areas.In this paper we have developed a Tropical Cyclone Potential Impact Index (TCPI) based on the air mass trajectories,disaster information,intensity,duration,and frequency of tropical cyclones.We analyzed the spatial pattern and interannual variation of the TCPI over the period 1949-2009,and taking the Super Typhoon Saomai as an example have examined the relationship between the TCPI and direct economic losses,total rainfall,and maximum wind speed.The results reveal that China’s TCPI appears to be a weak decreasing trend over the period,which is not significant overall,but significant in some periods.Over the past 20 years,the TCPI decreased in the southern China coastal provinces of Hainan,Guangdong and Guangxi,while it increased in the southeastern coastal provinces of Zhejiang,Fujian and Taiwan.The highest values of TCPI are mainly observed in Taiwan,Hainan,the coastal areas of Guangdong and Fujian and Zhejiang’s southern coast.The TCPI has a good correlation (P=0.01) with direct economic loss,rainfall,and maximum wind speed. 相似文献
18.
This research analyzes the relationship between tropical cyclones and fine particulate matter (PM2.5) for landfalling Atlantic tropical cyclones from 2000 to 2015. Daily mean PM2.5 concentrations were collected from the United States Environmental Protection Agency. Tropical cyclone data were acquired from Tropical Prediction Center Best Track Reanalysis in Unisys weather. GRIdded Binary (GRIB formatted) data were downloaded from the Data Support Section of the Computational and Information Systems Laboratory at the National Center for Atmospheric Research (NCAR). Tracks of tropical cyclones were overlaid with the interpolated daily mean PM2.5 concentration value. Results suggest that, in general, tracks are distant from areas with the largest PM2.5 concentrations. To examine the cause-effect nature of this relationship, simulation using the Weather Research and Forecasting (WRF) model suggests that the intensity of Hurricane Lili was weakened only after passing the most PM2.5-polluted area in Louisiana. This result suggests that aerosol loading may weaken the intensity of tropical cyclones, at least in some cases. 相似文献
19.
Yuk Yee Yan 《Singapore journal of tropical geography》1997,18(2):210-217
The universal scale of apparent temperature (AT) and clo, a unit measuring the amount of clothing insulation required to maintain comfort, were used to examine the weather stress in Hong Kong. Hourly AT and clo values were computed using hourly air temperature, wind speed, vapour pressure and cloud cover data from 1980 to 1994. Results of both AT and clo reflected highly corresponding changes of thermal stress. It is found that the most stressful time in winter and summer occurred in the early morning and afternoon, and cool weather and tropical ensembles were required to surmount the extreme weather stress respectively. A greater percent of time with severe heat stress than those with extreme cold stress was discovered. These results also indicated that clo is a more informative weather stress index than AT since it provides both the thermal stress and clothing requirements to sustain comfort. 相似文献
20.
探析中国碳排放强度非均衡性及其演变的驱动力可以为中国制定科学合理、公平高效的区域减排方案提供科学依据。论文基于Theil指数,测算了中国2005—2015年省级尺度化石能源燃烧碳排放强度的非均衡程度;从地理区域、经济部门、能源种类和影响因素等视角解析了碳排放强度非均衡性及其变化的驱动力。研究结果表明,2005—2015年,中国碳排放强度总体上逐年降低,但其在省级尺度上的非均衡性不断增强。从地理区域来看,中国碳排放强度的非均衡性主要来源于东北、东、中、西4大区域内部,且东部和西部地区内部不断扩大的碳强度差异日益成为中国碳排放强度非均衡性增强的重要原因。工业和煤炭分别是碳排放强度非均衡的主要经济部门来源和能源种类来源,也是加剧碳排放强度非均衡性的关键动力。就影响因素而言,各省区技术水平的差距主导了碳排放强度的省际差异及其增长。研究结果可以为中国区域减排方案的制定提供科学依据。 相似文献