【作者】 董雯；

【导师】 刘志辉；

【作者基本信息】 新疆大学 ， 自然地理学， 2010， 博士

【摘要】 我国有许多河川的径流量呈下降的趋势,在西北地区尤为明显。在这些趋势的变化中,如何区分人类活动和气候变化的影响程度是当前流域水文水资源和气候变化研究的热点和难点。自八十年代以来,由于人类活动和气候变化所导致的水资源的减少,使得水资源的供需矛盾日益加剧,由此带来区域生态环境的进一步恶化。伴随着现代科学技术和计算机的发展及应用,使得原来只能作定性研究的径流形成机制和过程达到数学模型模拟预报的阶段,流域分布式水文模型的改进、研发和完善,成为水文预报和规划的重要工作,在实现区域社会经济可持续发展方面具有重要作用。针对目前艾比湖流域存在的生态环境恶化问题,本研究选择具有长期研究基础和意义的新疆精河流域(简称流域,艾比湖流域的主要组成部分之一)为典型研究区,阐明了流域径流变化的驱动因素主要是人类活动和气候变化以及流域水文气象资料的代表性,利用1957-2008年流域的实测水文气象资料,通过使用数理统计和非参数Mann-Kendall趋势与变点检验方法等时间序列分析方法,分析了流域年平均气温、年降水量序列和年径流序列的变化趋势、变化点及各自的周期变化,探讨了流域50多年来气候和径流量的变化特征。为流域后期的水文模拟预测研究提供一定的参考依据。基于对流域自然环境、径流形成过程及水文特征等方面系统研究的考虑,运用区域气候模式RegCM3,选取NNRP2全球再分析数据作为初始场及侧边界条件,选择适合的物理方案,实现了有限区域的数值气象模拟和预报。以流域1957-2008年的水文气象资料为基本数据源,根据流域多年径流系数的变化特性,结合流域水文特性的分析结果,采用有序聚类法分析了流域年径流序列变化的阶段性,确定了人类活动对水文序列显著干扰的转折起始点为1981年,将1981年之前的流域水文序列视为流域天然时期。考虑到流域的实际情况,用1981年之前的实测值对分布式水文模型SWAT进行了校准和验证。根据校准的模型参数和1981年以后的实测气象数据及由区域气候模式RegCM3数值气象模拟结果校核的流域缺失年份的气象插值数据(简称校核的气象数据),驱动SWAT模型模拟了人类活动时期的流域径流量。基于地理信息技术(“3S”技术),结合区域气候模式RegCM3的数值气象预报结果,运用SWAT模型预测了人类活动期间流域的年径流量。基于上述计算年径流量系列,在经过论证的流域现状水平的基础上,采用水文频率分析方法,对流域未来设计情景下的年径流量进行了概率预测。具体研究成果如下：(1)运用区域气候模式RegCM3,选取NNRP2全球再分析数据作为初始场及侧边界条件,选择适合的物理方案,实现了有限区域的数值气象模拟和预报。将模拟值与流域内及附近9个站点实测的多年气温平均值和多年降水平均值进行比较分析,结果显示,各项指标误差范围都小于10%,模拟效果良好。不仅为后期流域的水文模拟预测提供理论依据和数据来源,而且也为其他流域水文预报及无资料地区的水资源管理和规划提供了重要参考。(2)基于“3S”技术,提取了SWAT模型所需的大量地表数据和参数信息。利用1981年之前的实测数据校准并验证SWAT模型,为消除模型中间的状态变量初始值人为因素的影响,实测资料的前三年(1957-1959年)作为模型调整期,1960-1969年为模型校准期,1970-1980年为模型的验证期。模拟结果显示,模拟值与实测值比较接近,最大相对误差不超过10%,平均相对误差小于5%,模型的效率系数E都在0.85以上。由此说明,应用SWAT模型模拟流域径流量具有较高的可信度。根据前面校准的模型参数和1981年以后的实测气象数据及校核的气象数据,运用SWAT模型模拟了人类活动时期的流域年径流量(简称模拟值)。(3)在前人研究成果的基础上,根据流域的实际情况,本研究提出了人类活动和气候变化对流域径流量影响程度的分离方法(简称分离法),利用流域年径流深的背景值(1981年以前的多年平均径流深)、实测值及模拟值,运用分离法定量分解出1981-2008年人类活动和气候变化对流域中下游年径流量的影响程度。并在上述研究的基础上,结合区域气候模式的数值气象预报,运用SWAT模型预测了2009-2018年流域的年径流量,使用分离法定量预测了这10年人类活动和气候变化对流域中下游年径流量的影响程度。通过与流域背景值进行比较分析可以看出,人类活动在80年代和近10年来对流域中下游径流量的影响最为明显,其影响程度都占流域中下游径流减少总量的85%以上；在90年代,气候因素对流域中下游径流的影响量占径流减少总量的近10%。总体来看,人类活动是使流域中下游径流减少的主因,占流域中下游径流减少总量(290.2mm)的85.7%。在气候变化的影响中,流域年降水量虽略有所增加,但气温升高使得蒸发量增加,对流域径流量减少也有一定影响。从流域径流量的空间分布来看,在流域上游山区,基本没有人为活动影响,气候变化是导致年径流量变化的主要因素；在流域中下游平原地区(精河水文站至精河铁路大桥),人类活动(主要是农业生产活动)是影响年径流量减少的最重要因素。从预测结果来看,流域自2009-2018这十年的平均入湖(艾比湖)年径流量小于1.5×108m3,加上博尔塔拉河目前的入湖(艾比湖)年径流量(不足3.5×108m3)已远远低于艾比湖最低生态阈值(5×108m3)。故艾比湖地区已出现了严重的水资源短缺和生态危机,仅仅靠流域自身通过节约用水、调整工农业生产结构及技术改造等措施已不能及时扭转这种局面,可见对流域进行生态输水势在必行。(4)本研究根据校准的模型参数和实测得到的较长系列降水、气温资料模拟了流域的径流过程,其代表了近期人类活动水平下“再现”1981-2008年多年降水情况下的径流量。假定1981-2008年共28年的降水具有足够的代表性,可以代表未来的降水情况,并且人类活动维持在20世纪末的水平,本研究根据该计算年径流量系列,在经过论证的流域现状水平(Cv=0.12,Cs/Cv=2.00)的基础上,采用水文频率分析方法,设计并预测了流域规划的近期和远期目标情景下的年径流量情势。结果显示：为了使保证率p=75%,近期目标要求流域的输水量为8.62×108m3,远期目标为14.39×108m3。可见,跨流域调水可以满足流域多方面的实际用水需求。综上所述,由于流域人口的增长和社会经济的发展以及外来人口的大量迁入,水资源开发利用强度在不断加大,尤其是人类活动大规模地开荒种地,使得流域存在严重的春季缺水现象。通过定量分析人类活动和气候变化对流域中下游年径流量的影响程度,可以看出,流域水资源紧缺的主要影响因素是人类活动造成的,再加上气温上升导致的蒸发强烈,使得流域年径流量逐年递减。针对流域的水文特性、水资源时空分布特征和生态环境的现状,在流域内修建水利工程,进行各种取水、蓄水、跨流域调水等行为将会直接改变河流的径流量,跨流域引水量会增加流域径流量,同时会逐渐改善整个流域的生态环境。通过以上分析和研究,结合人类活动和气候变化对流域中下游年径流量影响程度的预测结果,建议增加流域水利设施的资金投入,在流域内全面开展工农业节水型建设,有必要考虑实施跨流域调水,实施水文水资源的优化配置,从根本上解决流域内资源性缺水、季节性缺水、经济需水与生态需水矛盾等问题。通过该研究一方面为流域未来进一步进行径流变化趋势分析研究打下一定的理论基础,另一方面对提高流域用水效率、调节水资源时空分布不均匀、改善生态环境、发展生态可持续农业、推进区域循环经济的建设及可持续发展都具有很重要的实际意义。更多还原

【Abstract】 Recorded runoffs in many rivers in China have been decreasing, particularly in northwest region. How to identify the quantitative effect of climate change and human activities on runoff is a hot topic, a difficulty problem as well. Since the eighties, the reduction of water resources due to human activities and climate change has intensified the contradiction of water supply and demand, also further resulted the ecological environment deterioration in the region. With development and application of modern scientific technology and computer, the original runoff that can only give qualitative study of the formation mechanism and the process has reached the stage of mathematical model simulation and prediction. To research and improve the distributed basin hydrological model, it becomes an important task in hydrological forecasting and planning, which play an important role in achieving sustainable economic development in the region.View of the already existing deterioration of the ecological environment in Ebinur Lake Basin, this research choose Jinghe Basin in Xinjiang (named valley, one of the main components of Ebinur Lake Basin) for the typical study area researched for a long term. It is explained that the major drivers of runoff change is climate change and human activities and that the representation of the hydrological and meteorological data in the valley. In this thesis, on the basis of hydrographical and meteorological data for 52 years (1957～2008), the variation features of precipitation and runoff and their response relationship are analyzed with the methods of nonparametric test (Mann-Kendall) and correlation analysis. This research reveals that the change characters of climate and runoff in the valley for 52 years, which can provide some reference for the further hydrological simulation study.This research achieved a limited area numerical meteorological prediction based on Regional Climate Model RegCM3 with regarding NNRP2 as the initial field and lateral boundary conditions and choosing appropriate physical programs. Based on the systematic study of natural environment, runoff course and hydrological characteristics in the study area, this research chose the hydrological and meteorological data from 1957 to 2008 in Jinghe Basin, and analyzed the stages of annual runoff changes using the cluster method and determined human activities affecting the hydrological sequence marked a turning point in 1981 according to change character of the annual runoff coefficient and analysis results of watershed hydrological characteristics, which is regarded the natural sequence of hydrological prior to the 1981.The average annual runoff depth is regarded as background prior to the 1981 by accounting the actual situation of the study area, and this research calibrated and validated the SWAT Model using the measured values prior to the 1981.It is simulated for the watershed runoff according to the calibrated model parameter and measured values after 1981 and calibrated meteorological data in missing year. The individual effect of human activities on annual runoff was forecasted combining the numerical meteorological forecast results of regional climate model RegCM3 and the spatial information technology ("3S") by SWAT model. Based on the calculation of annual runoff series and calibrated watershed situation by specialist organization, this research probably predicted annual runoff situation of Jinghe Basin under assumed scenarios by the hydrological frequency analysis method.Key findings include as follows:(1) This research achieved a limited area numerical meteorological prediction based on Regional Climate Model RegCM3 with regarding NNRP2 as the initial field and lateral boundary conditions and choosing appropriate physical programs. By comparison of the measured average values in 9 stations, simulating results showed that various indicators are less than 10% error range, forecasting results are better. Which not only provide the theoretical basis on the interpolation of the latter hydrological simulation in the study area, but also offer an important reference for hydrological forecasting, water resources management and program in the areas without data. (2) This research extracted a large number of surface data and parameters required by SWAT Model based on "3S" technology, and calibrated and validated the SWAT Model using measured values prior to the 1981,the model simulation period was divided into trial period (1957-1959) in order to decreasing human errors, calibration(1960-1969) and validation (1970-1980) periods. Results indicated that the annual runoff simulated by SWAT Model corresponded very well with measured values. The largest relative error is less than 10%, and the average relative error is less than 5%,all of the Nash-Sutcliffe simulation efficiency E in the model is above 0.85. Therefore, the watershed runoff simulation by SWAT Model is very feasible. The watershed runoff was simulated according to the calibrated model parameter, measured values after 1981 and calibrated meteorological data.(3) Based on previous study and the actual situation of the study area, the quantitative separation method of human activities and climate change on annual runoff was put forward. The individual effect of human activities and climate change on annual runoff was separated with the quantitative separation method by comparison of background values, measured values, forecasted values and the simulated values in hydrological model.By comparison and analysis, the results indicated that the relative impact of human activities in the downstream is the most obvious in the 80’s and over the past 10 years, which reduced 85% of the total downstream reduction; the impacts of climate change on runoff is about 10% of the downstream runoff reduction in the 90’s. Overall, human activities are main reasons of runoff reduction in the downstream,which is 85.7% of the downstream reduction (290.2mm). Although the impacts of climate change has a slight rise in annual precipitation, but higher temperatures makes the evaporation increase, which has affected the reduction of runoff too.The climate change is a major factor of runoff reduction in the mountainous catchments of the valley according to watershed runoff spatial distribution; human activities are main reasons of runoff reduction in the plain region of the valley. The total annual runoff of Jinghe and Bortala River flowing Ebinur Lake have been decreased under the ecological limited value (5×108m3) based on the forecasting results by specialist organization. So human beings in Ebinur Lake region have to face the lack of water resources and the environmental deterioration, it is hard to change this situation only by decreasing water waste, improving industrial and agricultural structure and technology integration and so on. Then, it is necessary to transfer water from other basin.(4) This research simulated runoff process according to the regulated model by the recent data and a long series of measured precipitation and temperature. This runoff process represents the "reproduction" 1981-2008 multi-year rainfall runoff according to recent level of human activity. It assumed that the precipitation of 1981-2008 can represent the future rainfall and human activities maintained the level of the late 20th century. According to the calculation of annual runoff series, this research predicted annual runoff situation in Jinghe Basin under assumed scenarios by means of the hydrological frequency analysis and based on calibrated watershed situation(Cv=0.12,Cs/Cv=2.00). Results indicated the required water quantity in basin is 8.62 x 108m3 for short-term goal and 14.39 x 108m3 for long-term goal in order to ensure the rate of p=75%. It shows that the inter-basin water Transfer may meet the actual demand water.In a word, as the valley population growth and socio-economic development as well as the massive shift of population from outside, the intensity of water resources development and utilization continued to increase. Particularly in large-scale human activities, land reclamation farming, which made serious water depletion in spring. By quantitative analysis of the influence of human activity and climate change on annual runoff, it can be inferred that basin water shortage is largely resulted in human activities. And the strong evaporation with rising temperatures also made valley’s annual runoff quantity reduce.In the light of the hydrological characteristics, spatial distribution of water resources and present situation of the ecological environment in the study area, the construction of water conservancy projects in the valley such as demand water, store water and inter-basin water transfer will directly change the river runoff, And thus, the watershed runoff will increase and could also gradually improve the entire basin environment. Through the above analysis and research and the valley’s annual runoff predicted results, it is recommended to increase the funding of water conservancy facilities in Jinghe Basin, to carry fully out water-saving construction in the valley. It is also necessary to implement inter-basin water transfer and the water resources optimal allocation, and to solve thoroughly the valley’s water resources shortage, seasonal water scarcity, the conflicts between ecological and economic water requirement and so on.The process and results of this research on the one hand lay a theoretical foundation for further analysis of watershed runoff in the future. On the other hand, it offers very important practical significance in regulating the uneven spatial and temporal distribution of water resources, improving the water utilization efficiency, modifying ecological environment, developing eco-sustainable agriculture, promoting building of regional cycle economy and sustainable development.更多还原