Impact of climate change on the surface water of Kaidu River Basin

To reveal the changing trend and annual distribution of the surface water hydrology and the local climate in the Bayanbuluk alpine-cold wetlands in the past 50 years, we used temperature, precipitation, different rank precipitation days, evaporation, water vapor pressure, relative humidity, dust storm days and snow depth to analyze their temporal variations. We conclude that there were no distinct changes in annual mean temperature, and no obvious changes in the maximum or minimum temperatures. Precipitation in warm season was the main water source in the wetlands of the study area and accounted for 92.0% of the annual total. Precipitation dropped to the lowest in the mid-1980s in the past 50 years and then increased gradually. The runoff of the Kaidu River has increased since 1987 which has a good linear response to the annual precipitation and mean temperature in Bayanbuluk alpine-cold wetland. Climate change also affected ecosystems in this area due to its direct relations to the surface water environment.

Impact of climate factors on runoff in the Kaidu River watershed:path analysis of 50-year data

Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the period of 1958-2007 in the Kaidu River watershed,this paper analyzed the changes in air temperature,precipitation and runoff and revealed the direct and indirect impacts of daily air temperature and precipitation on daily runoff by path analysis.The results showed that mean temperature time series of the annual,summer and autumn had a significant fluctuant increase during the last 50 years（P 0.05）.Only winter precipitation increased significantly（P 0.05） with a rate of 1.337 mm/10a.The annual and winter runoff depthes in the last 50 years significantly increased with the rates of 7.11 mm/10a and 1.85 mm/10a,respectively.The driving function of both daily temperature and precipitation on daily runoff in annual and seasonal levels is significant in the Kaidu River watershed by correlation analysis.The result of path analysis showed that the positive effect of daily air temperature on daily runoff depth is much higher than that of daily precipitation in annual,spring,autumn and winter,however,the trend is opposite in summer.

A simulation-based two-stage interval-stochastic programming model for water resources management in Kaidu-Konqi watershed,China

This study presented a simulation-based two-stage interval-stochastic programming （STIP） model to support water resources management in the Kaidu-Konqi watershed in Northwest China. The modeling system coupled a distributed hydrological model with an interval two-stage stochastic programing （ITSP）. The distributed hydrological model was used for establishing a rainfall-runoff forecast system, while random parameters were pro- vided by the statistical analysis of simulation outcomes water resources management planning in Kaidu-Konqi The developed STIP model was applied to a real case of watershed, where three scenarios with different water re- sources management policies were analyzed. The results indicated that water shortage mainly occurred in agri- culture, ecology and forestry sectors. In comparison, the water demand from municipality, industry and stock- breeding sectors can be satisfied due to their lower consumptions and higher economic values. Different policies for ecological water allocation can result in varied system benefits, and can help to identify desired water allocation plans with a maximum economic benefit and a minimum risk of system disruption under uncertainty.

Sensitivity of mountain runoff to climate change for Urumqi and Kaidu rivers originating from the Tianshan Mountains

The mountain watersheds of Kaidu River and Urumqi River, which separately originate from the south and north-side of the Tianshan Mountains in Xinjiang, are selected as the study area. The characteristics and trends on variation of temperature, precipitation and runoff, and the correlativity between temperature, precipitation, and runoffwere analyzed based on the past 40 years of observational data from the correlative hydrological and weather stations in the study areas. Various weather scene combinations are assumed and the response models of runoff to climate change are established in order to evaluate the sensitivity of runoff to climate change in the study areas based on the foregoing analysis, Results show that all variations of temperature, precipitation, and runoff overall present an oscillating and increasing trend since the 1960s and this increase are quite evident after 1990. There is a markedly positive correlation between mountain runoff, temperature, and precipitation while there are obvious regional differences of responding degree to precipitation and temperature between mountain runoff of Ummqi River and Kaidu River Basins Also, mountain runoff of Urumqi River Basin is more sensitive to precipitation change than that of Kaidu River Basin, and mountain runoff of Kaidu River Basin is more sensitive to temperature change than that of Ummqi River Basin.

Multifractal process of runoff fluctuation of the Kaidu River in Xinjiang, China

Based on the hydrological data in the headwater region of the Kaidu River during 1972-2011, the multifractal process of runoff fluctuation was analyzed. Results indicated that, in the past 40 years, the overall runoff of the Kaidu River in Xinjiang has shown significant multifractal behavior. Its singular curve 1nχq（ε）-1n（ε） verified a favorable scale invariance over the entire time scale, r（q）-q proved that evolution of the runoff time series presented multifractal characteristics. Moreover, the multifractal spectrumf（α）-α curve was hooklike leftward which indicated that, compared to relatively large runoff events. And △f〈0 indicated that these relatively small events took the leading role; B〈0 explained the Kaidu River＇s daily-runoff ascending tendency presented during 1972-2011. Besides that, the multifractal behavior of the Kaidu River＇s runoff variability over four decades was also analyzed. Generally speaking, by decades, their four corresponding spectrum variations were not noticeable. These △α values showed larger runoff events occupied the leading position with some local values falling. During the 1970s to the 1990s, △f〈0 illustrated the probability of the daily runoff at the lowest point is always larger than that of the highest during three continuous decades. At the beginning of the 21 st century, for △f〉0 the trend presented was contrary from the 1970s to the 1990s. B values suggested an overall trend of increases during 1972-2011. Until the 21 st century, the runoff with a slightly descending tendency on the whole explained these relatively large runoff events taking the leading role for the Kaidu River; but sometimes, some small events also played the dominant role.

Climate Change and Its Effects on Runoff of Kaidu River, Xinjiang, China:A Multiple Time-scale Analysis

This paper applied an integrated method combining grey relation analysis, wavelet analysis and statistical analysis to study climate change and its effects on runoff of the Kaidu River at multi-time scales. Major findings are as follows: 1) Climatic factors were ranked in the order of importance to annual runoff as average annual temperature, average temperature in autumn, average temperature in winter, annual precipitation, precipitation in flood season, average temperature in summer, and average temperature in spring. The average annual temperature and annual precipi- tation were selected as the two representative factors that impact the annual runoff. 2) From the 32-year time scale, the annual runoff and the average annual temperature presented a significantly rising trend, whereas the annual precipita- tion showed little increase over the period of 1957-2002. By changing the time scale from 32-year to 4-year, we ob- served nonlinear trends with increasingly obvious oscillations for annual runoff, average annual temperature, and annual precipitation. 3) The changes of the runoff and the regional climate are closely related, indicating that the runoff change is the result of the regional climate changes. With time scales ranging from 32-year, 16-year, 8-year and to 4-year, there are highly significant linear correlations between the annual runoff and the average annual temperature and the annual precipitation.

Impacts of Global Warming Perturbation on Water Resources in Arid Zone: Case Study of Kaidu River Basin in Northwest China

The main goal of this study was to assess the long-term impacts of global warming perturbation on water resources of the Kaidu River Basin in Northwest China. Temperature, precipitation and hydrology data during the past 29 years from 1979 to 2007 were collected and analyzed using parametric and non-parametric methods, the connection between temperature and precipitation by the combination of grey correlation analysis method and the hypothesis testing for trend of climate change. The results show a high increase in temperature in the study area as well as an extreme and highly variable hydrological regime in this region, where flash floods can exceed the total runoff from a sequence of years. These variations may be due to the geographical location of the Kaidu River Basin in arid zone. It also reveals that precipitation has a much greater impact on stream flow than that of temperature. The development of new approaches was proposed as responses to climate change in this arid region.

气候变化对天山地区极端径流的影响—以开都河为例

【目的】揭示天山地区极端径流演变规律,预估不同气候变化情景下天山地区极端径流特征。【方法】基于Sen slope、MK检验、Pettitt检验、概率分布函数、SWAT模型和GCM模式分析极端径流演变特征。【结果】1959—2018年,开都河流域年、夏、秋和冬季径流呈不显著增加趋势,春季径流呈显著增加趋势,径流变化与降水的相关性大于与同期气温的相关性。极端径流频率、强度和持续时间呈增加趋势,初洪时间呈显著推迟趋势。Log-Pearson3函数对极端径流的模拟表现最优,50 a重现期洪水次数、高流量最长持续时间、平均峰值流量重现水平分别为7.09次、79.04 d和180.04 m^(3)/s。未来气候变化情景下,洪水次数增加,极端强度(平均年最大流量)增大,持续时间(高流量最长持续时间、高流量平均持续时间)和平均强度(平均极端径流流量、平均峰值流量)减小,初洪时间呈提前趋势,且最高和最低极端径流强度(平均极端径流流量、平均峰值流量、平均年最大流量)重现水平分别发生在SSP245和SSP370情景。【结论】气候变化对天山极端径流具有重要影响,未来该地区将经历更频繁的极端径流事件和更为严重的单次特大洪水,研究结果对制定气候变化适应策略和水资源管理方案具有重要的指导意义。

1955—2020年博斯腾湖水盐收支估算与水盐平衡分析

为了探讨变化环境下开都河来水、人类水土开发和水利工程调节等对博斯腾湖水盐收支变化规律的影响,根据开都-孔雀河流域河流-湖泊-水利工程间的水力联系及水盐运移转化过程,构建了博斯腾湖水盐收支平衡模型,基于1955—2020年气象、水文、矿化度、开发利用的观测资料,分析了博斯腾湖逐年、分阶段和多年平均水盐收支变化规律。结果表明,受开都河来水和人类活动的影响,1955—2020年博斯腾湖水盐变化具有明显的4阶段特征。1987年以来水盐变化速率明显升高;焉耆盆地和孔雀河引水量较为稳定,开都河入湖水量占总入湖水量的81.89%,在1955—2020年博斯腾湖水位变化中起主导作用;1955—1987年农田排盐量占总入湖盐量的37.24%,其中1972—1986年农田排盐量接近总入湖盐量的50%,农田排盐量是湖水矿化度急剧升高的主要原因;1983年博斯腾湖西泵站运行后,湖水矿化度整体处于下降趋势,2020年降低到1.0 g/L以下。新时期在对开都-孔雀河流域严格遵守水资源三条红线控制的同时,加强扬水泵站、宝浪苏木分水闸及达吾提闸的联合运行,完全可以将湖水矿化度控制在1.0 g/L水平以下。研究结论可为博斯腾湖可持续利用和管理提供参考。

Combining BPANN and wavelet analysis to simulate hydro-climatic processes a case study of the Kaidu River, North-west China

Using the hydrological and meteorological data in the Kaidu River Basin during 1957-2008, we simulated the hydro-climatic process by back-propagation artificial neural network （BPANN） based on wavelet analysis （WA）, and then compared the simulated results with those from a multiple linear regression （MLR）. The results show that the variation of runoff responded to regional climate change. The annual runoff （AR） was mainly affected by annual average temperature （AAT） and annual precipitation （AP）, which revealed different varia- tion patterns at five time scales. At the time scale of 32-years, AR presented a monotonically increasing trend with the similar trend of AAT and AP. But at the 2-year, 4- year, 8-year, and 16-year time-scale, AR presented non-linear variation with fluctuations of AAT and AP. Both MLR and BPANN successfully simulated the hydro- climatic process based on WA at each time scale, but the simulated effect from BPANN is better than that from MLR.

面向生态系统服务供需的开都-孔雀河流域生态安全格局研究

构建干旱区生态安全格局有利于促进区域生态系统服务供应与需求之间的动态平衡。以干旱区开都-孔雀河流域为研究区,利用InVEST模型、RWEQ模型和Getis-Ord Gi*模型分析生态供给源地,以土地利用程度、地均GDP、人口密度和夜间灯光指数分析生态需求源地,并基于最小累积阻力模型确定供给源地与需求源地之间的生态廊道,从而构建研究区生态安全格局。研究结果表明:(1)开都-孔雀河流域生态供给源地14个,占研究区面积的21.46%,重点生态需求源地共9个斑块,占流域总面积4.63%;生态廊道126条,重要廊道17条,总长度654.68km;生态节点65个,重点生态节点24个。(2)开都-孔雀河流域生态系统服务供给与需求空间错位明显,高供给区域与高需求区域呈现出以城镇边界为分界线的明显特征。(3)结合研究区自然地理特征和景观生态系统服务流动性,运用阻力面模型,构建“两核心、两片区、三横四纵多节点”的开都-孔雀河流域生态安全格局可为保障区域生态系统服务功能和可持续发展政策的制定提供科学参考。

近60年开都河源区径流演变及驱动因素定量分析

探明开都河径流和降水的演变特征及其关系,对了解流域的水文循环过程、进行水资源管理具有重要的现实意义。基于开都河大山口水文观测站径流量实测数据,利用Mann-Kendall趋势和突变检验以及累积距平法,分析开都河近60a的径流和降水演变规律,利用双累积曲线法定量研究降水和人类活动对开都河径流变化的贡献量。结果表明:(1)开都河年径流量波动较小,多年平均值、最大和最小值分别为35.44×10^(8)m^(3)、57.09×10^(8)m^(3)和24.61×10^(8)m^(3);(2)径流量整体呈上升趋势,以0.166×10^(8)m^(3)/a的速率递增,于1995年发生由少到多的突变;(3)开都河源区降水年际变化较小,多年平均值、最大和最小值分别为271.48mm、406.6mm以及191.4mm,且在1998年发生突变;(4)在径流量增加过程中,降水和人类活动对其贡献率分别为68.2%、31.8%,影响量分别为4.71×10^(8)m^(3)和2.2×10^(8)m^(3)。研究成果为开都河源区水资源管理、利用和水土流失整治提供数据基础和决策依据。

基于地理探测器的开都-孔雀河流域植被覆盖度时空变化及驱动力分析

植被覆盖度(FVC)是反映生态环境质量的评价指标,系统研究植被覆盖变化和驱动机制对区域生态管理至关重要。本研究基于MODIS数据,运用Sen+Mann-Kendall趋势分析法、地理探测器模型等方法,分析新疆开都-孔雀河流域植被覆盖度的演变趋势,探讨植被覆盖度与驱动因子之间的空间关联,并识别主导因子。结果表明:(1)2000-2020年开都-孔雀河流域植被覆盖整体呈上升趋势,年增长速率为每10年0.013。2011年之前植被覆盖度均值略有小幅度波动,之后植被覆盖度持续增加,在2019年达到最大值29.0%。空间尺度上,2020年极低植被覆盖度分布度最广,占研究区面积的51.93%,21年间减少了5010.31 km^(2),其次是高植被覆盖度,占研究区面积的22.84%。(2)开都-孔雀河流域以极低覆盖度与低覆盖度之间转化为主。研究区植被有轻微的改善趋势,其中17.82%的区域呈极显著(P<0.01)、显著增加趋势(P<0.05);71.90%的区域变化不显著(P>0.05)。(3)研究区植被覆盖主要受高程和土地利用类型的影响,其解释力均在0.45以上。两两因子之间的协同作用影响显著高于单个因素,其中高程和土地利用类型两两相交的解释力最高为0.743。

博斯腾湖流域径流变化及年内分配特征

以博斯腾湖流域两大主要入湖源流——开都河和黄水沟为例,基于新疆塔里木河流域管理局1956—2021年逐月实测径流量资料,采用集中度、线性回归、Mann-Kendall秩次检验法等方法,研究开都河和黄水沟径流变化及年内分配特征。结果表明:开都河和黄水沟年径流量总体呈增加趋势,年径流量整体出现“减少—增加—减少”的阶段性变化;开都河和黄水沟年径流量分别在1996、1994年发生突变,突变后径流量年际变率大,年平均径流量比突变前高;逐月径流量整体呈增加趋势,冬季月径流量增加趋势显著;全年各月径流分布呈单峰型,年内径流量主要集中在夏季,径流量峰值均出现在7月;突变后各月平均径流量均高于突变前和多年平均值;各项指标特征值表明,开都河年内径流量分配有均匀发展态势,黄水沟年内径流量依然集中;开都河径流量主要受降水和气温共同影响,黄水沟径流量主要受气温变化的影响。

开都河源区径流量演变规律及影响因素分析

【目的】厘清气候变化下开都河源区的径流演变规律及其影响因素,为流域水资源开发利用提供科学参考。【方法】基于开都河源区1960—2019年的水文气象数据,采用Mann-Kendall检验法、R/S分析法、有序聚类法、小波分析法,分析开都河源区径流量演变规律,并基于双累积曲线法、累积斜率变化率法、气候弹性系数法定量分析气候变化和人类活动对径流量变化的贡献率。【结果】1960—2019年,开都河源区年径流量以1.714×108m3/10a的速率增加,Hurst指数为0.83,径流量变化存在3个主周期,分别为36、21、9 a,径流量突变点为1995年;开都河源区气温和降水量分别以0.239℃/10 a和7.670 mm/10 a的速率增加,Hurst指数分别为0.85和0.83,与径流量的相关系数分别为0.560和0.598;基于双累积曲线法、累积斜率变化率法、气候弹性系数法得出的气候变化对开都河源区径流量变化的贡献率分别为89.9%、73.1%、43%,人类活动对径流量变化的贡献率分别为10.1%、26.9%、57%,3种方法对基准期径流量模拟的误差分别为2.1%、0.2%、4.1%。【结论】开都河源区年径流量呈极显著增加趋势,气候变化是导致径流量增加的主要原因。

基于SPEI的开都河流域干旱时空演变特征分析

基于开都河流域5个国家基本气象站1961—2020年的逐日气象资料,计算了年和季节为主要时间尺度的SPEI指数数据,并利用Morlet小波分析、Mann-Kendall检验、趋势归因等方法,研究该区域的干旱时空演变规律及其原因。结果表明:近60年,除冬季外,其余时间尺度上的开都河流域均呈干旱化趋势。在空间分布上,流域的年和夏季变化一致,自北向南呈“偏湿—偏干”趋势;春季与秋季变化趋势相同,自西向东呈“偏干—偏湿”趋势;冬季则整体呈“偏湿”趋势。气温是开都河流域干旱变化的主导因素,但流域北部地区干旱变化以降水影响为主,南部地区则受气温影响为主;和静与焉耆区域除冬季外,气温对干旱趋势的贡献均远高于降水贡献,表明该区域干旱化较为严重。开都河流域各时间尺度上的干旱均基本2~6 a一遇,干旱特征多以轻旱为主,中旱次之。其中,春季不仅是重旱事件发生最多时期,还是流域干旱事件发生的主要时期。

自然因子对开都河流域植被NDVI变化的地理探测

为揭示自然因子及因子之间的交互作用对开都河流域植被时空变化特征,以归一化植被指数(以下简称植被NDVI)为指标,结合11种自然因子,采用线性回归分析和地理探测器模型,分析了2001—2020年开都河流域植被NDVI的时空变化、空间分异及驱动力。结果表明,2001—2020年,研究区植被NDVI总体呈上升趋势,中高和高植被覆盖区显著改善,植被NDVI呈西高东低分布,低、中植被覆盖向中高和高植被覆盖转化明显;高程的解释力最高(40.30%),主导植被NDVI时空格局;自然因子对植被NDVI影响存在交互作用,以双变量增强和非线性增强效应为主,其中尤以土壤类型和坡度的交互作用影响力最强。分析了研究区适宜植被生长的各因子范围或类型,可为当地植被恢复政策提供有益参考。

20世纪下半叶开都河与博斯腾湖的水文特征

开都河属于雪冰融水和雨水混合补给的河流 ,流域共有冰川 72 2条 ,冰川总面积为 4 4 5km2 ,冰川总储量为 2 2 .4km3 .开都河年径流补给源中 ,积雪和冰川及地下水补给占有相当大的比例 .开都河是博斯腾湖的主要补给源 ,对博斯腾湖生态与环境起着至关重要的作用 .1987年以来 ,由于开都河天然年径流量的大幅度增加 ,博斯腾湖水位不断持续上升回复到上世纪 5 0年代水平 ,目前 ,已达到历史最高水位 .

干旱区资料稀缺流域日径流过程模拟

选取具有物理基础的分布式水文模型MIKE SHE来模拟大尺度资料稀缺地区水文过程。以塔里木河主要源区之一开都河流域为研究区域,将流域内气象水文站点观测数据与遥感数据相结合,运用GIS空间分析方法修正数据输入。利用气象、土壤类型、土地利用和地表覆盖、数字高程和降雨等资料,研究大气、陆面、地表水和地下水的相互作用机理,通过模型敏感性分析确定了5个"自由"参数,并依据出山口水文站数据对模型进行率定和验证。结果表明,MIKE SHE能在水文、气象站点稀少,土壤及水文地质数据缺乏的条件下,模拟开都河流域的日径流过程,模型效率系数达到0.7以上,率定期与验证期水量平衡误差均小于3%,模拟径流与实测径流高度相关。

开都河流域径流对气候变化的响应研究

开都河属塔里木河的源流之一,随着塔里木河流域近期综合治理的深入进行,开都河径流变化对气候的响应关系已逐渐成为国内外科学家关注的热点问题之一。鉴于此目的,该文采用经典的Mann Kendall和Mann Whitney检验方法,利用该流域巴音布鲁克气象站和大山口水文站1958～2002年的实测资料,分析对比了气温、降雨和径流序列变化特征。结果表明:除春季外,其他季节的年径流基本表现为1958～1973年偏丰、1974年～1986年偏枯和1987年～2000年偏丰,并在1987年～2000年间表现为显著上升的趋势;年平均气温经历了高 低 高三阶段,其中夏季气温总体呈上升趋势;降雨的空间差异性明显,上游年降雨量1973后跳变减少,其中夏季降雨量于1977年～1988年间为多年最小值;中游夏季降雨量1987年后跳变增加。以径流自身的特征变化为时段划分基础,对比了径流、降雨和气温变化过程,研究表明:夏季年际降雨与气温变化是引起夏、秋、冬季径流变化的根本原因;其中年降雨变化对径流变化起主导作用,夏季气温变化导致的冰川融水变化对径流具有一定调节作用,70年代～80年代冰川融水减少使径流减少幅度大于降水减少幅度,而90年代冰川融水增加使径流增加幅度大于降水增加幅度。