西北干旱区水中氟的分布规律及环境特征   总被引：20，自引：1，他引：19  

王根绪  程国栋 《地理科学》2000,20(2):153-159

西北干旱区天然水休事广泛分布以ＮａＦ和ＫＦ为主的氟特质。随干旱区内陆水系的产生、径流消亡,从山区至册前细土平原,Ｆ－的迁移分布具有显著的淋溶－径流 、径流－蒸发 与溶滤－蒸发浓缩富集３个水文化学分带;在白来者纱及第四系下更新统以来湖相沉积的湖盆洼地以及沙漠边缘地区,地下水中Ｆ－相对富集,且具有深部地下水Ｆ－含量大于浅层地下水及地表水的垂直分带性;Ｆ－的富集与贫化与水化学特征关系密切,一般情况下,低Ｓ  相似文献   

西部干旱区卫星雷达遥感找水试验研究   总被引：4，自引：0，他引：4  

王飞跃  王俊锋  吴军虎  万余庆 《国土资源遥感》2000,11(4):14-18,27

从地下水、土壤水和大气降水的相互关系出发,结合干旱区的气候特点,提出了西部干旱区土壤水主要受地下水补给的观点;根据微波对土壤水分敏感的特性,提出通过卫星雷达遥感技术探测地下水的思路。通过对典型干旱区的阿拉善左旗的试验研究,取得了理想的效果  相似文献   

Soil water movement and deep drainage through thick vadose zones on the northern slope of the Tianshan Mountain: Croplands vs. natural lands     

《China Geology》2020,3(1):113-123

Regional aridity is increasing under global climate change, and therefore the sustainable use of water resources has drawn attention from scientists and the public. Land-use changes can have a significant impact on groundwater recharge in arid regions, and quantitative assessment of the impact is key to sustainable groundwater resources management. In this study, the changes of groundwater recharge after the conversion of natural lands to croplands were investigated and compared in inland and arid region, i.e., the northern slope of the Tianshan Mountain. Stable isotopes suggest that soil water in topsoil (< 2 m) has experienced stronger evaporation under natural lands than croplands, and then moves downward as a piston flow. Recharge was estimated by the tracer-based mass balance method, i.e., chloride and sulfate. Recharge rates under natural conditions estimated by the chloride mass balance (CMB) method were estimated to be 0.07 mm/a in deserts and 0.4 mm/a in oases. In contrast, the estimated groundwater recharge ranged from 61.2 mm/a to 44.8 mm/a in croplands, indicating that groundwater recharge would increase significantly after land changes from natural lands to irrigated croplands in arid regions. Recharge estimated by the sulfate mass balance method is consistent with that from the CMB method, indicating that sulfate is also a good tracer capable of estimating groundwater recharge.  相似文献   

The PMIP3 Simulated Climate Changes over Arid Central Asia during the Mid‐Holocene and Last Glacial Maximum     

XU Hongn  WANG Tao  WANG Huijun  MIAO Jiapeng  CHEN Jianhui  CHEN Shengqian 《《地质学报》英文版》2020,94(3):725-742

In this study, the climate changes over Arid Central Asia(ACA) during the mid-Holocene(approximately 6,000 calendar years ago, MH) and the Last Glacial Maximum(approximately 21,000 calendar years ago, LGM) were investigated using multimodel simulations derived from the Paleoclimate Modelling Intercomparison Project Phase 3(PMIP3). During the MH, the multimodel median(MMM) shows that in the core region of ACA, the regionally averaged annual surface air temperature(SAT) decreases by 0.13°C and annual precipitation decreases by 3.45%, compared with the preindustrial(PI) climate. The MMM of the SAT increases by 1.67/0.13°C in summer/autumn, whereas it decreases by 1.23/1.11°C in spring/winter. The amplitude of the seasonal cycles of the SAT increases over ACA due to different MH orbital parameters. For precipitation, the regionally averaged MMM decreases by 5.77%/5.69%/0.39%/5.24% in spring/summer/autumn/winter, respectively. Based on the analysis of the aridity index(AI), compared with the PI, a drier climate appears in southern Central Asia and western Xinjiang due to decreasing precipitation. During the LGM, the MMM shows that the regionally averaged SAT decreases by 5.04/4.36/4.70/5.12/5.88°C and precipitation decreases by 27.78%/28.16%/31.56%/27.74%/23.29% annually and in the spring, summer, autumn, and winter, respectively. Robust drying occurs throughout almost the whole core area. Decreasing precipitation plays a dominant role in shaping the drier conditions, whereas strong cooling plays a secondary but opposite role. In response to the LGM external forcings, over Central Asia and Xinjiang, the seasonal cycle of precipitation has a smaller amplitude compared with that under the PI climate. In the model-data comparison, the simulated MH moisture changes over ACA are to some extent consistent with the reconstructions, further confirming that drier conditions occurred during that period than during the PI.  相似文献   

The exploitation of an arid landscape by a pastoral society: the contemporary eastern Badia of Jordan     

Alan G. Rowe 《Applied geography (Sevenoaks, England)》1999,19(4):101

The paper reconsiders the use of arid landscapes as a resource by pastoral societies in the light of recent socioeconomic developments, using Bedouin livestock herding in the Jordanian Badia as a case study of a pastoral system in transition. The paper argues that in the contemporary Badia context, landscape is exploited by users in a wide variety of ways, and for the acquisition of both tangible and non-tangible resources. The study concludes that the modernization and commercialization of livestock production in the Badia does not necessarily imply a diminishing of ties between herder and land resources, and suggests instead that the process of modernization in livestock production may in fact generate a wider spectrum of options for its exploitation.  相似文献   

论干旱区农业走内涵式发展道路的意义   总被引：6，自引：1，他引：5  

姜逢清 《中国沙漠》1999,19(1):78-81

根据干旱区生态环境的特点,讨论了农业内涵式发展与外延式发展的区别,同时结合新疆等一些干旱地区的具体情况,分析了单纯走外延式农业发展道路的弊端与局限性,并重点讨论了在实行农业内涵式发展的重要意义。指出内涵式发展模式为干旱区农业持续发展的最佳模式。从该模式的自身特点来看,在干旱区农业发展过程中,采用这一模式将更加符合干旱区资源的持续利用与经济的持续发展原则。  相似文献   

1975-2007年中亚干旱区内陆湖泊面积变化遥感分析   总被引：8，自引：2，他引：6  

白洁  陈曦  李均力  杨辽 《湖泊科学》2011,23(1):80-88

中亚干旱区内陆湖泊的湖面变化反映了气候波动和人类活动对流域水文过程的影响.本文以中亚干旱区平原区尾闾湖泊、吞吐湖泊和高山湖泊三类典型内陆湖泊为研究对象,利用1975-2007年Landsat遥感影像,基于归一化水体指数提取湖泊水域边界信息,分析近30年来内陆湖泊湖面变化特征.结果表明,近30年来,研究区内有超过一半的内...  相似文献   

干旱区湖泊沉积物中过剩²¹⁰Pb的沉积特征与风沙活动初探   总被引：1，自引：0，他引：1  

陈永福  赵志中 《湖泊科学》2009,21(6):813-818

过剩~(210)Pb不仅是沉积物年龄测定的重要手段,而且是环境示踪的一种主要方法,干旱区湖泊主要为封闭湖泊,其沉积物所接受的过剩~(210)pb沉积在大气沉降背景外,主要受风沙侵蚀来源的影响.因此,较高的过剩~(210)Pb沉积通量有可能与区域风沙活动有关.本文在对比分析近几年来发表在各期刊中的湖泊~(210)Pb数据的基础上,计算各个湖泊多年平均过剩~(210)Pb的沉积通量并与大气过剩~(210)Pb沉降背景比较,从而初步确定中国北方干旱区风沙活动的可能区域.然后对所确定的典型风沙多发区,利用过剩~(210)Pb模式(PF-CRS)计算沉积物沉积速率,并与相应区域的"尘暴"记录对比,进而论证该方法在指示风沙活动方面的可靠程度.  相似文献   

末次间冰期亚洲中部干旱区干湿变化的模拟研究          下载免费PDF全文

江南萱  燕青  王会军 《大气科学学报》2023,46(1):55-68

利用国际古气候模拟对比计划第四阶段的多模式结果,分析了末次间冰期亚洲中部干旱区的干湿变化及机制。多模式集合平均结果表明,末次间冰期亚洲中部干旱区年降水减少0.7%,其中中亚地区的年降水减少2.8%,新疆地区年降水增加1.8%。水汽收支方程表明,末次间冰期中亚地区在雨季(冬春季)的降水变化主要与垂直动力项有关,新疆地区在雨季(夏季)的降水变化主要与垂直动力与热力项有关。此外,基于Penman-Montieth方法计算的亚洲中部干旱区的干旱指数在末次间冰期减小约10.2%,表明末次间冰期亚洲中部干旱区气候明显变干且存在旱区扩张的现象,这主要受到潜在蒸散变化的调控。潜在蒸散的增加进一步受到有效能量增加与地面风速增大的调控。本研究从模拟的角度揭示了末次间冰期亚洲中部干旱区干湿变化的可能特征及机制,在一定程度上有助于理解旱区气候在增暖情景下对轨道参数的响应特征。  相似文献   

西北干旱区夏季大气边界层结构及其陆面过程特征   总被引：18，自引：3，他引：15  

张强  王胜 《气象学报》2008,66(4):599-608

在中国西北干旱区影响大气边界层形成和发展的气候环境和大气环流背景都具有一定特殊性.文中用外场观测试验资料,分析了位于西北干旱区的敦煌荒漠夏季大气边界层气象要素结构特征,发现该地区无论白天的对流边界层还是夜间的稳定边界层均比一般地区更深厚.在夏季晴天,夜间稳定边界层厚度超过900 m,最厚可以达到1750 m,其上的残余层一般能达到4000 m左右的高度;白天混合层最高达3700 m,混合层顶的逆温层顶盖的厚度大约450 m,甚至更厚,对流边界层厚度能够超过4000 m,对流边界层进入残余层后发展十分迅速.研究表明,白天深厚的对流边界层是夜间保持清晰而深厚的残余混合层的先决条件,夜间深厚的残余混合层又为白天对流边界层的发展提供了一个非常有利的热力环境条件.该地区经常性出现连续性晴天使得大气残余层的累积效应得以较长时间持续发展,创造了比较有利于大气对流边界层发展的大气热力环境条件.同时,该地区陆面过程和近地层大气运动特征也为这种独特的大气热力边界层结构提供了较好的支持.就该地区发展超厚大气对流边界层的物理机理而言,地表显著增温是强有力的外部热力强迫条件,近地层强感热通量提供了较充足的能量条件,较大的对流运动和湍流运动的速度是必要的运动学条件,大气残余层的累积效应提供了有利的热力环境条件.  相似文献