春季融雪期黑土和白浆土坡面细沟侵蚀研究

发布时间：2018-04-10 01:16

本文选题：东北黑土区　切入点：融雪侵蚀　出处：《沈阳农业大学》2017年硕士论文

【摘要】：春季融雪期土壤由于受到融雪径流、冻融作用及未完全解冻层影响,细沟发育有别于降雨期。融雪期细沟侵蚀在许多地区都有发生,但该时期细沟侵蚀的研究远落后于降雨期。本研究以东北黑土区黑土和白浆土为研究对象,采用野外实地测量与室内模拟相结合的方式,进行春季融雪期坡面细沟侵蚀研究。通过对野外典型垄作农田细沟形态及分布指标进行测量,分析黑土和白浆土坡面融雪期细沟侵蚀的形态、侵蚀程度及空间分布特征。在此基础上,选取冻融温差,冻融循环次数,土壤含水率,径流量和解冻深度5个影响因素,进行融雪期细沟侵蚀室内模拟实验,以进一步探究融雪期各因素对细沟侵蚀的影响。得出以下主要结论:(1)融雪期垄作农田细沟形态特征。利用野外观测结果,根据细沟走向与垄台之间相对位置关系,将黑土和白浆土垄作农田中由融雪侵蚀形成的细沟分为顺垄型、断垄型和复合型三种类型。对黑土坡面来说,顺垄型细沟平均长度(168.05cm)和宽度(5.53cm)较大而深度(4.81cm)最小;断垄型细沟平均长度(74.72cm)及变异程度最小,深度(5.25cm)最大;复合型细沟平均长度(215.42cm)最大而宽度(5.14cm)最小。对白浆土坡面来说,顺垄型细沟的平均宽度(10.25cm)、深度(3.57cm)及二者的变异程度最大,而宽深比系数小,形态相对"窄深";断垄型细沟平均长度(38.90cm)、宽度(7.72cm)、深度(2.26cm)均最小;复合型细沟平均长度(145.46cm)最大而细沟宽度的变异程度最小。(2)融雪期垄作农田细沟分布特征。不同坡向来说,黑土和白浆土坡面融雪期细沟侵蚀程度规律相似,阳坡的细沟侵蚀量、细沟密度和细沟割裂度均大于阴坡,说明阳坡的破碎程度及细沟侵蚀程度大于阴坡。不同坡位来说,黑土和白浆土坡面融雪期细沟侵蚀强烈地段均集中在中、下部位置,而两种土壤细沟形态受坡位的影响存在差异。黑土坡面上,阴坡细沟宽深比系数和细沟侵蚀量最大值均出现在下部(距坡顶260～312m位置),在此区域断垄型细沟侵蚀量最大,其次为顺垄型,复合型;阳坡细沟宽深比系数最大值出现在距坡顶54～81m区域。距坡顶81～108m区域的细沟侵蚀量最大,占该坡面细沟侵蚀总量的64%,顺垄型和复合型贡献细沟侵蚀量较大,断垄型较小。白浆土坡面上,阴坡细沟宽深比系数最大值出现在距坡顶0～24m区域,细沟形态从坡上到坡下部由"宽浅"向"窄深"变化。阴坡发育的细沟在距坡顶72～96m区域侵蚀量最大,在此区域顺垄型细沟侵蚀量最大,其次为复合型,断垄型;阳坡细沟宽深比系数最大值出现在距坡顶75～100m区域。在距坡顶125～150m区域细沟侵蚀量最大,占该坡面细沟侵蚀总量的77%,顺垄型和复合型细沟贡献侵蚀量较大,断垄型较小。(3)融雪期各因素对细沟侵蚀的影响。分析冻融温差、冻融循环次数、土壤含水率、径流量和土壤解冻深度对融雪期细沟形态和侵蚀量的影响,得出解冻深度是影响黑土细沟宽深比的首要因素,径流量是影响黑土和白浆土细沟侵蚀量的首要因素。径流量对黑土细沟宽深比影响较小,对白浆土影响较大。冻融循环次数对两种土壤的细沟侵蚀量的影响较小;相同条件下,黑土与白浆土细沟形态差异较大,白浆土的细沟侵蚀量大于黑土的细沟侵蚀量;冻融温差在0℃左右冻融上下波动时,黑土和白浆土细沟侵蚀量较大。含水率对黑土细沟侵蚀量影响程度大于白浆土,冻融温差和含水率对黑土和白浆土细沟宽深比的影响较接近;未解冻的冻结层对黑土和白浆土侵蚀量的增大均有一定的抑制作用。
[Abstract]:The spring snowmelt soil due to snowmelt runoff, freezing and thawing and incompletely thawed layer effects, different from the period of rainfall. The snowmelt period rill rill erosion in many areas have occurred, but the period of rill erosion on far behind the rainfall period. In this study, the black soil and Albic Soil in the black soil region of Northeast China as the research the object, by using field measurements and indoor simulation combination, the spring snowmelt period of rill erosion research. Through the measurement of morphology and distribution index of typical field ridge farmland rill, black soil and albic soil slope analysis of snowmelt rill erosion morphology, erosion degree and spatial distribution characteristics. On this basis, selection of frozen melting temperature, freeze-thaw cycles, soil moisture, runoff and thaw depth of the 5 factors of snowmelt rill erosion simulated experiment, to further explore the factors of snowmelt. Effects on erosion rill. The main conclusions are as follows: (1) the characteristics of rill ridge farmland snowmelt. Using field observation results, according to the trend and rill ridge relative position, and Albic Soil in farmland soil in the ridge formed by snowmelt erosion rill is divided into smooth ridge type, rate type and composite type three types. On black soil slope, the average length of a ridge along the rill (168.05cm) and width (5.53cm) and large depth (4.81cm) minimum rate; the average length of rill type (74.72cm) and the minimum degree of variation, the maximum depth (5.25cm); the average length of the compound (215.42cm) and maximum rill width (5.14cm) minimum. Albic soil slope, the average width of the ridge along the rill type (10.25cm), depth (3.57cm) and the maximum variation degree of two, and the ratio of width to depth coefficient of small, relatively narrow and deep form "; the average rate of rill length type (38.90cm), width (7.72cm), depth (2.26cm) had the smallest; the average length of the compound (145.46cm) and the minimum maximum rill rill width variation. (2) the distribution characteristics of farmland rill ridge snowmelt. Different slope, slope surface soil and albic snowmelt rill erosion regularity is similar to that of the sunny slope rill erosion, rill density and rill lacerative degree was higher than that of sunny slope slope, the fracture degree and rill erosion degree is greater than the slope. Different slope, slope and albic black soil erosion surface area strongly snowmelt rill are concentrated in the lower position, and two kinds of soil fine groove shape is affected by slope position. There are differences in the black soil slope, slope rill the ratio of width to depth of rill erosion amount coefficient and the maximum values appeared in the lower part (260 ~ 312m distance from the top of the slope position) in this area, type rate of rill erosion is the largest, followed by the smooth ridge type, compound type; sunny rill width depth ratio coefficient maximum In the distance from the top of the slope region of 54 to 81m. 81 to 108m distance from the top of the slope area of the rill erosion amount is the largest, accounting for 64% of the total amount of the rill erosion, smooth ridge type and composite type with a large amount of rill erosion rate, small. Albic soil slope, slope rill width to depth ratio of the maximum in the distance of the top 0 to the 24m area, rill morphology from the slope to the slope by the "shallow" to "narrow and deep changes. The development of slope rill in the distance from the top of the slope region of 72 to 96m maximum erosion in this area, along the ridge of rill erosion is the largest, followed by the composite rate; rill width depth ratio coefficient of slope the value in the distance of 75 ~ 100m in the slope area. The region of 125 to 150m distance from the top of the slope rill erosion is the largest, accounting for 77% of the total amount of the rill erosion, smooth ridge type and complex type of rill erosion rate with larger, smaller type. (3) the influencing factors of snowmelt erosion rill. Temperature of freezing and thawing analysis, The freeze-thaw cycle, soil moisture, affect runoff and soil thaw depth of rill erosion and snowmelt, the effects of soil thaw depth is deeper than the primary factor of rill width, runoff is the primary factor affecting erosion and lessive soil. Rill runoff on black soil rill width to depth ratio little effect, albic soil influence. Influence of freeze-thaw cycles on two soil rill erosion amount; under the same conditions, black soil and Albic Soil rill morphological difference, rill erosion of PLANOSOL rill erosion amount is greater than the black soil; freeze-thaw temperature at 0 degrees Celsius on freezing and thawing under the fluctuation, and albic soil erosion rill large amount of moisture. The degree of impact on soil rill erosion amount is greater than PLANOSOL, freeze-thaw temperature and moisture content of black and white slurry soil rill width to depth ratio effect is close to the frozen layer of frozen unsolved; There is a certain inhibition effect on the increase of the erosion amount of the black soil and the white pulp soil.

【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157.1

【相似文献】