基于景观单元的黑河中游绿洲水文过程模拟研究

发布时间：2018-01-18 12:28

本文关键词：基于景观单元的黑河中游绿洲水文过程模拟研究　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

【摘要】：黑河中游位于我国西北干旱区,水资源短缺,用水矛盾突出。其绿洲是我国粮食主产区,农业以灌溉为主,水文过程受人为活动影响剧烈。由于干旱区水文过程具有"散耗型"的特点,传统的以描述产汇流过程为主的湿润区流域水文模型不宜直接应用于该地区。为量化干旱区的水文转化参量、预测人类活动对水文过程的影响、促进当地水资源的科学管理,需建立适用于该区域的水文过程模型。本文选取黑河中游绿洲为研究区,在监测资料和田间试验分析基础上,建立了具有不同景观单元的绿洲水文过程模型,开展了黑河中游绿洲水文过程模拟及情景预测研究。主要研究内容和成果如下:(1)分析了黑河中游地下水位分布的空间变异性。结果表明,普通克里金方法、普通克里金的Yamamoto修正法与泛克里金方法都适用于黑河中游地下水位的空间插值。Yamamoto修正法更适用于预测地下水位极高值与极低值点,但整体预测精度略低于其它两种方法。在进行区域尺度地下水位空间分布预测时,可以根据实际情况来选取相关的地下水位插值方法。本文建立的绿洲水文过程模型,在地下水动态模拟时,初始水位的分布由于空间变化相对较小,空间插值采用了整体精度最高的普通克里金方法。(2)开展了农田灌溉侧向渗漏试验,利用二维土壤水动力学模型HYDRUS-2D对农田不同灌水定额、田块宽度以及土壤层状结构下的农田灌溉侧向渗漏过程进行模拟分析。结果表明,农田灌溉侧渗比(侧渗损失与灌溉量之比)会随灌水定额的增大而增大、随田块面积的增大而减小、田块土壤的层状结构亦会影响侧渗比,细质土覆盖粗质土时,有利于减小侧渗比。对于黑河中游绿洲农田,从田块尺度和土壤结构来看,在绿洲水文过程模拟中可以忽略灌溉引起的侧向损失,仅考虑农田水分的垂向运移。(3)建立了农田非饱和带水量平衡模型,将其模拟结果与一维土壤水动力学模型HYDRUS-1D模拟结果进行对比验证,分析了不同潜水埋深及灌水定额条件下,研究区主要作物种植下农田非饱和带水分转化关系。结果表明,两个模型得到的作物生长过程中土壤储水量、蒸散发量、根区深层渗漏量及农田渗漏补给地下水量具有良好的一致性,说明农田非饱和带水量平衡模型可以用于描述研究区典型农田土壤水分动态变化过程。(4)建立了包气带农田、林草地、裸地及水域等不同景观单元的概念性水文模型,并将其与地下水动力学模型FEFLOW进行松散耦合,形成基于景观单元的黑河中游绿洲水文过程模型。利用区域水均衡数据、2000～2010年区域遥感蒸散发数据以及地下水位观测数据对耦合模型进行模型率定。结果表明:该模型能有效地量化非饱和带不同景观单元的水转化参量,并可靠地模拟地下水动态变化特性以及绿洲区域水分消耗与补给规律。(5)将基于景观单元的黑河中游绿洲水文模型应用于维持现状及不同节水情景下的绿洲水文过程模拟预测。结果表明,随着灌溉定额的减小,非饱和带储水量增加值以及研究区蒸散发总量均呈下降趋势;提高渠系衬砌率使渠系水利用系数至90%、却维持现状地下水开采量,会减少渠系水渗漏补给地下水的水量,反而加重地下水亏空;但提高渠系衬砌率的同时减小地下水开采量将利于维护区域地下水均衡。
[Abstract]:The middle reaches of Heihe is located in the northwest arid area of China, the shortage of water resources, water contradiction. The oasis is China's major grain producing areas, agricultural irrigation, hydrological processes affected by human activity intensity. Because of the characteristics of arid region hydrology process with "Dissipative", the hydrological model is not suitable for humid areas to the river runoff the process of the traditional direct application in this area. For the hydrological drought area of quantitative transformation parameters, predict the impact of human activities on hydrological process, promote the scientific management of local water resources, to establish suitable hydrological model of this area. This paper selected the middle reaches of Heihe oasis as a study area, in the analysis of monitoring data and field test on the basis of established oasis hydrological process models with different landscape units, carried out the research of modeling and scenario prediction of hydrological processes in the middle reaches of Heihe oasis. The main research contents and results are as follows: (1) Analysis of the spatial variability of groundwater level distribution in the middle reaches of Heihe. The results showed that the ordinary Kriging method, ordinary Kriging and Universal Kriging method modified Yamamoto methods are applied to the underground water level in the middle reaches of Heihe.Yamamoto spatial interpolation correction method is more suitable for the prediction of groundwater level extremely high value and low value, but the overall prediction accuracy is slightly lower than the other two kinds of methods. In the prediction of spatial distribution of regional groundwater level scale, can be related to the water table interpolation method to select according to the actual situation. The oasis hydrological process model established in this paper, the dynamic simulation of groundwater, the distribution of the initial water level due to the spatial variation is relatively small, the spatial interpolation using ordinary Kriging method, the highest overall accuracy. (2) carried out irrigation lateral leakage test, using two-dimensional soil water dynamics model of farmland irrigation quota HYDRUS-2D, Tian Irrigation lateral leakage process block width and soil layer structure under simulated and analyzed. The results showed that irrigation infiltration ratio (lateral seepage loss and irrigation volume ratio) will increases with the increase of irrigation quota, decreases with the increase of farmland area, farmland soil layer structure also affects infiltration ratio fine soil cover, coarse soil, reduce lateral seepage ratio. For farmland in Heihe oasis, from field scale and soil structure, the loss caused by the lateral irrigation can be ignored in the simulation of hydrological processes in oasis farmland water, only considering the vertical migration. (3) the establishment of farmland with water saturation balance model, the simulation results with the one-dimensional soil water dynamics model of HYDRUS-1D simulation results were verified and analyzed different groundwater depth and irrigation conditions, main crop planting area of farmland moisture in unsaturated zone Conversion. The results showed that two models of crop growth process of soil water storage, evapotranspiration, root zone and deep seepage recharge of underground water in farmland has good consistency, shows that farmland unsaturated water balance model can be used to describe the change process of soil moisture dynamics in Typical Farmland in the study area. (4) the establishment of the vadose zone of farmland, forest and grassland, bare land and water conceptual hydrological model of different landscape units, and its loose coupling and FEFLOW groundwater dynamics model, the formation of the oasis in the middle reaches of Heihe hydrological landscape unit. Based on the model of regional water balance data, 2000~2010 regional remote sensing evapotranspiration and groundwater observation data the data of the coupling model of model calibration. The results show that the model can effectively quantify the unsaturated zone in different landscape units of water transformation parameters, and reliable mode The dynamic characteristics of groundwater and the oasis water consumption and recharge. (5) the oasis hydrological process of landscape units in Heihe oasis hydrological model is used to maintain the status quo and different water saving scenarios based on simulation. The results show that with the small reduction of irrigation quota, the unsaturated zone water storage and increase the value of the study area. The total amount of emission decreased; improve the canal lining rate to canal water utilization coefficient to 90%, but to maintain the status quo of the exploitation of groundwater, will reduce the canal water recharge groundwater water, aggravate the groundwater deficit; but to improve the canal lining rate and reduce groundwater exploitation will be conducive to the maintenance of regional groundwater balance.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S274;P343

【参考文献】