Temporal and spatial variability of dryness/wetness in China during the last 530 years   总被引：8，自引：1，他引：8  

W.-H. Qian  D. Chen  Y. Zhu  H.-Y. Shen 《Theoretical and Applied Climatology》2003,76(1-2):13-29

Summary The main characteristics of spatial and temporal variability of dryness and wetness during the last 530 years (1470–1999) are classified over five centuries. They have been investigated by using 100-site dryness/wetness index data that has recorded the historical weather conditions that affect agriculture and living conditions in eastern China. A set of principal modes of spatial variability and time coefficient series describing the dominant temporal variability are extracted by a diagnostic method, the rotated empirical orthogonal function (REOF) analysis. The long-term precipitation around Beijing, north China and the long-term runoffs in the middle Yangtze River are used to confirm the dry/wet variability in north China and the mid-low Yangtze River over the last two centuries.When considering the data from the last 530 years as a whole, the first two modes of dryness/wetness variability are found in the mid to low sections of two major valleys in eastern China, the Yellow and Yangtze River valleys. These valleys experienced the largest dryness/wetness variability in the history of eastern China. The third and fourth modes are located in northwest and northeast China. The fifth and sixth modes are situated in south and southwest China. However, over the last 500 years the strength and location of principal modes have experienced significant changes. During the 20th century, the first mode is found in the lower Yangtze River valley, the second mode in south China while the third mode is located in the mid-low Yellow River valley. During the 19^th century, the first three modes are situated in the mid-low Yellow River, the mid-low Yangtze River and south China, respectively. The first two modes in the 18^th century are located in the mid-low Yellow River and the mid-low Yangtze River valleys. The largest change of all modes occurred in the 17^th century with the first mode in northeast China, the second mode in northwest China, and the third mode in the mid-low Yangtze River valley. During the 16^th century, the first two modes are found in the mid-low Yangtze River and the mid-low Yellow River valleys.In each of the last five centuries, some special dryness/wetness processes are characterized in the mid-low Yangtze River and the mid-low Yellow River (north China). During the 20^th century, continuous and severe wetness is experienced in the mid-low Yangtze River in the last two decades. A two-decade wetness period in north China was followed by a severe dry period in the late 19^th century. Inter-annual variability, decade and two-decade oscillations of dryness/wetness are experienced in the series of different modes from one century to another. Dry/wet variations in north China and the middle Yangtze River are confirmed by series of data on local precipitation and runoff.  相似文献   

中国西北气候由暖干向暖湿转型的特征和趋势探讨   总被引：341，自引：10，他引：341       下载免费PDF全文

施雅风  沈永平  李栋梁  张国威  丁永建  胡汝骥  康尔泗 《第四纪研究》2003,23(2):152-164

由于全球显著变暖和水循环加快,使得中国西北主要是新疆地区于1987年气候发生突然变化,随着温度上升,降水量、冰川消融量和径流量连续多年增加,内陆湖泊水位显著上升,洪水灾害也迅猛增加,同时,植被有所改善,沙尘暴日数锐减,从而改变了19世纪末期至20世纪70年代的变暖变干趋势.以降水量增加超过蒸发量增加所导致的径流量增长及湖泊水位上升作为气候向暖湿转型的主要标准,西北地区目前的气候变化可分为3个区域,即1)显著转型区;2)轻度转型区;3)未转型区.作者初步认为,西北气候向暖湿转型可能是世纪性的,预期西北东部在21世纪上半期也会向暖湿转变,但预测有较大的不确定性.  相似文献   

主分量与广东北江年最大流量预测          下载免费PDF全文

刘利平  陈创买  陈健  张漫莉  王彦斯 《水科学进展》2003,14(4):485-488

提出一种应用因子场的主分量建立北江长期洪水预报模型的方法,对发生暴雨洪水有重大影响的500hPa高度场和太平洋海温场作主分量分析,提取其含高信息量的主分量作为预报因子,通过相关和逐步回归计算建立模型.详细分析了用该模型对珠江的重要支流——北江年最大流量的拟合和预测,用该模型对北江流域年最大流量的预测表明,模型是有效的,效果较好,对较大洪水年的拟合效果尤其令人满意.  相似文献   

扎龙湿地沼泽的提取模型研究   总被引：6，自引：2，他引：6  

韩敏  程磊  刘权 《国土资源遥感》2004,15(1):43-46

利用扎龙湿地TM图像,通过分析各类地物的光谱特征、谱间结构特征以及采样剖面线,发现了扎龙湿地沼泽的光谱特征,并由此建立了一个基于知识发现的沼泽提取模型。提取结果表明,建立的沼泽提取模型能够实现自动提取扎龙湿地的芦苇沼泽,其精度可以达到98%。  相似文献   

冲淤河道水位预报模型及其应用   总被引：4，自引：0，他引：4       下载免费PDF全文

芮孝芳  陈洁云 《水科学进展》1998,9(3):245-251

根据河流动力学基本方程,采用水文学与水-沙关系相结合的方法,建立了适用于不受回水顶托影响,以悬移质为主且水-沙关系良好的冲淤河道的水位预报模型,应用于渭河咸阳-华县河段,精度提高。  相似文献   

滇中地区缺水成因分析及对策研究   总被引：1，自引：0，他引：1  

伍立群 《水文》2004,24(2):40-44

近年来，滇中地区总需水量日益增加，而供水水源始终不能满足需求，水资源供需矛盾日渐突出，严重制约了该地区经济社会的可持续发展。从多角度分析了滇中地区的水资源紧缺及其缺水成因，根据该地区实际情况，研究了缺水问题的一些对策。  相似文献   

从黑河流域地下水年龄论其资源属性   总被引：16，自引：1，他引：16  

陈宗宇  聂振龙  张荷生  程旭学  赫明林 《地质学报》2004,78(4):560-567

地下水资源的可持续性是当前干旱区流域水资源管理的首要问题之一 ,我国西北内陆干旱区地下水的可持续开发必须首先要了解地下水系统的更新能力 ,地下水的放射性同位素测年可以提供系统循环时间和更新能力的重要信息。本文利用地下水中放射性氚 (3H )和碳 (1 4C)测年方法 ,计算黑河流域地下水的年龄 ,进而讨论地下水的更新性。结果表明 :潜水年龄多数小于 5 0 a,具有可再生的资源的属性 ,其中山前戈壁带和张掖盆地细土平原潜水地下水年龄小于 4 0 a,为 196 3年以来补给。酒泉东盆地排泄区承压含水层中地下水的年龄为 2 338～5 5 6 9a,额济纳附近的深层承压含水层中 ,地下水的年龄为 5 4 86～ 86 30 a,地下水资源更新性较差。但是张掖盆地河流附近深层承压地下水年龄小于 5 0 a,具有一定的更新性。上述认识不仅对黑河流域水资源管理和生态环境建设具有重要意义 ,而且对西北类似的内流盆地的地下水系统的研究有着借鉴意义  相似文献   

Effect of no-flow in the Lower Yellow River on groundwater formation and usage in areas along the banks     

Jianfeng CAO  Xueyan YE  Kaijun WANG  Jiyi JIANG 《Frontiers of Earth Science》2008,2(4):379-383

Frequent flow cutoff has a serious effect on the eco-environment of the region along the Lower Yellow River. The authors study the impact on lateral seepage quantity and groundwater cycling caused by cutoff of the Yellow River and compare it with that of the year 1999 through the numerical simulation model of groundwater flow system of the affected zone. The lateral seepage quantity decreased 53.8% on flow cutoff stage from Huayuankou to the river entrance and breaking time of 300 d. The lateral seepage quantity will decrease 46.3% if flow cutoff is from Jiahetan to the river entrance and breaking time is 300 d, and it will decrease 75.2% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 19.8% if flow cutoff is from Luokou to the river entrance and breaking time is 300 d, and it will decrease 25.1% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 4.7% if flow cutoff is from Lijin to the river entrance and flow cutoff occurs throughout the year. Flow cutoff of the Yellow River has a minor effect on the shape of groundwater flow domain of the affected zone. Thus, the boundary condition of the shallow groundwater system will not change. Although flow cutoff has a major influence on the riverside source fields in the Lower Yellow River, it will not have a significant effect on groundwater resources macroscopically in the affected zone of the Yellow River due to its large storage capacity. __________ Translated from Journal of Jilin University (Earth Science Edition), 2007, 37(5): 937–942 [译自: 吉林大学学报(地球科学版)]  相似文献   

甘肃疏勒河流域水权分配方案分析探讨     

刘岩峰 《地下水》2008,30(6):65-68

通过对疏勒河流域近27年水文基础资料的收集、整理、分析,对水资源进行评价的基础上,按照总量控制、定额管理的原则,结合现状年2006年社会经济指标、取用水指标,逐级逐层进行了初始水权分配,完成了疏勒河流域不同水源类型、不同行业主要用水户的初始水权界定,为解决流域内水资源利用存在的问题,实现水资源的可持续利用,促进经济社会的长久可持续发展提供了一定的依据。  相似文献   

黑河中游盆地水资源转化规律研究   总被引：2，自引：1，他引：1  

胡兴林  蓝永超  王静  常得中 《地下水》2008,30(2):23-27

基于近二十多年黑河中游盆地的地表水和地下水观测资料,通过对盆地水资源转化规律的认识,利用水文系统分析法分析了该区域地表水、地下水相互转化规律,建立了盆地出口断面水资源量转化模型和盆地平均地下水水位变幅变化模型,经模型计算值与实测值比较吻合的较好,故可运用模型预测该盆地出口断面的水资源量和地下水水位的变化幅度。根据黑河出山径流不同频率的来水量,预测了现状条件下中游绿洲区平均地下水水位的变化幅度。得出了应该充分利用地表水和地下水的相互转化提高水资源的总体利用率,单方面考虑提高地表水利用率的做法有可能破坏地下水资源、降低水资源的总体利用率和造成生态与环境恶化的结论。  相似文献