药乡小流域降雨径流过程特征研究

发布时间：2018-05-06 23:41

  本文选题：药乡小流域 + 降雨径流　； 参考：《山东农业大学》2017年硕士论文

【摘要】：山东省处于北方土石山区,山丘区面积占约2/3。该区域山地干旱瘠薄,岩层破碎且风化严重,生态环境十分脆弱,土壤肥力和保水保肥能力低下,水土流失严重,土壤侵蚀量为全国平均值的3倍,因此开展山东山丘区水土流失治理工作迫在眉睫。通过对山丘区降雨-径流特征及相关关系的研究将有助于从过程与机制上深入了解流域径流对降雨的响应机理,进而为采取相应的水土保持措施提供理论依据,为基于强降雨产生的洪水过程下水土流失的规划以及洪水的利用提供参考。本研究选择位于山东鲁中南山丘区的泰安药乡小流域,以该流域2012-2016年的降雨、径流等实地观测数据为基础,通过对该流域进行降雨产流分析,得出降雨与产流之间的定量定性关系,并运用不同的基流分割方法进行径流组分的划分,从而得出更适用于该流域的基流分割方法,然后对洪水退水过程线进行分割,以期为山东山丘区产流过程的研究提供理论参考。主要研究结果如下:(1)药乡小流域降雨具有明显的季节变化,且呈单峰性分布,主要集中在5-9月,占到全年降雨量的85.6%,侵蚀性降雨总量占全部降雨总量的82.5%,其中7-8月所占比例最大,约占全部侵蚀性降雨的18.7%-40.4%。各降雨特征值的最大值均出现在7月份,降雨极不平衡。径流较降雨来说有一定的滞后效应。通过皮尔逊相关分析和逐步回归方法分析降雨与径流之间的相关性,得出降雨量、降雨历时、最大30 min雨强是产流的主控因子,且均与径流总量呈正相关,降雨量和最大30 min雨强对产流的影响更大。(2)当两场降雨的降雨量、降雨历时等降雨指标相近时,是否有前期降雨就成为影。响产流的主要因素。当有前期降雨时,径流随降雨的变化响应十分敏感,径流量达到峰值的时间几乎与降雨量的峰值同步。当无前期降雨时,径流会滞后于降雨产生,滞后时间的长短取决于土壤的干燥程度。(3)通过K值均值聚类分析方法,根据降雨量、降雨历时和降雨侵蚀力将药乡小流域2012-2016年间的180场降雨划分成三种雨型。平均雨量较小,降雨历时较短,降雨侵蚀力较小的降雨被划分为雨型Ⅰ ;中等雨量,较长降雨历时和中等降雨侵蚀力的降雨被划分为雨型n;降雨历时中等,降雨量大且降雨侵蚀力大的降雨被划分为雨型Ⅲ。不同雨型引起的产流差异十分明显,引起药乡小流域产流的主要为雨型Ⅱ,占全部产流的 50.3%。(4)同时运用数字滤波法和基流指数法对药乡小流域径流过程进行基流分割,得出最适宜的方法为数字滤波法,且最合适的过滤参数取a为0.525,β为0.925。在洪水过程中下一次洪水的起涨时刻从该次洪水与上次洪水的拐点开始,而上一次洪水未退完的那部分径流从该点继续消退直至结束;退水过程的第二段与第一段相比更为平缓。
[Abstract]:Shandong Province is located in the northern earth-rock mountain area, the hilly area accounts for about 2 / 3. In this region, the mountain area is arid and barren, the rock layer is broken and weathered seriously, the ecological environment is very fragile, the soil fertility and the ability of retaining water and fertilizer are low, the soil and water loss is serious, the amount of soil erosion is 3 times of the national average. Therefore, it is urgent to carry out soil erosion control work in Shandong hilly area. The study on the characteristics of rainfall and runoff and the correlation between rainfall and runoff in hilly areas will be helpful to understand the response mechanism of watershed runoff to rainfall in terms of process and mechanism, and to provide theoretical basis for the adoption of corresponding soil and water conservation measures. It provides a reference for the planning of soil and water loss and the utilization of flood caused by heavy rainfall. In this study, Taian Yao Xiang small watershed, located in the mountainous region of Shandong Province, was selected. Based on the field observation data of rainfall and runoff in the basin from 2012 to 2016, the runoff yield of the watershed was analyzed. The quantitative and qualitative relationship between rainfall and runoff is obtained, and different basic flow segmentation methods are used to divide the runoff components, which is more suitable for the watershed, and then the flood receding process line is segmented. In order to provide a theoretical reference for the study of runoff production process in Shandong hilly area. The main results are as follows: (1) the rainfall in the small watershed of Yixiang has obvious seasonal variation and has a single peak distribution, mainly concentrated in May-September. The total amount of erosive rainfall accounts for 82.5% of the total rainfall in the whole year, and the proportion of July to August is the largest, accounting for 18.7-40.4% of all the erosive rainfall. The maximum value of each rainfall characteristic value appears in July, the rainfall is extremely unbalanced. Runoff has some lag effect compared with rainfall. Through Pearson correlation analysis and stepwise regression analysis, the correlation between rainfall and runoff is analyzed. The results show that rainfall, rainfall duration and maximum rainfall intensity of 30 min are the main controlling factors of runoff production, and are positively correlated with the total runoff. Rainfall and maximum rainfall intensity of 30 min have more influence on runoff. The main factor that causes abortion. When there is early rainfall, the response of runoff with rainfall is very sensitive, and the time when runoff reaches its peak is almost synchronized with the peak of rainfall. When there is no early rainfall, the runoff will lag behind the rainfall, and the lag time depends on the dry degree of the soil. Rainfall duration and rainfall erosivity divide 180 rainfall patterns into three types in 2012-2016. The rainfall with less average rainfall, shorter rainfall duration and less rainfall erosion was divided into rain type 鈪，

本文编号：1854450