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Climate change may cause shifts in the natural range of species especially for those that are geographically restricted and/or endemic species. In this study, the spatial distribution of five endemic and threatened species belonging to the genus Onosma (including O. asperrima, O. bisotunensis, O. kotschyi, O. platyphylla, and O. straussii) was investigated under present and future climate change scenarios: RCP2.6 (RCP, representative concentration pathway; optimistic scenario) and RCP8.5 (pessimistic scenario) for the years 2050 and 2080 in Iran. Analysis was conducted using the maximum entropy (MaxEnt) model to provide a basis for the protection and conservation of these species. Seven environmental variables including aspect, depth of soil, silt content, slope, annual precipitation, minimum temperature of the coldest month, and annual temperature range were used as main predictors in this study. The model output for the potential habitat suitability of the studied species showed acceptable performance for all species (i.e., the area under the curve (AUC)>0.800). According to the models generated by MaxEnt, the potential current patterns of the species were consistent with the observed areas of distributions. The projected climate maps under optimistic and pessimistic scenarios (RCP2.6 and RCP8.5, respectively) of 2050 and 2080 resulted in reductions and expansions as well as positive range changes for all species in comparison to their current predicted distributions. Among all species, O. bisotunensis showed the most significant and highest increase under the pessimistic scenario of 2050 and 2080. Finally, the results of this study revealed that the studied plant species have shown an acute adaptability to environmental changes. The results can provide useful information to managers to apply appropriate strategies for the management and conservation of these valuable Iranian medicinal and threatened plant species in the future.  相似文献   

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山西气候变化特征与旱涝灾害趋势判断   总被引:6,自引:0,他引:6  
根据山西18个气象站自建站以来到2010年的气温和降水资料,应用趋势分析法、Mann-Kendall突变检验、马尔可夫模型等分析了山西近60a来的气候变化及旱涝趋势。结果表明:1)山西近60a来气候总体上具有暖干化特征,年平均气温呈波动上升趋势,其增长率为0.29℃/10a。20世纪90年代以来气温上升迅速,在1992年气温发生突变,1992年以前为冷期,以后为暖期。2)降水量总体呈减少趋势,为-12.77mm/10a。降水变化与气温变化呈负相关。3)马尔可夫模型预测显示在气温突变后2012~2016年降水处于\"正常\"状态的概率较大。  相似文献   

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石家庄地区极端寒热和强降水的观测事实   总被引:1,自引:0,他引:1       下载免费PDF全文
利用石家庄地区17个观测站1972-2009年的气温和降水资料,选取8个极端气温指数和5个极端降水指数,分析气温和降水极端事件的变化规律。结果表明:近38 a,炎热日数呈增加趋势,寒冷日数、霜冻日数和结冰日数呈减少趋势,其中寒冷日数和霜冻日数呈显著减少趋势。中东部县市热指数的增加趋势和冷指数的减少趋势最明显。极端最高气温和极端最低气温呈弱的升高趋势;最高气温极小值和最低气温极大值则呈显著升高趋势。4个气温极值指数趋势变化的空间分布差异较大。大雨日数和暴雨日数均呈弱的增加趋势,各站的大雨日数和暴雨日数增加或减少的趋势不明显。1日和3日最大降水量均呈弱的上升趋势,但绝大部分站上升或下降的变化趋势不明显。强降水强度呈弱的增强趋势,暴雨强度的线性趋势为0.83 mm/(d.10 a)。大部分站大雨以上强度的增强或减弱趋势与暴雨强度一致。  相似文献   

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咸阳市气候暖干化及干旱灾害趋势判断   总被引:3,自引:2,他引:3  
依据咸阳市1961-2009年气象资料,利用Z指数和Mann-Kendall气候突变检验法对咸阳市的气候变化特征进行了分析。结果显示:(1)近49年来,咸阳市出现3年重旱、2年大旱、8年偏旱,重旱大旱年份出现在20世纪80年代中期以后,偏旱年份大部分出现在90年代和21世纪初的几年。(2)各季节重旱年份主要出现在20世...  相似文献   

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近40a西北干旱区极端气候变化趋势研究   总被引:6,自引:2,他引:6  
本文选取了西北干旱区21个代表站点1961-2000年逐日气温和逐日降水量资料。用百分位阈值法分析极端年最低温度、年最高温度和极端降水量变化特征及其各分区极端气候变化趋势。研究结果表明:(1)西北干旱区近40a年最低温度的天数有减少的趋势,而年最高温度的天数略有增加趋势。(2)西北干旱区年最低温度有增加趋势,年最高温度略有减少趋势。从分区看,北疆和南疆的年最低温度有升高趋势,年最高温度有下降趋势;河西走廊、柴达木盆地年最低温度和最高温度有升高趋势。(3)近40a西北干旱区极端降水的天数增加了2天。  相似文献   

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PDSI和Z指数在西北干旱监测应用中差异性分析   总被引:3,自引:0,他引:3       下载免费PDF全文
利用西北地区137个气象台站1961~2003年气象资料,分别计算了西北地区的Z和PDSI两种干旱指数,并对其结果进行了对比分析.结果认为:两种指数在多数地区多数季节可以互相兼容,但Z指数适宜于在雨季表征干湿事件,而PDSI则适宜于西北的所有地区和所有季节,并对当地干旱事件的反映更为敏感;在对不同程度干旱面积的表征上,PDSI对轻旱的表征反映较为敏感,而Z指数对重旱的反映更为敏感;对于中等程度的干旱而言,两种指数表征下的干旱面积较为统一;从西北地区的实际情况出发,PDSI对干旱的表征更为客观.  相似文献   

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利用柴达木盆地气象站收集的降水和气温数据,计算了SPI和SPEI两种干旱指数,并用于评价研究区不同时间尺度的干旱特征。然而,由于测站分布稀疏,两种指数在区域干旱评价方面存在不足。在此基础上基于全球范围内的scPDSIpm数据集,并用PDSI指数分析了干旱演变特征及时空分布规律,研究发现:①温度在年际尺度对研究区的干旱情况影响较大,而在月尺度和半年尺度上对研究区干旱情况影响不明显;②PDSI指数与SPEI和SPI干旱指数的相关系数较高(0.7以上),与两者具有较好的一致性,PDSI更适宜于无资料地区的干旱评价;③研究区中部干旱状况最为严重,东部边缘和西北部干旱频次相对较少,但2000年以来这种趋势得到改善。本研究对评价不同干旱指数的适用性及资料缺乏地区的干旱评价具有重要的指导意义。  相似文献   

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根据中国甘肃省近3000年干旱、饥荒、虫害的历史资料,系统研究了甘肃省干旱的历史发生规律及其产生的影响。结果显示:甘肃省历史时期旱灾频繁且有愈演愈烈的趋势,干旱与饥荒存在较为明显的正相关,干旱引发的虫害也会加重饥荒,同时,由干旱引发的一系列问题会导致社会秩序的不稳定,在古代就表现为朝代的更替及战争。作者建议,随着全球气候变暖,甘肃省的生计将受到更加严重的影响,气候变化导致的贫困问题会进一步加剧,社区应对气候变化的政策措施需要决策机构给予尽早关注。  相似文献   

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罗布泊红柳沙包记录的极端气候事件及影响因素   总被引:1,自引:0,他引:1       下载免费PDF全文
赵娟  赵元杰  夏训诚 《干旱区研究》2012,29(6):1094-1099
罗布泊地区的红柳沙包,具有清晰的沉积纹层,与树木年轮一样,具有准确的计年和储存环境信息的功能。通过对罗布泊典型红柳沙包中沙层沉积厚度、落叶阳离子含量、C/N、δ13C、δD、δ18O等序列中记录的环境代用指标极端值与极端气候事件的相关性分析发现,环境代用指标极端值与极端气候事件之间有很好的对应关系。依此分析了近160 a罗布泊地区极端气候事件的发生规律和影响因素。  相似文献   

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新疆阿勒泰地区近50年来极端气温与降水变化   总被引:1,自引:0,他引:1  
利用新疆阿勒泰地区六个气象代表站点1961~2008年的观测资料,研究了近50年来阿勒泰地区的极端气温与极端降水量的变化。结果表明:阿勒泰地区近50年以来极端最高与最低气温、月与年最大日降水量、年降水强度、冬与夏季降水强度及大雨和暴雨和热月都呈上升的趋势,冷月呈下降的趋势。其中平均极端最低气温60年代最低,80年代开始...  相似文献   

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根据石羊河流域及周边共11个气象站点1959—2012年的逐日气象资料,利用大气环流模型Had CM3的输出和SDSM统计降尺度模型,生成A2、B2两种排放情景下未来石羊河流域各站点2020 s,2050 s和2080 s的ET0和降水日值;使用作物系数法,扣除有效降雨量,计算现状和未来不同作物净灌溉定额、流域净灌溉需水量和耗水量;应用反距离加权插值法(IDW)研究作物净灌溉定额的空间分布特征。结果表明,石羊河流域小麦、玉米、甜椒、棉花、胡麻和苹果的多年平均作物净灌溉定额都呈现从西南到东北递增的趋势,预测未来气候变化情景下,6种典型作物净灌溉定额呈增加趋势;多年平均流域净灌溉需水量为12.65×108m3,多年平均耗水量为15.42×10~8m~3;在种植结构维持现状条件下,预计2020 s,2050 s和2080 s,在Had CM3模式的A2情景下净灌溉需水量分别为13.45×108m3、15.02×10~8m~3、16.94×10~8m~3,耗水量分别为15.53×10~8m~3、16.65×10~8m~3、18.18×108m~3,B2情景下净灌溉需水量分别为13.55×108m3、14.63×10~8m~3、15.51×10~8m~3,耗水量分别为15.56×10~8m~3、16.34×10~8m~3、17.00×108m3~,未来流域净灌溉需水量和耗水量都呈明显上升趋势,且A2情景下的上升幅度大于B2情景。石羊河流域的农业灌溉需水在未来将持续增加,2050 s之后增加趋势更为显著。  相似文献   

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Understanding the impact of climate change on water resources is important for developing regional adaptive water management strategies.This study investigated the impact of climate change on water resources in the Yarmouk River Basin(YRB)of Jordan by analyzing the historical trends and future projections of temperature,precipitation,and streamflow.Simple linear regression was used to analyze temperature and precipitation trends from 1989 to 2017 at Irbid,Mafraq,and Samar stations.The Statistical Downscaling Model(SDSM)was applied to predict changes in temperature and precipitation from 2018 to 2100 under three Representative Concentration Pathway(RCP)scenarios(i.e.,RCP2.6,RCP4.5,and RCP8.5),and the Soil and Water Assessment Tool(SWAT)was utilized to estimate their potential impact on streamflow at Addasiyia station.Analysis of data from 1989 to 2017 revealed that mean maximum and minimum temperatures increased at all stations,with average rises of 1.62℃ and 1.39℃,respectively.The precipitation trends varied across all stations,showing a significant increase at Mafraq station,an insignificant increase at Irbid station,and an insignificant decrease at Samar station.Historical analysis of streamflow data revealed a decreasing trend with a slope of-0.168.Significant increases in both mean minimum and mean maximum temperatures across all stations suggested that evaporation is the dominant process within the basin,leading to reduced streamflow.Under the RCP scenarios,projections indicated that mean maximum temperatures will increase by 0.32℃ to 1.52℃,while precipitation will decrease by 8.5%to 43.0%throughout the 21st century.Future streamflow projections indicated reductions in streamflow ranging from 8.7%to 84.8%over the same period.The mathematical model results showed a 39.4%reduction in streamflow by 2050,nearly double the SWAT model's estimate under RCP8.5 scenario.This research provides novel insights into the regional impact of climate change on water resources,emphasizing the urgent need to address these environmental challenges to ensure a sustainable water supply in Jordan.  相似文献   

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Meteorological drought has been an inevitable natural disaster throughout Mexican history and the northern and northwestern parts of Mexico(i.e., the studied area), where the mean annual precipitation(MAP) is less than 500 mm, have suffered even more from droughts in the past. The aim of this study was to conduct a meteorological drought analysis of the available MAP data(1950–2013) from 649 meteorological stations selected from the studied area and to predict the drought features under the different IPCC-prescribed climate change scenarios. To determine the long-term drought features, we collected 1×10~4 synthetic samples using the periodic autoregressive moving average(PARMA) model for each rainfall series. The simulations first consider the present prevailing precipitation conditions(i.e., the average from 1950 to 2013) and then the precipitation anomalies under IPCC-prescribed RCP 4.5 scenario and RCP 8.5 scenario. The results indicated that the climate changes under the prescribed scenarios would significantly increase the duration and intensity of droughts. The most severe impacts may occur in the central plateau and in the Baja California Peninsula. Thus, it will be necessary to establish adequate protective measures for the sustainable management of water resources in these regions.  相似文献   

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Convincing data now show that temperatures are increasing, and that changing precipitation patterns are already affecting agriculture. Predicted future impacts vary by region, but all are projected to suffer productivity declines by the late twenty-first century unless successful mitigation measures are implemented soon. Exacerbating the climate change challenge, doubling of overall crop productivity will be required by mid-century. Clearly, crop protection will become increasingly difficult as higher-yielding varieties present a larger and more tempting target to all pests, and the pests themselves extend their ranges poleward and into other new geographies owing to reduced winter kill and longer growing seasons. Fortunately, good progress on enhancing crop protection technology to meet these challenges is already being made, but the scope of this climatic provocation is such that complacency is not an option. Increased investment into new technologies and adoption of new agricultural practices with improved adaptive and mitigation potential are both essential.  相似文献   

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黄河源区是气候变化敏感区及生态环境脆弱区,也是黄河的主要产流区,其气候变化问题备受关注.利用黄河源区均一化气温和降水观测数据,系统分析了近60 a黄河源区平均气候与极端气候事件的变化特征.结果表明:1960—2019年黄河源区年平均气温、平均最高及最低气温表现出增温趋势的一致性,且源区东部增温幅度高于西部;黄河源区年均...  相似文献   

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