通辽市近50年气候变化分析   总被引：4，自引：1，他引：3  

王俊  申广立  李春云  刘亚玲  姜秀萍  夏莹 《内蒙古气象》2010,(6):18-22

利用通辽市7个气象台站1959—2008年平均气温、降水量、日照时数资料,用趋势分析和累积距平、信噪比、F检验等方法,分析通辽市近50年的气候变化特征。结果表明:(1)年平均气温上升趋势显著,近50年增温1.9℃,且通过0.001显著检验,突变发生在1988年,近10年是最温暖时期。其中南部、西部升温较少,北部、东部升温较多。四季均温变化与年均温趋势一致,但略有差异。增温幅度最大为冬季,其次为春季,最小为夏季;突变时间最早为秋季、发生在1987年,最晚为夏季、发生在1994年。(2)年降水量呈减少趋势,近50年约减少71mm,且通过0.10信度检验,南部的库伦和北部的鲁北减少最为显著。四季降水量的变化不同步,夏、秋季减少,冬、春季稍有增加。年降水量呈阶段性变化,目前是降水量最少时期。年日照时数西南部及扎旗北部是增多的,其余地区明显减少。  相似文献   

青藏高原东部龙羊峡水库气候效应的变化趋势分析   总被引：4，自引：0，他引：4  

隋欣  杨志峰 《山地学报》2005,23(3):280-287

以青海省境内黄河干流龙羊峡水库为例,应用基于气象要素分析水库气候效应的数学模型,计算了水库蓄水后对局地气候的净影响,深入探讨了气候效应随时间的变化趋势。结果表明,龙羊峡水库蓄水以来,对局地气候有明显影响,环境风险度有较大提高,且水库对不同的气象要素的影响随蓄水时间的增加呈现不同趋势。  相似文献   

Temporal trends of bulk precipitation and stream water chemistry (1977–1997) in a small forested area,Krusné hory,northern Bohemia,Czech Republic     

N. E. Peters  Jiri Cerny  Miroslav Havel  Radovan Krejci 《水文研究》1999,13(17):2721-2741

The Krusné hory (Erzgebirge or Ore Mountains) has been heavily affected by high atmospheric pollutant deposition caused by fossil fuel combustion in an adjacent Tertiary coal basin. Long‐term routine sampling of bulk precipitation (1977–1996) and stream water (1977–1998) in a forested area on the south‐eastern slope of the mountains were used to evaluate trends and patterns in solute concentration and flux with respect to controlling processes. From 1977 to 1996, the annual volume‐weighted Ca²⁺ and SOconcentrations decreased in bulk precipitation. However, after 1989, when a pronounced and continuous decrease occurred in coal production, annual volume‐weighted concentrations decreased for most solutes, except H⁺. The concentration decreases were marked, with 1996 levels at or below 50% of those in 1989. The lack of a trend in H⁺ is attributed to similar decreases in both acid anions and neutralizing base cations. Stream water concentrations of most solutes, i.e. H⁺, Ca²⁺, Mg²⁺, SONOwere highest at the onset of sampling in 1977, decreased markedly from 1977 to 1983 and decreased more gradually from 1983 to 1998. The spruce forest die‐back and removal reduced dry deposition of these solutes by reducing the filtering action, which was provided by the forest canopy. A notable decrease in stream water Ca²⁺ concentrations occurred after 1995 and may be due to the depletion of Ca²⁺, which was provided by catchment liming in 1986, 1988 and 1989. Solute flux trends in bulk atmospheric deposition and stream water generally were not significant and the lack of trend is attributed to the large interannual variability in precipitation quantity and runoff, respectively. All solutes except Na⁺ varied seasonally. The average seasonal concentrations varied between the solutes, but for most solutes were highest in winter and spring and lowest in summer, correlating with the seasonal trend in runoff. For Ca²⁺, Mg²⁺ and SOthe concentration minimum occurs in September and the maximum occurs in February or March, correlating with the seasonal baseflow. These solutes are primarily controlled by the contribution of soil water and groundwater to stream flow. During snowmelt, the meltwater generally causes concentrations to decrease as soil water and groundwater are diluted. For NO₃ , average minimum concentrations occur in August at the end of the growing season concurrent with the lowest stream flow, and the maximum occurs in February and March with high stream flow during snowmelt. Seasonal stream water NOconcentration variations are large compared with the long‐term decrease. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

高原湖泊水质变化趋势及驱动因素研究:以四川邛海为例     

任春坪  郑丙辉 《湖泊科学》2024,36(3):756-769

邛海是四川第二大湖泊,地处高原,距离西昌市城区不足5 km,生态位置重要。本文以近20年邛海湖区主要水质监测数据为依据,采用M-K检验定量解析了水生态环境历史变化特征,建立邛海污染物浓度、营养状态指标的时空对应关系,分析其驱动因素,识别风险并提出对策建议。结果表明:(1)1980s-2000年是有记录以来邛海水质最差的时期,总氮(TN)、总磷(TP)浓度远超地表水Ⅲ类标准;(2)2003—2020年,邛海氨氮(NH₃-N)、高锰酸盐指数(COD_Mn)年际变化总体呈下降趋势,TN、TP、透明度、溶解氧浓度年际变化趋势总体不明显,COD_Mn、TN、TP浓度在研究期间出现多个显著变化过程;(3) 2003—2020年,邛海营养状态整体为中营养水平,综合营养状态指数TLI(Σ)为33.82±6.88,叶绿素a(Chl.a)浓度为(4.234±3.903) μg/L,TLI(Σ)和Chl.a浓度年际变化没有显著趋势;(4)多年数据统计表明,邛海宾馆所在区域水质最差,邛海湖心水质最好,2003—2020年COD_Mn、TP等指标最大单月浓度均出现在邛海宾馆所在水域;(5)COD_Mn浓度在枯水期低于丰水期,NH₃-N浓度在枯水期高于丰水期,TP浓度高值和低值集中出现在枯水期,TN各月浓度没有显著差异,Chl.a浓度与COD_Mn、TP、NH₃-N浓度呈显著正相关,从水体中氮磷比来看,磷是邛海藻类生长限制性元素;(6)面源污染主要通过邛海大小支流入湖,环湖湿地对邛海面源污染削减效果总体有限,未来邛海发生水华的风险较大,建议以小流域为单元推进陆源污染控制,按照“游在邛海,吃、住在城区”的理念布局旅游发展,探索用“物理+生态”方式调控和预防邛海水生态系统失衡的问题。  相似文献   

全野外数字测图技术的现状及发展趋势   总被引：3，自引：0，他引：3  

马俊海  吕长广 《测绘与空间地理信息》2006,29(5):15-17

对全野外数字测图技术的现状进行归纳和分析,指出了目前各种全野外数字测图方法中存在的不足,提出了全野外数字测图技术的发展趋势。  相似文献   

Rainfall and temperature trends in India     

U. C. Kothyari  V. P. Singh 《水文研究》1996,10(3):357-372

An investigation was carried out to identify trends in the rainfall and temperature regimes of the Ganga basin in India and in India as a whole. Long-term data on the monsoon and annual rainfall and the average annual temperature for India as a whole, and on the monsoon rainfall, number of rainy days and annual maximum temperature of the Ganga basin were analysed. The trends in these data were detected using non-parametric methods. The results of this study showed that the rainfall variables had a decreasing trend and the temperature had an increasing trend. These trends were observed to have begun around the second half of the 1960s, and have implications for the Indian economy. As the Indian economy continues to be based on agriculture, water resource management for irrigation plays a vital part in its growth. Present methods of design and management for water resource systems assume the climatic regime to be stationary. If indeed the climatic regime has changed, it will be necessary to develop new management approaches which consider this change.  相似文献   

Trends in groundwater quality     

Jim C. Loftis 《水文研究》1996,10(2):335-355

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Trends in the chemistry of precipitation and surface water in a national network of small watersheds     

Brent T. Aulenbach  Richard P. Hooper  Owen P. Bricker 《水文研究》1996,10(2):151-181

Trends in precipitation and surface water chemistry at a network of 15 small watersheds (< 10 km²) in the USA were evaluated using a statistical test for monotonic trends (the seasonal Kendall test) and a graphical smoothing technique for the visual identification of trends. Composite precipitation samples were collected weekly and surface water samples were collected at least monthly. Concentrations were adjusted before trend analysis, by volume for precipitation samples and by flow for surface water samples. A relation between precipitation and surface water trends was not evident either for individual inorganic solutes or for solute combinations, such as ionic strength, at most sites. The only exception was chloride, for which there was a similar trend at 60% of the sites. The smoothing technique indicated that short-term patterns in precipitation chemistry were not reflected in surface waters. The magnitude of the short-term variations in surface water concentration was generally larger than the overall long-term trend, possibly because flow adjustment did not adequately correct for climatic variability. Detecting the relation between precipitation and surface water chemistry trends may be improved by using a more powerful sampling strategy and by developing better methods of concentration adjustment to remove the effects of natural variation in surface waters.  相似文献   

气候变化对石羊河流域生态环境的影响分析          下载免费PDF全文

罗晓玲  丁思聪  杨梅  李岩瑛  刘明春 《沙漠与绿洲气象(新疆气象)》2022,16(4):49-56

为探讨气候变化对石羊河流域生态环境的影响，利用流域多年（1959-2018年）气象、水文和卫星遥感资料，采用线性倾向率、滑动t检验等方法,分析流域气温、降水、河流流量、植被覆盖、沙尘暴的变化事实及趋势，并使用相关系数（pearson）法研究气温和降水分别与环境要素的关系，得到气候变化对流域生态环境的影响程度。结果表明:气温呈显著上升趋势，增温速度为下游0.42℃．（10a）-1＞中游0.36℃．（10a）-1＞上游0.35℃．（10a）-1, 近10年增温最显著，较60年代升高了1.67℃。四季气温均呈显著上升趋势，增温速度为冬季＞秋季＞春季＞夏季。降水呈波浪略增加趋势，增幅为上游8.3mm．（10a）-1＞中游7.0mm．（10a）-1＞下游4.1mm．（10a）-1，近10年增加最显著，较60年代增加了17%。四季降水呈弱增加趋势，增加幅度为夏季＞春季＞秋季＞冬季。河流流量以波浪式持平变化；植被覆盖面积和归一化差异植被指数（NDVI）显著增大；沙尘暴频次显著减少，近10年较60年代减少了13.05d。流域气候暖湿化近20年较显著，气候变化有利于增加本地水资源总量、提高地表植被覆盖率、抑制沙尘暴的发生，对生态环境和大气环境质量改善有积极作用。  相似文献   

Analysis on the key findings related to emission trends and drivers from the IPCC AR6 report北大核心CSCD     

谭显春  戴瀚程  顾佰和  黄晨  朱开伟  马啸天  闫洪硕  刘心远  朱衍磊 《气候变化研究进展》2022,(5):538-545

"Emission Trends and Drivers" chapter, an important basis for international climate negotiations, is one of the core contents of each assessment report. The trends and driving factors of greenhouse gas emissions from 1990 to 2019 are discussed in this chapter in the Sixth Assessment Report (AR6) released in April 2022. Compared with the content in the Fifth Assessment Report (AR5), in terms of historical emission trends, AR6 focuses on the changes from 2010 to 2019, highlights the importance of the 1.5°C temperature control target, pays more attention to carbon dioxide (CO2) emissions and non-carbon dioxide greenhouse gas emissions related to land use change, and further emphasizes the carbon emission trend and its regional evolution trend from the perspective of production and consumption. Besides, the short-term impact of COVID-19 on global carbon emissions is explored. In terms of driving factors, besides analyzing the global and regional economic driving factors, the economic driving factors and differences in energy, industry, construction, transportation, agriculture, forestry and other land use (AFOLU) sectors are also studied, which systematically reflects the similarities and differences of driving factors at the global, regional and departmental levels. The results affirm the positive impact of existing climate policies on climate mitigation highlight the benefits of technological change and innovation on climate mitigation, and identify the adverse impact of carbon locking of fossil energy infrastructure. Finally, based on the full analysis of the key conclusions in AR6, some suggestions on China's low-carbon development are given. © 2022 Chinese Journal of Digestive Endoscopy All rights reserved.  相似文献