Influence of climate variability and human activities on stream flow variation in the past 50 years in Taoer River,Northeast China     

Kai Zhang  Lijuan Li  Peng Bai  Jiuyi Li  Yumei Liu 《地理学报(英文版)》2017,27(4):481-496

Taoer River Basin, which is located in the west of Northeast China, is an agropastoral ecotone. In recent years, the hydrological cycle and water resources have changed significantly with the deterioration of the environment. Many water problems such as river blanking, wetland shrinking and salinization have occurred in this region. All of these phenomena were directly caused by changes in stream flow under climate variability and human activities. In light of the situation, the impact of climate variability and human activities on stream flow should be identified immediately to identify the primary driving factors of basin hydrological processes. To achieve this, statistical tests were applied to identify trends in variation and catastrophe points in mean annual stream flow from 1961 to 2011. A runoff sensitive coefficients method and a SIMHYD model were applied to assess the impacts of stream flow variation. The following conclusions were found: 1) The years 1985 and 2000 were confirmed to be catastrophe points in the stream flow series. Thus, the study period could be divided into three periods, from 1961 to 1985 (Period I), 1986 to 2000 (Period II) and 2001 to 2011 (Period III). 2) Mean annual observed stream flow was 31.54 mm in Period I, then increased to 65.60 mm in Period II and decreased to 2.92 mm in Period III. 3) Using runoff sensitive coefficients, the contribution of climate variability was 41.93% and 43.14% of the increase in stream flow during Periods II and III, suggesting that the contribution of human activities to the increase was 58.07% and 56.86%, respectively. 4) Climate variability accounted for 42.57% and 44.30% of the decrease in stream flow, while human activities accounted for 57.43% and 55.70% of the decrease, according to the SIMHYD model. 5) In comparison of these two methods, the primary driving factors of stream flow variation could be considered to be human activities, which contributed about 15% more than climate variability. It is hoped that these conclusions will benefit future regional planning and sustainable development.  相似文献   

Spatial and temporal variability of satellite-derived sea surface temperature in the southwestern Atlantic Ocean     

Andrés L. Rivas 《Continental Shelf Research》2010

  相似文献   

A survey of recent changes in the main components of the ocean tide   总被引：1，自引：0，他引：1  

P.L. Woodworth 《Continental Shelf Research》2010

Changes in the ocean tide during the 20th century have been reported for several parts of the world by different authors. However, it has not always been clear whether the observed changes have been local or regional in scale. This paper reports on a survey of tidal changes in recent decades using a quasi-global data set of tide gauge information. Little evidence has been found in Europe or the Far East (including Australasia and Asia) for the extensive regional changes to the main tidal constituents reported recently for N America. However, evidence for change in smaller regions can be identified wherever the density of tide gauge information allows. Therefore, it seems that tidal changes may be commonplace around the world, although not necessarily with large spatial scales. All of the reported changes have been difficult to explain. However, it is hoped that quasi-global surveys such as the present one may eventually provide further insights.  相似文献   

Simulating temporal variability in catchment response using a monthly rainfall–runoff model     

D.A. Hughes 《水文科学杂志》2015,60(7-8):1286-1298

Abstract

Temporal variability can result from shifts in climate, or from changes in the runoff response due to land- or water-use changes, and represents a potential source of uncertainty in calibrating hydrological models. Parameter values were determined using Monte Carlo parameter sampling methods for a monthly rainfall–runoff model (Pitman model) for different sub-periods on four catchments, with different types and degrees of temporal variability, in Australia and Africa. For some catchments, parameters were not dependent upon the sub-period used and fell within expected ranges given the relatively high degree of model equifinality. In other catchments, dependencies can be identified that are associated with signals contained within the sub-periods. While the Pitman model is relatively robust in the face of temporal variability, it is concluded that better simulations will always be obtained from calibration data that include signals representing the total variability in climate, land-use change and catchment responses.  相似文献   

Impact of bushfire and climate variability on streamflow from forested catchments in southeast Australia     

Yanchun Zhou 《水文科学杂志》2015,60(7-8):1340-1360

Abstract

This paper quantifies the impacts of bushfire and climate variability on streamflow from three southeast Australian catchments where bushfires occurred in February 1983. Three hydrological models (AWRA-L, Xinanjiang and GR4J) were first calibrated against streamflow data from the pre-bushfire period and then used to simulate runoff for the post-bushfire period with the calibrated parameters. The difference in simulated streamflow between pre- and post-bushfire periods provides an estimate of the impact of climate variability on streamflow. The impact of bushfire on streamflow is quantified by removing the climate variability impact from the difference in mean annual observed streamflow between post- and pre-bushfire periods. For the first 15 years after the 1983 bushfires, the results from hydrological models for the three catchments indicate that there is a substantial increase in streamflow; this is attributed to initial decreases in evapotranspiration and soil infiltration rates resulting from the fires, followed by logging activity. After 15 years, streamflow dynamics are more heavily influenced by climate effects, although some impact from fire and logging regeneration may still occur. The results show that hydrological models provide reasonably consistent estimates of bushfire and climate impacts on streamflow for the three catchments. The models can be used to quantify relative contributions of forest disturbance (bushfire, logging and other forest management) and climate variability. The results presented can also help forest managers understand the relationship between bushfire and climate variability impacts on water yield in the context of climate variability.  相似文献   

Temporal abiotic variability structures invertebrate communities in agricultural drainage ditches     

《Limnologica》2015

Abiotic variability is known to structure lotic invertebrate communities, yet its influence on lentic invertebrates is not clear. This study tests the hypothesis that variability of nutrients and macro-ions are structuring invertebrate communities in agricultural drainage ditches. This was determined by investigating invertebrate adaptations to disturbance using insect life-history strategies. Many low-lying agricultural areas contain drainage ditches which potentially provide suitable habitat for aquatic invertebrates. In the province of North Holland (The Netherlands) the extensive network of eutrophic ditches are hydrologically managed, creating seasonal variability of water quality arising from agricultural run-off and the inlet of mineral rich, river derived water. This temporal variability was analysed from monitoring data, collected over a 7 month period (February till August) and covering 84 ditches in three soil regions; sand, clay and peat. Invertebrate diversity was determined as local (α diversity), regional (γ diversity) and species-turnover (β diversity). We ran canonical correspondence analysis and linear mixed models to determine correlations between invertebrate diversity, functional community composition and specific abiotic parameters, including variability (expressed as the Median Absolute Deviation). Invertebrate α diversity was positively correlated to variability in water transparency and negatively correlated to average pH, with the two parameters reflecting a water quality gradient in the environment. Insect life-history strategies expressed adaptations to abiotic variability and harsh (eutrophic) conditions. These adaptations were mainly achieved through good dispersal abilities and developmental trade-offs. The results support measures to reduce influxes of excess nutrients to this network of ditches.  相似文献   

滇池流域降水时空变异特征分析     

刘佳旭  李丽娟  李九一  王志勇 《地球信息科学学报》2015,17(4):451-461

降水是区域水资源形成的主要影响因素,其时空变化趋势也直接影响着各种生态系统的结构、服务功能及空间分布与演变。降水时空变异分析是认识区域水资源形成与时空演变的主要手段和方法。本文利用滇池流域及周边雨量站逐月数据,采用回归分析、距平、空间相关性分析、Mann-Kendall检验、Co-kriging插值及交叉验证等方法,对1953-1987年和2007-2012年2个时序系列的时空变异特征分析结果表明：（1）1953-1987年春、秋和冬季降水量有升高趋势,夏季呈减少趋势,但各季节的增减趋势不显著,2007-2012年春、夏、冬季呈减少趋势,秋季为增加趋势,近期降水量明显有减少趋势;（2）1953-1987年流域降水量呈现增加趋势（11.12 mm/10a）,大致经历下降-上升-下降过程,2007-2012年流域降水量呈显著的锯齿状减少趋势,处于枯水期;（3）1953-1987年各时段的雨量主要呈现负相关性（不显著）,2007-2012年间呈现正相关性,通过LISA统计分析认为,空间异质性随地理位置和时间而变化;（4）年均降水量与雨季降水量的空间分布特征基本相似,出现2个降水高值区和2个低值区对顶分布态势。但在2007-2012年,降水量的高值范围有所减少,低值区范围相应有所扩大。  相似文献   

考虑参数空间变异性多层土坡系统可靠度分析     

蒋水华  李典庆 《岩土力学》2015,36(Z1):629-633

多层土坡在岩土工程实际中十分常见,不仅土体参数存在一定的空间变异性,而且土体框架呈现明显的层状分布特征,然而目前对考虑土体参数空间变异性的多层土坡稳定可靠度研究的远远不够。提出了基于多重响应面边坡系统可靠度分析的蒙特卡洛模拟（MCS）方法,给出了计算流程图,系统地研究了考虑土体参数空间变异性的多层土坡系统可靠度问题。结果表明,提出方法能够有效地分析考虑参数空间变异性低失效概率水平的多层土坡系统可靠度问题,并且具有较高的参数敏感性分析计算效率。  相似文献   

江苏丰沛地区浅层地下水氟含量的空间变异与分布特征          下载免费PDF全文

曹志洋  冯启言  吴晴晴  孟磊 《水文地质工程地质》2010,37(3):127-132

在实地调查和采样分析的基础上,运用地质统计学方法,研究了丰沛地区浅层地下水氟含量的空间变异和分布特征。结果表明:丰沛地区62.75%的水样氟含量超过了国家饮用水标准,最大7.11mg/L,平均含量为1.51mg/L。其中39.22%的水样氟含量在1～2mg/L,3.92%的水样氟含量超过4mg/L。丰沛地区浅层地下水氟含量在一定范围内存在空间自相关性,具有明显的各向异性特征。在空间分布上,氟含量总体呈现西北、东南高和东北低的特征,氟含量大于1.00mg/L的面积约占整个研究区域的87.21%,大于2.20mg/L的面积约占12.12%。丰沛地区浅层地下水氟含量超过1.00mg/L的最大概率0.953,其中概率达到0.85以上的为高风险区域,面积297.18km2,占整个研究区的10.81%,主要分布在丰沛地区的西北部和东南部。  相似文献   

Spatial and temporal variability of daily precipitation in Haihe River basin, 1958–2007     

CHU Jianting  XIA Jun  XU Chongyu  LI Lu  WANG Zhonggen 《地理学报》2010,20(2):248-260

The seasonal variability and spatial distribution of precipitation are the main cause of flood and drought events. The study of spatial distribution and temporal trend of precipitation in river basins has been paid more and more attention. However, in China, the precipitation data are measured by weather stations (WS) of China Meteorological Administration and hydrological rain gauges (RG) of national and local hydrology bureau. The WS data usually have long record with fewer stations, while the RG data usually have short record with more stations. The consistency and correlation of these two data sets have not been well understood. In this paper, the precipitation data from 30 weather stations for 1958–2007 and 248 rain gauges for 1995–2004 in the Haihe River basin are examined and compared using linear regression, 5-year moving average, Mann-Kendall trend analysis, Kolmogorov-Smirnov test, Z test and F test methods. The results show that the annual precipitation from both WS and RG records are normally distributed with minor difference in the mean value and variance. It is statistically feasible to extend the precipitation of RG by WS data sets. Using the extended precipitation data, the detailed spatial distribution of the annual and seasonal precipitation amounts as well as their temporal trends are calculated and mapped. The various distribution maps produced in the study show that for the whole basin the precipitation of 1958–2007 has been decreasing except for spring season. The decline trend is significant in summer, and this trend is stronger after the 1980s. The annual and seasonal precipitation amounts and changing trends are different in different regions and seasons. The precipitation is decreasing from south to north, from coastal zone to inland area.  相似文献