人类活动对塔里木河年径流影响量的估算   总被引：16，自引：4，他引：16  

周红  秦嘉轮  卫江益 《干旱区地理》2002,25(1):70-74

塔里木河流域与环境的研究，一直是近年来新疆环境演化和可持续发展研究的热点问题。大规模的区域开发活动对该流域生态环境产生了根本性的影响，区域整体生态环境趋于恶化。本文通过对年径流量累积曲线和年径流量的相关分析，估算出人类活动对塔里木河各河段的年径流量变化及其对生态环境造成的影响。  相似文献   

Proglacial Sediment—Landform Associations of a Polythermal Glacier: Storglaciären, Northern Sweden     

James L. Etienne  Neil F. Glasser  Michael J. Hambrey 《Geografiska Annaler: Series A, Physical Geography》2003,85(2):149-164

Mapping and laboratory analysis of the sediment—landform associations in the proglacial area of polythermal Storglaciären, Tarfala, northern Sweden, reveal six distinct lithofacies. Sandy gravel, silty gravel, massive sand and silty sand are interpreted as glaciofluvial in origin. A variable, pervasively deformed to massive clast‐rich sandy diamicton is interpreted as the product of an actively deforming subglacial till layer. Massive block gravels, comprising two distinctive moraine ridges, reflect supraglacial sedimentation and ice‐marginal and subglacial reworking of heterogeneous proglacial sediments during the Little Ice Age and an earlier more extensive advance. Visual estimation of the relative abundance of these lithofacies suggests that the sandy gravel lithofacies is of the most volumetric importance, followed by the diamicton and block gravels. Sedimentological analysis suggests that the role of a deforming basal till layer has been the dominant factor controlling glacier flow throughout the Little Ice Age, punctuated by shorter (warmer and wetter climatic) periods where high water pressures may have played a more important role. These results contribute to the database that facilitates discrimination of past glacier thermal regimes and dynamics in areas that are no longer glacierized, as well as older glaciations in the geological record.  相似文献   

湘北红壤坡地雨水过程的水土流失及其影响   总被引：7，自引：0，他引：7  

谢小立  王凯荣 《山地学报》2003,21(4):466-472

模拟主要利用方式构建的垫面为主导因子,采用径流场实测方法,通过4a(1998～2001年)实地观测试验,剖析不同下垫面对雨水地表径流及其过程的影响。研究表明:降雨(时间分布及其强度)是影响地表径流特征的主导因素;年降雨量与地表径流量和系统水土流失量呈正相关。不同垫面地表径流产量有显著性差异;雨水径流过程的土壤和养分流失有相似的表现。在假定雨水年份的基础上,应用不同雨水年份出现概率指标,推算出:湘北红壤坡地现今利用状况下,雨水产地表径流过程的年均水土流失量及其养分(有机质、N、P、K)损失量;和可最大开发利用时,可能带来的水土流失与养分损失。提出"利用坡地集雨利用优势,构建与单元生态系统水循环平衡相适应的坡地农林复合生态系统,通过水平衡生态建设来维系生态系统的水分平衡"观点。  相似文献   

高山增水效应及其水资源意义   总被引：9，自引：1，他引：9  

丁贤荣 《山地学报》2003,21(6):681-685

根据高山上云、雾、雨、雪、径流等水资源丰富现象，分析了高山冰川、植被、地形等与汽-水作用关系，提出高山增水效应概念和高山区水资源开发与保护的新思路。高大山体及其造成的垂向对流、高山冰川和高山植被共同作用形成了高山增水效应，并形成良性增水系统。山体愈高大，增水效应愈明显。对内陆干旱地区开发利用更多的高山水资源具有意义。  相似文献   

气候变化对洮河流域水资源的影响   总被引：7，自引：3，他引：7  

张济世  康尔泗  姚尽忠  陈仁升  蓝永超  蒲瑞丰  王书功 《中国沙漠》2003,23(3):263-267

过去40多年来，洮河流域主要产流区甘南高原的气候和生态环境发生了显著变化，通过对引洮工程的引水区——流域上游40多年的实测水文气象数据的统计分析发现，降水和径流总体下降趋势非常明显，20世纪80年代至90年代降水径流减少更多，达35％；而气温则呈上升趋势，但上升幅度没有降水径流的下降幅度大。由于气候升温变暖、草原载畜过量以及过度砍伐森林，导致气候干旱化、山区水土流失加剧、草原植被退化和沙漠化，这一切都将对未来引洮工程发挥效益产生不利影响。  相似文献   

50a来洮河流域降水径流变化趋势分析   总被引：7，自引：2，他引：7  

张济世  康尔泗  蓝永超  陈仁升  姚尽忠  蒲瑞丰  陈满祥 《冰川冻土》2003,25(1):77-82

洮河流域 40多年水文实测资料分析表明 ,由于受气候变化及人类活动影响 ,流域降水和径流特征发生了明显变化 ,降水与径流总体呈下降趋势 ,其下降的线性斜率分别为 - 0 .86～ - 1.34mm·a-1和 - 1.5 7～ - 3.36m3·s-1·a-1;而气温呈缓慢上升趋势 ,其上升的线性斜率为 0 0 2℃·a-1.降水的减少和温度的升高已经导致甘南草原荒漠化 ,使许多湿地和湖泊干涸 ;径流的减少和温度增加在近2 0a来有进一步加剧的趋势 .  相似文献   

慕士塔格峰洋布拉克冰川消融的观测分析   总被引：6，自引：11，他引：6  

蒲健辰  姚檀栋  段克勤 《冰川冻土》2003,25(6):680-684

2001年7月4日至8月8日,在慕士塔格峰西侧的洋布拉克冰川海拔4600～4460m区间的冰舌段,进行了短期的冰面消融观测.慕士塔格峰冰川区暖期短,冰面强消融时期比较集中.观测期间,冰面纯消融厚度为640～1260mm水层,日平均消融厚度达26～39.6mm,推算冰舌区年消融量不低于1700～2000mm,比青藏高原内部的冰川消融强烈的多.7月21-22日出现最大消融值,在海拔4460m和4600m,日消融量分别为144.5mm和59.5mm.冰面消融随海拔上升而减小,日平均消融梯度:在裸露冰区为0.40～0.55mm·10m-1;在表碛覆盖区为0.21～3.53mm·10m-1,变幅较裸露冰区大.按裸露冰区的消融梯度计算出海拔4800m处的日平均消融量,和过去的研究资料比较,2001年冰面日平均消融量较1987年和1960年的消融量大,反映出慕士塔格峰区影响冰川消融的气候与全球气候变暖的特点是一致的.  相似文献   

0．7Ma以来的念青唐古拉山脉隆升过程——来自冰川剥蚀作用的证据   总被引：1，自引：0，他引：1  

朱大岗赵希涛  孟宪刚吴中海邵兆刚  冯向阳杨朝斌 王建平 《地质论评》2003,49(6):630-637

通过对念青唐古拉山冰碛地层划分及冰碛物同位素测年，发现最早一期冰碛物形成于0．7～0．6MaBP，指示自中更新世以来念青唐古拉山脉开始隆升，主峰地区发生了大规模的冰川剥蚀作用，形成了大面积分布的冰碛高平台；0．2～0．14MaBP念青唐古拉山又快速隆升，并堆积了刚刚伸出各大沟谷口的高侧碛；0．07～0．03MaBP念青唐古拉山再次小规模隆起，形成各大沟谷内的侧碛和终碛垄；0．01Ma BP还有小规模冰川活动。念青唐古拉山主峰地区的冰川剥蚀作用反映出的山脉隆升过程，可较好地与青藏高原的隆起过程相对比，它应是青藏高原隆升的响应。  相似文献   

Calibration of an oscillating nozzle‐type rainfall simulator     

Bofu Yu  Cyril A. A. Ciesiolka  Paul Langford 《地球表面变化过程与地形》2003,28(13):1483-1490

Nozzle‐type rainfall simulators are commonly used in hydrologic and soil erosion research. Simulated rainfall intensity, originating from the nozzle, increases as the distance between the point of measurement and the source is decreased. Hence, rainfall measured using rain gauges would systematically overestimate the rainfall received at the ground level. A simple model was developed to adjust rainfall measured anywhere under the simulator to plot‐wide average rainfall at the ground level. Nozzle height, plot width, gauge diameter and height, and gauge location are required to compute this adjustment factor. Results from 15 runs at different rain intensities and durations, and with different rain gauge layouts, showed that a simple average of measured rain would overestimate the plot‐wide rain by about 20 per cent. Using the adjustment factor to convert measured rainfall for individual gauges before averaging improved the estimate of plot‐wide rainfall considerably. For the 15 runs considered, overall discrepancy between actual and measured rain is reduced to less than 1 per cent with a standard error of 0·97 mm. This model can be easily tested in the ?eld by comparing rainfall depths of different sized gauges. With the adjustment factor they should all give very similar values. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Short‐term erosion rates from a 7Be inventory balance     

Christopher G. Wilson  Gerald Matisoff  Peter J. Whiting 《地球表面变化过程与地形》2003,28(9):967-977

Detailed soil erosion studies bene?t from the ability to quantify the magnitude of erosion over time scales appropriate to the process. An inventory balance for ⁷Be was used to calculate sediment erosion in a 30·73 m² plot during a series of runoff‐producing thunderstorms occurring over three days at the Deep Loess Research Station in Treynor, Iowa, USA. The inventory balance included determination of the pre‐ and post‐storm ⁷Be inventories in the soil, the atmospheric in?ux of ⁷Be during the event, and pro?les of the ⁷Be activity in the soil following the atmospheric deposition. The erosion calculated in the plot using the ⁷Be inventory balance was 0·058 g cm^?2, which is 23 per cent of the annual average erosion determined using ¹³⁷Cs inventories. The calculated erosion from the mass balance is similar to the 0·059 g cm^?2 of erosion estimated from the amount of sediment collected at the outlet of the 6 ha ?eld during the study period and the delivery ratio (0·64). The inventory balance of ⁷Be provides a new means for evaluating soil erosion over the time period most relevant to quantifying the prediction of erosion from runoff. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献