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 共查询到17条相似文献,搜索用时 62 毫秒
1.
THECLIMATICCONDITIONSOFPOLAR-TYPEGLACIERSDEVELOPMENTINCHINA¥HuangMaohuan(黄茂桓)(LanzhouInstituteofGlaciologyandGeocryology,theC...  相似文献   

2.
THEORIGINANDCHARACTERISTICSOFTHEGLACIALDEBRISFLOWINTHEDUKUHIGHWAYOFTIANSHANMOUNTAINS,CHINA¥XiongHeigang(DepartmentofGeography...  相似文献   

3.
The evolution of the inland lakes in arid and semi-arid zones is accorded with the climatic fluctuation. The humid climate is in harmony with the higher water level and greater lake water quantity budget while arid climate is in correspondence with the lower water level and little water budget. Based on the analysis of the lake fluctuation and lake budget change, with the aid of the data of geom'orphology, palynology, sedimentology and chronology, It is found that the climate experienced a warm and humid period during 7000-3500 yr. B. P. and showed a drying and warming trend in the last century in the Central Asia.  相似文献   

4.
CLIMATIC VARIATIONS IN CHINA OVER THE LAST 2000 YEARS   总被引:4,自引:0,他引:4  
1 INTRODUCTIONIn the last years, evidence for climate changes showed that the timing of the two great climatic events of “Medieval Warm Period” (MWP) and “Little Ice Age” (LIA) differed geographically (HUGHES et al., 1994, JONES and BRADLEY, 1992). In other words, the cold or warm periods in one region were often not coincident with those in other regions. The Northern Hemisphere warmth degree in the Middle Ages was lower than or at most comparable to that in the mid-20…  相似文献   

5.
The Huanghe and Yongding rivers were formed before the early and middle Pliocene epoch. Then they became interior rivers because of the appearance of interior fault lake basins at the end of the Pliocene epoch. The interior flow period continued until the end of the early Pleistocene or the middle pf the Middle Pleistocene, and then they changed into the exterior rivers again till today.  相似文献   

6.
This paper deals mainly with the water resources of China's lakes scattered over five drainage basins with a total area of 71,787 km2 and a total storage capacity of 7,088 million m8, the fresh water capacity of which amounts to about 2,261 million m3, varying from year to year or even within a year. Attention should be paid to the reasonable utilization of water resources and the problems that have already emerged should be carefully and skillfully handled.  相似文献   

7.
THECAUSESANDDEVELOPMENTALTRENDOFDESERTIFICATIONINTHEMIDDLEREACHESOFTHEYARLUNGZANGBORIVERANDITSTWOTRIBUTARIESINXIZANGDongGuang...  相似文献   

8.
The concentrations of Zn, Cd, Pb, Cu ions are shown to be similar in natural waters of Tianshan Mountains and Qinghai-Tibet plateau and to be similar in those of the sea water. The average and variability of concentrations of trace metal ions in fresh water are Zn 5.7±1.5, Cd 0.092±0.038, Pb 0.048±0.011, and Cu 1.1±0.20 ppb. The average concentrations in the East China Sea are Zn 7.3 (5.5 in 1976), Cd 0.12, Pb 0.036, and Cu 0.94 ppb. It proves that the homogeneous distribution of trace metal ions (free ion and unstable complexes) in natural waters is present in the nature as a rule.  相似文献   

9.
The effects of using different types of glass fiber filters (GF/F, GF/C) and of sample treatments evaluated. Studies on the variation of suspended matter (SM) and particulate organic carbon (POC) showed that: 1) the transversal and day to night variations are important and must be taken into account in order to get a corrcet river flux; 2) no regular seasonal variations of SM and POC observed, as they are controlled essentially by the climatological, hydrologic, physiochernical, biological, and geological conditions of the drainage area.  相似文献   

10.
There are 37 lakes in the Qaidam Basin: 1 freshwater lake, 6 brackish-water lakes, 2 saline-water lakes and 28 salt lakes.The pH value of salt lake brines is 7.014 on the average, and the average total mineralization is 340.75 g/1. Their water bodies belong mainly to the five-component equilibrium system, :Na, K, Mg//SO4, Cl-H2O, which can be further grouped into sodium-magnesium sulfate subtype, magnesium sulfate subtype, chloride transition subtype and chloride type water by their hydrochemical property. The salt lake brines of the first salt forming epoch (N2-Q3) were of the sulfate type. In the second salt forming epoch (Q3-Q4), some of them were of the chloride type.The pH value of brines decreases with the increase of total mineralization. The pH value is lower when the total mineralization is from 50-310 g/1 and higher when the total mineralization is from 310-355 g/l, however, when the total mineralization is higher than 355 g/1, the pH value decreases slowly again.The total mineralization of th  相似文献   

11.
使用区域气候模式RegCM3,进行植被变化对中国区域气候影响的数值模拟试验。模拟结果表明:植被退化使气候变得更加恶劣,退化区降水减少,大气变得干燥,气温升高;而植被增加使得降水增加,大气湿度增大,气温降低。地表植被的变化可通过地气问相互作用激发出大气偏差风环流,从而影响大范围气候,乃至全球气候。  相似文献   

12.
植被变化引起我国气候变化的数值模拟   总被引:1,自引:0,他引:1  
使用区域气候模式RegCM3,进行植被变化对中国区域气候影响的数值模拟试验。模拟结果表明:植被退化使气候变得更加恶劣,退化区降水减少,大气变得干燥,气温升高;而植被增加使得降水增加,大气湿度增大,气温降低。地表植被的变化可通过地气问相互作用激发出大气偏差风环流,从而影响大范围气候,乃至全球气候。  相似文献   

13.
Studiesshowthattheglobalsurfacetemperaturewilriseatarateof0.3℃per10ainthenextseveraldecades(Houghtonetal.,1990,1992;Shi,1995;...  相似文献   

14.
以青藏高原西南部塔若错的34cm浅湖芯为研究对象,对其沉积物样品进行总有机碳、无机碳、总氮、微量元素、正构烷烃含量及碳氮比等多项指标的分析测定。采用过剩210 Pb和137 Cs计年法对该湖芯进行了定年和沉积速率研究,获得了近300年的连续湖泊沉积环境序列。在明确了各指标气候环境指示意义的前提下,综合对比分析湖芯中各项气候环境指标,并结合定年结果重建了塔若错湖区近300年来的气候环境变化。结果表明:塔若错湖区气候环境变化可分为3个明显阶段:早期为1705~1778年,该地区气候环境温暖湿润,湖区植被广泛发育;中期为1778~1860年,湖区处于小冰期末次阶段,气候环境寒冷而湿润,植被发育受阻;后期为1860年至今,为小冰期结束后偏暖干化时期。其中,后期又可分为3个亚阶段:1860~1924年,湖区气候环境稍暖且干旱,植被稍有发育;1924~1969年,湖区气候环境呈现偏冷干特点,植被发育暂缓;1969年至今,湖区气候回暖,环境干旱化有所缓解,植被开始逐渐发育。在气候冷暖变化上,该湖芯记录与古里雅冰芯记录和青海湖湖泊沉积记录都有较好的可对比性,只是在起讫年代上存在一些差异。  相似文献   

15.
I INTRODUCTIONThe second longest river in China is the Huanghe(Yellow) River on the north of Mt Bayankala on theQinghai-Xizang (Tibet) Plateau. It winds its way through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan, Shandong, and emptiesinto the Bobal Sea at Kenli County of ShandongProvince. It has a total length of 5464km with adrainage area of 752 443km2. The rushing currentsfrom Longyangxia Gorge to Qingtongxia Gorge in itsupper reaches, running g…  相似文献   

16.
成都平原中西部近40年气候特征及其变化研究   总被引:6,自引:1,他引:6  
利用成都平原中西部5个气象观测站的降水、温度和日照资料,分析了成都平原中西部降水、温度和日照的分布规律、气候特征及其变化,得出以上地区年平均气温存在准4年的振动周期;1990年以来大部分地区存在降水减少,气温升高,日照减少的现象.  相似文献   

17.
川渝地区夏季降水变化气候特征分析   总被引:2,自引:0,他引:2  
利用川渝地区34站1960—2006年共计47年的逐月降水量资料,采用经验正交函数(BOF)分解、旋转经验正交函数(REOF)分解、小波分析等方法详细讨论了川渝地区夏季降水量的时空变化特征。结果表明:川渝地区夏季降水量时空分布不均,川渝地区夏季降水量可以分为3个区,分别是川西高原区、盆地中部区和盆地东部区。近50年来,川渝地区夏季降水量具有显著不同的年代际变化特征,川西高原和盆地东部夏季降水量长期变化呈增加的趋势,而盆地中部呈减少的趋势。川渝各区夏季降水量具有显著不同的多时间尺度的周期变化特征,其中川西高原具有准15年和准5年的周期变化特征,盆地中部具有准14年、准6年和准3年的周期变化,盆地东部具有准16年、准8年和准3年的周期变化特征。  相似文献   

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