【作者】 李勋贵；

【导师】 李佩成；

【作者基本信息】 长安大学 ， 地质工程， 2008， 博士

【摘要】 流域水资源系统是天然系统和人工系统的耦合系统。气候变化和人类活动可直接对水资源产生影响。除此之外,人类活动还改变着流域下垫面条件,改变着天然状态下的径流形成机制。因此,研究气候变化和人类活动在水资源系统中的作用和影响、开展流域水资源的评价利用具有重要意义。本论文分理论与应用研究两大部分。在理论研究中,论文系统阐述了水资源系统耦合的理论基础,建立了水资源耦合系统模型,提出模型弹性系数的分形计算公式,为开展流域的人类活动影响研究提供简便有效的工具;引入地统计学方法,研究了流域水文要素的空间自相关性,通过对比选用了克里格空间插值方法;根据高含沙河流径流和水资源利用特点,提出的汛期弃水系数计算的分级统计法,可以有效便捷地确定不同沙限的河道水资源可利用量,从而为河流水资源的可持续开发利用研究提出了一种新的理论方法。在应用部分,针对泾河流域的水文要素演变、气候变化的影响、人类活动的影响等特点,用文中提出的理论、模型、方法进行了深入研究,取得一些创新性成果。论文的主要研究成果如下:(1)泾河流域降水具有强烈的空间自相关性,流域年降水由南向北递减,呈现出较显著的减少趋势;泾河流域年降水量年际变化幅度大,流域年降雨量Cv值由流域的北部、西部向南部、东部递减;泾河流域年蒸发量在空间的分布规律是从北向南依次递减,年际变化较明显,测站年蒸发量的Cv值小于年降水量的Cv值,蒸发量的年际变化小于降水量的年际变化;流域南部年平均气温较高,而流域北部气温较低,泾河流域年均气温从1984年以来有较为明显的增加,流域平均增温0.71℃。(2)泾河流域张家山站天然年径流量呈现出显著的递减趋势,这与流域年降水呈现出递减趋势有关,流域降水量的减少幅度占到了张家山站天然年径流量减少幅度的一半左右,泾河流域降雨量的变化是天然径流变化的最主要原因。(3)运用逐步回归法,以1956-2004年的年降水和年天然径流资料为基础研究杨家坪以上流域、雨落坪以上流域和杨家坪-雨落坪-张家山区间年降水量对张家山站年天然径流量的影响,发现杨家坪以上流域年降水量每变化10mm,即532.5mm±10mm,张家山年天然径流量将变化0.11亿m~3,即19.8亿m~3±0.11亿m~3;雨落坪以上流域年降水量每变化10mm,即513.5mm±10mm,张家山年天然径流量将变化0.24亿m~3,即19.8亿m~3±0.24亿m~3;杨家坪-雨落坪-张家山区间年降水量每变化10mm,即591.8mm±10mm,张家山年天然径流量将变化0.10亿m~3,即19.8亿m~3±0.10亿m~3。(4)基于系统理论和水资源系统耦合关系,建立了水资源耦合系统模型,实现了天然水文过程和人工系统中的人类活动影响的耦合,提出分形法来计算水资源耦合系统中的输入对输出的弹性系数和系统内部状态对输出的弹性系数,从而方便于对人类活动影响的研究。(5)基于本研究提出的水资源耦合系统模型研究了人类活动对径流的影响,并与其它研究者使用其它方法的研究成果进行了比较,结果表明,应用本研究提出的水资源耦合模型来研究人类活动对径流的影响时,所需资料较少且更容易获得,计算过程较为简单且计算结果有较好的合理性和可靠性,从而为研究分析人类活动对径流的影响提供一种简便有效的工具。(6)如果把人类活动对径流的影响量与天然径流量的比值来表征人类活动对径流的影响强度,则人类活动对径流的影响强度在20世纪70年代以前相对较小,其平均影响强度仅为0.071,70年代为0.104,80年代为0.132,90年代为0.168,2000-2003年为0.270,人类活动对径流的影响强度呈现增强的趋势,20世纪70年代以前流域的人类活动对径流的影响强度较小,流域状态可以认为是天然状态,20世纪70年代以后人类活动影响强度逐渐增强。(7)河道水资源可利用量决定于河道内最小生态需水量和汛期难控制利用的洪水量或汛期弃水量的大小。根据泾河流域径流特点提出分级统计法来确定河道水资源可利用量,并与传统方法进行比较,结果表明分级统计法的计算成果更为合理。基于分级统计法计算成果,当河道水资源利用的沙限为10%时,泾河河道水资源可利用量的多年平均值(1981-2001年)为9.87亿m~3,泾惠渠灌区渠首工程可引水量的多平均值为8.66亿m~3,泾惠渠灌区渠首工程实际引水量的多年平均值为3.56亿m~3,泾惠渠灌区渠首工程可引水量潜力的多年平均值为5.09亿m~3,渠首工程可引水量占天然来水量的44.92%,泾惠渠灌区渠首工程可引水量潜力占天然来水量的26.40%,占渠首工程可引水量的58.78%。(8)随着引水沙限的提高,泾惠渠灌区渠首可引水量和可引水量潜力也随之增加,例如当河道水资源利用沙限为12%、14%、16%、18%、20%时,渠首工程可引水量的多年平均值(1981-2001年)分别为8.78亿m~3、8.87亿m~3、8.94亿m~3、8.99亿m~3、9.07亿m~3,分别较10%沙限时增多0.12亿m~3、0.21亿m~3、0.28亿m~3、0.33亿m~3、0.41亿m~3,增加幅度较大;当河道水资源利用沙限为12%、14%、16%、18%、20%时,渠首工程可引水量潜力的多年平均值分别5.21亿m~3、5.31亿m~3、5.37亿m~3、5.43亿m~3、5.51亿m~3,分别较10%沙限时增多0.12亿m~3、0.21亿m~3、0.28亿m~3、0.33亿m~3、0.41亿m~3,增加幅度较大。更多还原

【Abstract】 Water resources system of watershed is a coupling system with natural system and man-made system. Climate changes and human activities have direct influence on water resources. In addition, human activities can also change the underlaying surface condition of river basin and the formation mechanism of runoff. Therefore, it’s important to reveal the role and effect of climate changes and human activities on water resources system and to perform the evaluation and utilization of watershed water resources. This dissertation consists of two components, the theoretical research part and the applied one. In the theoretical part, (1) the theoretical basis of water resources system coupling has been expatiated, the model of water resources coupling system has been built and the fractal formulas for the elasticity coefficients of the model have been proposed, which offers one simple and effective tool to analyze human activities of watershed; (2) spatial autocorrelation of watershed hydrological elements has been analyzed with geostatistics and the Krigine interpolation method has been selected by comparing; (3) on the basis of the characteristic of runoff and water resources utilization, a grade statistical method to calculate coefficient of abandoned water in flood season has been presented to determine effectively and conveniently the river available amount of water resources under different sand limit of river water resources utilization, which provides a new approach for the study of sustainable exploitation and utilization of watershed water resources. In the application part, the characteristics such as the evolvement of hydrological elements, the impact of climate change and human activities etc. have been analyzed deeply with the presented theories, models and methods in this study and some innovation achievements have been obtained. Major results obtained are shown as follows:(1) The precipitation of Jinghe River Basin shows strong spatial autocorrelation. The mean annual precipitation exhibits a decreasing trend from south to north in spatial distribution and a distinct decreasing trend in temporal distribution. The interannual change of mean annual precipitation is evident. The values of coefficient of variation (Cv) for rainfall decrease from the north to the south, the west to the east of the Jinghe River Basin. The evaporation capacity of Jinghe River Basin shows a north-to-south decreasing trend in spatial distribution. The interannual change of evaporation is rather distinct. The values of Cv from evaporation are smaller than those from rainfall, which demonstrates that the interannual change of evaporation is weaker than that of precipitation. The air temperature in the south of Jinghe River Basin is higher than that in the northern. The watershed has a distinct increase of 0.71℃in temperature from the year of 1984.(2) The natural annual runoff from the hydrologic station of Zhangjiashan in the Jinghe watershed exhibits a remarkable decrease trend, which has close relationship with the decrease trend of precipitation in the river basin. About half of the decrease degree of natural annual runoff from Zhangjiashan has been resulted from the decrease of precipitation. The precipitation change in Jinghe River Basin is the most important influence factor on natural runoff change.(3) The influence of mean annual precipitation from the watersheds controlled by hydrologic station of Yangjiaping, Yuluoping or among the station of Yangjiaping- Yuluoping- Zhangjiashan on the natural annual runoff of Zhangjianshan over 70-year (from 1956 to 2004) time periods with the approach of stepwise regression has been carried out. Results demonstrate that when the mean annual precipitation from the watershed controlled by Yangjiaping varies 10mm (532.5mm±10mm), the natural annual runoff of Zhangjiashan will vary 0.011 billion m~3 (1.98 billion m~3±0.011 billion m~3), while the precipitation from the watershed of Yuluoping or Yangjiaping- Yuluoping- Zhangjiashan varies 10mm, respectively, that is (513.5mm±10mm) or (591.8mm±10mm), the natural annual runoff of Zhangjiashan will vary 0.024 billion m~3 (1.98 billion m~3±0.024 billion m~3) or 0.010 billion m~3 (1.98 billion m~3±0.010 billion m~3).(4) On the basis of system theory and the coupling relationship of water resources system, the coupling system of water resources was built. The coupling of natural hydrological process and influence from human activities of man-mad system has been achieved. A fractal method has been presented to determine the two elasticity coefficients, that is, the input-to-output one and the inner state-to-output one, of the water resources coupling system. Therefore, the study on influence of human activities is easy to perform.(5) The influence of human activities on runoff has been carried out based on the presented model of water resources coupling system. The performance of the proposed water resources coupling model is compared with that of other methods used by other researchers. Results show that data demanded for the presented model in this study is few and easier obtained, the calculating process is simpler and the calculating results are more rational and credible with the proposed water resources coupling model in this study, which offers a simple and efficient tool to analyze the influence of human activities on runoff.(6) If the influence intensity of human activities on runoff is defined as the ratio of influence amount of human activities on runoff to natural runoff, the influence intensity is only 0.071 before 1970’s, while 0.104 in 1970’s, 0.132 in 1980’s, 0.168 in 1990’s and 0.270 in 2000-2003, which shows that the influence intensity increases. The influence intensity before 1970’s is very small and the state of river basin at that time period can be considered as the natural one. The influence intensity becomes stronger and stronger after 1970’s.(7) The available amount of river water resources is controlled by the smallest amount of water required by the inner river entironment and the flood discharge hard to control and utilize or abandoned flood amount in flood season. A grade statistical method has been proposed to calculate the available amount of river water resources based on the runoff characteristic of Jinghe River. The results from the presented grade statistical method are compared with those from the traditional method. Results demonstrate that the results from the grade statistical method are more rational. When the sand limit of river water resources utilization is set as 10 percent, according to the results of the grade statistical method, the mean annual available amount of river water resources from 1981 to 2001 for Jinghe River is 0.987 billion m~3, the available amount of diversion project for Jinghuiqu irritation district is 0.866 billion m~3, the available potential amount of diversion project for Jinghuiqu irritation district is 0.509 billion m~3; the ratio of the available amount of diversion project to the natural runoff is 0.4492; the ratio of the available potential amount of diversion project to the natural runoff or the available amount of diversion project is 0.2640 or 0.5878.(8) The available amount and the available potential amount of diversion project for Jinghuiqu irritation district will increase with the increase of the sand limit of river water resources utilization. For example, when the sand limit of river water resources utilization is 12%, 14%, 16%, 18% or 20%, the mean annual available amount of diversion project for Jinghuiqu irritation district over 21-year (from 1981-2001) time periods is 0.878 billion m~3, 0.887 billion m~3, 0.894 billion m~3, 0.899 billion m~3 or 0.907 billion m~3, respectively, which is larger 0.012 billion m~3, 0.021 billion m~3, 0.028 billion m~3, 0.033 billion m~3 or 0.041 billion m~3 than that of 10% sand limit of river water resources utilization; the available potential amount of diversion project is 0.521 billion m~3, 0.531 billion m~3, 0.537 billion m~3, 0.543 billion m~3 or 0.551 billion m~3, respectively, which is larger 0.012 billion m~3, 0.021 billion m~3, 0.028 billion m~3, 0.033 billion m~3 or 0.041 billion m~3 than that of 10% sand limit of river water resources utilization.更多还原