祁连山区气候变化与流域径流特征研究

用气候学、水文学及统计学方法,分析了国家级祁连山森林生态站长期定位监测数据,气温、降水对流域径流的影响关系,据此研究了该流域水热条件下流域径流,分析得出试验流域多年平均降水量为354.3mm,年平均气温为1.6℃,年平均出山径流为118.2mm,径流系数为0.33;随着季节温度的升高,径流量呈增加之势,反之亦然;随季节降水量的增加,径流量同时也呈增加的趋势。研究表明了温度、降水与流域出山径流量密切相关,为不同季节气候变化对流域径流的影响提供科学依据。     

诺敏河流域植被覆盖时空演变及其与径流的关系研究

基于GIMMS/NDVI数据对诺敏河流域1982-2006年间植被覆盖的时空演变特征进行了研究,并结合SCS模型模拟地表径流,在流域和像元尺度分析植被NDVI变化与径流的关系。研究表明:诺敏河流域植被NDVI值较高,但25a间整体呈下降趋势,NDVI减少的区域占总面积的82.5%,植被覆盖有所降低;NDVI空间差异明显,NDVI的高值区主要分布在中上游林区,而耕地分布较多的下游地区NDVI值相对较低。流域尺度上植被NDVI与径流不具有明显的相关性。但从像元尺度来看,植被NDVI和径流的正相关和负相关共存,流域不同空间位置的植被变化与径流的关系并不一致。     

塔里木盆地绿洲分布与河流径流量的关系

利用2007年SPOT NDVI数据集对塔里木盆地绿洲进行了提取,估算出塔里木盆地的典型绿洲总面积为54923.86km2,占塔里木盆地总面积约10%;包括典型绿洲和荒漠草原在内的植被覆盖地区总面积101392.56km2,占塔里木盆地面积约18%。基于ArcGIS的距离分析功能,以自然流域为基础,把塔里木盆地绿洲划分成17个区域,并对河流径流量与区域内绿洲面积之间的关系进行了分析,显示河流径流量大小与区域内绿洲分布面积有显著的关系。     

河西走廊3大内陆河近51年出山径流分布特征

以河西走廊疏勒河、黑河和石羊河1955～2005年时段的河流流量和气象实测数据为资料,应用多种数值诊断方法,系统分析了流域内51年间出山径流的季节及年际变化等.结果表明,走廊内出山径流的年内分配差异较大;三大河流的夏汛流量的峰值出现在同一时期,出山径流量自西向东疏勒河、黑河和石羊河分别占年总出山径流量的74.75%、75.04%和80.94%;径流的年际变化,平水年份最多,占总序列的38.56%,偏枯年大于偏丰年7.84%,说明出山径流量呈减少趋势;累积滤波器和Kendall秩次相关分析结果表明,年出山径流的变化趋势总体呈缓慢下降趋势,三大河流的年出山径流系列累积平均曲线在2005年趋于重合;Morlet分析结果预示未来径流量将处于相对偏少期.     

全球变暖情境下天山山区水循环要素变化的研究

根据有关水文气象台站的观测资料,分析了1960~2005年来天山山区气温、降水、径流的变化。结果表明:受全球升温的影响,自上个世纪80年代以来天山山区气温明显升高,近十年来增温幅度最大;天山南坡降水增加幅度高于天山北坡,尤其是天山南坡西段是近十年降水增幅最大的区域。大多数水文站出山口径流量呈现增加的趋势。天山南坡从上个世纪80年代后期开始增加,天山北坡径流1996年后增加显著。近十年来天山南坡中西段河流出山径流量增加幅度在30%以上,并且春、夏、秋、冬四季径流量都呈增加趋势。相对来说,春夏两季天山南坡以降水补给为主的小河径流增加幅度较大;秋季天山山区受冰川融水补给的河流径流增幅较大;受冬季气温升高的影响,冬季天山南北坡的河流径流增幅都较大。     

河西走廊三大内陆河流域出山径流变化特征及其影响因素分析

以1961-2010年河西走廊三大内陆河流域出山年径流资料为基础,综合运用趋势分析、MannKendall突变检测、Morlet小波分析、R/S分析、降水-径流深度双累积曲线等多种数理分析方法,研究了河西走廊三大内陆河流域出山年径流的变化特征、影响因素及未来可能的变化趋势。结果表明:(1)1961-2010年,石羊河流域出山年径流呈微弱减少趋势,黑河流域和疏勒河流域出山年径流呈显著增加趋势,50年来黑河流域和疏勒河流域出山年径流存在显著突变特征;(2)1961-2010年,石羊河流域和黑河流域出山年径流经历了"枯-丰-枯-丰"4次交替,疏勒河流域出山年径流经历了"枯-丰"2次交替;(3)1961-2010年,石羊河流域、黑河流域、疏勒河流域出山年径流变化的主周期分别为5年、22年和15年,但不具有统计显著性;(4)河西走廊三大内陆河流域出山年径流变化受祁连山区降水影响较大,山区人类活动对年径流变化影响较小;(5)未来石羊河流域出山年径流可能呈减少趋势,黑河流域和疏勒河流域出山年径流可能呈增加趋势。     

气候变化下乌伦古河流域农业面源污染负荷响应

以新疆乌伦古河流域为研究区,基于SWAT模型构建适用于该流域的面源污染分布式水文模型,采用情景设置法设定9种气候变化情景。分析不同气候变化情景对流域径流及面源污染负荷的影响,识别重点影响区域,为流域面源污染防控提供科学依据。结果表明：（1）径流、总氮和总磷在率定期和验证期的决定系数R²均在0.75以上,纳什系数E_ns均在0.55以上,建立的SWAT模型能够用于乌伦古河流域农业面源污染负荷模拟;（2）增加20%的降水量,径流量增加48.01%、总氮负荷增加23.19%、总磷负荷增加29.65%,气温变化对径流量的影响小于降水量变化对径流量的影响;（3）各子流域年均单位面积总氮负荷为0.01～164.79 kg·hm^-2·a^-1,单位面积总磷负荷为0.01～45.10 kg·hm^-2·a^-1,气候变化对面源污染影响较大区域主要分布在福海县的阿尔达乡、富蕴县的吐尔洪乡、库尔特乡、恰库尔图镇,及青河县的阿热勒乡、阿热勒托别镇、塔克什肯镇等。说明降水增多是乌伦古河流...     

阿克苏河径流量时间变化特征及成因分析

运用多种统计方法,对1957-2003年塔里木河最大的源流--阿克苏河年径流量序列进行分析,发现阿克苏河年径流量序列呈明显的上升趋势,大致以4 a左右的周期均匀变化.年径流量作为气温上升的滞后反应,20世纪90年代以来快速增加.通过普查相关和引用积雪卫星遥感资料分析,前期山区降水和气温的年际变化是造成河水径流量稳定变化的主要原因,由气温变化导致的山区积雪融水是阿克苏河径流的重要补给来源.夏季的气温、降水的突然变化是引起径流量突然增大甚至引起洪水的主要原因.     

近20年和田绿洲水资源变化及其驱动力分析

以和田绿洲20年遥感影像图、多年的野外实地调查资料和统计资料,分析了和田绿洲近20年以来水资源时空变化及其驱动力因子。应用RS/GIS进行空间分析,通过主成分分析、多元回归分析,最终定性的确定影响和田绿洲水资源变化的主要因素。遥感解释结果表明:在近20年过程中水资源各类型有明显的变化,其中湖泊和人工水库的变化最明显,水资源总体上表现减少的变化趋势,减少总水域面积为4317.313hm2。主成分析结果表明,人为社会因素、自然气候因素等两大类因索是影响和田绿洲水资源变化的两个主成分。主成分结果进一步表明对整个和田河净流量的时空变化而言,人为社会因素对水资源产生负作用,而自然气候因素呈现短期的积极作用。其主要原因:第一,和田绿洲是个典型的干旱地区,生态环境极为脆弱、水资源欠缺,人类盲目的生产活动更加剧了和田河净流量的大幅度减少;第二,和田河是冰川融水与降水混合补给的河流,冰川积雪融水是和田河径流重要补给来源,在气候变暖情况下,气温升高导致径流增加,但冰川积雪资源处于相对枯竭状况,河川径流量仅会呈现短时间增加,因此说气候变暖起着短期的积极作用。     

气候变化对干旱缺水区中尺度流域水文过程的影响

基于1997-2003年的气象水文资料,选择了黄土高原泾河流域上游,对半分布式生态水文模型SWIM进行了率定和验证,并以流域历史气象条件为基准,固定其它气候因素不变,针对单一气候因素变化(降水或温度)进行了情景模拟,分析、评价了降水和温度对流域径流量、蒸散量和土壤蓄水量各水文过程的影响。结果表明:流域降水量增加(减少),年径流、蒸散及蒸散分量、土壤蓄水量均增加(减少),且降水转化为各水量平衡分量的比例大小依次为径流量(蓝水)>蒸散量(绿水)>土壤蓄水量;流域温度升高,蒸散及其分量随之增加,但径流和土壤蓄水量则随之相应减少。研究结果对于变化环境下的干旱区流域水资源管理具有一定的意义。     

新疆车尔臣河及其水资源利用研究

车尔臣河是塔里木盆地东南部最大的一条河流,主要依靠雪冰融水和地下水补给。上游山区由于有库木库里盆地和吐拉盆地对径流的调节,水量各季节变化比较平稳,特别是春季占全年径流量的29%,是新疆春季径流所占比例最大的河流之一,春灌基本不缺水。农业灌溉和生态用水各占水资源总量的一半。绿洲虽不断扩大,但中游地下水位仍较高,植被未发生明显退化,同时还向台特玛湖输送一定水量。因此,对车尔臣河水资源利用应保持原生态状况,不宜人工修建大型水利工程。由于车尔臣河出山口有巨大的洪积冲积扇,渗漏量占出山口径流量约30%,是一个比较理想的天然地下水库,所以今后经济发展用水应以开发地下水为主。     

Impacts of temperature and precipitation on runoff in the Tarim River during the past 50 years

The relationship between climate change and water resources in the Tarim River was analyzed by combining the temperature,precipitation and streamflow data from 1957 to 2007 from the four headstreams of the Tarim River (Aksu,Hotan,Yarkant and Kaidu rivers) in the study area.The long-term trend of the hydrological time series including temperature,precipitation and streamflow were studied using correlation analysis and partial correlations analysis.Holt double exponential smoothing was used to fit the trends between streamflow and the two climatic factors of Aksu River,Hotan River and Yarkant River.The streamflow of the main stream was forecasted by Autoregressive Integrated Moving Average Model (ARIMA) modeling by the method of time series analysis.The results show that the temperature experienced a trend of monotonic rising.The precipitation and runoff of the four headstreams of the Tarim River increased,while the inflow to the headstreams increased and the inflow into the Tarim River decreased.Changes of temperature and precipitation had a significant impact on runoff into the four headstreams of the Tarim River: the precipitation had a positive impact on water flow in the Aksu River,Hotan River and Kaidu River,while the temperature had a positive impact on water flow in the Yarkant River.The results of Holt double exponential smoothing showed that the correlation between the independent variable and dependent variable was relatively close after the model was fitted to the headstreams,of which only the runoff and temperature values of Hotan River showed a significant negative correlation.The forecasts by the ARIMA model for 50 years of annual runoff at the Allar station followed the pattern of the measured data for the same years.The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed a decreasing tendency in the Tarim River flow of 3.07% every ten years.The results showed that global warming accelerated the water recharge process of the headstreams.The special hydrological characteristics of the arid area determined the significant association between streamflow and the two climatic factors studied.Strong glacier retreat is likely to bring a series of flood disasters within the study area.     

黑河中游植被覆盖率变化趋势及其驱动因子分析

利用2002~2011年的黑河干流中游归一化值被指数数据获得植被覆盖率变化趋势,选取合适的NDVI阈值将整个区域划分为"绿洲区"和"荒漠区",并分别探讨了地下水埋深、中游耗水量及累积降水量对两种区域面积和植被覆盖率变化的影响。结果表明:黑河干流中游植被覆盖率整体呈增长趋势,由2002年的32%增长到了2011年的36%,对植被覆盖率增长贡献最大的因素为绿洲区扩张,10年间绿洲区面积占比增长了10%;影响绿洲扩张的主要因素为地下水位埋深和中游耗水量,绿洲区植被覆盖率变化较小,可忽略其影响。荒漠区植被覆盖率的变化主要受累积降水量影响。利用地下水位埋深、中游耗水量、累积降水量可预测区域植被覆盖率的变化趋势,区分人类活动和气候变化对区域植被覆盖率的影响是可行的。     

Impact of agricultural development on variation in surface runoff in arid regions: a case of the Aksu River Basin

Located in the south of Xinjiang Uygur autonomous region,the Tarim River is the longest inland river in China.Agricultural development,excessive exploitation and low surface water use efficiency in the headstream regions have led to a marked decrease in the water supply to the mainstream.This,in turn,has resulted in the drying-up of the watercourse in the lower reaches of the Tarim River and serious deterioration of the eco-environment.The Aksu River Basin,the most important headstream of the Tarim River,was selected as the research area in this study.Taking elastic coefficient,water demand coefficient and water utilization intensity as the indices,we studied the impact of agricultural development on decreasing surface runoff since the 1950s.The results indicated that(1) the increasing rate of consumption of surface runoff outstripped the rate of increase measured in the natural catchment discharge,resulting in ever diminishing stream discharge into the Tarim River.Agricultural irrigation and seepage loss in irrigation canal systems were the major sources for runoff consumption,taking 63.72% of the overall runoff consumption.What's more,agricultural water consumption took up more than 97% of the water used for long-term production;(2) the expansion of cultivated land,change of planting structure and comparatively low agricultural irrigation efficiency all contributed to the decrease in surface runoff of the Aksu River.The elasticity coefficient of surface runoff reduction corresponding to the increase in planted area was 0.34 in the 1950s,while in the 2000s it had increased to 7.87.This reflected a more sensitive response of runoff decrease to cultivated land expansion.The increase in cotton and fruit production,without widely-used scientific irrigation methods and water-saving technology,led to considerable waste of the water resources.Meanwhile,the irrigation efficiency was still quite low,characterized by the waste of water resources,and the decrease of surface runoff;(3) in different stages,cultivated land area,planting structure and agricultural water use efficiency exerted different effects on runoff decrease.In the early stage,agricultural development showed no obvious effect on runoff decrease.Since the 1960s,the expansion in cultivated land resulted in large consumption of surface runoff;since the 1990s,not only expansion in cultivated land expansion,but also planting structure exerted significant impact on the consumption of surface runoff.Recently,though agricultural water use efficiency has improved in some regions to reduce the consumption of runoff to a certain extent,overall agricultural water use efficiency is still quite low;(4) during the investigation period,water consumption by agricultural development reflected the unbalanced relationship between human activities and water resources.     

Long-term variations in runoff of the Syr Darya River Basin under climate change and human activities

In this study,we analyzed the hydrological and meteorological data from the Syr Darya River Basin during the period of 1930–2015 to investigate variations in river runoff and the impacts of climate change and human activities on river runoff.The Syr Darya River,which is supplied by snow and glacier meltwater upstream,is an important freshwater source for Central Asia,as nearly half of the population is concentrated in this area.River runoff in this arid region is sensitive to climate change and human activities.Therefore,estimation of the climatic and hydrological changes and the quantification of the impacts of climate change and human activities on river runoff are of great concern and important for regional water resources management.The long-term trends of hydrological time series from the selected 11 hydrological stations in the Syr Darya River Basin were examined by non-parametric methods,including the Pettitt change point test and Mann-Kendall trend tests.It was found that 8 out of 11 hydrological stations showed significant downward trends in river runof f.Change of river runoff variations occurred in the year around 1960.Moreover,during the study period(1930–2015),annual mean temperature,annual precipitation,and annual potential evapotranspiration in the river basin increased substantially.We employed hydrological sensitivity method to evaluate the impacts of climate change and human activities on river runoff based on precipitation and potential evapotranspiration.It was estimated that human activities accounted for over 82.6%–98.7%of the reduction in river runoff,mainly owing to water withdrawal for irrigation purpose.The observed variations in river runoff can subsequently lead to adverse ecological consequences from an ecological and regional water resources management perspective.     

近50年来喀什噶尔河流域气温、降水及径流的变化趋势

应用喀什噶尔河流域内7个气象站、3个水文站的观测资料,分析了全流域、平原区和帕米尔高原的气温、降水以及出山口控制站年径流量的变化特征.结果显示:①从20世纪90年代开始,喀什噶尔河全流域以及平原区和帕米尔高原的年以及冬、秋季明显增暖,近5年春季迅速增温.从90年代起,全流域与高原区的年降水量明显增加,近5年平原区也明显增加;自90年代起全流域的春季、夏季降水明显增加,而近5年秋、冬季增湿迅速;近5年平原区的秋、春季以及冬季降水增加明显,高原区却以夏、秋季增湿最明显.②喀什噶尔河全流域以及平原区和帕米尔高原的年气温与降水量都呈显著的线性增加趋势.平原区的秋、冬季气温显著上升,冬季最明显,夏季呈不显著的下降趋势;平原区的四季降水呈不显著的上升趋势.帕米尔高原的夏、秋、冬季气温呈显著的上升趋势,秋季最明显;帕米尔高原的四季降水呈上升趋势,只有夏季的增湿趋势较显著.③喀什噶尔河年径流量(3站合计)近47年来呈显著的线性上升趋势,以3.0%·(10 a)-1的速率增加.流域内3条河流情况有所不同,克孜河径流量的线性增加趋势最明显,而盖孜河呈不显著的下降趋势.     

Glacier mass balance and its impacts on streamflow in a typical inland river basin in the Tianshan Mountains,northwestern China

Glaciers are known as natural 'solid reservoirs', and they play a dual role between the composition of water resources and the river runoff regulation in arid and semi-arid areas of China. In this study, we used in situ observation data from Urumqi Glacier No. 1, Xinjiang Uygur Autonomous Region, in combination with meteorological data from stations and a digital elevation model, to develop a distributed degree-day model for glaciers in the Urumqi River Basin to simulate glacier mass balance processes and quantify their effect on streamflow during 1980-2020. The results indicate that the mass loss and the equilibrium line altitude (ELA) of glaciers in the last 41 years had an increasing trend, with the average mass balance and ELA being -0.85 (±0.32) m w.e./a (meter water-equivalent per year) and 4188 m a.s.l., respectively. The glacier mass loss has increased significantly during 1999-2020, mostly due to the increase in temperature and the extension of ablation season. During 1980-2011, the average annual glacier meltwater runoff in the Urumqi River Basin was 0.48×10⁸ m³, accounting for 18.56% of the total streamflow. We found that the annual streamflow in different catchments in the Urumqi River Basin had a strong response to the changes in glacier mass balance, especially from July to August, and the glacier meltwater runoff increased significantly. In summary, it is quite possible that the results of this research can provide a reference for the study of glacier water resources in glacier-recharged basins in arid and semi-arid areas.     

近51a来乌鲁木齐河源区径流特征及对气候变化的响应

基于天山乌鲁木齐河源区1959-2009年的径流与气象记录,采用线性回归、M-K突变检验法和水量平衡模型分析了河源区气候、冰川及融水量的变化特征。研究发现:河源区冰川径流量与冰川物质平衡成负相关关系,过去51a间河源1号冰川融水径流共增加157.48×104m3,冰川融水径流量增加主要是由冰川退缩和降水量增加造成的。自20世纪90年代以后,冰川融水径流量增加显著,但整个河源区径流量却在减少,与气温升高导致蒸散能力增强、地下冰结构变化及冰川融水补给能力下降等有关。     

Monitoring and analysis of snow cover change in an alpine mountainous area in the Tianshan Mountains,China

Estimating the snow cover change in alpine mountainous areas (in which meteorological stations are typically lacking) is crucial for managing local water resources and constitutes the first step in evaluating the contribution of snowmelt to runoff and the water cycle. In this paper, taking the Jingou River Basin on the northern slope of the Tianshan Mountains, China as an example, we combined a new moderate-resolution imaging spectroradiometer (MODIS) snow cover extent product over China spanning from 2000 to 2020 with digital elevation model (DEM) data to study the change in snow cover and the hydrological response of runoff to snow cover change in the Jingou River Basin under the background of climate change through trend analysis, sensitivity analysis and other methods. The results indicate that from 2000 to 2020, the annual average temperature and annual precipitation in the study area increased and snow cover fraction (SCF) showed obvious signs of periodicity. Furthermore, there were significant regional differences in the spatial distribution of snow cover days (SCDs), which were numerous in the south of the basin and sparse in the central of the basin. Factors affecting the change in snow cover mainly included temperature, precipitation, elevation, slope and aspect. Compared to precipitation, temperature had a greater impact on SCF. The annual variation in SCF was limited above the elevation of 4200 m, but it fluctuated greatly below the elevation of 4200 m. These results can be used to establish prediction models of snowmelt and runoff for alpine mountainous areas with limited hydrological data, which can provide a scientific basis for the management and protection of water resources in alpine mountainous areas.     

Investigation of crop evapotranspiration and irrigation water requirement in the lower Amu Darya River Basin,Central Asia

High water consumption and inefficient irrigation management in the agriculture sector of the middle and lower reaches of the Amu Darya River Basin(ADRB)have significantly influenced the gradual shrinking of the Aral Sea and its ecosystem.In this study,we investigated the crop water consumption in the growing seasons and the irrigation water requirement for different crop types in the lower ADRB during 2004–2017.We applied the FAO Penman–Monteith method to estimate reference evapotranspiration(ET0)based on daily climatic data collected from four meteorological stations.Crop evapotranspiration(ETc)of specific crop types was calculated by the crop coefficient.Then,we analyzed the net irrigation requirement(NIR)based on the effective precipitation with crop water requirements.The results indicated that the lowest monthly ET0 values in the lower ADRB were found in December(18.2 mm)and January(16.0 mm),and the highest monthly ET0 values were found in June and July,with similar values of 211.6 mm.The annual ETc reached to 887.2,1002.1,and 492.0 mm for cotton,rice,and wheat,respectively.The average regional NIR ranged from 514.9 to 715.0 mm in the 10 Irrigation System Management Organizations(UISs)in the study area,while the total required irrigation volume for the whole region ranged from 4.2×109 to 11.6×109 m3 during 2004–2017.The percentages of NIR in SIW(surface irrigation water)ranged from 46.4%to 65.2%during the study period,with the exceptions of the drought years of 2008 and 2011,in which there was a significantly less runoff in the Amu Darya River.This study provides an overview for local water authorities to achieve optimal regional water allocation in the study area.