城市小流域空间特征对降雨-径流过程影响的模拟研究
文献类型：学位论文
| 作者 | 姚磊 |
| 学位类别 | 博士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 陈利顶 |
| 关键词 | 城市化，降雨-径流，水文模型，不透水面，空间分布特征 Urbanization, Rainfall-runoff, Hydrological model, Imperviousness, Spatial pattern. |
| 其他题名 | Modelling the influences of catchment spatial characteristics on rainfall-runoff process at community scale |
| 学位专业 | 生态学 |
| 中文摘要 | 城市化进程为人类社会带来了巨大的便利和财富，同时也带来了一系列城市环境问题。城市化进程导致城市区域原有的水文过程发生显著变化，大大增加了城市暴雨洪水灾害的发生风险。因此，城市暴雨洪水问题也逐渐成为城市水文学的研究热点。通过探究和分析城市空间格局特征对降雨 -径流过程的影响可为调控城市暴雨洪水风险提供客观可行的方法参考，一定程度上也能为城市格局规划提供理论支持。 本文主要基于水文模型从社区尺度开展有关城市小流域空间特征对降雨-径流过程影响的研究。首先，本研究在城区尺度模拟分析了北京市五环地区 (城市建成区)的潜在降雨-产流风险，并以此识别了北京市五环内具有较高风险的功能区类型。在此基础上，选取典型的具备完整排水系统的居民小区，通过布设雨量筒和径流计完成对该小区降雨-径流数据监测，并利用该实测数据完成对水文模型(Storm Water Management Model, SWMM)的关键水文参数率定。在构建好的模型基础上，分析城市建成区内小型汇水流域的不透水面以及空间分布格局特征在不同情景下对降雨-径流过程的潜在影响。主要结论如下： (1)从城区尺度上讲，北京市五环内城市功能区各异的不透水面(建设用地)比率使得不同功能区之间的降雨-产流风险差异显著。各城市功能区的降雨-产流风险分布具有显著的正相关性，呈现中心城区高、五环边缘低的环状分布格局。其中，商业和居住区的降雨-产流风险较高，且大都分布在四环以内；低产流风险区主要分布在四环外围，内部构成主要为绿地功能区。 (2)城市小流域的两种不透水面特征 (包括总不透水面率和有效不透水面率 )对流域降雨-径流过程起到决定性作用，变量间存在显著的多元线性回归关系。合理调控两种不透水面比例可以有效降低城市小型流域暴雨洪水风险。 (3)不同的降雨情景对两种不透水面特征的水文贡献影响显著。降雨量较小时(本研究中为<26.9mm)，流域有效不透水面对降雨-径流过程起主要影响；而随着降雨量增加(> 26.9 mm)，总不透水面特征则成为影响流域降雨-径流过程的关键空间要素。此外，不同的雨峰系数或者降雨历时也会显著影响(降低)流域不透水面特征对关键径流过程参数(径流峰值和峰现时滞)的预测能力。 (4)城市小流域的空间分布特征与其降雨-径流过程有着密切的关系。通过调整(优化)流域中不透水面的空间分布格局，使得流域内大部分不透水面(即建筑和路面)远离流域出水口分布，可以有效的削减整个流域的径流洪峰值(最大削减量约为 9%左右)。通过合理的城市空间布局优化策略以调整流域不透水面结构、分布以及排水系统结构可以实现对城市暴雨洪水的有效管控。 |
| 英文摘要 | Rapid urbanization has brought great convenience and wealth for human beings. However, it also cause a series of urban environmental problems. This induces significant alterations for urban hydrological processes, which increases the storm-induced flood risk and poses great threat to urban society and resident properties. The urban flood risk thus become the major focus in the urban hydrological studies. Therefore, exploring and evaluating the potential influence in urban rainfall-runoff process by urban landscape pattern can provide a feasible method reference for urban stromwater management task. Additionally, it also provide a certain extent of theory support for urban landscape planning. In this paper, a model-based analysis is conducted from the urban community scale to explore the relationship between urban spatial pattern and rainfall-runoff process. First of all, this paper discusses the potential changing spatial pattern of rainfall-runoff risk within the five-ring road area of Beijing, in order to provide meaningful theoretical guidance for the future urban storm flood management assigned with the highest urban functional zones. Then, we choose the built-up region of Beijing as the case area, where we select several residential sites (catchments) with complete drainage system as the study areas. In these sites, we monitor a time-series rainfall-runoff data by setting rainfall and runoff gauge equipment. The Storm Water Management Model (SWMM)thus is built and calibrated based on the catchment’s GIS and rainfall-runoff data. Based on the hydrological model, we analyze the potential hydrological impact of the impervious and spatial pattern characteristics of micro urban catchments under various designed scenarios. The main conclusions of this paper are summarized as below: (1) From the viewpoint at the city scale, runoff risks differed significantly from each other across different urban functional zones due to the difference and diversity of the impervious surface rate. In general, runoff risk zones experienced a circular pattern,which decreased from the central to the peripheral region. In most cases, the commercial and residential zones located in the core area of the city were prone to higher runoff generation and risks. Large parks and natural green areas, on the other hand, can help to minimize the flooding risk, and thus can be treated as the low- risk zones. These zones are mainly situated within the fourth to fifth-ring road areas of Beijing city. (2) The two impervious metrics of the small urban catchments (i.e., total impervious area and directly connected impervious area) plays a decisive role in affecting rainfall-runoff process. Storm-induced flood risk in small scaled urban catchment can be effectively mitigated by reasonable control of the two types of impervious area. (3) In small scale urban catchment, different rainfall conditions (including rainfall depth, peak ratio, and duration) pose significant influences in the hydrological performance of imperviousness. When the rainfall amount is lower than a certain threshold (in this study, this threshold is determined at 26.9 mm), the directly connected impervious area contributes as the most important metric in predicting the variations in rainfall-runoff (i.e., total and peak runoff volumes). With the increase of rainfall (> 26.9 mm), the total impervious area becomes as the key element in affecting rainfall-runoff process. Moreover, different rainfall peak ratios and durations will be significantly affected the hydrological ability to predict the key runoff parameters by imperviousness. (4) This study also demonstrate the significant relationship between spatial pattern and rainfall-runoff process in small scale urban catchment. Replacing most of the impervious surfaces in the urban catchment (i.e., buildings and roads) away from the catchment outlet through landscape optimization can effectively cut the peak flow volume of the catchment (up to 9%). In addition, reasonable control of the drainage junction number will also benefit the urban stormwater management task. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/37036]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 姚磊. 城市小流域空间特征对降雨-径流过程影响的模拟研究[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
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