气候变化对黑河流域水资源系统的影响及综合应对

发布时间：2018-05-11 13:50

本文选题：气候变化 + 水资源系统　；参考：《东华大学》2014年博士论文

【摘要】：气候变化深刻影响着水资源系统的供水和需水过程,进一步加剧了水资源的供需矛盾。黑河流域在还未有效解决水资源供需分配不平衡问题,且流域生态环境恶化态势尚未得到有效遏制的同时,又面临着黑河水量调度的要求。在气候变化影响下,黑河流域水资源演变规律发生变化且出现新的水资源问题：流域水资源供需不平衡态势加剧,社会经济用水进一步挤占生态用水,流域社会-经济-生态-环境整体效益有待进一步提高。为维持黑河流域的水资源安全,本文在融合现代水文水资源学研究新进展的同时,结合野外原型观测、地理信息技术与数值模拟技术的优势,从水资源系统学角度,系统辨识了气候变化下水资源系统的相互作用机制,从水资源、可利用水资源、可供水、需水、缺水角度,识别了气候变化对水资源系统的影响过程。本文研究拓展了气候变化对水资源系统的影响评估理论与方法。本文基于水资源系统的角度评价气候变化对水资源系统的影响,以评估供水和需水预测为主线,将水文的常态过程和极值过程纳入到水资源系统的影响评估中,重点关注供水量和需水量在时间节律和空间差异方面的变化,拓展了传统气候变化影响评估模式的研究范畴和方法。与传统气候变化对水资源影响评估不同的是：本文结合SWAT水文模型和现代水资源评价技术,先从水循环的演变规律出发,整体识别气候变化对水资源量、可利用水资源量和可供水量的影响,逐级反映气候变化对供水的影响过程；针对气候变化对需水过程的影响评价,本文基于物候变化规律,采用物候观测资料和积温阈值方法,识别了气候变化对典型作物和天然植被生育期的影响,其技术核心是基于需水机理的物候预测技术和需水评估技术；在分析供需平衡时,不仅考虑了传统评价模式中的缺水量因素,还考虑了缺水时间和缺水区域,为黑河流域调水方案的修正提供技术支撑,克服了以往调水曲线研究对气候变化考虑不足的问题。在以上理论基础及评估结果的支持下,从系统角度,提出基于水资源系统的集合应对框架。在满足自然规律的基础上,通过水利工程群的优化调度,控制水资源在时空尺度上的合理分布；调整社会经济发展格局,使水资源在不同用水户之间合理配置,满足经济社会发展需求。本文研究的主要成果和结论如下： (1)变化环境下水资源演变规律及旱涝事件演变规律识别根据太阳黑子与水文气象要素的关系,结合Morlet小波和Mann-Kendall两种分析方法,将研究时段划分为1960～1991年基准期以及1992～2010年对比期。黑河流域降水量和气温均呈增加趋势,且时空分布发生变化。上游丰水区域降水增幅最大、气温增幅较小,下游缺水区域降水减少、气温增幅最大。单场降水强度增大且降水时间推后集中在8、9月份,最高气温推后至7月中下旬发生。河川径流量增加,莺落峡水文站径流量由基准期的15.61亿m3增加为16.80亿m3。对比期相对于基准期,8-11月径流量占全年径流量的比例由43.78%增加为46.96%,径流丰水期逐渐后移。受调水工程影响,黑河中游地下水位下降,而下游地下水位埋深变浅。调水之后,中游地下水位下降幅度为2.96m左右,从上游到下游、距离河道越远,地下水位降幅越大。黑河下游年均地下水埋深降低,降幅为0.20m,从东西两河上游至下游,距离河道越远,地下水位埋深变浅程度逐渐降低, 干旱发生次数和覆盖范围增加,干湿交替频次增大,从上游到下游干旱持续时间加大。干旱之后第一场降水强度大于同时期平均降水量,以中游旱后降水强度最高、下游最小,旱后发生洪涝的潜在风险增加。干旱时期气温高于同期非干旱期气温,实际水汽压低于同期值。随着干旱持续日数的延长,气温增加、实际水汽压降低；受干旱程度的影响,气温和实际水汽压以6月份变化最大,其次是7月和8月；6月份气温和水汽压干旱期与多年平均的差值从上游到下游逐渐降低。 (2)气候变化对黑河流域水资源系统的影响气候变暖使黑河流域需水量呈增加态势,基准期流域需水量为18.65亿m2,对比期为21.23亿m2,增幅为13.8%。除7月份以外,其他月份需水量均增加,其中需水量最大的月份依次为6月、7月和5月。需水呈现出明显的空间差异：上游需水量5月份增加量最大,中游需水量以5月和8月最大,下游6月份需水比例提高。随着保证率的提高,气候变化影响下黑河流域需水量整体呈增加趋势,以中游需水增加最大,且整体需水时间逐渐前移。对于流域整体的需水变化,在25%频率下,以9月和5月需水量增加最大；50%频率下,以8月和7月需水量增加最大；90%频率下,以6月、5月和7月需水量增加最大。气候变化影响下,丰水年可利用水资源量增多,且汛期可利用水资源量进一步增多；平水年可利用水资源量增加；枯水年可利用水资源量减少,且干旱时期可利用水资源量进一步减少。90%频率下,黑河流域可利用水资源量下降了0.91亿m3,减幅为5.1%,干旱时期可利用的水资源量更小；50%频率下,可利用水资源量增加了1.21亿m3,增幅为5.8%,5-8月可利用水资源量增大；25%频率下,可利用水资源量增幅为15.7%,4-8月汛期可利用水资源量增大。缺水存在明显的时空变化。丰水年缺水时间集中在4-5月,平水年缺水时间也为4-5月但缺水增加明显,枯水年以6月份缺水增幅最大。黑河中游区域缺水率增大,干旱进一步加大,且缺水时间逐渐往前推移；上游目前受气候变化影响不明显,供水基本可满足需水的要求；对于下游,由于受到黑河近年连续丰水年的影响,其缺水率反而由22.0%降到15.9%,丰水年和平水年缺水率下降,枯水年缺水率微弱增加,缺水时间提前到3～4月。 (3)气候变化影响下水资源系统的集合应对从水资源系统的角度提出了应对气候变化影响的集合策略。在规划层面,实施面向常态管理与应急管理统一的集合管理方式,进行组合风险分区,制定面向旱涝急转的集合应对预案；在实施层面,实施面向常态与极值过程的合理配置和水利工程群的联合调度,对水库汛限水位进行动态控制,并优化黑河流域分水方案。对于干旱而言,主要表现为水资源短缺问题,应从水循环的自然过程和社会过程两端入手,重点加强水资源在各个环节的优化利用,即通过合理开发、合理优化、合理配置和统一调度,规避干旱风险。
[Abstract]:Climate change has a profound influence on water supply and water demand in water resources system, which further exacerbates the contradiction between supply and demand of water resources. In Heihe basin, the imbalance of supply and demand of water resources has not been solved effectively, and the deterioration situation of the ecological environment has not been effectively checked. Meanwhile, the requirement of water dispatching in Heihe is also faced. Under the influence, the evolution law of water resources in the Heihe River Basin has changed and new water resources are emerging. The imbalance situation of water supply and demand is aggravated, the social and economic water is further occupied by the ecological water, and the overall benefit of the social economy ecological environment of the basin needs to be further improved.
In order to maintain the water resources safety of the Heihe River Basin, this paper combines the new progress of modern hydrology and water resources studies, and combines the advantages of the field prototype observation, the geographic information technology and the numerical simulation technology, and systematically identifies the interaction mechanism of the water resource system from the view of water resources systematics, from the water resources and the use of water. Resources can provide water supply, water demand and water shortage, and identify the impact of climate change on water resources system.
This paper expands the theory and method of the impact assessment of climate change on water resources system. Based on the view of water resources system, this paper reviews the impact of climate change on water resources system, and takes the water supply and water demand prediction as the main line, and integrates the hydrological normal process and extreme value process into the impact assessment of water resources system, focusing on the impact of water resources system. The change of water supply and water demand in time rhythm and spatial difference has expanded the research scope and method of traditional climate change impact assessment model.
The impact assessment on water resources is different from the traditional climate change. In this paper, based on the SWAT hydrological model and the modern water resource evaluation technology, first from the evolution of the water cycle, the overall identification of the amount of water resources, the amount of water resources and the water supply can be used as a whole, and the effect of climate change on the water supply is reflected by the stage by level.
In view of the impact of climate change on water demand, based on phenological changes, the effects of climate change on the growth period of typical crops and natural vegetation are identified by phenological observation data and accumulated temperature threshold methods. The key technology is phenological prediction based on water requirement and water requirement assessment technology.
In the analysis of supply and demand balance, not only the water shortage factors in the traditional evaluation model, but also the water shortage time and water shortage area are considered, which provide technical support for the correction of the water transfer scheme in the Heihe basin, and overcome the problem of the shortage of the previous study of the water transfer curve to the climate change.
With the support of the above theoretical basis and evaluation results, a set coping framework based on water resources system is proposed from the point of view of the system. On the basis of satisfying the natural law, the rational distribution of water resources on the space-time scale is controlled through the optimal scheduling of water conservancy engineering groups, and the economic development pattern of the society is adjusted to make water resources in different water users. Reasonable allocation to meet the needs of economic and social development.
The main results and conclusions of this paper are as follows:
(1) evolution law of water resources and identification of drought and flood events in changing environment
According to the relationship between sunspot and hydrometeorological elements, combining the two analysis methods of Morlet wavelet and Mann-Kendall, the study period is divided into 1960~1991 year datum period and 1992~2010 year contrast period.
The precipitation and air temperature in the Heihe River Basin are increasing, and the spatial and temporal distribution changes. The precipitation increase in the upstream region is the largest, the temperature increase is small, the precipitation in the downstream water shortage area is reduced and the temperature increases. The intensity of single field precipitation increases and the precipitation time is concentrated in the month of 8,9, the highest temperature is pushed back to the late mid 7 month.
The flow rate of river river increases, the runoff of yingyu gorge hydrologic station increases from 1 billion 561 million m3 of the datum period to 1 billion 680 million m3. relative period relative to the datum period, and the ratio of 8-11 month runoff to annual runoff increases from 43.78% to 46.96%, and the runoff period is gradually moved back.
Under the influence of water diversion project, the water level of the middle reaches of the middle reaches of Heihe falls, and the lower water level in the lower reaches is shallow. The lower water level of the middle reaches is about 2.96M, from the upstream to the lower reaches, the farther the river is, the greater the decline of the groundwater level. The lower groundwater depth in the lower reaches of the lower reaches of Heihe is reduced to 0.20m, from the upper and lower reaches of the East and the West rivers to the lower reaches. The farther away the river is, the lower the depth of groundwater table becomes.
The frequency and coverage of drought increased, and the frequency of dry and wet alternation increased, and the drought duration increased from the upstream to the lower reaches. The first rainfall intensity after drought was greater than the average precipitation at the same time. The rainfall intensity in the middle reaches of the middle reaches was the highest, the lower reaches the lower, and the potential of the flood after drought increased.
The temperature in the drought period is higher than the non drought temperature in the same period. The actual water vapor pressure is lower than that of the same period. With the extension of the drought duration, the temperature increases and the actual water vapor pressure decreases. The temperature and the actual water vapor pressure change most in June, followed by July and August, and the temperature and water vapor pressure droughts in June and the years average in June. The difference is gradually reduced from the upstream to the lower reaches.
(2) impacts of climate change on water resources system in Heihe Basin
The climate warming makes the water demand of Heihe basin increase, the water requirement of the base basin is 1 billion 865 million m2, and the contrast period is 2 billion 123 million m2. The increase of water demand in other months is 13.8%. except July. The largest water demand months are in June, July and May. The water demand shows obvious spatial difference: the upstream water demand increases in May. The largest volume of water demand in the middle reaches was in May and August, and the ratio of water demand in the lower reaches increased in June.
With the increase of the guarantee rate, the water demand in the Heihe basin is increasing under the influence of climate change, with the maximum water demand in the middle reaches, and the overall water demand is moving forward gradually. The water requirement of the whole basin is increased at the 25% frequency in September and May, and the water demand in August and July increases with the 50% frequency rate, and the 90% frequency is increased. In June, May and July, the maximum amount of water demand is increased.
Under the influence of climate change, the amount of water resources can be increased in the year of abundant water, and the amount of water resources can be further increased in flood season. The amount of water resources can be increased in the year of flat water, the amount of water resources can be reduced in the dry year, and the water resources can be reduced further by the.90% frequency in the dry period. The water resources in Heihe basin can be reduced by 91 million m3 The decrease is 5.1%, the amount of water resources available in the drought period is smaller; under the 50% frequency, the amount of water resources can be increased by 121 million m3, the increase is 5.8%, the amount of water resources can be increased in 5-8 months, and the amount of water resources can be increased by 15.7% in the 25% frequency, and the amount of water resources can be increased in the 4-8 month flood season.
The water shortage existed obvious spatio-temporal changes. The water shortage time in the year of abundant water was concentrated in 4-5 months, the water shortage time in the flat water year was 4-5 months, but the water shortage increased obviously. The dry water year was the biggest increase in June. The water shortage rate in the middle reaches of Heihe increased, the drought was further increased, and the water shortage was gradually moving forward; the upstream is not obviously affected by the climate change at present. Water supply can basically meet the requirements of water demand; for the lower reaches, the water shortage rate of Heihe has been reduced from 22% to 15.9% in recent years. The water shortage rate in the year of high water year is reduced, the rate of water shortage in the dry year is weak, and the time of water shortage is early to 3~4 months.
(3) the response of the water resources system to the impacts of climate change.
From the point of view of water resources system, a collection strategy to deal with the impact of climate change is put forward. At the planning level, a set management mode is implemented for the unification of normal management and emergency management, combined risk zoning, set up a set coping plan for drought and waterlogging, and a rational allocation of normal and extreme value process is implemented at the implementation level. The joint dispatching of the water conservancy project group will dynamically control the limited water level of the reservoir and optimize the water separation scheme in the Heihe basin. For the drought, the water resources shortage is mainly manifested as the shortage of water resources. It should start with the natural process of the water circulation and the social process at both ends of the water cycle, and strengthen the optimization and utilization of the water resources in each link, that is, through rational development and reasonable development, it is reasonable. Optimization, rational allocation and unified scheduling to avoid drought risk.

【学位授予单位】：东华大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P339;TV213

【参考文献】