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《水利发展研究》2004,4(9):55-55
全球气候变暖使中国冰川年融水量相当于一条黄河据研究,亚洲地区冰川面积近40年来平均减少了7%,中国冰川目前年融水总径流量564亿m3,占全国径流总量的2%,占西部地区径流量的10%,接近黄河年径流总量。中国科学院青藏高原研究所所长姚檀栋指出,冰川融水的增加,使中国西北地区河流径流量年增加5.5%以上,尤其是使新疆境内的许多河流流量大幅增加,20世纪80年代以后,新疆径流量增加了32%。不过,他也指出,尽管从表面上看冰川融水给西北干旱地区补给了大量水源,但气温上升同样使地表水的蒸发量加大,对于缓减旱情的实际作用不太明显。(摘自“央视国际… 相似文献
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《水利天地》2016,(9)
冻结层上水的水文地球化学特征的研究对了解寒区冻结层上水具有重大的意义。文章通过对冻结层上水的水文地球化学特征的研究,以理论分析和实例阐述的方式指出:(1)冻结层上水化学特征的主要影响因素为自然因素;(2)地下水相变过程对冻结层上水化学特性的影响为使冻结层上水的化学成分和矿化度发生变化;(3)水文地球化学特征受不同季节包气带水分迁移过程的影响,其演化机理主要为:浓缩低温蒸发机理、低温—蒸发浓缩机理、低温—迁移机理;(4)通过对形成于勒拿河河漫滩阶地的季节性融化层的水化学状况的考察,得出:冻结层上水的水化学动态的主要特点主要由水的相变和包气带岩层水分迁移过程决定,可划分出3种主要的冬季冻结层上水的化学成分的浓缩机理:低温-结晶、低温-蒸发、低温-迁移机理。 相似文献
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内蒙古黄河河套地区土壤冻结期潜水蒸发消耗的特点与规律 总被引:3,自引:0,他引:3
一、前言河套地区土壤在一年之中有近半年的时间有冻结现象,属于季节性冻土区。冻结期的潜水蒸发消耗与非冻结期相比较,有着不同的特点和规律。在非冻结期,表土水分蒸发以及作物、植物吸收利用,使表土变干,引起下部土壤水分和潜水通过土壤毛管向上迁移,形成潜水蒸发。在冻结期,潜水的消耗表现为下部非冻结层水与潜水向冻结层迁移、累积,含水量猛烈增加直至出现过饱和状态(和非冻结期状况比较),大部分水分被冻结为固相,出现土体膨胀,而有少部分的水分被蒸发散失掉。潜水蒸发消耗与冻土表层水分散失量不是同步的,也不是等量的。冻结末期有部分水量又回补给地下水。因此,冻结期与非冻结期潜水蒸发消耗有着 相似文献
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寒区冻泉与冰丘形成机理这一问题一直备受人们关注。在充分梳理既有研究成果的基础上,指出:寒区地下潜水排泄到地表的过程主要受冻土因素、气候因素,以及其自身形成、补给、水循环等因素的影响;冻结泉不仅可以由季节性融化层中的冻结层上水形成,还可以由冻结层上地下水形成;在低温作用影响下,引起了地下水在地表排泄口的冻结,促进了冰丘的形成。 相似文献
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张雷 《甘肃水利水电技术》2011,(1)
河川径流是气候与环境变化综合影响的产物,降雨与径流变化趋势,直接影响到流域内水资源量的多寡。根据克里雅河流域基本控制站50多年的降雨、径流实测水文资料,采用水文统计相关,分析降雨、径流变化趋势。得出克里雅河流域受全球气温升高因素影响,冰川融水加速,冰川厚度减少,降雨量变化趋势在加强。径流补给源发生变化,径流线型趋势呈现增势。分析成果为流域综合治理,优化水资源配置提供理论参考。 相似文献
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Hydrological Changes of the Irtysh River and the Possible Causes 总被引:2,自引:1,他引:1
Feng Huang Ziqiang Xia Fan Li Lidan Guo Fucheng Yang 《Water Resources Management》2012,26(11):3195-3208
Hydrological changes of the Irtysh River were analyzed concerning the changes of annual runoff and its distribution features within a year measured by coefficient of variation and concentration degree. Abrupt changes were detected by the heuristic segmentation method. Possible causes of the hydrological changes were investigated considering climate changes and human activities (especially the reservoir operation). The Mann-Kendall method was applied to estimate whether the temperature and precipitation was changed. The increased precipitation in winter may increase the runoff of April. The increased temperature and the decreased precipitation in the flood season may decrease the runoff. At the middle reaches, the impact of the reservoirs at the upper reaches is significant and may be the main factor leading to the abrupt decreases in annual runoff and its intra-annual variability and concentration. The increased water surface area of the reservoirs aggravates the evaporation and leads to annual runoff reduction. The reservoirs regulate runoff by storing water in the flood season and releasing water in the dry season. While at the lower reaches, the annual runoff remained steady and its intra-annual variation and concentration were reduced gradually because the impact of the reservoirs is relative small and the climatic impact may be more relevant. 相似文献
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三峡水库蓄水对其库区降雨量-径流量关系变化的影响程度对于库区水资源规划有着重要意义。选用万县水文站1977-2017共计41 a的降雨量和径流量实测值,确定了各蓄水阶段降雨量和径流量的分布情况,引入Copula函数模型计算各阶段的联合分布函数,定量分析水库调蓄对两者关系的影响,预测了2017年后水文情势。结果表明:采用Copula函数联合分布数学模型能较好计算三峡库区万州段不同阶段的降雨量-径流量关系。万州段从天然河道变为库区河道后,降雨量-径流量关系发生了较大变化。在天然河道阶段,降雨量和径流量均采用皮尔逊III型分布最为合理;三峡水库工程施工期和初步蓄水阶段,降雨量变为Gumbel分布,径流量变为对数正态分布;试验性蓄水阶段,降雨量变为对数正态分布,径流量恢复至皮尔逊III型分布。年降雨量和年径流量在施工期及初步蓄水阶段较天然河道阶段均有所减少,年降雨量变幅区间减小38.4%,年径流量变幅区间减小20.6%;试验性蓄水阶段的年降雨量增多,变幅区间增大24.5%,而年径流量减少,变幅区间减小57%。通过该数学模型预测三峡库区万州段今后年径流量不小于3 490×108 m3(±5%),最大不超过4 055×108 m3(±5%);年降雨量不小于1 048 mm(±5%),最大值不超过1 842 mm(±5%)。该研究可为三峡库区万州段流域水资源开发利用与水文序列的重构工作等提供科学依据,也可为其他库区内河道的水文特性变化关系的研究提供参考。 相似文献
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灞河流域气候因子对水沙变化的影响 总被引:1,自引:0,他引:1
利用灞河流域蓝田气象站和马渡王水文站1960—2012年的气象、水文实测资料,分析灞河流域气候及水沙变化规律,同时运用相关性分析、灰色关联分析、多元线性回归模型等多种方法探讨了该流域水沙变化与气候变化的关系。结果表明:灞河流域降雨量、蒸发量、径流量和输沙量皆呈显著下降趋势,而气温呈上升趋势;降雨量与水沙都有重要的相关关系,1960—1990年影响径流量的气候因子敏感度由大至小依次为降雨量、气温、蒸发量,而1991—2012年则为降雨量、蒸发量、气温,当气温和蒸发量不变时,降雨量每增加1 mm,两阶段的年径流量分别增加0.14亿m3和0.08亿m3;1960—2012年影响输沙量的气候因子敏感度由大至小依次为降雨量、气温、蒸发量,当气温和蒸发量不变时,降雨量每增加1 mm,年输沙量增加0.668万t。 相似文献
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利用全球气候模式输出结果,经统计降尺度模型降解后得到流域尺度的降水和气温要素,根据实测资料建立气温—蒸发回归关系以及新安江水文模型,使用耦合模拟和MK趋势分析评估未来气候变化情景下赣江流域水资源量的变化趋势和幅度。研究结果表明:未来不同排放情景下的年降水量、年蒸发量和年径流量等水文气候要素变化趋势以显著增加为主。未来年降水量、年蒸发量和年径流量的多年平均值相对基准期有较小幅度增加,最大增幅为年径流量的13.81%。降水、蒸发和径流的年内变化有明显的季节性特征,汛期径流增加、非汛期径流减少的不均匀情况加剧,在一定程度上可能增加赣江流域未来的防洪压力和枯水期供水压力。 相似文献
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若尔盖高原的降水量微弱减少与蒸发量持续上升,使若尔盖高原径流量与储水量逐年降低,直接减少了若尔盖高原的湿地面积和对黄河上游径流量的补给。基于红原、若尔盖和玛曲站的气象数据和7个水文站的径流量数据(1981-2011年),并对数据序列进行插补与计算,获得若尔盖高原的径流量变化与气候因子的响应关系,进而计算储水量变化。计算结果表明:若尔盖高原向黄河年均补水(67. 08±14. 90)×108m3,并以0. 48×108m3/a速率持续减少。降水量每减少1 mm将导致黑河与白河的年径流量分别减少0. 02×108和0. 05×108m3。蒸发量每增加1 mm将导致黑河与白河的年径流量分别减少0. 12×108和0. 27×108m3。1981-2011年若尔盖高原的年均储水量为(59. 30±18. 69)×108m3,其年均递减速率为0. 49×108m3/a。本研究有助于认识若尔盖高原对于黄河上游水资源保障的重要性。 相似文献
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南水北调中线工程从汉江中上游的丹江口水库引水,作为调水工程水源区,研究汉江上游的径流变化趋势及特征具有重要意义。采用累积距平法和Mann-Kendall趋势分析法分析典型测站的长系列年径流量变化趋势,采用滑动t检验和有序聚类法分析年径流量突变情况。以汉江上游典型水文站武侯站、洋县站、汉中站和石泉站为例。结果表明:20世纪50年代以来,汉江上游径流量总体呈减少趋势,尤其在20世纪90年代以后减少趋势显著。各站年径流量的变化趋势相似,年代平均径流量存在高低交替的现象。突变分析表明4个水文站径流的突变年份均为1990年。汉江上游径流量减少主要受降水量的减少、社会经济用水的增加及水资源开发利用等方面的影响。 相似文献
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Zhengmao Liu Xianguo Lu Sun Yonghe Chen Zhike Haitao Wu Yanbo Zhao 《Water Resources Management》2012,26(6):1455-1475
Naoli river basin(NRB), with an area of 24,863 km2, is the largest basin and also the largest marsh distribution area in Sanjiang Plain, Heilongjiang, China. The hydrological
evolution process of wetland in NRB has made a marked ecological responses for anthropic activities, also reflects the drying
trend of the Sanjiang Plain, Northeast China. Global climate warming also contributes to the hydrological evolution process.
The following key research results are obtained: (1) The monthly average water level of Naoli river at Caizuizi hydrological
station in different ages showed a marked decline tendency, the annual mean water level dropped from 96.63 m during 1960–1969
to 95.59 m during 2000–2005, the water level drawdown is 1.04 m; (2) The annual runoff flowing into wetlands in NRB decreased.
Duration of Naoli river and its tributaries being thoroughly frozen from riverbed to river-water-surface showed an prolonged
trend, and the water level drawdown in frozen seasons increased. The water storage capacities of wetlands in NRB declined.
(3) The interactions between ground water and surface water in wetland areas are close. The ground water level variation span
is bigger than that of surface water level in wetland areas of NRB. The drawdown of ground water level promotes the surface
water level to decline, correspondingly. In recent 20 years, the cultivated area extension of rice field in upstream NRB has
made an adverse influence on the hydrological processes of wetlands. (4) The wetland area decrease and farmland area increase
significantly contribute to the runoff depth decrease of wetlands in NRB. The runoff depth variability has been mostly posed
by anthropic activities. (5) Reservoirs, ditches and dykes in NRB have greatly changed the runoff generation processes. Thickness
of the seasonal frozen soil layer becoming thinner and the evaporation potential becoming bigger also contribute to the runoff
depth reduction and the water level drawdown of rivers. The present study results will provide a scientific basic for developing
an integrated watershed management program for NRB, especially, restoring the wetland hydrological processes, maintaining
or improving the wetland structure and enhancing the wetland service functions. 相似文献
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以渭河中下游林家村、咸阳、临潼和华县等4个典型水文站资料为例,采用滑动平均法、累积距平和线性倾向估计法分析年径流量变化趋势;采用滑动t检验,有序聚类法和Mann-Kendall法分析年径流量的突变情况。结果表明:20世纪70年代以来,渭河流域径流量呈减少趋势,各站年径流量的变化趋势相似,各水文站径流量突变点发生在70年代初和90年代初。不同水文站突变情况存在差异,林家村突变点发生在1970年和1990年,咸阳站在1970年和1990—1992年之间,临潼站在1968年和1990—1994年之间,华县站在1968年和1990年。渭河流域径流量变化是气候变化和人类活动共同作用的结果,前者主要表现为降水和潜在蒸发量的变化,后者主要体现在流域内水利工程的建设。 相似文献
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An analysis of Lake Superior water levels from 1948–1999 reveals that the seasonal cycle has decreased in amplitude by 20% (from 40 cm to 32 cm). This change is manifested as a downward trend in summer and autumn lake levels (when levels are typically highest) accompanied by roughly no change in winter and spring lake levels (and an overall 4-cm drop in annual mean levels). The decreased rates of seasonal rise and fall in lake level over the 51-year interval reflect a large decrease in the net monthly influx of water during the late spring (up to –1,360 m3/s) coupled with a nearly compensating increase in net influx during late autumn (up to +1,100 m3/s). Analysis of the Lake Superior water budget indicates that these changes are primarily the result of trends in runoff and over-lake precipitation. A systematic decrease in outflow through the St. Marys River is also evident during July-December (in association with the lower lake levels), as well as a moderate shift in the seasonal pattern of lake evaporation (but not the annual mean). The observed water budget trends are primarily related to variations in climate, rather than lake regulation. Land surface effects are also important, as suggested by a 20% increase in annual mean evapotranspiration during the 51-year interval and large changes in monthly storage (e.g., snowmelt, groundwater, etc.). Significant uncertainties are present in the calculated water budget, and it is suggested that a likely source of error is in measured precipitation and (especially) runoff. 相似文献