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1.
起伏地形下黄河流域太阳散射辐射分布式模拟研究   总被引:6,自引:0,他引:6       下载免费PDF全文
针对天文、大气、宏观地理与局地地形等因子对起伏地形下太阳散射辐射的复杂作用,将影响起伏地形下太阳散射辐射的天空因素与地面因素分开处理.通过基于数字高程模型(DEM)数据的起伏地形下天文辐射模型和地形开阔度模型,综合考虑地面因素对散射辐射的影响;基于常规地面气象站观测资料建立的水平面散射辐射模型考虑天空因素对散射辐射的影响;依据各向异性散射机理,建立了起伏地形下太阳散射辐射分布式计算模型,探索出一条利用DEM数据和常规气象观测资料实现山区太阳散射辐射定量模拟的技术路线.以1 km×1 km分辨率的DEM数据作为地形的综合反映,实现了起伏地形下黄河流域1 km×1 km分辨率的太阳散射辐射分布式模拟.  相似文献   

2.
复杂地形下黄河流域月平均气温分布式模拟   总被引:3,自引:0,他引:3  
通过对常规气象站月平均气温资料的分析,发现在影响气温的众多因素中,海拔高度、太阳总辐射、地表长波有效辐射对气温具有显著影响.建立了月平均气温的物理经验统计模型,结合复杂地形下太阳总辐射分布式模拟结果,提出了依托常规地面气象观测资料实现复杂地形下月平均气温分布式模拟的方法,生成了黄河流域1km×1km分辨率月平均气温、月平均最高气温、月平均最低气温的空间分布图.分析表明,模拟结果能较好地反映气温的宏观分布趋势和局地分布特征.交叉验证结果表明,模型具有很好的稳定性,各月平均气温、月平均最高气温、月平均最低气温的模拟误差平均为0.19~0.35℃;加密站验证和个例年验证表明,模型具有良好的空间维和时间维模拟能力.提出的月平均气温分布式模型立足于常规地面气象观测资料,不依赖于山地野外考察资料,可以方便地在广大地区推广应用.  相似文献   

3.
起伏地形下天文辐射分布式估算模型   总被引:20,自引:1,他引:20       下载免费PDF全文
基于数字高程模型(DEM),建立了起伏地形下天文辐射分布式估算模型.模型全面考虑了地形因子对天文辐射的影响,只需DEM数据作为输入项,适用于遥感图像处理、地理信息系统等数据处理平台.以1km×1km分辨率的DEM数据作为地形的综合反映,计算了我国全年各月天文辐射的空间分布.结果表明:我国年天文辐射总量有明显的纬向分布特点,随着纬度的降低,年天文辐射总量由北向南增加;由于受坡向、坡度和地形遮蔽因子影响,山区天文辐射表现出非地带性分布特征.本文所提供的我国天文辐射数据产品,可作为基础地理数据供相关研究应用.  相似文献   

4.
南黄海北部盆地中、新生代构造热演化史模拟研究   总被引:1,自引:2,他引:1       下载免费PDF全文

盆地深部地球动力学过程控制和影响着浅部的构造热演化过程,针对南黄海北部中、新生界断陷盆地,将地球动力学模拟技术与传统古温标法相结合,对研究区中、新生代伸展断陷期演化以来的构造热演化史进行了研究.对基于改进McKenzie模型的数值模拟的原理、方法和过程进行了探讨,包括理论与计算构造沉降趋势拟合、伸展系数计算与误差校正、模拟参数定义及一维模拟结果的三维初步应用等方面.研究表明,南黄海北部盆地中生代以来伴随裂陷拉张过程其古热流整体呈现升高趋势,至晚白垩世末到古新世期间最高可达80 mW·m-2,古地温梯度最高可达49 ℃/km,部分单井构造沉降史模拟结果显示多期拉张特征,裂后期热流持续降低,至渐新世末到中新世热流约为65 mW·m-2,与现今热流值相当.利用一维数值模拟获取的相应参数及热史恢复结果,对盆地的古地温场进行了三维模拟恢复,取得了较好的应用效果,研究方法和成果对于盆地构造演化、油气资源评价及成藏模拟等均有重要意义.

  相似文献   

5.
郭羽羽  李思悦  刘睿  张静 《湖泊科学》2021,33(3):737-748
为探究不同时空尺度土地利用与水质的相互关系,以黄河流域为研究对象,基于2018年河流水质与土地利用数据,提取3种空间尺度(1000 m河段缓冲区、500 m河岸带缓冲区、子流域)的景观格局指数,结合4个季节河流水质指标,采用冗余分析方法定量探讨土地利用对河流水质的多时空尺度影响,获得水质资源管理最有效的时空尺度.结果表...  相似文献   

6.
ABSTRACT

The summer precipitation (June–September) in the source region of the Yellow River accounts for about 70% of the annual total, playing an important role in water availability. This study divided the source region of the Yellow River into homogeneous zones based on precipitation variability using cluster analysis. Summer precipitation trends and teleconnections with global sea-surface temperatures (SST) and the Southern Oscillation Index (SOI) from 1961 to 2010 were investigated by Mann-Kendall test and Pearson product-moment correlation analysis. The results show that the northwest part (Zone 1) had a non-significantly increasing trend, and the middle and southeast parts (zones 2 and 3) that receive the most precipitation displayed a statistically significant decreasing trend for summer precipitation. The summer precipitation in the whole region showed statistically significant negative correlations with the central Pacific SST for 0–4 month lag and with the Southern Indian and Atlantic oceans SST for 5–8 month lag. Analyses of sub-regions reveal intricate and complex correlations with different SST areas that further explain the summer precipitation variability. The SOI had significant positive correlations, mainly for 0–2 months lag, with summer precipitation in the source region of the Yellow River. It is seen that El Niño Southern Oscillation (ENSO) events have an influence on summer precipitation, and the predominant negative correlations indicate that higher SST in equatorial Pacific areas corresponding to El Niño coincides with less summer precipitation in the source region of the Yellow River.
Editor Z.W. Kundzewicz; Associate editor D. Gerten  相似文献   

7.
李华贞  张强  顾西辉  史培军 《湖泊科学》2018,30(4):1138-1151
根据黄河流域1960—2005年5个水文站逐日流量、77个气象站1959—2013年逐日降水数据,结合流域内主要农作物种植面积及大型水库资料,全面探讨气候与农业面积变化及人类活动对黄河流域径流变化的影响.研究表明:黄河流域所有流量分位数总体呈下降趋势,并于1980s中后期到1990s中期发生突变.降水变化是黄河流域径流变化的主要影响因素.在考虑不同流量分位数情况下,农作物种植面积变化对不同分位数径流变化的影响也有差异性.花园口站农作物种植面积变化对径流量量级和可变性均有显著影响;其余4站各项气候变化与农作物种植指标参数较大,虽均未达到10%的显著性水平,但仍会对径流的量级变化产生影响.对唐乃亥站,农作物耕作面积的下降减少了灌溉用水,在0.5流量分位数时有高达60%增加径流量的间接作用.对于头道拐站,农作物耕作面积的增加使得流域总蒸发量增加,灌溉用水增加,在0.3流量分位数时有高达40%减少径流量的间接作用.该研究为气候变化与人类活动影响下黄河流域水资源优化配置提供重要理论依据.  相似文献   

8.
Based on the regional water resources character, the concept of soil water resources is first redefined, and then associated with their transfer relationship in the hydrological cycle, Evapotranspiration (ET)-based consumption structure and consumption efficiency of soil water resources are analyzed. According to ET 's function in productivity, the consumption efficiency of soil water resources is di- vided into three classes: high efficient consumption from vegetation transpiration, low efficient con- sumption from soil evaporation among plants with high vegetation coverage and inefficient consump- tion from soil evaporation among plants with low vegetation coverage and bare soil evaporation. The high efficient and low efficient consumption were further classified as productive consumption. The ineffi- cient consumption is considered non-productive consumption because it is significant in the whole hydrological cycle process. Finally, according to these categories, and employing a WEP-L dis- tributed hydrological model, this paper analyzes the consumption efficiency of soil water resources in the Yel- low River Basin. The results show that there are 2078.89×108 m3 soil water resources in the whole basin. From the viewpoint of consumption structure, the soil water resources are comprised of 381.89×108 m3 transpiration consumption from vegetation and 1697.09×108 m3 evaporation consumption from soil among plants and bare soil. From the viewpoint of consumption efficiency, soil water re- sources are composed of 920.11×108 m3 efficient consumption and 1158.86×108 m3 of inefficient con- sumption. High efficient consumption accounts for 41.5 percent of the total efficient consumption of the whole basin, low efficient for 58.5 percent. Furthermore, consumption efficiency varies by region. Compared with ET from different land use conditions, the whole basin appears to follow the trend of having the greatest proportion of consumption as inefficient consumption, followed by low efficient consumption, and then the least proportion as high efficient consumption. The amount of inefficient consumption in some regions with vegetation is less than in other regions without vegetation. The amount of inefficient consumption in grasslands is much greater than in forestlands. However, the proportion of low efficient consumption is the greatest in crop fields. The amount of high efficient con- sumption in grasslands and forelands is similar to the corresponding low efficient consumption. However, the low efficient consumption in grasslands is larger than in the forelands. Therefore, when adjusting the utilization efficiency of soil water resources, vegetation coverage and plant structure should be modulated in terms of the principle of decreasing inefficient consumption, improving low efficiency ET and increasing high efficiency ET according to area character.  相似文献   

9.
On the basis of the mean air temperature, precipitation, sunshine duration and pan evaporation at 23 meteorological stations in the headwater catchment of the Yellow River basin from 1960 to 2001, the long‐term monotonic trend and abrupt changes for major climate variables have been investigated. The plausible monotonic trend of annual climatic time series are detected using a non‐parametric method. The abrupt changes have been investigated in terms of a 5 year moving averaged annual series, using the moving t‐test (MTT) method, Yamamoto method and Mann–Kendall method. The results showed that the annual air temperature has increased by 0·80 °C in the headwater catchment of the Yellow River basin during the past 42 years. One obvious cold period and one warm period were detected. The warmest centre was located in the northern part of the basin. The long‐term trend for annual precipitation was not significant during the same period, but a dry tendency was detected. According to the Kendall slope values, the declining centre for annual precipitation was located in the eastern part and the centre of the study area. The long‐term monotonic trend for annual sunshine duration and pan evaporation were negative. The average Kendall slopes are ? 29·96 h/10 yr and ? 39·63 mm/10 yr, respectively. The tests for abrupt changes using MTT and Yamamoto methods show similar results. Abrupt changes occurred in the mid 1980s for temperature, in the late 1980s for precipitation and in the early 1980s for sunshine duration and pan evaporation. It can be seen that the abrupt changes really happened in the 1980s for the climate variables. Different results are shown using the Mann–Kendall method. Both the abrupt changes of temperature and precipitation took place in the early 1990s, and that of pan evaporation occurred in the 1960s. The only abrupt change in sunshine duration happened during the similar period (in the 1980s) with the results detected by the MTT and Yamamoto methods. The abrupt changes which occurred in the 1990s and 1960s are not detectable using the MTT and Yamamoto methods because of the data limitation. However, the results tested by the MTT and Yamamoto methods exhibited great consistency. Some of the reasons may be due to the similar principles for these two methods. Different methods testing the abrupt climatic changes have their own merits and limitations and should be compared based on their own assumption and applicable conditions when they are used. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

10.
The temporal trends of reference evapotranspiration (ETref) reflect the combined effects of radiometric and aerodynamic variables, such as global solar radiation (Rs), wind speed, relative humidity and air temperature. The temporal trends of annual ETref during 1961–2006 calculated by Penman‐Monteith method were explored and the underlying causes for these trends were analysed in the Yellow River Basin (YRB). The contributions of key meteorological variables to the temporal trend of ETref were detected using the detrended method and then sensitivity coefficients of ETref to meteorological variables were determined. For ETref, positive trends in the upper, middle and whole of YRB, and significant negative trend (P = 0·05) in the lower basin were obtained by the linear fitted model. Significant increasing trend (P = 0·05) in air temperature and decreasing trend in relative humidity were the main causes for the increasing trends of ETref in the upper, middle and whole basins. For the whole basin, the increasing trend of ETref was mainly caused by the significant increase (P = 0·05) in air temperature and to a lesser extent by a decrease in the relative humidity, decreasing trends of Rs and wind speed reduced ETref. The spatial distribution of sensitivity coefficients addressed that the sensitive regions for ETref response to the changes of the four meteorological variables are different in the YRB. The sensitive region lay in the upper basin for Rs, the northwest portion of the middle basin for wind speed, the south portion of YRB for relative humidity and the west portion of the upper basin and the north portion of the middle basin for air temperature. In general, Rs was the most sensitive variable for ETref, followed by relative humidity, air temperature and wind speed in the basin scale. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

11.
我国滑坡灾害频发,尤其是西部地区,滑坡的隐蔽性强且危害巨大,对其灾害隐患进行早期识别对防灾减灾意义重大.传统的人工排查、大地测量等手段在山区难以开展且耗时耗力,合成孔径雷达干涉测量技术(InSAR)作为新兴的遥感测量手段,可以更精确、高效地进行大范围的滑坡灾害隐患识别.以黄河流域刘家峡-兰州段为研究区,采用永久散射体I...  相似文献   

12.
A series of independent faulted basins developed in the present middle reaches of the Yellow River during late Cenozoic, among which the Sanmen Lake Basin is located in the east edge of the Loess Plateau, a transitional zone between the second and third macromorphological step of China. The thick strata of the Sanmen Group deposited in the large basin. The Sanmen Group is a perfect place for the study on paleoenvironmental change, tectono-climatic cycles as well as the formation and evolution of the Yellow River. In this paper, the paleoenvironmental changes, regional tectonic movement and the evolutionary process of the Sanmen Lake Basin during the past 5 Ma were reconstructed based on the analysis of paleomagnetic stratigraphy, pollen, TOC and carbonate content from the Huangdigou outcrop near the Sanmenxia Reservoir, Pinglu County, Shanxi Province. The sedimentary records from the outcrop indicate that the basin was first formated by fault activity at about 5.4 MaBP, and after the strong tectonic movement at 3.6 MaBP the lake enlarged and the rainfall of summer monsoon increased. There was no great climatic transition near 2.6 MaBP, corresponding to the bottom age of loess in the Loess Plateau. After Olduvai event (about 1.77 MaBP) the Picea and Abies were presented in the sediments, which indicates a colder climate. The tectonic movement at 1.2 MaBP caused the light angular discordance between the upper and lower Sanmen Group. The sedimentary records show a cold and wet climate during the prosperous periods of loess accumulation such as L15, L9, L6. The tectonic intensification periods of the Sanmen Basin correspond with the tectonic movements in the Qinghai-Xizang Plateau chronologically. The earliest age of the outflow from the Paleo-Sanmen Lake or the partly cutting off of the Sanmenxia Gorge was about 0.41- 0.35 MaBP. The age of cutting thoroughly the Sanmenxia Gorge by the Yellow River and the disappearance of the Paleo-Sanmen Lake was about 0.15 MaBP, which symbolized the formation of the present Yellow River and had an important influence on the environmental and morphological evolution in the middle and lower reaches of the Yellow River.  相似文献   

13.
Regional evapotranspiration is an important component of the hydrological cycle. However, reliable estimates of regional evapotranspiration are extremely difficult to obtain. In this study, the evapotranspiration simulated by three complementary relationship approaches, namely the Advection–Aridity (AA) model, the Complementary Relationship Areal Evapotranspiration (CRAE) model and the Granger (G) model, is evaluated with the observations over the Yellow River basin during 1981–2000. The simulations on overall annual evapotranspiration are reasonably good, with mean annual errors less than 10% except in extreme dry years. The AA model gives the best estimation for the monthly evapotranspiration, and the CRAE and GM models slightly overestimate in winter. In addition, the AA model presents the same closure error of water balance over the Yellow River basin as model G, which was less than that by the CRAE model. In rather dry and rather wet cases (with higher or lower available energy), all three models perform less well. Empirical parameters of these models need to be recalibrated before they can be applied to other regions. The distribution of evapotranspiration over the Yellow River basin is also discussed. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

14.
长江流域降水极值时间序列的分布特征   总被引:3,自引:0,他引:3  
苏布达  姜彤 《湖泊科学》2008,20(1):123-128
在1960-2005年长江流域147气象观测站汛期4-9月逐日降水资料基础上,通过计算逐站大于95th强降水及其间隔天数、小于1.27mm/d的持续天数,分析长江流域降水极值时间序列的时空分布特征,并建立概率分布模式.研究发现,长江上游四川盆地附近及中下游鄱阳湖流域东南部是汛期强降水中心,也是长江流域强降水最集中发生的地区.汛期降水强度小于1.27mm/d的天数,在上游干流、岷沱江流域、乌江上游地区为多.但此处干旱持续天数最短,干旱形式并不严重.而在金沙江上、下游,洞庭湖流域,鄱阳湖流域东南部支流及下游干流区干旱持续天数较长.长江流域大于95th强降水的间隔天数与小于1.27mm/d的干旱持续天数服从Weibull-Ⅱ型分布.分布参数变化的模式较准确的反映降水极值时间序列的时空变化特征.  相似文献   

15.
In this research, the regional extreme‐dry‐spell frequency in the middle reaches of the Yellow River Basin (YRB) is studied by the L‐moments method. The research area has been divided into three subregions (regions 1, 2 and 3), which have been identified as homogenous regions. The results of a goodness‐of‐fit test indicate that a generalized normal distribution is the optimal regional model for regions 1 and 2 whereas a generalized Pareto distribution is the optimal regional model for region 3. The return period analysis figures out that the maximum length‐of‐dry‐spell (MxDS) values increase from south to north in the southern part and increase from northeast to southwest in the northern part of the middle reaches of the YRB under different return periods. The increments of quantiles of dry spell under different return levels indicate that drought risk in region 1 is higher than that in regions 2 and 3. The analysis of the occurrence day of MxDS shows that MxDS mostly occurred during winter of 1998 and spring of 1999 in most stations during the considered period. By comparing summer MxDS events, it can be found that mean MxDS values have slightly increased in regions 1 and 2 during the last five decades. The maximum mean MxDS values appeared in the 2000s for regions 1 and 2 and in the 1990s for region 3. The atmospheric circulation shows that the positive anomaly centre in the west of North China, negative anomaly centre in the east of North China and the strong western Pacific subtropical high led to the decrease of precipitation in North China during the summer of 1997. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

16.
南海北部珠江口与琼东南盆地构造-热模拟研究   总被引:6,自引:3,他引:6       下载免费PDF全文
珠江口盆地和琼东南盆地位于南海北部的大陆边缘,本文在此地区选取了13条典型剖面,进行了构造沉降史和热史的模拟,初步探讨了其新生代以来的构造-热演化历史.其研究结果表明:珠江口盆地存在两次热流升高过程,分别为始新世(56.5~32 Ma)和渐新世(32~23.3 Ma).琼东南盆地存在三期加热和两期冷却过程,始新世盆地热流缓慢升高,渐新世西部地区热流持续升高,而东部地区热流升高持续至16 Ma,并在5.4 Ma以来存在一期快速沉降,由西向东加热事件逐渐变弱.南海北部陆缘存在多期次裂谷作用、热流升高的特征;"热沉降"阶段也非完全处于热衰减期,晚期也存在热流升高的加热事件,这些都有别于典型的被动大陆边缘盆地的热演化模式.  相似文献   

17.
Tao Gao  Huailiang Wang 《水文研究》2017,31(13):2412-2428
The Mann–Kendall test, composite analysis, and 68 high‐quality meteorological stations were used to explore the spatiotemporal variations and causes of precipitation extremes over the Yellow River basin (YRB) during the period of 1960–2011. Results showed that (a) the YRB is characterized by decreases of most precipitation indices, excluding the simple daily intensity index, which has increasing trends in most locations, suggesting that the intensity of rainfall and the probability of occurrence of droughts have increased during the last decades. (b) Trends of extreme precipitation show mixed patterns in the lower reach of the YRB, where drought–flood disasters have increased. The increases in heavy rainfall and decreases in consecutive wet days in recent years over the northwestern portions of the YRB indicate that the intensity and frequency of above‐normal precipitation have been trending upward in domains. In the central‐south YRB, the maximum 1‐day precipitation (RX1day) and precipitation on extremely wet days (R99p) have significantly increased, whereas the number of consecutive dry days has declined; these trends suggest that the intensity of precipitation extremes has increased in those regions, although the frequency of extreme and total rainfall has decreased. (c) The spatial distributions of seasonal trends in RX1day and maximum 5‐day precipitation (RX5day) exhibited less spatial coherence, and winter is becoming the wettest season regionwide, particularly over the central‐south YRB. (d) There were multiple and overlapping cycles of variability for most precipitation indices, indicating variations of time and frequency. (e) Elevation is intimately correlated with precipitation indices, and a weakening East Asian summer monsoon during 1986–2011 compared to that in 1960–1985 may have played an important role in the declines in most indices over the YRB. Therefore, the combined effects from local and teleconnection forcing factors have collectively influenced the variations in precipitation extremes across the YRB. This study may provide valuable evidence for the effective management of water resources and the conduct of agricultural activities at the basin scale.  相似文献   

18.
依据行星对应区理论模型,以1900—2014年期间我国黄河流域发生的31个7级以上大地震为例,计算了对应年份的火星视位置、冲日位置以及月球回归赤纬,研究了火星视位置、冲日位置对大地震的影响规律。结果表明:(1)在月球回归赤纬角的天文背景下,火星冲日是触发大地震的第2个主要天文因子,黄河流域大地震受火星冲日位置的影响很明显;(2)火星视赤纬介于20°~22°之间时,是黄河流域的无震期,特别是在该视位置范围内冲日时,黄河流域不会发生大震;(3)火星在其它流域冲日时,如果月球回归赤纬也不对应黄河流域,则该流域将会发生大地震。诸天文因子共同作用,构成了某流域是否发生大震的先决条件。  相似文献   

19.
王昊  冉祥滨  臧家业  刘军  曹磊  刘森  马永星 《湖泊科学》2018,30(5):1246-1259
根据长江与黄河各一个完整水文年的调查数据,并结合历史资料分析了我国这两条大型河流活性硅((RSi,RSi=溶解硅(DSi)+生物硅(BSi))的入海通量及长时间序列的变化规律与影响因素.结果表明,长江与黄河RSi的组成存在显著的差异,二者水体中BSi/RSi的平均比值分别为0.22和0.49;黄河DSi的年平均浓度为长江的74%,而BSi年平均浓度却是长江的3倍.黄河水体中相对较高的BSi浓度反映了黄河流域水体浑浊度与土壤侵蚀程度较高,源自黄土高原高的泥沙输送量是导致黄河水体中BSi浓度较长江高的主要原因.长江与黄河下游RSi通量在丰水期、平水期与枯水期的比值分别为5.3∶3.1∶1.6与3.8∶3.4∶2.8,长江半数以上的RSi入海通量是在丰水期输出的,而黄河在3个时期的差异不明显.相比于径流的变化,1958-2014年间长江DSi通量变化主要是由DSi浓度的变化引起的,流域气候变化(如温度变化)是其浓度及其通量年代际变化的重要原因;而黄河1985-2001年间DSi通量下降是由于径流量与DSi浓度降低的双重原因引起的.气候变化,特别是温度的变化会对流域硅的风化速率与硅的产出产生重要影响,但其具体的影响有待进一步揭示.  相似文献   

20.
Abstract

Measurements made in the past few decades undeniably indicate change in the climate. The most visible sign of global climate change is air temperature, while less visible indicators include changes in river water temperatures. Changes in river temperature can significantly affect the environment, primarily the biosphere. The physical, biological and chemical characteristics of the river are directly affected by water temperature, although estimation of this relationship presents a complex problem. Although river temperature is influenced by hydrological and meteorological factors, the purpose of this study is to model daily water temperature using only one known parameter, mean air temperature. The relationship between the daily mean air and daily water temperature of the River Drava in Croatia is analysed using linear regression, stochastic modelling or nonlinear regression and multilayer perceptron (MLP) feed-forward neural networks. The results indicate that the MLP models are much better models which can be used for the estimation and prediction of daily mean river temperature.
Editor D. Koutsoyiannis; Associate editor M. Acreman  相似文献   

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