燕北山区板栗林地水土流失分区协同防治模式研究

发布时间：2018-06-18 23:12

本文选题：燕北山区 + 板栗林　；参考：《中国科学院大学(中国科学院教育部水土保持与生态环境研究中心)》2017年硕士论文

【摘要】：燕山板栗分布区是典型的山地区,山高坡陡,地少林多,山地利用在当地农林发展中占有重要地位。在板栗林种植、经营中,板栗林下地表裸露,缺乏灌草和枯枝落叶层保护,土壤多为风化物,结构疏松,抗蚀性差;加之地面坡度大,每遇暴雨林下冲沟密布,面蚀与沟蚀严重,土壤大面积沙砾化。随着近年来山地开发种植板栗林趋热,其水土流失问题也日益显现,引起广泛重视。本研究在对研究区域作了大量实地调查和实验的基础上,提出板栗林地水土流失分区协同防治模式,得出以下主要结论:(1)随着板栗林经营年限的增加,其土壤初始入渗率对比为:经营多年的板栗林坡面(10mm/min)经营多年的板栗林水平沟(8mm/min)新开垦的板栗林坡面(6mm/min)=新开垦板栗林水平沟(6mm/min),而其土壤稳定入渗率相当,新垦板栗林土壤的水稳性指数平均是经营多年板栗林的4.9倍,新垦板栗林土壤表层覆被物能有效减少表土冲刷,而经营多年的板栗林由于树下无草覆盖,土壤抗冲性较差。(2)板栗林土壤抗蚀和抗冲能力随着经营年限的增加明显下降。对于经营多年的板栗林,采取维修水平沟的补救措施;对于新开垦板栗林则要按照发生细沟侵蚀的临界坡长统一规划,合理经营。(3)分区协同防治措施对于板栗林坡地的径流和产沙均有一定的调控作用,间隔8m布设工程挡坎的两年削流减沙率达到61.70%和97.41%,间隔6m布设工程挡坎的两年削流减沙率分别为54.15%和85.31%,两种措施下的板栗林地侵蚀强度均远低于地区侵蚀背景值,综合比较,选择8m拦挡坎更适合直型坡板栗林地水土流失的防治。(4)直型坡板栗林坡面径流量受各降雨特征因子的综合影响,单独的降雨因子未表现出对于坡面径流的主导性;坡面产沙量均不是由某一个单独的降雨特征值所决定的,但相对于对照小区,措施小区次降雨产沙量与雨强间的相关性被弱化。(5)分区协同防治措施在大暴雨(雨强较大)条件下对于板栗林地的径流调控效果显著,在降雨量较大但平均雨强较小的情况下的坡面径流调控效果不及大暴雨的调控效果。通过对不同雨型的径流泥沙调控率分析,分区协同防治模式对于板栗林坡面径流泥沙的调控在雨强较大的情况下能发挥出较好的效果。(6)对照小区情况下,分区协同防治模式的径流量和泥沙量均表现为随着平均雨强和I30的增大而呈现出减小的趋势;措施小区情况下,分区协同防治模式的径流量表现为随着平均雨强和I30的增大而呈现出减小的趋势,产沙量表现为随着平均雨强和I30的增大而呈现出增大,随着降雨量的增大而减小的趋势;(7)从工程造价来看,分区协同防治模式工程造价远低于北方土石山区坡改梯工程造价,具有良好的经济适用性。
[Abstract]:The distribution area of Chinese chestnut in Yanshan is a typical mountain area with steep mountain slopes and many small forests. Mountain utilization plays an important role in the development of local agriculture and forestry. In the cultivation and management of Chinese chestnut forests, the surface of the ground under the chestnut forest is exposed, lacking shrub and litter protection, the soil is mostly weathered, the structure is loose, and the corrosion resistance is poor. In addition, because of the large slope of the ground, the gullies are dense under every rainstorm forest. The surface erosion and furrow erosion are serious, and the soil is sand-gravel in a large area. In recent years, the problem of soil and water loss has become more and more obvious with the development and planting of chestnut forests in mountainous areas, which has attracted extensive attention. On the basis of a large number of field investigations and experiments on the study area, the paper puts forward a coordinated control model of soil and water loss in chestnut forest land, and draws the following main conclusions: 1) with the increase of the management years of Chinese chestnut forest, The initial infiltration rate of the soil was compared as follows: 10 mm / min of chestnut forest slope for many years of operation; 8 mm / min of Chinese chestnut forest horizontal ditch after many years of operation; 6 mm / min of newly reclaimed chestnut forest slope surface; = 6 mm / min of newly reclaimed chestnut forest level ditch, but the stable infiltration rate of the soil was equal to that of the newly reclaimed chestnut forest. The soil water stability index of newly reclaimed chestnut forest was 4.9 times of that of the Chinese chestnut forest for many years. The soil surface mulch of newly cultivated chestnut forest could effectively reduce the erosion of topsoil, but the perennial Chinese chestnut forest had no grass cover under the tree. The soil erosion resistance and erosion resistance of Chinese chestnut forest decreased obviously with the increase of management years. For the Chinese chestnut forest that has been under operation for many years, remedial measures should be taken to maintain the horizontal ditch; for the newly reclaimed chestnut forest, the critical slope length of the rill erosion should be unified according to the plan. Reasonable management. 3) Regional coordinated control measures have certain regulation effect on runoff and sediment yield of Chinese chestnut forest sloping land. The reduction rate of runoff and sediment in two years was 61.70% and 97.41% respectively, and that of the two years with 6 m interval was 54.15% and 85.31 respectively. The erosion intensity of Chinese chestnut woodland was much lower than the regional erosion background value. The selection of 8m barrier bar is more suitable for soil and water loss control of Chinese chestnut forest on straight slope. 4) the runoff of Chinese chestnut forest on straight slope is affected by various rainfall characteristic factors, and the single rainfall factor does not show the dominant effect on the runoff on the slope. The sediment yield on the slope is not determined by a single rainfall characteristic value, but it is relative to the control plot. The correlation between secondary rainfall sediment yield and rainfall intensity was weakened. 5) the effect of coordinated control measures on runoff of Castanea mollissima forest land was significant under the condition of heavy rain (heavy rain intensity). Under the condition of higher rainfall but less average rainfall, the effect of runoff regulation on slope is not as good as that of heavy rain. Based on the analysis of runoff and sediment regulation rate of different rain types, the results showed that the control of runoff and sediment on the Chinese chestnut forest slope surface by the zonal coordinated control model could play a better effect in the case of larger rainfall intensity than that in the control plot. The runoff and sediment amount in the pattern of sub-area coordinated control showed a decreasing trend with the increase of average rain intensity and I30. With the increase of average rain intensity and I _ (30), the runoff of the zonal cooperative control model showed a decreasing trend, and the sediment yield increased with the increase of the average rain intensity and the increase of I _ (30). From the point of view of project cost, the project cost of divisional cooperative prevention and control mode is far lower than that of slope transformation project cost in northern earth-rock mountain area, which has good economic applicability.
【学位授予单位】：中国科学院大学(中国科学院教育部水土保持与生态环境研究中心)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S664.2;S157

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