IMHE OpenIR  > 山地灾害与地表过程重点实验室
干热河谷冲沟土壤水热状况时空差异及其影响因素
Alternative Titlehe Spatial and temporal differences and the influencing factors of soil water content and temperature of gully erosion in Yuanmou Dry-hot Valley
Language中文
郭敏
Thesis Advisor熊东红
2016
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Name硕士
Degree Discipline自然地理学
Keyword土壤水分 土壤温度 时空变化 影响因素 干热河谷
Other Abstract

干热河谷水土流失严重,冲沟侵蚀强烈,植被恢复一直是该区的生态环境建设的重要工作之一。以往的植被恢复及水土保持措施忽视了冲沟各部位土壤水热状况的差异,对各部位均采用单一的治理措施,治理效果不甚理想。本研究采用野外调查、长期定位监测、室内实验和理论分析相结合的方法,对干热河谷冲沟土壤水热状况时空差异及其影响因素展开研究,以便为采取针对性的水土流失控制、冲沟治理及植被恢复提供理论指导。为探明冲沟各部位土壤水热状况时空差异,本研究选取了3条典型冲沟进行土壤水分和土壤温度长期监测,研究了冲沟各部位土壤水分、土壤温度的时空动态变化特征及其差异,并结合土壤理化性质和气象要素进行了影响因素分析。研究结果表明:(1)冲沟各部位的土壤含水量在时间尺度和空间尺度都表现出了规律的变化。冲沟各部位的土壤含水量在时间序列上表现出明显的旱雨季之分,其最低值和最高值分别出现在5月(4.9%)和9月(16.8%);各部位间表现为:集水区<沟床<沟头,且随土壤深度的增加表现出先减少后增加的变化趋势,在土壤水分含量最低的40~60cm土层(3.8%)出现了类似于土壤干层的现象。各部位10cm土层的土壤含水量在监测时段内几乎都高于凋萎系数,但集水区20cm、30cm和40cm土层的土壤含水量均低于凋萎系数。(2)冲沟各位的土壤温度在时间和空间上均表现出了规律的变化。冲沟各部位的土壤温度在时间序列上均表现出先增加后减小的变化趋势,在各部位间的大小表现为:集水区>沟头>沟床,且均在6月份和12月份达到全年土壤温度最高值(34.84℃)、最低值(16.04℃),其日变化均表现为正弦曲线变化,其中集水区土壤温度条件恶劣,沟床土壤温度变化相对和缓。(3)冲沟的土壤温度和土壤含水量在时间和空间上均表现出差异。集水区土壤含水量变异系数最大,沟头土壤含水量的变异系数最小,30cm土层5月时土壤含水量的变异系数最大;集水区土壤温度的变异系数最小。(4)冲沟各部位土壤水分和温度状况的差异受土壤理化性质及气象要素的影响。土壤水分含量受降雨影响明显,土壤温度与气温密切相关,且该区具有雨热不同期的特点。(5)基于上述冲沟土壤水热状况时空差异,在植被恢复过程中应对各部位采取针对性措施。沟床水分条件较好,土壤温度及其日较差较小,植被恢复时应优先考虑沟床,且在其相对优越的水热条件下可种植有经济效益的作物;沟头水热条件较集水区更好,但因其常有崩塌发生不利于植物根系着床,该部位在植被恢复物种筛选时应考虑根系发达的灌木或小乔木,以阻滞沟头侵蚀力强的集中流,尽快拦截、固定崩积物;集水区土壤水分含量低且土壤温度高,生境条件恶劣,在该部位可考虑采用人工措施如水平沟整地或采取地表覆盖措施来截留水分并降低蒸发,物种也应选择更耐旱而高温的物种。在旱季尤其是5月时应辅以人工灌溉改善冲沟水分条件,帮助植物顺利度过水分困难期。 

;

Soil erosion is extremely serious due to gully erosion in Yuanmou dry-hot valley region of Jinsha River, where vegetation restoration has been the important work. Previous vegetation restoration practices have ignored the differences of soil water content and temperature among different positions of the gully, and all positions have taken the same restoration measures, so the comprehensive governance effect is not satisfied. In this study, based on the field survey, long term monitoring, laboratory experiments and theoretical analysis method, the spatial and temporal differences and their influencing factors of soil water content and temperature of different gully positions in the dry-hot valley were studied, in order to provide theoretical guidance on the appropriate measures controlling soil erosion and restoring vegetation. To investigate the spatial and temporal differences of soil water content and temperature in different gully positions, three typical gullies were chosen to carry out the long-term monitoring, and thus studied possible influencing factors, such as the physical and chemical properties of soil and meteorological factors. The results indicated that:(1)Soil moisture content in various gully positions all showed regular change trends in spatial and temporal scales. Soil moisture content in various parts of the gullies showed obvious differences between drought season and rainy season, and the minimum and maximum content appeared in May (4.9%)and September(16.8%) respectively; the soil moisture content of various gully positions increased in the order of drainage area gully head> gully bed in spatial scale, especially, the maximum and minimum temperature appeared in June(34.84℃) and December(16.04℃), respectively; their daily variations all showed the sine function trends, and soil temperature condition is bad in watershed, change relatively gentle in gully bed.(3)Soil temperature and soil water content in gully showed the differences in time and space. Variation coefficient of soil water content in watershed is the largest, Variation coefficient of soil water content in gully head is the lowest, Variation coefficient of soil water content is the largest In 30 cm soil layer in May; Variation coefficient of soil temperature in watershed is the lowest.(4)Each part of the gully soil moisture and temperature condition difference is influenced by soil physical and chemical properties and meteorological elements.Soil water content affected obviously by rainfall, soil temperature is closely related to the temperature, and the area has the characteristics of the rain heat over the same period.(5)Based on the spatiotemporal differences of gully soil water content and temperature, different control measures should be taken in various gully positions during the vegetation recovery processes. For the gully bed position, soil water content was the highest, and soil temperature and diurnal variation range are both smaller, which should be given priority to conduct the vegetation recovery measures, and some economic crops can be planted. In addition, for the gully head position, although soil water content condition was better than drainage area, it is difficult for seeds implantation and roots growth because of the frequent collapse incidents, so the shrub or small arbor can be considered when adopting the vegetation recovery measures. For the drainage area position, soil moisture content is low and the soil temperature is high, which has a bad habitat condition, so we should consider to take artificial measures to retain moisture and reduce evaporation, such as horizontal trench or ground cover , and should choose some drought-enduring and high-temperature-enduring species. During the drought season, especially in May, when having a poor rainfall condition, we should supplement artificial irrigation to improve water conditions to help plants survive during the difficult period. 

Document Type学位论文
Identifierhttp://ir.imde.ac.cn/handle/131551/18874
Collection山地灾害与地表过程重点实验室
Affiliation中国科学院成都山地灾害与环境研究所
Recommended Citation
GB/T 7714
郭敏. 干热河谷冲沟土壤水热状况时空差异及其影响因素[D]. 北京. 中国科学院大学,2016.
Files in This Item:
File Name/Size DocType Version Access License
干热河谷冲沟土壤水热状况时空差异及其影响(3177KB)学位论文 开放获取CC BY-NC-SAView Application Full Text
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[郭敏]'s Articles
Baidu academic
Similar articles in Baidu academic
[郭敏]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[郭敏]'s Articles
Terms of Use
No data!
Social Bookmark/Share
File name: 干热河谷冲沟土壤水热状况时空差异及其影响因素.pdf
Format: Adobe PDF
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.