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1.
三江平原挠力河上游流域水文过程及其驱动力模型研究 总被引：1，自引：0，他引：1
以三江平原挠力河上游流域为研究对象,选择年均流量和洪峰流量两个水文参变量,对流域降水、耕地面积和各水文参变量的统计回归分析,分别建立水文过程的单因素模型,用于分析气候变化、土地利用变化对水文过程的影响。在定量区分土地利用变化和气候变化的水文效应基础上,利用最小二乘法建立基于降雨量和耕地面积两种因素的流域水文过程驱动力模型。研究结果表明:(1)1956-1975年间降雨量对水文过程的影响非常显著,之后影响逐渐降低,总体上为气候模型对年均流量的模拟能力高于洪峰流量;(2)流域耕地面积,自1954年以来不断扩张,但未对水文过程产生显著影响,对洪峰流量的影响高于对年均径流的影响;(3)研究区的水文过程驱动力模型的模拟效果较好,相比单因素模型,年均流量和洪峰流量的模拟精度均得到较大提高,RMSE分别为0.5和1.04;对年均流量的模拟精度更高一些,决定性系数为0.933;(4)总体上,研究区水文过程受气候变化的影响程度高于土地利用变化,但土地利用变化对水文过程的影响不容忽视,尤其是对洪峰流量的影响呈增大趋势。 相似文献
2.
该文利用已有资料,综述了纳木错流域冰川湖泊对气候变暖的敏感响应。太阳辐射是气候变化的主要能量来源,西风和印度季风的不均匀分布对高原冰川和湖泊的影响具有区域差异性。在气候变暖背景下,1970年以来,纳木错流域的冰川呈退缩趋势,湖泊面积呈扩大趋势,湖泊结冰时间延迟,融化时间提前,平均降水量变化趋势不明显。以上指标的变化都不具有周期性,很难识别太阳黑子的活动周期。冰川融化是湖泊面积扩大的主要因素,冻土融化产生的水量也是湖泊面积扩大不可忽视的原因。 相似文献
3.
在全球气候变化背景下,植被动态变化以及植被对气候变化的响应方式已经成为生态学和地理学领域的热点。本文对比分析了南方亚热带季风区将乐县不同类型森林植被对不同时间尺度的干旱响应的差别。基于2000-2017年MODIS-EVI数据及气象站点数据,用最大值合成法、趋势分析法以及相关分析法,分析了森林植被及气象因子的动态变化特征,并对比不同森林植被对气候变化响应的差别。研究表明：① 2000-2017年,研究区植被覆盖度、EVI和降水均显著增加,区域内湿度增加,森林长势渐趋良好;② EVI在生长季初期和末期与同期的降水、温度均显著正相关（P<0.1）,初期森林受降水因子的影响更大,末期受温度因子的影响大;③ 1-3月和周年的气候变化对森林的生长至关重要,长时间尺度的湿度增加对森林生长具有显著的促进作用,SPEI的时间尺度越长与EVI的相关性也越大;④ 针阔混交林与同期温度、降水的相关系数最高,并且与不同时间尺度的SPEI相关性均比较高,属于气候敏感型林型,在生产经营中要谨慎预防气候变化对该林型带来的伤害;⑤ 森林覆盖度变化与降水和SPEI_24的相关性极显著,长时间尺度的降水变化是影响森林植被覆盖率变化的重要因素之一。 相似文献
4.
蒸散发是地表陆气水分交换的纽带,准确量化蒸散发的时空演变格局对于水资源规划与管理至关重要。本文基于GLEAM模型的蒸散发及其组分数据集,借助7个通量观测站数据、120个流域的流域水量平衡及PML_V2蒸散发产品,在中国九大流域系统评估了GLEAM-ET产品,分析了植被恢复背景下,蒸散发（ET）及其组分（植被蒸腾Ec,截留蒸发Ei,土壤蒸发Es）在1980—2020年的时空演变格局。本文主要得到以下结论：① GLEAM-ET产品在中国九大流域具有较好的适用性,其性能与气候类型有关,干旱区效果优于湿润区。此外,GLEAM与PML_V2模型在九大流域相关性较好（R>0.7）,分布格局与变化趋势整体保持一致。② 全国尺度上,ET均值为416.88 mm,增长速率为1.21 mm/a。Ec与ET均呈自东南向西北递减的分布格局,而Es与其相反。Ec、ET在九大流域均呈显著增加趋势（p<0.001）。Ei、Es在季风区流域分别呈显著增加和显著减小趋势;在内陆区流域呈不显著减小（p>0.05）和显著增加趋势。③在植被恢复背景下,ET组分比例发生了变化。Ec占比变化存在南北差异,南方流域Ec占比均减小,北方流域均增加。Ei占比在各流域均增加,Es占比均减小。黄河流域ET组分对植被恢复的响应最为明显,Ec占比增加了5.21%,Es占比减小了5.56%。 相似文献
5.
降水数据的准确性和时空分辨率成为水文过程模拟的关键。卫星遥感降水资料的日益丰富为资料缺乏区的水文模拟带来了新的突破。本研究拟在资料缺乏、下垫面复杂,观测难、建模难的柴达木盆地高寒内陆河流域—巴音河中上游,基于近5年的TMPA 3B42、GPM IMERG V5及GPM IMERG V6逐日降水数据和气象站点观测数据建立SWAT模型,采用流域出口径流数据及不同的参数化方案分别率定4个模型,比较和探究不同数据在巴音河流域的适用性。结果表明：① 在月、年尺度上,实测降水数据及TMPA 3B42 V07对应的SWAT模型径流模拟效果较好,前者模拟精度较后者仅高6%~12%,且二者对于流域水量平衡的刻画均较准确。说明TMPA 3B42数据对应的径流模拟结果误差相对较小,可直接用于高寒内陆河流域水文模拟;② GPMIMERG V5数据对应的那什系数NSE值为0.13（月）、-1.58（年）,误差百分数PBIAS值为41.2%（月、年）,均方根误差与标准误差比率RSR值为0.93（月）、1.61（年）,其径流模拟误差较大,模拟效果不可信,说明GPMIMERG V5数据集并不适用于巴音河流域水文模拟;③ GPMIMERG V6-F对应的月径流模拟结果明显优于GPMIMERG V5-F,前者模拟精度较后者提高4倍,但其模拟的年径流对应的NSE值为-0.12,RSR值为1.09。该研究可为资料缺乏的高寒内陆河流域生态水文过程模拟提供参考。 相似文献
6.
【目的】考察脉动气流掠过沸腾水面时,流动参数对水分蒸发效果的影响,探究脉动气流强化蒸发过程的机理。【方法】建立二维物理与数学模型,采用商用软件ANSYS FLUENT 14.5进行数值模拟,研究正弦脉动气流掠过沸腾水面时水分的蒸发情况,分析一定蒸发时间内脉动气流的振幅、频率、气流速度以及温度对水分蒸发的影响。【结果】相比于匀速气流,气流脉动时沸腾表面水分的相对蒸发量提高了约50%;脉动气流的相对振幅从0增加至1.0时,沸腾表面水分的相对蒸发量提高了约1.8倍;脉动气流的频率从0 Hz增加至110 Hz时,沸腾表面水分的相对蒸发量呈现出先增加后减小的变化;气流速度从4 m/s增加至10 m/s时,沸腾表面水分的相对蒸发量提高了约15.3倍;脉动气流的温度对沸腾表面水分蒸发的影响不明显;气流脉动时,水分蒸发速率呈周期性变化。【结论】脉动气流周期性地对水面水蒸气浓度边界层进行扰动,强化了水面的对流传质,从而促进了水分蒸发。 相似文献
7.
近百年来龙感湖地区湖泊营养化过程 总被引：5，自引：0，他引：5
由于近年来社会经济的迅速发展，湖泊富营养化问题日趋严重。其中湿地的破坏是导致人湖营养盐增加的一个重要原因。对湿地变化与湖泊营养盐状况关系的分析是制定湖泊环境整治和生态修复的重要科学依据。湖泊沉积物含有丰富的生物和理化方面的信息，在缺乏长期湖泊监测记录的情况下。可以用来重建湖泊及其流域过去变化的历史。根据龙感湖表层沉积物^210Pb活度比变化，分析了该地区近百年来沉积物中湿地花粉、总磷和磁性参数．探讨了湖泊营养化过程及机理。研究表明，龙感湖近百年来营养级的增加是与湿生植被的破坏密切相关。20世纪上半叶的湖泊富营养化响应于磁性参数指示的流域土壤侵蚀速率的增加，而20世纪70年代以来湖泊营养程度的加重则与龙感湖流域农业化肥的使用和湿地植被破坏而导致湿地功能减弱有关。龙感湖流域内人类对湖周潍地的改造．破坏了湿地植被，助长了人湖物质的增加。湖泊营养相对富集，最终导致水体富营养化发生。 相似文献
8.
水汽输送及降水模式对流域水文模型及水资源研究具有重要意义。汉江流域水资源对南水北调以及下游生态环境有重要影响,研究汉江流域水汽输送和降水的时空分布特征是水文模拟和水资源环境管理的基础。本文利用NCEP/NCAR再分析资料和汉江流域19个气象站点的降水资料,以及GIS数据库和分析工具,分析了汉江流域的水汽通量、可降水量、实测降水量和降水转换率的计算方法;以汉江流域1998年7月的气候再分析资料和降水资料为例,计算并分析了汉江流域1998年7月可降水量与实测降水量的空间分布特征,以及降水转化率的分布特征;探讨了水汽输送、可降水量、实测降水量,以及降水转化率的相关性和空间分布特征。通过分析汉江流域1981-2010年的可降水量和实际降水量的分布表明,汉江流域可降水量与降水量变化趋势基本相同,降水转换率近年有所增加。 相似文献
9.
为进一步了解高原土壤湿度变化及其与中国降水的关系,利用青藏高原东部地区1991～2012年22个站10cm、20cm、50cm 3个层次的土壤相对湿度观测资料,分析高原东部地区土壤湿度的时空分布特征.同时利用全国1992～2012年的降水资料与1992～2011年的土壤相对湿度资料,采用求相关系数的方法分析高原东部土壤湿度与全国降水的关系.结果表明:(1)西藏东部土壤相对湿度由东至西呈递减趋势.(2)10cm土层较干,20cm土层的相对湿度是3层中最大的,50cm土壤的湿度变化较为平缓;表层土壤湿度变化较明显.21年来,各层土壤湿度呈不明显下降趋势.(3)高原东部地区土壤湿度与中国东部降水有显著关系,若东部高原春季土壤湿度偏湿(干),则江淮流域夏季降水偏少(多). 相似文献
10.
为进一步了解高原土壤湿度变化及其与中国降水的关系,利用青藏高原东部地区1991~2012年22个站10cm、20cm、50cm 3个层次的土壤相对湿度观测资料,分析高原东部地区土壤湿度的时空分布特征。同时利用全国1992~2012年的降水资料与1992~2011年的土壤相对湿度资料,采用求相关系数的方法分析高原东部土壤湿度与全国降水的关系。结果表明:(1)西藏东部土壤相对湿度由东至西呈递减趋势。(2)10cm土层较干,20cm土层的相对湿度是3层中最大的,50cm土壤的湿度变化较为平缓;表层土壤湿度变化较明显。21年来,各层土壤湿度呈不明显下降趋势。(3)高原东部地区土壤湿度与中国东部降水有显著关系,若东部高原春季土壤湿度偏湿(干),则江淮流域夏季降水偏少(多)。 相似文献
11.
在一般的水动力模拟中,人湖河口的数量和位置基本是不变的.都阳湖水位高动态变化的特征,导致了人湖河口数量和位置变化等特殊的运动边界问题.本文在分析水动力模拟的湖泊形态结构特征的基础上,概化了高水位湖相型、中水位涨水型、中水位退水型和低水位河相型4种水动力形态结构模式,以解决高水位变幅导致的边界移动、人湖河口数量和位置变化... 相似文献
12.
Poyang Lake is the largest freshwater lake in China, and it has a seasonal flooding cycle that significantly changes the water level every year. The aim of this paper was to explain how these hydrological changes influence diatom populations in Poyang Lake. The yearly hydrological cycle can be divided into 4 phases: low water-level phase, increasing water-level phase, high water-level phase and decreasing water-level phase. Variations in the abundance of planktonic diatoms were studied using quarterly monitoring data collected from January 2009 to October 2013. Generally, diatoms were dominant in Poyang Lake and accounted for more than 50% of the total phytoplankton biomass except in July 2009 (26%) and January 2012 (35%). Aulacoseira granulata and Surirella robusta were the predominant species in all four phases, and they accounted for 25.02% to 56.89% and 5.07% to 14.78% of the total phytoplankton biomass, respectively. A redundancy analysis (RDA) showed that changes in physico-chemical parameter were related to the water level, and changes in diatom biomass were related to nitrite levels and pH. These results indicate that changes in environmental parameters related to both seasonal variations and water-level fluctuations caused variations in diatom biomass and community composition in Poyang Lake. Furthermore, extreme hydrological events can have different influences on the diatom community composition in the main channel and lentic regions. This research provides data on the diatom variations in Poyang Lake and will be useful for establishing biological indicators of environmental change and protecting Poyang Lake in the future. 相似文献
13.
《中国海洋湖沼学报》2021,(4)
With the increase in the need for flood prevention and lake resource used by humans,the construction of floodgates and sluices has changed the hydrological connection between rivers and lakes,and between adj acent lake s.In river-disconnected lake s,exploitation and use of lake re sources have resulted in water quality decline and mechanical disturbance intensification to a different degree.Of the large number of river-disconnected lakes in the middle-lower reaches of the Changjiang(Yangtze) River,the Futou Lake,and the Xiliang Lake lie close together and are,historically,directly connected,and so do Liangzi Lake and Baoan Lake.The extent of human disturbance is severe in the Futou Lake and the Baoan Lake,but relatively mild in the Xiliang Lake and Liangzi Lake.The freshwater rosette-forming submerged plant Vallisneria natans is one of the dominant species in the four lakes.Using microsatellite markers,we studied the genetic variation of V.natans subpopulations in lakes with different intensities of human disturbance and historical direct hydrological connections.Our results showed that human disturbance decreased plant density and clonal growth in V.natans,but might increase genetic and clonal diversity at a subpopulation level and enhance gene flow among subpopulations by sexual propagule movement.Under similar climatic conditions,different intensities of disturbance seem to have such a high selective potential to differentiate genetically adjacent lake populations that they outperform the forces of gene flow through historical direct hydrological interconnection,which tends to produce genetic homogeneity.Our findings imply that human disturbance has a profound effect on the evolutionary process of natural populations of submerged plants.Moreover,increased subpopulation genetic diversity can enhance resistance and resilience to environmental disturbances.To a certain degree,we could expect that disturbed populations have the possibility of re storing spontaneously if humans cease to perturb natural ecosystems in the future. 相似文献
14.
Extreme seasonal water level fluctuations characterize natural floodplain lakes in monsoon regions, which are crucial for ensuring lake water security, including flood prevention water supply and health of aquatic ecosystem. In order to achieve this goal, we established a hydrological regime assessment method based on a set of hydrological indicators for lakes with heavy seasonal water level fluctuations. The results suggest that time-sensitive hydrological indicators and specific time scales for various water security aspects must be considered. We discovered that it is more practical and meaningful to combine the water level classification derived from statistical analyses with characteristic hydrological values linked to water security. The case study of Poyang Lake results show that there are no discernable trends of Poyang Lake water regime status over the last 35 years, and the two periods of poor status are in accordance with climate variation in the lake basin area. Scholars and policy makers should focus on both floods and droughts, which are the main water security problems for Poyang Lake. It is hoped that this multi-scale and multi-element hydrological regime assessment method will provide new guidelines and methods for other international scholars of river and lake water assessment. 相似文献
15.
Effect of water level fluctuations on wintering goose abundance in Poyang Lake wetlands of China 总被引：1，自引：0，他引：1
Shaoxia Xia Yu Liu Bin Chen Yifei Jia Huan Zhang Guanhua Liu Xiubo Yu 《中国地理科学(英文版)》2017,27(2):248-258
The Poyang Lake is a Ramsar site and is the important over-wintering site for migratory waterbirds along the East Asian–Australasian Fly way. Examining the effects of water level fluctuations on waterbird abundance and analyzing the influencing mechanism is critical to waterbird protection in the context of hydrological alteration. In this study, the effect of water level regime on wintering goose abundance was examined and the influencing mechanism was interpreted. Synchronous waterbirds survey data, hydrological data, Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index(MODIS-NDVI) data and habitat data derived from Landsat TM/ETM data and HJ/CCD data were combined. The satellite-derived Green Wave Index(GWI) based on MODIS-NDVI dataset was applied to detect changes in goose food resources. It was found that habitat size and vegetation conditions are key factors determining goose abundance. Geese numbers were positively correlated with habitat area, while intermediate range of vegetation productivity might benefit the goose abundance. Water level affects goose abundance by changing available habitat areas and vegetation conditions. We suggested that matching hydrological regime and exposed meadows time to wintering geese dynamics was crucial in the Poyang Lake wetlands. Our study could provide sound scientific information for hydrological management in the context of waterbird conservation. 相似文献
16.
LIU Wen-hui XIE Chang-wei ZHAO Lin WU Tong-hua WANG Wu ZHANG Yu-xin YANG Gui-qian ZHU Xiao-fan YUE Guang-yang 《山地科学学报》2019,(5)
Zonag, Kusai, Hedin Noel and Yanhu Lakes are independent inland lakes in the Hoh Xil region on the Qinghai-Tibet Plateau. In September2011, Zonag Lake burst after the water level had increased for many years. Floods flowed through Kusai and Hedin Noel Lakes into Yanhu Lake; since then, the four small endorheic catchments merged into one larger catchment. This hydrological process caused the rapid shrinkage of Zonag Lake and continuous expansion of Yanhu Lake. In this study,based on satellite images, meteorological data and field investigations, we examined the dynamic changes in the four lakes and analyzed the influencing factors. The results showed that before 2011, the trends in the four lake areas were similar and displayed several stages. The change in the area of Zonag Lake corresponded well to the change in annual precipitation(AP), but the magnitude of the change was less than that of a non-glacier-fed lake. Although increased precipitation was the dominant factor that caused Zonag Lake to expand, increased glacier melting and permafrost thawing due to climate warming also had significant effects. After the 2011 outburst of Zonag Lake, due to the increasing AP and accelerating glacier melting, the increases in water volume of the three lakes were absorbed by Yanhu Lake, and Yanhu Lake expanded considerably. According to the rapid growth rates in water level and lake area, Yanhu Lake is likely to burst in 1-2 years. 相似文献
17.
为探究白泉湿地公园建设过程中白泉湖开挖对白泉的影响,在系统分析白泉泉域水文地质条件的基础上,采用地下水数值模拟专业软件GMS建立2012—2014年白泉泉域地下水流数值模型。在此基础上,利用10年平均和10年典型2种降雨情景对公园建成前、后白泉水位和流量进行预测。通过对比分析,结果表明公园建成后未来10年白泉可以保持持续喷涌,不会有断流情况的发生。在保证白泉湖景观用水的前提下,每天至少有100 m^3的泉水通过河道排泄到小清河。白泉湿地公园建成后,随着附近地下水的进一步减采,白泉的流量将逐渐增大,白泉湖的景观水位更加有保障。 相似文献
18.
INTRODUCTIONThedistingnishingc~teristicsofQinghaboe,thebiewstsalinelakeinCfuna,are:vastwaterm,higheleVation,closeddrinagbasinandattrativenaedland-scape.The~clakeleveldIDPsincethebegiwhngofthiscentwhascausedaseriesofenvironrnntalProblems(degenndionofghanggIaSSlandaIDunthelake,desertffica-tioninthebeacharea,aeOianerosionoftheeXposedlakebed,deCrainwaersuPPliesandincreaseinthewaterndnends).IncentalAsia,mostofthewell-knOWnlargelakes,includingla.kessuchasIssyk-kul(SeVaStyanvandSndmov,l… 相似文献
19.
Using fuzzy theory and variable weights for water quality evaluation in Poyang Lake,China 总被引：1，自引：0，他引：1
Achieving water purity in Poyang Lake has become a major concern in recent years, thus appropriate evaluation of spatial and temporal water quality variations has become essential. Variations in 11 water quality parameters from 15 sampling sites in Poyang Lake were investigated from 2009 to 2012. An integrative fuzzy variable evaluation(IFVE) model based on fuzzy theory and variable weights was developed to measure variations in water quality. Results showed that: 1) only chlorophyll-a concentration and Secchi depth differed significantly among the 15 sampling sites(P 0.01), whereas the 11 water quality parameters under investigation differed significantly throughout the seasons(P 0.01). The annual variations of all water quality variables except for temperature, electrical conductivity, suspended solids and total phosphorus were considerable(P 0.05). 2) The IFVE model was reasonable and flexible in evaluating water quality status and any possible ′bucket effect′. The model fully considered the influences of extremely poor indices on overall water quality. 3) A spatial analysis indicated that anthropogenic activities(particularly industrial sewage and dredging) and lake bed topography might directly affect water quality in Poyang Lake. Meanwhile, hydrological status and sewage discharged into the lake might be responsible for seasonal water quality variations. 相似文献
20.
In the mid-eastern China,there are few or no lakes which are in the absence of anthropogenic disturbances,or their sediments remain undisturbed.As a result,the reference lakes distribution and paleolimnological reconstruction approaches usually are inappropriate to estimate lake reference conditions for nutrients.This yields the necessity of using the extrapolation methods to estimate the lake reference conditions for nutrients within those regions.The lake reference conditions for nutrients could be inferred inversely from the law of mass conservation,current lake nutrient concentration,and the loadings from watershed.Considering the scarcity of hydrological and water quality data associated with lakes and watersheds in China,as well as the low requirement of the watershed nutrient loadings models for these data,the soil conservation service(SCS) distributed hydrological model and the universal soil loss equation(USLE) were applied.The SCS model simulates the runoff process of the watershed,thereby calculating dissolved nutrients annually.The USLE estimates the soil erosion and particulate nutrients annually in a watershed.Then,with the loadings from atmospheric deposition and point source,the previous annual average nutrient concentrations could be acquired given the current nutrient concentrations in a lake.Therefore,the nutrient reference conditions minimally impacted by human activities could be estimated.Based on the proposed model,the reference conditions for total nitrogen and total phosphorus of Chaohu Lake,Anhui Province,China are 0.031 mg/L and 0.640 mg/L,respectively.The proposed reference conditions estimation model is of clear physical concept,and less data required.Thus,the proposed approach can be used in other lakes with similar circumstances. 相似文献