罕台川流域上游水土保持措施减水减沙效益研究

发布时间：2018-07-21 10:56

【摘要】：罕台川流域上游属黄土丘陵沟壑区第—副区,其水土保持治理具有典型性,本文以罕台川流域上游为研究区,在全面认识该流域上游土地利用现状、水土保持治理现状和流域水沙特点的前提下,通过设置标准径流小区试验观测确定不同土地利用类型径流深、侵蚀模数的基础上,基于典型淤地坝的蓄水量、拦沙量和使用寿命的研究,进而采用“水保法”计算罕台川流域上游1998年、2013年水土保持措施的减水减沙效益；同时运用“水文法”计算了罕台川流域上游1990～1999年、2000～2010年水土保持措施的的减水减沙效益,对比分析了“水文法”和“水保法”减水减沙效益计算结果。主要得出以下结论：(1)罕台川流域降雨量年际变化较大,年内70%以上年降雨是季节性降雨。径流含沙量高,径流和输沙量年际差异极大,近期减少明显。径流、输沙量年内分配不均。(2)坡面不同土地利用类型2013年径流深、侵蚀模数变化趋势一致,表现为：荒地封育治理种草经济林乔木林灌木林乔灌混交林,荒地的径流深、侵蚀模数最大,分别为10.7mm和8279t/km2·a,乔灌混交林的径流深、侵蚀模数最小,分别为4.5mmm和2696t/km2·a。(3)1980～1989年建成的骨干坝使用寿命26年,比设计淤积年限延长6年。1990～1999年建成的骨干坝使用寿命30年,比设计淤积年限延长10年。2000～2009年建成的骨干坝、中型坝和小型坝使用寿命分别为34年、20年和11年,分别比设计淤积年限延长14年,10年和6年。2010年后建成的骨干坝、中型坝使用寿命分别为36年和22年,分别比设计淤积年限延长16年和12年。(4)基于“水保法”计算罕台川流域上游1998年、2013年水土保持治理减水量分别为83.57万m3和215.20万m3,减水效益分别为13.90%和35.81%；减沙量分别为76.86万t和190.77万t,减沙效益分别为16.40%和40.71%。(5)基于“水文法”计算罕台川流域1990～1999年、2000～2010年水土保持治理减水量分别为182万m3、851万m3,减沙量分别为243万t、364万t,减水效益分别为13.07%、61.09%,减沙效益分别为60.45%、90.55%。(6)对比分析了“水保法”和“水文法”计算罕台川流域上游水土保持措施的减水减沙效益的计算结果,指出两种方法计算结果存在差别的原因。得出今后研究中要将“水保法”和“水文法”同时运用来相互印证。
[Abstract]:The upper reaches of the Hantaichuan Basin belong to the second sub-region of the Loess Hilly and Gully region, and its soil and water conservation management is typical. This paper takes the upper reaches of the Hantaichuan Basin as the study area, and fully understands the present situation of land use in the upper reaches of the basin. Based on the present situation of soil and water conservation and the characteristics of river basin water and sediment, the runoff depth and erosion modulus of different land use types are determined by setting up standard runoff plot test observation, based on the water storage capacity of typical silt dam. Based on the study of sediment retention and service life, the benefits of water and sediment reduction of soil and water conservation measures in the upper reaches of Hantaichuan River Basin in 1998 and 2013 were calculated by using "soil and Water Conservation method". At the same time, the water and sediment reduction benefits of soil and water conservation measures in the upper reaches of Hantai River Basin from 1990 to 1999 are calculated by using "hydrological method", and the results of water and sediment reduction benefits of "hydrological method" and "soil and water conservation method" are compared and analyzed. The main conclusions are as follows: (1) the annual rainfall in Hantaichuan Basin varies greatly, and more than 70% of the annual rainfall in the year is seasonal rainfall. The runoff sediment content is high, the runoff and sediment transport amount are greatly different from one year to another, and the recent decrease is obvious. The distribution of runoff and sediment transport is uneven in the year. (2) the runoff depth of different land use types on the slope in 2013 and the change trend of erosion modulus are the same, which are as follows: barren land closure, recommended economic forest, tree forest, shrub forest and shrub mixed forest, and the runoff depth of the wasteland, The erosion modulus is the largest, 10.7mm and 8279t/km2 a, respectively. The runoff depth and erosion modulus of Arbor and Irrigation mixed forest are the smallest, which are respectively 4.5mmm and 2696t/km2 A. (3) the service life of the backbone dam built from 1980 to 1989 is 26 years. The service life of the backbone dam, which was built from 1990 to 1999 and 10 years from 2000 to 2009, is 30 years longer than the designed silting life. The service life of the medium-sized dam and the small dam are 34, 20 and 11 years, respectively. The service life of medium dam and core dam built after 2010 are 36 years and 22 years respectively, which are 14 years, 10 years and 6 years longer than that of design siltation, respectively, and the service life of medium dam after 2010 is 36 years and 22 years respectively. (4) based on the method of soil and water conservation, the reduction of water and soil conservation in the upper reaches of Hantaichuan basin in 1998 was 835700 m3 and 2.152 million m3, respectively, and the benefit of water reduction was 13.90% and 35.81%, respectively. The sediment reduction was 768600 t and 1.9077 million t, respectively, and the benefit of sediment reduction was 16.40% and 40.71% respectively. (5) based on the hydrological method, the water reduction of soil and water conservation in the basin of Hantaichuan from 1990 to 1999 was 1.82 million m ~ 3851 million m ~ (3), and the sediment reduction was 2.43 million m ~ (3), respectively. T, 3.64 million t, the benefits of water reduction are 13.07 and 61.09, respectively, and the benefits of sediment reduction are 60.45 and 90.55, respectively. (6) the results of calculation of water and sediment reduction benefits of soil and water conservation measures in the upper reaches of Hantai River Basin are compared and analyzed by "soil and water conservation method" and "hydrological method". The reasons for the difference between the two methods are pointed out. It is concluded that both soil and water conservation law and hydrology law should be used to confirm each other in the future research.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S157

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