【作者】 汪丽娜；

【导师】 穆兴民； 张晓萍；

【作者基本信息】 中国科学院研究生院（教育部水土保持与生态环境研究中心） ， 水土保持与荒漠化防治， 2007， 硕士

【摘要】 本文以黄土高原粗泥沙集中来源区为对象,以流域为单元,采用野外调查与室内分析、定量与定性分析相结合的方法,系统研究了1960-1999年间黄土高原粗泥沙集中来源区皇甫川、孤山川、窟野河、秃尾河和佳芦河5条流域河川径流、输沙量的时空变化,取得如下主要结论:分析了流域径流量和输沙量年际变化的基本特征。各流域年均径流量及变差系数,皇甫川为1.41×108 m3和0.65,孤山川为0.76×108 m3和0.63,窟野河为6.08×108 m3和0.40,秃尾河为3.51×108 m3和0.21,佳芦河为0.63×108 m3和0.56。各流域年均输沙量及变差系数,皇甫川为4525.98×104 t和0.82,孤山川为1967.31×104 t和0.63,窟野河为9750.14×104 t和0.81,秃尾河为2103.01×104 t和0.92,佳芦河为1344.98×104 t和0.67。根据径流量、输沙量的极值比和径流量、输沙量变差系数,得出粗泥沙集中来源区5条流域的河川径流量、输沙量年际变化都比较大;5条流域最小径流量出现的年份均为1999年;皇甫川、孤山川和窟野河流域最小输沙量出现的年份均为1999年,秃尾河、佳芦河流域的输沙量最少年份分别为1969、1983年;各流域最大径流量、输沙量出现年份均在1980年以前。采用距平累积法、Mann-Kendall法及Pettit法系统分析了5条流域径流量和输沙量年际变化过程及其趋势。指出:(1)与各流域多年平均值相比,5条流域径流量都经历了明显的增加期、减少期和稳定期三个阶段;(2)5条流域的年径流量、输沙量变化从上世纪70年代末以来表现出明显的减少趋势,皇甫川、孤山川、窟野河、秃尾河和佳芦河流域径流量显现趋势性减少的突变年份分别为1976年、1979年、1979年、1979年和1976年。秃尾河和佳芦河流域输沙量发生趋势性减少的临界年份为1978年;皇甫川、孤山川、窟野河流域输沙量也表现出趋势性减少,但没有通过0.05信度检验水平。采用不均匀系数等方法分析了流域径流量和输沙量年内分配特征。结果表明:(1)按日历年,各流域月平均径流量年内变化具有“双峰型”变化特征;皇甫川、窟野河和秃尾河流域月平均输沙量年内分配呈现双峰型趋势,孤山川和佳芦河流域输沙量则呈现“单峰型”。(2)分析了5条流域径流量、输沙量的集中度和集中期,除秃尾河流域径流量的集中期为7月份外,其余4条流域径流量的集中期均为8月份;皇甫川流域的径流量集中度最大,秃尾河流域的径流量集中度最小。5条流域输沙量集中期均为8月份;皇甫川和孤山川流域的输沙量集中度最大,秃尾河流域的输沙量集中度最小。(3)以连续最大4个月(6-9月)径流量占年径流量百分比(ξr)、月最大与最小径流量差值(Δr)反映各流域径流量年内分配极不均匀性,从1960-1999年径流量年内分配不均匀性的变化幅度有减少的趋势。以河流输沙量的相对变化幅度( )和河流输沙量的绝对变化幅度( )衡量各流域输沙量的年内分配变化幅度较为激烈,但5条流域输沙量年内变化幅度的激烈程度有缓和的趋势。分析了粗泥沙集中来源区内的流域水沙协同关系。利用数学理论推导和各流域逐年径流量、逐年输沙量累积关系曲线,进一步论证了除皇甫川流域外,其余4条流域水沙协同关系呈弱化趋势的主要原因是径流量、输沙量年际减少量的非同步性。皇甫川和佳芦河流域的洪峰和沙峰出现的月份基本上吻合,而孤山川、窟野河和秃尾河流域的输沙量最大的月份同时或滞后于径流量最大的月份。皇甫川、窟野河、秃尾河和佳芦河流域的径流量与含沙量间呈正相关关系,而孤山川流域的水沙异源使得该流域的水沙关系较差。在同一时段中,皇甫川流域的降雨损失量最大,形成径流深度最小,径流模数数值最小;而秃尾河流域的降雨损失量最小,形成径流深度最大,径流模数数值最大。分析了粗泥沙集中来源区内各流域径流量和输沙量的空间变化特征。除佳芦河流域外多年平均径流系数表现为由北向南增加的趋势;多年平均径流量、多年平均输沙量、多年平均输沙率和多年平均输沙模数在空间上并未呈现任何变化趋势。以流域地貌作为径流、输沙的再分配因子,选取水土保持人类活动影响相对较小的1959-1969年期间的水文泥沙资料,建立了包含粗泥沙集中来源区5条流域在内的黄河中游20多条支流水沙与流域地貌因素的定量关系。结果表明:在研究区内,研究的地貌参数与流域径流量或输沙量之间表现出类似的变化趋势,即年均输沙量或径流量与集水区面积或河道干流长呈显著的正相关关系,与河道平均坡降呈幂函数减少关系,而与流域相对高差未表现出某种趋势性变化特征。年均径流系数与地貌参数之间均没有表现出明显的趋势性变化。更多还原

【Abstract】 The temporal-spatial characteristics of the five catchments runoff and sediment of coarse sand source regions at Huangfuchuan (HFC), Gushanchuan (GSC), Kuyehe (KYH), Tuweihe (TWH) and Jialuhe (JLH) in the Loess Plateau were studied through the field investigation and the laboratory analysis using the data from the year of 1960 to 1999. The main results are as follows:The basic characteristics of runoff and sediment were analysesed from the year of 1960 to 1999. The results showed the means value of runoff and variation coefficient of HFC, GSC, KYH, TWH, and JLH are 1.41×108 m3 and 0.65, 0.76×108 m3 and 0.63, 6.08×108 m3 and 0.40, 3.51×108 m3 and 0.21, 0.63×108 m3and 0.56, respectively. The means value of sediment and variation coefficient of the above regions are 4 525.98×104 t and 0.82, 1 967.3×104 t and 0.63, 9 750.14×104 t and 0.81, 2 103.01×104 t and 0.92, 1 344.98×104 t and 0.67, respectively. The means value of runoff and sediment, stream flow and sediment of five catchments have a large variation during the studied period according to the ratio between the largest and smallest runoff and the ratio between the largest and smallest sediment among the studied years. The minimal values of the total runoff for the five catchments are all appeared in 1999 without exception. The minimal values of the sediment in HFC, GSC, and KYH are also appeared in 1999. The minimal values of the sediment in TWH and GLH are appeared in 1969 and 1983, respectively. The maximum values of runoff and sediment of five catchments are all displayed before 1980.Annual stream flow and sediment for five catchments was studied using the cumulative departure method, the Mann-Kendall method and Pettit method. The results showed that (1) Five catchments have all experienced the obvious increasing, reducing, and stabilization period compared with the means value of runoff. (2) An obvious decreasing trends of runoff and sediment were detected since 1970`s in the studied catchments. The change points of runoff for the five catchments occurred in 1976,1979,1979,1979, and 1976, respectively. The change points of sediment for TWH and JLH started in1978. HFC, GSC, and KYH also displayed a reduction of the sediment, but significant differences were not detected (P>0.05).The change character of runoff and sediment within a year were studied by using uneven coefficient method. The results are: (1) Monthly average river flows for many years’have two peaks in five catchments according to calendric years. Changing process line of monthly average sediment for many years was a peak, except HFC, KYH, and TWH catchments of which sediment remain has two peaks. (2) Concentrating scheduled time of runoff and sediment, centralized degree of them were analysesed. Concentrating scheduled time of runoff is in August, except TWH, which of runoff concentrating scheduled time is in July. The catchment, which is the maximal centralized degree of runoff, is HFC, and the catchment of minimal runoff centralized degree is TWH. Concentrating scheduled time of sediment is on summer floods, and the peak value is in August. The catchment, which is the maximal centralized degree of sediment, is HFC and GSC, the catchment of minimal sediment centralized degree is TWH. (3) The non-uniform of stream flow distribution in coarse sand source regions of the Loess Plateau has been analyzed by the ratio of continuously maximum four months` runoff and the subtracts value of the maximum and minimum runoff value in a year. The changing of the non-uniform of stream flow distribution within the year is reducing from 1960 to 1999. The non-uniform of sediment distribution in coarse sand source regions of the Loess Plateau has been analyzed by the relatively and absolutely changing of sediment. The changing of the non-uniform of sediment distribution is also reducing.The relationship between runoff and sediment were also analyzed in coarse sand source regions of the Loess Plateau. The results also further indicated that the water and sand coordination relations assumes the attenuated tendency in the other four catchments except HFC, using mathematics theory reasoning method and accumulation curve of runoff and sediment year by year because of decrement non- synchronism between runoff with sediment. The month of sand peak is almost simultaneously appeared with runoff peak in HFC and JLH. Most of the month of sand peak shows simultaneous or late than that of sand peak in GSC, KYH, and TWH. Because of allos of the runoff and sediment, the correlativity between runoff with sediment in GSC appeared not to be related. But the other four catchments` runoff seemed to be well fit with the sediment. In same period, among the five catchments, the maximal rain loss amounts is HFC ,which is the minimal runoff depth value and the minimal runoff modulus value, and the catchment of minimal rain loss amounts is TWH, which is the maximal runoff depth value and the maximal runoff modulus value.The spatial character of runoff and sediment in coarse sand source regions of the Loess Plateau were also analyzed. The mean annual runoff coefficient displayed the tendency of increasing from north to south, except JLH. But the mean annual runoff, the mean annual sediment, the mean annual sediment rates and the mean annual sediment modulus were not related among the catchments. The Quota relations, between geomorphologic factors with water and soil, have been established in Yellow River middle reaches, more than 20 branches, which contained the five catchments in coarse sand source regions of the Loess Plateau by taking geomorphologic factors as the redistribution factor of runoff and sediment and by selecting the hydrology silt material from 1959 to 1969, when the influence of human activity in water and soil conservation was smaller. The results showed that both the mean annual runoff and the mean annual sediment load seemed to be well fit by positive linear regression with the catchments area and the length of main river course. Both the mean annual runoff and the mean annual sediment load appeared a negative exponential regression with the mean slope gradient of river course. There is no obviously relationship between the mean annual runoff coefficient and geomorphologic factors.更多还原