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1.
中国西北地区干旱气象灾害监测预警与减灾技术研究进展及其展望 总被引：18，自引：1，他引：17
干旱灾害是制约中国西北地区社会经济发展、农业生产和生态文明建设的重要自然灾害,而且随着气候变暖西北地区极端干旱事件发生频率和强度均呈增加趋势,影响不断加重。"中国西北干旱气象灾害监测预警及减灾技术研究"成果是在数十个国家级科研项目的支持下,经过过去20年的理论研究和应用技术开发所取得的一系列创新性成果。该成果对西北干旱形成机理及重大干旱事件发生、发展的规律取得了新认识,尤其是发现了形成西北干旱环流模态的4种主要物理途径;研制了西北干旱预测的新指标、干旱监测的新指数及监测农田蒸散的新设备,明显提高了干旱监测准确性和针对性;提出了山地云物理气象学新理论,研发了水源涵养型国家重点生态功能区——祁连山空中云水资源开发利用技术;发现了干旱半干旱区陆面水分输送和循环的新规律,揭示了绿洲自我维持的物理机制;认识了干旱气候变化对农业生态系统影响的新特征,建立了旱作农业对干旱灾害的响应关系;开发了旱区覆膜保墒、集雨补灌、垄沟栽培、适宜播期等应对气候变化的减灾技术,为西北实施种植制度、农业布局及结构调整和农业气候资源高效利用提供了科学方案。该成果的完成提升了中国干旱防灾减灾技术水平,培养了中国干旱气象科技队伍,推进了西北地区干旱气象业务服务能力,对西北地区社会经济发展、农业现代化和生态文明建设等方面起到了重要的促进作用。在此基础上,展望了西北地区干旱气象科学研究中迫切需要、有可能突破的主要领域。 相似文献
2.
通过分析我国东北、华北、西北地区东部、西南以及黄淮、江淮和江汉5个区域不同时间尺度气象干旱指数与20 cm土壤相对湿度的相关关系, 探讨了前期气象干旱对后期土壤湿度的影响, 并利用多元线性回归方法分区域、分季节建立了土壤湿度预测模型.结果表明: 春季, 东北地区土壤湿度主要受前5~6个月, 尤其是上年秋末冬初的降水的影响, 而其他4个区域土壤湿度主要受前1~2个月大气水分的影响;各区域夏季土壤湿度与前1~2个月时间尺度上的大气水分相关最密切;秋季, 东北地区20 cm土壤湿度主要受前2~4个月的气象干旱的影响, 其余区域土壤湿度仍与前1~2个月尺度的大气水分相关最密切.基于前期气象干旱指数建立的各区域、各季节的土壤湿度回归模型对当地土壤湿度具有一定的拟合能力, 平均估计偏差在10.1%~13.9%之间, 其中, 西北地区东部和华北地区春、夏季偏差较大, 2008-2011年间干旱等级拟合准确率在65%~74.9%之间;东北、西南、黄淮、江淮和江汉区域拟合较好, 拟合准确率在88%以上. 相似文献
3.
The agricultural development of mountainous areas in China is undergoing the transformation from the traditional agricultural land use mode dominated by single and inefficient grain production to the new agricultural land use mode such as high-yield and efficient horticultural crops. The research on the impact of farmland fragmentation on the agricultural land intensity degree is the basis of agricultural modernization and land remediation in mountainous areas. Based on the UAV high-resolution remote sensing image data of two typical villages in Guizhou Province and the questionnaire survey data of farmers, using the road accessibility index of farmers' plot, the area index and the shape index to measure the degree of farmland fragmentation, we analyzed the impact of different degrees of farmland fragmentation on the traditional and new types of farmland use intensification. The research showed that the farmland fragmentation had a significant negative impact on the intensive degree of agricultural land, but the impact on the intensive degree of agricultural land in different ways of use was different. With the intensification of the degree of farmland fragmentation, the impact on the input and output of horticultural crops and other new-type agricultural land utilization was less than that of grain crops and other traditional agricultural land utilization. Adjusting agricultural structure and transformation of farmland utilization greatly alleviated the negative impact of farmland fragmentation on farmland intensity in mountainous areas. 相似文献
4.
利用1961-2012年中国区域586个气象站的降水、气温、日照时数、相对湿度、风速等资料计算了逐月K干旱指数, 在此基础上, 对全国16个区的干旱持续性特征进行了研究. 结果表明: 华北、河套、西北地区东部、西南地区北部、黄淮及新疆南部地区干旱的持续性较强, 常发生3个月以上的长期干旱过程, 并且容易在旱情解除后的短期内(1个月)再次出现干旱; 而南方、东北和新疆北部地区干旱的持续性较弱, 以1个月的短期干旱为主, 且干旱过程之间的时间间隔相对较长, 大多为3个月以上; 华北、河套、西北地区东部、西南地区北部和南部、以及华南地区的干旱过程在冬、秋季开始的频次最高, 且大部分在春季结束, 而冬、春两季的干旱明显比夏、秋两季偏多. 100°E以西(新疆北部除外)的广大地区干旱过程的开始时间主要集中在秋季, 结束时间集中在春、冬两季; 同时, 冬季和秋季干旱多发, 其次是春季, 夏季出现的干旱频次最少. 相似文献
5.
Spatio-temporal distributions of climate disasters and the response of wheat yields in China from 1983 to 2008 总被引：1，自引：0，他引：1
Climate disasters are now on the rise and more likely to increase in frequency and/or severity under climate change in the future. To clearly illustrate spatial–temporal distributions of climate disasters and the response of wheat yields to disasters over the past three decades, several disaster indices including the impact of climate disasters, the sensitivity to climate disasters and the response index of wheat yield losses to climate disasters were defined and calculated. The impact and sensitivity indices were examined by the agricultural production losses due to climate disasters, and the response of wheat yields to climate disasters was assessed by wheat yield loss compared with the 5-year moving average. The results showed that the indices of climate disaster impacts and sensitivities as well as response index of wheat yields to climate disasters could represent the spatial–temporal distributions of climate disasters well in the whole China. Droughts in northern China had higher impacts and sensitivities than those in southern China during the period 1983–2008, but the impacts of floods were opposite. In northern China, although impacted area by drought was larger than that by flood, the flood sensitivities were larger than drought sensitivities when flood happened. Although drought significantly affected wheat yields in most of the regions with drier conditions during 1983–2008 in major wheat-producing regions, better management practices like irrigation and drought-tolerant cultivars applied in the Huang-Huai-Hai Plain can adapt to climate disasters especially droughts. To ensure the stability of agricultural production, future food security will need to be achieved through quantifying the relative effects of climate disasters and effective adaptation to increasingly frequent extreme climate events. 相似文献
6.
干旱作为我国西北地区东部影响最大的气象灾害, 可引起农业减产、水资源短缺、土地荒漠化和生态环境恶化等严重问题.在国家新一轮西部大开发战略实施之初, 在全球气候变暖背景下, 有必要对干旱发展的最新特征和演变趋势进行详细分析研究, 为加强防旱、抗旱,促进经济发展提供科学决策依据和参考.采用国家干旱标准综合干旱指数(CI指数), 利用西北地区东部74个气象代表站逐日气温、降水资料, 分析了西北地区东部不同级别干旱日数在各个季节的时空分布和变化趋势. 结果表明: 在气候变暖背景下, 西北地区东部从长期趋势看, 春、夏、秋季干旱呈加剧趋势, 冬季干旱呈减轻趋势. 21世纪以来春、夏季干旱进一步加剧, 尤其是夏季加剧更显著, 而秋、冬季干旱出现了减弱的新趋势. 在西北地区东部主降水期3-11月重-特旱加剧趋势比轻-中旱加剧显著, 南部干旱化趋势比北部更加明显. 尤其是宁夏同心地区春旱加剧非常显著, 已成为西北地区东部重-特旱最严重的地区.对于干旱发展的这一新动态, 必须引起有关部门的高度重视, 采取科学、有效手段加强防旱、抗旱. 相似文献
7.
Agricultural drought risk analysis based on three main crops in prefecture-level cities in the monsoon region of east China 总被引：2，自引：1，他引：1
Xinchuang Xu Quansheng Ge Jingyun Zheng Erfu Dai Xuezhen Zhang Shanfeng He Guangxu Liu 《Natural Hazards》2013,66(2):1257-1272
Drought, a frequent environmental disaster in the monsoon region of east China, significantly affects the agricultural economy. In recent years, researchers have emphasised drought risk management. This paper presents a preliminary method to analyse the risk of agricultural drought with regard to the loss of three main crops in individual prefecture-level cities in the monsoon region of east China. In this study, the agricultural drought risk is assessed by developing the index of consecutive rainless days and establishing loss rate curves based on the historical drought data from 1995 to 2008. The results show that the North China is seriously affected by drought hazard. Northeast China is the most sensitive to drought due to its large sown crop areas and weak irrigation. Approximately 11 % of the cities are in the extreme risk category; this category includes 26 % of the cultivated land area and 11 % of the total crop yields in the region. Twenty-three per cent of the cities, accounting for 28.5 % of the total cultivated land area and 26.4 % of the crop yields of the study area, are in high-risk areas, and 77 % of the cities with high and extreme risk levels are distributed in North and Northeast China. Moreover, 64 % of the cities in the monsoon region of East China are in moderate- and low-risk levels. These cities are primarily located south of the Yangtze River. In conclusion, minimising the risk of agricultural drought must be emphasised in northern China because of the high level of risk. 相似文献
8.
Plants and animals in brackish marshes are adapted to live within a wide, yet finite, range of conditions. Events that shift the environmental state beyond that range can dramatically alter habitats and, potentially, the numerous ecosystem services they provide. A prolonged exceptional drought in Texas (October 2010–January 2012) provided a unique opportunity to understand how brackish wetland habitats respond to an extreme environmental event. We examined marshes in the Lower Neches Wildlife Management Area (Texas, USA) that fell within the drought affected area, including restored areas and an adjacent reference marsh. To test our hypothesis that the brackish marsh community would be sensitive to drought conditions, we quantified emergent plant and submerged aquatic vegetation (SAV) and animal (invertebrates, fish) characteristics in summer 2010 and 2011. In spite of its severity, the exceptional drought of 2011 did not have a negative impact on emergent plant communities: biomass, stem density, and chlorophyll a concentrations were the same in pre-drought and drought years in all restored and reference areas. In contrast, SAV biomass was reduced by up to 100 % in the drought year. Some fish and invertebrate densities were also reduced by an order of magnitude or more, possibly due to the loss of SAV. Aquatic faunal species composition was markedly different in the drought year, largely due to the loss of the hydrobiid snail Probythinella protera and the gain of some marine species, including Gulf menhaden (Brevoortia patronus), brown shrimp (Farfantepenaeus aztecus), and white shrimp (Litopenaeus setiferus). By altering aquatic the plant and animal community, this drought event may subsequently reduce trophic support for higher consumers, or contribute to a decline in water quality. Restoration monitoring programs that only focus on relatively stress-resistant, emergent wetland plant communities may underestimate the sensitivity of these ecosystems to extreme environmental events like droughts. 相似文献
9.
Drought assessment would be insufficient and unreliable when using the existing indicators based on a single variable (e.g., precipitation) or a combination of two variables (e.g., precipitation and runoff). Therefore, the entropy theory was utilized to develop a hybrid drought index (HDI) that combines meteorological, hydrological, and agricultural information based on precipitation, runoff, and soil moisture data, respectively, and it was applied to characterize the drought condition in Northwest China. Furthermore, the linkages between the atmospheric circulation anomaly/sunspot activities and the HDI series in Northwest China were explored through cross wavelet analysis. The results indicated that (1) HDI has a good performance to capture drought in Northwest China due to its consideration of multiple variables; (2) the annual HDI series in Northwest China was dominated by an insignificantly upward trend, except for Xinjiang, and this trend will be the opposite in the near future; and (3) generally, all of the sunspot activities, El Niño-Southern Oscillation (ENSO) events, AMO (Atlantic Multidecadal Oscillation), and PDO (Pacific Decadal Oscillation) had strong associations with the HDI series in Northwest China, in which sunspot activities had the strongest effects on drought conditions, whereas the AMO had the relatively lowest impacts. This study sheds new light on developing the hybrid drought index, and the findings are valuable for local drought mitigation. 相似文献
10.
In recent years, tropical cyclones on the Pacific Northwest have decreased. We cannot infer that tropical cyclones impact China have reduced, because the Pacific Northwest is not homogeneous, and the variation characteristics of tropical cyclones in different sea areas are not clear. This paper uses gray relational density clustering algorithm to cluster tropical cyclone data sets between 1949 and 2008, according to the generated position of tropical cyclones, generated density and the possibility of landing. The Pacific Northwest is divided into different sea areas. Then, we analyze the risk of tropical cyclones generated in these sea areas. The results show that the probability of tropical cyclones landing generated in some sea areas is very high, reached 74 %, but the probability of tropical cyclones landing generated in other sea areas is only 2 %. Tropical cyclones generated in some sea areas are more likely to develop into typhoons, strong typhoons and so on, but the intensity of tropical cyclones generated in other sea areas is lower, there is little risk for China. Finally, according to the climate change stage trends, we divide the period 1949–2008 into three stages and analyze the tropical cyclone risk of each sea areas. 相似文献
11.
12.
干旱灾害对干旱气候变化的响应 总被引：14，自引：3，他引：11
通过分析中国北方50 a来的降水资料,结果表明:干旱气候变化的主要特征表现在20世纪90年代夏季降水量有明显的减少趋势,干旱化趋势主要发生在北方,主要包括河北、山西、山东和西北地区东部.西北地区西部降水有明显增多趋势,西北地区东部降水量持续偏少,干旱连年发生.干旱气候的产生带来了严重的干旱灾害,无论从全国或甘肃省的近50 a来干旱灾害可以看出,90年代的干旱发生最为频繁,干旱灾情最为严重,2000年是干旱最严重的一年.干旱气候变化引发干旱化趋势明显,其影响程度非常严重和深远,应重视和加强干旱气候与干旱灾害的监测预测和防御对策的研究. 相似文献
13.
The relationship between drought activity and vegetation cover in Northwest China from 1982 to 2013 总被引：1，自引：0，他引：1
Yelin Jiang Ranghui Wang Qing Peng Xiaoquan Wu Husen Ning Cheng Li 《Natural Hazards》2018,92(1):145-163
We investigated drought activity and the relationship between drought and vegetation in Northwest China over the period 1982–2013 using the standardized precipitation evapotranspiration index (SPEI) and the normalized difference vegetation index (NDVI). The indexes were, respectively, calculated from ground-based meteorological data and from remotely sensed satellite data. The spatial and temporal distributions of drought (SPEI) and of vegetation cover (NDVI) were compared using annual trends, and the relationships between these trends were analyzed. The results are: (1) Overall, Northwest China had a drought trend during the study period, although some a few regions show a significant wetness trend; (2) the mean annual NDVI fluctuates, but overall shows an increasing trend, particularly in some mountainous areas that have at least adequate water and vegetation cover, while unused land becomes degraded; (3) most regions show a positive correlation between SPEI and NDVI, although the western parts of the Tarim basin, Qaidam basin, and some regions in the southeastern part of study area show a negative correlation; and (4) the various regions respond differently to global climate change, but in general regions with more vegetation cover show increased vegetation growth, while regions with less vegetation cover are becoming degraded and thus more vulnerable to the adverse effects of climate change. 相似文献
14.
由于干旱使华北地区作物生态环境失去了平衡,粮食产量也不稳定,实践证明,使用含有镧系元素的抗旱肥料,达到了抗御冬旱、保苗、增产的效果。在华北地区及黄河中下游半干旱-半湿润地区使用抗旱肥料,具有广阔的前景。 相似文献
15.
利用西北五省区137个测站的1961-2009年逐月降水量资料计算标准化降水指数(SPI), 统计了逐月、春末夏初、初夏、夏季及秋季的干旱、重旱、特旱的频率及面积率, 分析其时空变化特征.结果表明: 新疆北部、青海的中部及甘肃河西是西北地区干旱频率较高的区域, 干旱频率在15个月以上, 新疆南部除个别月份干旱发生频率较高外, 总体干旱发生频率较低;干旱发生区域随月份有由南到北、由西向东变化的趋势;除新疆、青海、及甘肃个别区域重旱频率超过5月外, 其他区域基本上都在5月以下;新疆南部重旱频率仍然较低;夏季发生范围高于其他季节;新疆北部、甘肃河西是特旱的高发区. 不同等级的月及季节干旱面积率其逐年变化具有相似的特征, 西北干旱面积率的变化总体上可以分为3个阶段: 1961-1980年干旱面积率比较高, 平均在35%左右;1981-1990年为转折期, 干旱面积率下降到15%左右;而1991-2009年为稳定期, 干旱面积率变化不大.全球气候变暖导致西北地区降水量、冰川融水量、河川径流量增加和湖泊水位上升、面积扩大, 是1987年以来干旱面积率下降的原因. 相似文献
16.
《Applied Geochemistry》2000,15(1):117-132
Selenium deficiency (Keshan Disease) and toxicity diseases in humans occur within 20 km of each other in Enshi District in China and have been linked to environmental levels of Se. Low concentrations of Se are associated with Jurassic siltstones and sandstones, whereas high concentrations occur in areas underlain by Permian carbonaceous strata. Although these broad relationships between Se in the environment and the human population have been established previously, not all villages underlain by the carbonaceous strata suffer Se toxicity problems and the precise controls on Se distribution and availability have not been quantified. In the present study, soil, grain, drinking water and human hair samples are examined to determine the controls on Se availability in 3 Se environments in Enshi District. Five low-Se and Keshan Disease villages, 5 high-Se and no toxicity villages and 5 high-Se and toxicity villages were selected for the study. Results show that the majority of samples in the low-Se villages are deficient or marginal in Se, and that Se availability to plants is inhibited by adsorption onto organic matter and Fe oxyhydroxides in soil. Therefore, remediation strategies involving the application of Se fertiliser direct to the soil may not increase plant Se levels as expected. In the high-Se villages, localised lithological variations result in considerable ranges in Se concentrations in all sample types. Deficient and excessive levels of Se are recorded in samples from the same village. Selenium bioavailability in the high-Se toxicity villages is controlled by the total soil Se concentration and pH. A greater proportion of the Se is plant available in villages where the carbonaceous strata are interbedded with limestone. Villagers should be advised to avoid planting crops in these areas if possible. 相似文献
17.
西北地区空中水汽时空分布及变化趋势分析 总被引：69，自引：11，他引：58
使用NCEP/NCAR1958%D2000年再分析格点资料,分析了西北地区空中水汽和水汽输送的时空分布特征和变化趋势.结果表明:1)西北地区空中水汽地域分布主要集中在西北地区东部和西部的天山北部以及塔里木河流域盆地,而西北地区中部水汽含量较少,尤以青海的西部和北部为最;2)西北地区空中水汽主要来自印度洋孟加拉湾、南海以及阿拉伯海的水汽输送,北面还有一支来自西伯利亚和蒙古方向的水汽输送;3)西北地区空中水汽含量自50年代末至80年代中期呈明显下降趋势,而从80年代后期开始水汽又呈波动上升趋势.水汽增加地区主要在新疆北部沿河西走廊至甘肃中部祁连山区中段以及南疆盆地西部,而其它地区近年来水汽明显减少,其中减少幅度最大的地方位于西北中部的甘肃、青海、新疆交界处以及东部的陕西省;4)从空中水汽年代际变化趋势看,60～70年代西北大部分地区呈现减少趋势,而80～90年代全区普遍呈现增多趋势,以西北地区西部水汽增多趋势最为明显.最后讨论了影响西北地区水汽分布及输送的气候动力因子. 相似文献
18.
以鄱阳湖流域为研究区, 基于2011—2020年22个墒情站的逐日地面墒情监测数据、1956—2020年49个雨量站的日降雨数据及2016—2019年墒情站所在灌区的气象数据, 采用考虑植被生理状态的土壤水分亏缺指数(SWDI)表征农业干旱, 分析不同尺度下墒情、包气带缺水量和降水量的时空分布, 评估SWDI在鄱阳湖流域农业干旱监测中的适用性, 揭示该流域农业干旱时空演变特征及其对气象干旱的响应规律, 初步探讨土壤质地与农业干旱强度的相关性。结果表明: ① SWDI对鄱阳湖流域农业干旱诊断具有较好的适用性; ②近10 a该流域农业干旱呈显著加重趋势, 其中2019—2020年发生流域性重度农业干旱, 且夏、秋、冬连旱, 是近10 a的主导季节性农业干旱, 对水稻、油菜等粮食产量影响显著; ③相较于气象干旱, 农业干旱发生、结束时间分别平均约晚2.5周和3周, 历时长10.1周, 频次更低, 干旱等级更小; ④砂土持水性最差, 易发生特大农业干旱, 黏土、黏壤土保水性最好, 轻旱和中旱发生概率较大, 壤土、砂壤土和壤砂土则介于二者之间。 相似文献
19.
Xiangzheng Deng Quansheng Ge Zhigang Xu Shaoqiang Wang Hongbo Su Qunou Jiang Jifu Du Yingzhi Lin 《Frontiers of Earth Science》2009,3(1):1-8
Based on field survey and statistical analysis, the immediate impacts of the Wenchuan Earthquake happened on May 12, 2008,
are evaluated from two aspects, i.e., the influence on the prices and yields of grain and pork products in the local region
and that on China. Wenchuan Earthquake, undoubtedly, has some negative effects on the local agricultural yields in Sichuan
Province. It has caused immediate impacts on the grain and livestock breeding industry in the earthquake worst-hit counties.
For example, due to the earthquake, the grain yields in Sichuan Province will decreased more than 0.4% and the pork productions
decrease 5% at least. Thus, prices of grain and pork products are likely to rise in local mountainous areas over a short term.
Our studying results that the disaster rate, the hazard rate and the complete loss rate of grain productions are 18%, 10%
and 6% respectively in the earthquake worst-hit counties, while the disaster rate in the eastern plain areas even reach to
30%-49%. Even so, the results of model analysis for sample survey indicates that Wenchuan Earthquake has caused only marginal
impacts on agricultural production, does not heavily hurt the stability of the prices and yields of grain and pork products
at the national level. In other words,Wenchuan Earthquake had not affected the overall situation of national agricultural
production. It is estimated that the reduction rate of national grain yield is as low as 0.006%, and the price changes of
grain and pork products are no more than 0.5% and 2.2% respectively. 相似文献
20.
Despite the increasing public profile of same-sex issues, health policies are often shaped by heteronormative assumptions.
The health concerns of lesbian, gay, bisexual, transsexual/transgender, two-spirit, intersex, queer and questioning (LGBTTTIQQ)
people are complex and require broadening from an often exclusively sexual health and risk focus to a more holistic approach.
In this context, this paper illustrates how a critical feminist geography of health, with its focus on the mutual construction
of gender relations, space and place, potentially enhances and extends current understandings of public health policy and
practice. Moreover, the use of a policy lens foregrounding gender and other power relations suggests that feminist research
and coalitions facilitate participatory processes that address “the politics of discourse.” In particular, public health nursing
practice can enhance the construction of spaces of resistance that challenge heteronormative discourse through research strategies
focused on sexual minority communities’ health experiences and their visions for supportive care. In this respect, two strategies
consistent with public health priorities to increase knowledge and participate in alliances are described. Ethnographic research
with childbearing lesbians demonstrates that attention to institutional dynamics that foster safe spaces can facilitate access
to public health services. Public health nurses’ involvement in community coalitions can enhance dissemination of community
knowledges. The implications for gender inclusive and place-sensitive public health nursing practice include the development
of sensitive educators, meaningful educational curriculum and related program planning, explicit policies, community partnerships
and political leadership in institutional and research venues. 相似文献