元谋干热河谷土壤裂缝形态特征及发育规律研究

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > 成都山地所知识仓储（2009年以前）

题名	元谋干热河谷土壤裂缝形态特征及发育规律研究
作者	熊东红
学位类别	博士
答辩日期	2008
授予单位	中国科学院水利部成都山地灾害与环境研究所
授予地点	成都
导师	张信宝
关键词	土壤裂缝形态特征影响因子发育规律元谋干热河谷
其他题名	Soil Crack's Morphological Feature and it's Development Law in Yuanmou Dry-hot Valley Region
学位专业	自然地理学
中文摘要	干热河谷是我国典型脆弱生态区之一，也是我国西南山区荒山植被恢复的重点和难点。由于炎热干燥的气候和土壤强烈的膨胀收缩特性，旱季土壤开裂现象极为普遍。土壤开裂加速了土壤水分的蒸发散失，加剧了植物的干旱胁迫作用，是植被恢复工作在该区一直难以取得成功的重要原因之一。论文选择元谋干热河谷普通燥红土、变性燥红土、表蚀变性土和普通变性土等四种典型土壤为研究对象，主要采用野外调查、定位观测和模拟实验的方法，对干热河谷土壤裂缝发育形态特征、影响因子、发育规律进行了系统研究。研究成果为进一步深入研究土壤开裂、地面蒸发与植被生长的耦合作用奠定了良好基础，对于揭示干热河谷的土壤干旱和土地退化机制，以及因地制宜地制定植被恢复措施具有重要的理论和实践价值。主要研究结论如下： 1）土壤裂缝地表形态调查方法的确立及量化表征体系的建立。确定将照相法为本研究中的使用方法；提出从裂缝发育的形态强度、复杂度及连通度三个方面来定量描述裂缝形态，首次建立了包括裂缝面密度、线密度、面积－周长比、分形维数、形状指数等指标在内的裂缝形态量化指标体系。 2）查明了元谋干热河谷土壤裂缝不同发育程度的形态特征。将裂缝面密度作为裂缝发育程度划分的主要依据，确定了裂缝形态发育程度的分级标准：面密度≤5％属微度发育，5％＜面密度≤10％属轻度发育，10％＜面密度≤22％属中度发育，22％＜面密度≤27％属强度度发育，面密度＞27％属极强度发育；并建立了各形态指标与面密度的回归方程，查明了裂缝强度特征、复杂度特征及连通度特征随裂缝发育强度的规律性变化。 3）查明了元谋干热河谷土壤裂缝发育的主要影响因子。发现土壤开裂程度与粘粒含量、膨胀收缩性指标、容重均存在正相关性，与有机质含量、总孔隙度为较弱的负相关关系；控制土壤裂缝发育程度的第一位因子为胀缩度，第二位为0-30cm层粘粒含量，第三位为30-60cm层容重，第四位为0-30cm层有机质。 4）初步掌握了元谋干热河谷典型土壤裂缝的发育规律。初步查明了元谋干热河谷普通燥红土、变性燥红土、表蚀变性土及普通变性土随水分衰减其形态指标的动态变化规律，并建立了相应的回归方程。研究表明：不同土壤裂缝的最终发育强度不同，普通燥红土无论水分如何衰减，其面密度只能发育到微度范围；而变性燥红土、表蚀变性土和普通变性土均能发育到强度甚至极强度；随土壤水分的衰减，面密度、线密度、加权面周比的均呈上升并逐步趋于稳定；不同土壤裂缝发育过程中，由分形维数量度的裂缝复杂度呈不断降低的趋势，但其连通性均呈一致性地增强。
英文摘要	The Dry-hot Valley Region (DVR) is one of the typical ecologically fragile areas, as well as the focus of the revegetation work in southeast mountainous areas in China. Due to the extremely hot and dry climate and the high expansive-shrink property of soil, soil cracking phenomena are very common in the dry season. Soil cracking accelerates the water loss by means of evaporation, intensifying the damage of soil drought to plants, thus has become one of the key limit factors to the revegetation work in this region for several decades. In this paper, the general dry-red soil, the verti-dry-red soil, the erosive-vertisols and the general vertisols were taken as study soils. Based on the results of filed investigations, fixed-location observations and simulation experiments, the soil crack’s morphological features, influencing factors and development laws were studied. The quantitative indicator system for the crack morphology was established, the morphological features of soil cracks under various development degrees were clarified, and the regression equations were also established. The main contents and conclusions of this study are listed as follows: 1) Selection of investigation methods for soil crack morphology and establishment of the quantitative indicator system. The photography method was taken as the final investigation method for soil crack morphology. And the idea was proposed that crack morphology should be described quantitatively from the three aspects: development intensity, morphological complexity and connectivity. And the quantitative indicator system for soil crack morphology was firstly established, which includes crack area density, line density, ratio of area and perimeter, fractal dimension, shape index et al. 2) The morphological features of soil cracks under various development degrees were clarified. The crack area density was considered as the main index for the division of crack’s development degrees, and the division criteria of crack morphological development degrees were established: crack area density (CAD) ≤ 5% belongs to feeble development degree, 5% 27% belongs to extremely intensive development degree. The regression equations of the morphological indicators and CAD were also obtained. And the changing laws of intensity features, complexity features and the connectivity features along with CAD’s change were identified as well. 3) The main influencing factors of soil cracking in Yuanmou Dry-hot Valley were identified. Results indicate that soil cracking development has positive correlation with clay content, expansive-shrink property, and bulk density, and is negatively correlated to organic content and total porosity. The first controlling factor for soil cracking is expensive-shrink degree, then follows with clay content of 0-30cm layer, and then is bulk density of 30-60cm layer, and the forth one is organic content of 0-30cm layer. 4) The development laws of typical soil crack in Yuanmou Dry-hot Valley were unveiled. The dynamic laws of the four typical soils (the general dry-red soil, the verti-dry-red soil, the erosive-vertisols and the general vertisols) were identified and the corresponding regression equations were established. Results indicate: different soil types have different final development ends. The general dry-red soil can only develop into feeble degree, while the other three soil types can develop into intensive degree or even extremely intensive degree. With soil water decaying, the Crack Area Density, Line Density and Ratio of Area-perimeter all gradually increase and then keep stable. The crack complexity measured by Fractal Dimension continuously decrease while the crack connectivity uniformly strengthen in the soil cracking.
语种	中文
学科主题	土壤学
公开日期	2011-07-21
内容类型	学位论文
源URL	[http://192.168.143.20:8080/handle/131551/3284]
专题	成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前）成都山地灾害与环境研究所_山地灾害与地表过程重点实验室
推荐引用方式 GB/T 7714	熊东红. 元谋干热河谷土壤裂缝形态特征及发育规律研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2008.