【作者】 张莉；

【导师】 邹冬生； 苏以荣；

【作者基本信息】 湖南农业大学 ， 生态学， 2004， 硕士

【摘要】 我国的南方红壤地区水热资源丰富，是国家重要的粮食和经济作物基地。但降水分布的不均一性和受季节性高温影响，常造成伏、秋旱，给当地农业带来严重影响。因而如何合理有效地利用土壤水资源就成为保证农作物和林草植被生理需水、改善生态环境的关键。以关键性因素土壤水分为出发点，采用土壤水分测定仪(ECHO)和中子仪相结合，通过野外双环入渗实验和室内取样分析相结合的方法，分析了积水入渗过程中不同植被类型坡地土壤水分动态变化规律及再分布规律；取得的主要结论如下： 1) 松林地土壤水分渗透速率随时间递减最快，而自然荒坡地减少最慢，说明自然荒坡地土壤整体入渗性能最好，松林地土壤上层入渗性能较好；影响土壤入渗速率的主要因子是土壤结构性质、土壤初始含水量和土壤的地貌特征；三种入渗公式与实测点配合的情况总体来看是考斯加可夫公式最佳。 2) 土壤水分动态变化可划分为3个阶段，第一阶段的时间较短，一般为10min左右，即为土壤含水率基本不变的阶段：第二阶段为土壤含水率急剧增大阶段，此阶段一般维持10-30min：第三阶段为土壤含水率缓慢增大阶段。入渗对上层水分动态影响最大，10cm深度处水分变化最剧烈，达到稳定的时间最短，而50cm以下土层含水量变化相对平缓。 3) 入渗后土壤水分再分布规律是：随着供水停止后时间的延长，表层0～10cm内土壤含水率急剧降低，20～50cm土层的含水率开始有增大的趋势，然后逐渐减小。60cm以下土层的含水率略有变化；不同植被类型变化幅度为自然荒坡地＞农耕地＞松林地。相对于隔绝蒸发条件而言，有蒸发条件下土壤含水量减少幅度要大。更多还原

【Abstract】 Red soil regions of the South China,because water and hot resource is rich ,and become important grain in the country and industrial crops base.But for a quality of inequality in rainfall distributed and the influencing by the seasonal high temperature, often cause the dog days, drought in autumn, bring serious influence to local agriculture. Therefore how to utilize soil water resource rationally and effectively become the keys to guarantee physiological water requirements of vegetation and improve eco-environment. In the dissertation, soil water that restricts vegetation construction primarily is focused on.By the ECHO and Neutron Probe, and the experiment of infiltration natural condition,the laws of soil moisture dynamic state during infiltration period and soil water redistribution after infiltration under different slope vegetation types have been analysed . The main results are as follows:1) Pine forest land soil moisture permeate speed decreased is the fastest with time increased, natural hillside fields most slow,it proves the infiltration capacity of natural hillside fields soils is the best, pine forest land soil upper layer better;The main factors soil infiltration rate approached are soil natural structure,initial water content and graphic condition;The Kocrakob equation of three infiltration equation match best with survey .2) The dynamic change of the soil moisture can be divided into 3 stages, the time of the first stage is relatively short, generally about lOmin, it is the stage that the soil moisture content does not change basically; Increase sharply stage for the soil moisture content about 10-30min is the second stage; The third stage increases stage slowly for the soil moisture content . It is a largest influence on upper layer soil moisture dynamic state during infiltration, 10cm depth moisture changes most violent, it is shortest to reach steady time, and the water content of soil layer changesrelatively gentlely under 50cm.3) The law of soil moisture redistribute after infiltration as follows. The extension of time with supplying water of stopping, the soil moisture content is reduced sharply in top layer 10cm, the moisture content of 20-50cm soil layer begins to have the tendency to increase, then reduce gradually. The moisture content of the soil layer slightly changes under 60cm; Different vegetation types change the range are that the natural hillside fields is the greatest,and pine forest land smallest. Compare to the condition of evaporation isolated , the range is larger for soil water content to reduce in evaporation condition更多还原