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1.
海河流域潜在蒸散发的气候敏感性分析 总被引：19，自引：1，他引：18
蒸散发是水文循环的重要环节,分析潜在蒸散发对气候因子的敏感性有助于深入理解气候变化对水文循环的影响.本文基于Penman-Monteith公式,分析了海河流域潜在蒸散发对气温、风速、水汽压和太阳辐射的敏感性及其时空变化规律.研究结果表明:①在年尺度上潜在蒸散发对水汽压最为敏感,其次是温度和太阳辐射;在季节尺度上,春夏两季潜在蒸散发对温度最为敏感,对风速最不敏感;秋冬两季潜在蒸散发对水汽压最为敏感.对太阳辐射最不敏感;②从空间分布上看,潜在蒸散发对温度和水汽压的敏感系数以海河流域南部和冀东沿海的低海拔地区为最高,流域北部的燕山和太行山高海拔地区为最小;③潜在蒸散发对太阳辐射变化的敏感性表现出从南到北递减的趋势,对风速变化的敏感性则表现出由南往北递增的趋势;④趋势分析表明,海河流域1957～2008年间,潜在蒸散发对风速、太阳辐射和温度的敏感程度都呈增大趋势,其中对温度的敏感程度增大趋势最为明显,对水汽压的敏感程度有减弱的趋势. 相似文献
2.
澜沧江流域潜在蒸散发敏感性分析 总被引：4，自引：1，他引：3
蒸散发对气候变量的敏感性研究是近年来水文学的热点之一,对探讨水循环对气候变化的响应具有重要意义。本文利用1960年-2005年澜沧江流域及其周边35个气象站的逐日常规气象观测数据,基于Penman-Monteith公式,计算了1月、7月及年3个不同时间尺度下潜在蒸散发对平均气温、相对湿度、风速及日照时数的敏感系数,分析了澜沧江流域潜在蒸散发对各气候变量的敏感性及其时空变化规律。结果表明各站潜在蒸散发对各变量的敏感系数空间分异明显,流域整体上对日照时数最为敏感。几十年来对日照时数的敏感性在1月主要为增加趋势,7月则为减小趋势。 相似文献
3.
本文以湿润地区澜沧江支流黑江的景谷河流域为例,对遥感枯水下垫面要素进行了地理相关分析与其分区单元的建立。同时通过单元的波谱信息与水文参数信息转换研究,运用一定的算法,实施河流枯水资源量的估算,其结果与常规实测统计计算数据值基本一致。基于上述景谷河水文站多年水文资料和水文下垫面要素,包括地形地貌、地质岩性和植被等的综合分析认为：①景谷河流域枯水期的最小月流量为４月,其值仅是全年径流的１０％。②利用遥感空间信息分析水文下垫面单元特征,研究降水进入流域下垫面存贮水文系统内再分配过程诸环节的特性,提取并调整其模型参数,是一经济有效的方法 相似文献
4.
李秀云傅肃性宋现锋吴志刚 《资源科学》1999,21(3):6-10
本文以湿润地区澜沧江支流黑江的景谷河流域为例,对遥感枯水下垫面要素进行了地理相关分析与其分区单元的建立。同时通过单元的波谱信息与水文参数信息转换研究,运用一定的算法,实施河流枯水资源量的估算,其结果与常规实测统计计算数据值基本一致。基于上述景谷河水文站多年水文资料和水文下垫面要素,包括地形地貌、地质岩性和植被等的综合分析认为：①景谷河流域枯水期的最小月流量为4月,其值仅是全年径流的1.0%。②利用遥感空间信息分析水文下垫面单元特征,研究降水进入流域下垫面存贮水文系统内再分配过程诸环节的特性,提取并调整其模型参数,是一经济有效的方法。 相似文献
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气候变化下石羊河流域径流模拟与影响量化 总被引：2，自引：2，他引：0
石羊河流域是河西走廊水资源利用率最高、供需矛盾最突出的地区.本文选取石羊河中上游流域为对象,基于流域水文模型SWAT,研究1988年-2005年以及未来多种气候情景下出山口径流的变化特征,探讨气候变化对其中上游地区水文情势以及水资源的影响.研究表明:①采用SWAT模型对石羊河各条支流径流模拟已能够体现该流域中上游地区的降水径流特性,模拟精度满足未来气候变化对流域水文情势影响分析的要求;②通过调整历史降水和潜在蒸散发驱动SWAT模型对比分析未来A2和B2情景下2020s(2020年-2037年)、2050s(2050年-2067年)和2080s(2080年-2097年)三个时间段径流过程.未来A2和B2情景下石羊河流域降水和潜在蒸散发持续增加,但降水增幅略高.由此导致径流呈持续上升趋势,但增幅较小.A2与B2情景相比,A2情景下降水和潜在蒸散发的增幅均略高于B2情景.气候变化影响下未来石羊河流域径流量将略微增加,杂木寺断面增幅为1.37％～9.03％,而西营断面增幅为0.12％～5.04％.研究可为气候变化环境下的石羊河流域水资源综合管理规划提供技术支撑和依据. 相似文献
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WASMOD模型参数敏感性与相关性分析 总被引：1，自引：1，他引：0
对水文模型参数进行敏感性和相关性分析,可以减少率定参数的数量、提高模型运行效率,并可以为优化和改进模型结构提供依据.本文采用局部分析法和相关系数法讨论了WASMOD模型中的五个参数对目标函数的敏感程度以及参数之间的相关程度.研究发现,在黑河流域上游山区的径流模拟过程中,WASMOD模型中影响降水形态的温度参数a1对目标函数最为敏感;其次是影响地表径流的参数a6和影响融雪过程的温度参数a2;基流参数a5最不敏感.模型参数之间的相关性不是很强,这也说明,模型结构已得到很好的优化;为保证模型的模拟效果,模型参数的数量不能减少. 相似文献
8.
基于径流模拟的汉江上游区水资源对气候变化响应的研究 总被引：25，自引：4，他引：25
本文简要介绍了基于水文过程的、具有较强物理机制的流域分布式水文模型SWAT.然后由遥感和地理信息系统手段得到流域的土壤类型与植被覆盖及雨量气象站点分布图,通过改进的SWAT气象模拟器模拟出缺乏实测的日气象资料,再结合实测的降雨资料作为SWAT模型的输入,对两河口流域1981年～1985年进行年月径流模拟,并利用汉江上游地区两河口流域1981年～1985年5年间的年、月径流量实测资料,以月径流模拟的N-S模型效率系数为主要指标,对SWAT模型中3个最敏感参数ESCO、AWC和CN2进行敏感性分析,进而率定出使得月模拟效果最佳的参数值或参数变化值.参数率定后月径流模拟N-S模型效率系数达0.913,对数误差为0.339,峰值误差为-0.083.在5年准确月径流模拟基础上,以全球变化背景可能出现的25种不同气候变化模式为假设条件,研究了该流域径流及实际蒸发的响应,分析指出汉江流域降水的变化对水资源的影响要大于气温的变化对水资源的影响,降水增加或气温降低都会导致径流增加,而降水增加或气温增加都会导致实际蒸发的增加. 相似文献
9.
地表遥感蒸散发模型研究进展 总被引：3，自引：0，他引：3
蒸散发(Evapotranspiration,ET)包括植被蒸腾与土壤蒸发,是地表能量平衡与水量平衡的重要组成部分,也是陆面过程研究的关键参数。卫星遥感技术的兴起,使获取大尺度非均匀下垫面的地表特征参数成为可能,一系列旨在精确估算地表实际蒸散量的遥感模型由此应运而生,以满足局地、区域乃至全球尺度蒸散发估算的需求。通过分析净辐射通量和地表与近地面大气层湍流热通量交换的方式,将遥感蒸散发模型分为单层模型和双层模型,总结其模型原理,讨论典型模型的优缺点及适用条件,分析蒸散发反演存在的遥感模型精度的图像范围依赖性和分辨率依赖性、时间尺度扩展及不确定性、模型验证以及地表辐射温度和阻抗5个问题。指出今后应加强地表温度反演精度、时间尺度扩展、有云日地表蒸散发、地面观测等方面的研究。 相似文献
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近20年来中国内陆地表蒸散的时空变化 总被引：7，自引：1，他引：6
本研究利用NOAH陆面过程模型模拟了1986年-1996年,2000年-2008年两个时间段内的中国大陆地区地表水热过程参数的变化。按中国大陆的六大分区（东北、华北、华东、中南、西北和西南）,分析了1986年以来这六大区域的地表蒸散的时空变化特征,并利用1980年,1995年,2000年和2005年四期土地利用/覆盖变化数据、地表反照率数据、降雨数据及地表温度和土壤水分的模拟结果,分析了近20年来中国地表蒸散的时空变化特征及其原因。结果表明：华北地区年蒸散有下降趋势外,其余5个地区的年蒸散量都有所增加。增加幅度最大的地区依次为中南,西南,华东,东北和西北。地表温度与地表蒸散间有较好的响应关系,华北地区中部和山东半岛蒸散量下降趋势较明显,地表温度呈明显增加趋势;西南地区南部蒸散量增加趋势十分明显,地表温度呈现的下降趋势也十分明显。降雨的变化趋势与表层土壤水分的变化趋势有较好的一致性,说明降雨还是影响表层土壤水分的关键因子。除东北地区外,年降雨量与年蒸散的趋势也很一致,说明这些地区降雨量仍是决定蒸散的最主要因素。 相似文献
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基于SWAT模型的里下河平原区水文模拟 总被引：1，自引：0，他引：1
本文以江苏里下河平原区为研究对象,结合该流域DEM与实测水系,运用凹陷化算法提取河网,并通过人工修正以实现河网的合理概化,使提取的河网水系等要素基本符合里下河区域实际水文状况。然后构建里下河平原区SWAT水文模型,以2006-2011年水文站汛期流量数据为基础,对该区域水文进行模拟,并对模型的适用性做了评估。研究结果表明：影响该区域径流模拟前三位敏感参数分别为径流曲线数（CN2）、土壤蒸发补偿系数（ESCO）和基流α系数（ALPHA_BF）;经模型参数率定与验证检验,得出汛期内月模拟流量与实测流量的相关系数R2、Nash-Sutcliffe效率系数ENS均在0.80以上,相对误差|Re|均小于5.0%,表明SWAT模型在里下河平原区月径流模拟较好的适用性。该研究探讨了平原区分布式水文模型的应用,可为里下河平原区未来的水资源规划管理提供了科学参考依据。 相似文献
13.
K. Sri Manjari Pratibha Nallari A. Vidyasagar A. Jyothy A. Venkateshwari 《Indian journal of clinical biochemistry : IJCB》2012,27(2):152-156
Chronic pancreatitis (CP) presenting clinically with upper abdominal pain, as well as exocrine and endocrine insufficiencies, is characterized by irreversible morphological and functional alterations in the pancreas. The objective of the present study is to investigate the plasma levels of transforming growth factor-β 1 (TGF-β1), matrix metalloproteinases MMP-1 (collagenase) and MMP-3 (stromelysin) in CP. A total of 71 CP patients and 100 control subjects were considered for the study. Plasma levels of TGF-β1, MMP-1 and MMP-3 were determined by enzyme-linked immunosorbent assay in patients and control subjects. The plasma levels of TGF-β1 and MMP-1 were significantly elevated in patients compared to control group (*P = 0.0301, **P < 0.0001). However, there was no significant difference in the plasma levels of MMP-3 between patients and controls (P = 0.3756). The elevated levels of TGF-β1 and MMP-1 may influence the inflammatory reactions by enhancing the pancreatic stellate cell activation and deposition of extracellular matrix resulting in pancreatic fibrosis. Thus, the present study highlights the role of fibrogenic cytokine marker TGF-β1 and matrix metalloproteinases in the pathogenesis of CP. 相似文献
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Yildirim K Uzkeser H Keles M Karatay S Kiziltunc A Kaya MD Yildirim A 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(1):109-113
Introduction:
The aim of this study was to investigate whether serum levels of interleukin-1β (IL–1β) has any possible correlation on inflammatory parameters such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fibrinogen concentration in patients with familial Mediterranean fever (FMF) patients during attack-free period.Materials and methods:
The serum levels of IL-1β, as an indicator of cytokines status, and the acute phase response proteins, CRP, ESR and fibrinogen levels were evaluated in 35 attack-free patients with FMF and 25 healthy volunteers.Results:
Serum IL-1β levels were significantly higher in patients with FMF than control subjects (P = 0.018). There was no statistically significant difference in the serum levels of ESR, CRP and fibrinogen between two groups (P = 0.181, P = 0.816, P = 0.686, respectively). There was a significant correlation between IL-1β and CRP (r = 0.513, P = 0.002) values of FMF group.Conclusions:
In conclusion, our results confirm the presence of increased IL-1β levels in FMF patients during attack-free period. Serum IL-1β values seems to correlate with CRP levels. The elevation of IL-1β levels may be important in monitoring subclinical inflammation of attack free period in FMF patients. 相似文献15.
Mehul Jariwala S. Suvarna G. Kiran Kumar Alpa Amin A. C. Udas 《Indian journal of clinical biochemistry : IJCB》2014,29(2):181-188
A study of iron, zinc, copper and selenium concentration levels was carried out in three compartments namely, maternal serum (MS), colostrums and cord blood serum (CS) of healthy Indian mothers (n = 42) who delivered healthy normal neonates without any congenital anomalies at Bhabha Atomic Research Centre hospital, Mumbai. Fe, Zn, Cu in maternal serum, cord blood and colostrums were estimated by flame atomic absorption spectrometry while Se was determined by graphite furnace absorption spectrometry. It was seen that there was a significant difference in the level of trace elements in the three compartments. The average levels of Fe in the three compartments were 1,132 ± 519, 2,312 ± 789 and 1,183 ± 602 μg/L while Zn was 514 ± 149, 819 ± 224 and 7,148 ± 2,316 μg/L respectively. Mean Cu values were 1,614 ± 295, 301 ± 77 and 392 ± 174 μg/L respectively while Se values were 70 ± 15, 36 ± 10 and 23 ± 8 μg/L respectively. The results indicated a positive correlation of Fe and Zn concentrations in MS versus CS which were (r = 0.386), (r = 0.572) respectively and Fe levels in MS and colostrums (r = 0.235). A few inter element correlations were found within compartments. Zn and Se showed a negative correlation in both MS (r = −0.489) and colostrums (r = −0.258) while a positive inter correlation of Fe and Zn was seen in MS (r = 0.44) and in CS (r = 0.54). This study gave us an overview of the serum and colostrum values of mother and neonates in Indian population, data of which are scarce. 相似文献
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S. Pandey Ravi Ranjan R. M. Mishra Sw. Pandey R. Saxena 《Indian journal of clinical biochemistry : IJCB》2012,27(3):314-317
Hemoglobin D exist in four form; HbD trait, HbD-thalassemia, HbD sickle cell and HbD homozygous. HbD trait and HbD homozygous generally asymptomatic condition but when HbD co-inherit with thalassemia and sickle cell anemia, produces clinically significant conditions like chronic hemolytic anemia. Here we present a case of HbD Punjab with α 3.7 kb deletion and IVS-1-5 β-thalassemia across a family. Diagnosis of HbD patient was performed by high performance liquid chromatography and complete blood count was measured by automated cell analyzer. Molecular study for common alpha deletions done by Gap-PCR while beta thalassemia mutation identified by ARMS-PCR. Case was clinically significant due to the inheritance of HbD/β+thalassemia genotype. Thus observed case behaved like thalassemia intermedia due to co-existence of α 3.7 deletions with IVS 1-5 β-thalassemia mutation in HbD Punjab patient. 相似文献
17.
Yoshihiro Okamoto Mayuri Tanaka Asami Kasahara Takazumi Hara Yoshimitsu Gotoh Naoya Fujita Takashi Fukui Toshiyuki Masuzawa 《Indian journal of clinical biochemistry : IJCB》2012,27(4):400-404
Most cytokine receptors including interleukin (IL)-9 have soluble counterparts in body fluids. We planned to investigate the pathophysiological significance of the serum soluble IL-9 receptor (sIL-9R) level. We determined the serum sIL-9Rα chain (sIL-9Rα) levels in 96 healthy Japanese individuals to establish a control value by means of specific human sIL-9Rα ELISA, followed by a preliminary application in a patient with diarrhea positive hemolytic uremic syndrome. Age was negatively correlated with the sIL-9Rα level (Spearman r = −0.241, n = 96, p = 0.0180). The serum sIL-9Rα level showed a progressive decline to the normal adult level by the age of 30. The serum sIL-9Rα level of the patient with HUS was markedly higher than those of the age-matched control from the onset of the disease. Because of the remarkable age-dependent variability of sIL-9Rα in healthy subjects, disease-related changes, as well as therapy-dependent alterations, should be considered with caution. Thus, it is recommended that when the serum sIL-9Rα levels of patients are evaluated, the values should be compared with those of age-matched controls. The established control value will be used to discriminate between normal and the pathological conditions in our future studies. 相似文献
18.
Ghizal Fatima Abbas Ali Mahdi Siddharth Kumar Das Baby Anjum Nar Singh Verma Puneet Kumar Ragini Shrivastava 《Indian journal of clinical biochemistry : IJCB》2012,27(4):340-343
The present study was designed to test the hypothesis of a circadian variation in circulating levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in women with fibromyalgia syndrome (FMS). Serum levels of IL-6 and TNF-α were measured at 4 h intervals of the day in 50 women with FMS satisfying American College of Rheumatology criteria for FMS (age 36.68 ± 9.89) as well as 50 healthy control women (age 32.82 ± 10.53). Serum TNF-α levels were substantially increased in patients with FMS but showed no circadian variation. In contrast, no difference in the levels of IL-6 was found. Moreover, there was also no circadian variation in both the groups of patients and controls. We conclude that no circadian pattern exists in the circulating levels of serum IL-6 and TNF-α in patients with FMS, although TNF-α levels are found raised in patients with FMS. 相似文献
19.
Separation by dielectrophoresis of dormant and nondormant bacterial cells of Mycobacterium smegmatis
The dielectrophoretic behavior of active, dead, and dormant Mycobacterium smegmatis bacterial cells was studied. It was found that the 72-h-old dormant cells had a much higher effective particle conductivity (812±10 μS cm−1), almost double that of active cells (560±20 μS cm−1), while that of dead (autoclaved) M. smegmatis cells was the highest (950±15 μS cm−1) overall. It was also found that at 80 kHz, 900 μS cm−1 dead cells were attracted at the edges of interdigitated castellated electrodes by positive dielectrophoresis, but dormant cells were not. Similarly, at 120 kHz, 2 μS cm−1 active cells were attracted and dormant cells were not. Using these findings a dielectrophoresis-based microfluidic separation system was developed in which dead and active cells were collected from a given cell suspension, while dormant cells were eluted. 相似文献
20.
基于ERA-Interim再分析资料,采用通用热气候指数（Universal Thermal Climate Index,UTCI）,分析1979-2014年中国气候舒适度的空间格局和时空变化特征。结果显示：①中国除青藏高原地区外,年均UTCI呈纬向分布,由北向南增加;青藏高原地区呈“环岛状”分布。夏季“无热应力”覆盖面积最大,冬季最小;②“无热应力”频率最高值（> 70%）位于云贵高原南部,最低值（< 10%）位于青藏高原地区;极端冷应力在长江以北均有出现,内蒙古地区东部和东北北部（14%~32%）,及青藏高原大部（16%~40%）最为频繁;中国中东部和新疆盆地区域均有极端热应力出现,其中塔里木盆地东部频率在4%以上;③年均UTCI的趋势在中国东北部为正,西南部为负;最大的上升和下降趋势分别位于长江三角洲（（0.6~0.8）°C/10a和青藏高原西部（-0.8~0.6）°C/10a）。夏季UTCI在全国范围一致上升,冬季相反;④“无热应力”频率的趋势在中国北部为正,南部为负;上升和下降幅度最大的区域分别为青藏高原东部与黄土高原交界附近（（0.8~1.5）个百分点/10a~1.5个百分点/10a））和云贵高原南部（1.5个百分点/10a~2.8个百分点/10a）。极端冷、热应力频率在中国大部分地区均为增加趋势。 相似文献