【作者】 杨成波；

【导师】 王震洪；

【作者基本信息】 贵州大学 ， 环境科学， 2008， 硕士

【摘要】 贵州省位于西南喀斯特地区的中心,该省由于自然因素和人为因素相互耦合,大量的土地资源流失,出现大量的石漠化景观。由于贵州省地处亚热带湿润区,降雨量十分丰富,而降雨时空上的分布不均匀,暴雨频繁发生导致水土流失和土地生产力下降是限制当地可持续发展的主要原因。本文采用野外人工模拟降雨器设置不同降雨强度,研究贵州中度石漠化灌丛水土流失,以及用Hood入渗仪对中度石漠化地区灌丛的入渗过程进行研究,其主要结论如下:（1）在5个不同雨强条件下,3个不同岩石裸露率小区的径流量随时间的变化曲线大致是开始径流量逐渐增加,以后逐渐下降。整个曲线呈波动变化。在相同的雨强下,岩石裸露率相差大的小区,产生的径流量较大,岩石裸露率相差不大的2个小区,产生的径流量相差不大。岩石裸露率相差不大的2个灌丛生态系统,其累积径流量非常接近。岩石裸露率相差大的灌丛生态系统,累积径流量变化曲线相差大:累积径流量随时间的变化而逐渐增大。岩石裸露率为70%的灌丛生态系统的累积径流量比岩石裸露率分别为42%、32%的灌丛生态系统的累积径流量都大。岩石裸露率相差不大的灌丛生态系统的累积径流量比较接近。而3种不同岩石裸露率的灌丛生态系统都遵循二次函数方程分布。所有的回归方程均达到极显著水准p＜0.01,相关系数R²都大于0.93以上。（2）随着降雨强度的增加,开始的泥沙浓度逐渐增大。在相同雨强下,泥沙浓度变化过程并不稳定,开始泥沙浓度较高,以后泥沙浓度在波动中逐渐降低。总体来看,岩石裸露率为32%灌丛生态系统的泥沙浓度比其他2个灌丛生态系统都要高。在相同雨强下,泥沙量逐渐增加,当达到峰值后逐渐下降。随着雨强的增大,泥沙量也增大。3种不同岩石裸露率的灌丛生态系统在不同的降雨强度下泥沙累积量随时间的变化符合二次函数方程R=bo+b₁t+b₂t²。3种不同岩石裸露率的灌丛生态系统累积径流量与土壤侵蚀量之间存在着极为密切的正线性关系,线性回归方程为:R=ax+b。（3）通过灰关联分析,找出了影响地表径流系数的主次关系,即植被状况参数的灰关联度大小依次为:灌木层叶面积指数＞植物高度＞灌草层叶面积指数＞草本层叶面积指数。（4）对3个经验土壤入渗模型进行比较表明:Kostiakov方程在大多数情况下,拟合精度高于Horton方程和Philip方程,其中,Philip方程的精度最低,可以判断,对于喀斯特石漠化灌丛生态系统土壤,Kostiakov方程拟合效果最好。3个小区中的累积入渗量都随着土壤含水量的增加而降低。随着土壤含水量的增大3个小区的土壤入渗能力降低。不同土壤含水量条件下Hood入渗仪测定土壤入渗特征表明稳渗率随土壤含水量的增大而减少。（5）相同雨强下径流中养分含量开始比较高,随降雨历时的延长总氮、总钾、总氮浓度变化不明显.径流水溶液中流失的养分没有明显反映出与雨强的相关性,小雨强时有近似于高雨强下的流失浓度。在相同的雨强下,随着岩石裸露率的增大,径流养分流失量逐渐的增加;径流养分累积流失量与累积径流量之间可以用线形方程y=ax+b表示。即径流养分累积流失量随着累积径流量增加而增加。也就是说,随着降雨时间的延长,营养流失量流失越多,土地生产力逐渐降低,从而影响植物的生长。更多还原

【Abstract】 Guizhou Province is located at the central area of southwest Karst region. A great deal of land resources loss and a large number of stony desertification are usually seen in the area. As humid subtropical weather controls Guizhou Province, the rainfall is very rich, and the distribution on rainfall space-time is not even. It is a main reason for limiting local sustainable development that the torrential rain frequently causes soil erosion and land productivity to drop. In present research soil erosion and element loss of shrub forest were dealt with in intermediate rock desertification area of Guizhou when different rainfall intensity was set up controlled by the field artificial simulation rainfall device. Moreover, Hood infiltration device was used to test the soil infiltration to explain soil erosion. The main conclusions are as follows:（1） Under five different rainfall intensities conditions, the runoff volume was gradually increased with the passage of time, then gradually declined at three different rock exposed rate plots. In the same rainfall intensity, the bare rock big difference between the rate of district, the runoff larger rocks exposed rate similar to that of the two district, the runoff similar to that.The runoff volume was very similar at the two plots that the rock exposed rate was similar and that was very different among plots that the rock exposed rate was different. Cumulative runoff volume increased gradually with the changes of time. Cumulative runoff volume at the plot rock exposed rate of which was 70% exceeded the cumulative runoff at the plots with shrub plants the rock exposed rate of which were 42% and 32%. If the rock exposed rate of plots was close, the cumulative runoff of them was also very similar. The change curve of runoff at three different rock exposed rate plots can be described by R=b₀+b₁+b₂t² and the correlation efficient R² （>0.93） is very significant （p<0.01）.（2） With the increase in rainfall intensity, the beginning of sediment concentration is gradually increasing. In the same rainfall intensity, the concentration of sediment process is not stable, higher concentrations of sediment start later in the sediment concentration gradually reduce volatility. Overall, sediment concentration at the plots with 32% of the rock exposed rate is taller than the other plots. In the same rainfall intensity the sediment of plots with intermediate rock desertification began to increase, when it reached its peak it began to decline. With the increase of rainfall intensity, the sediment also increased. Cumulative sediment at three different rock exposed rate plots with intermediate rock desertification could be described by R =b₀ +b₁ + b₂t². Cumulative runoff and soil erosion at three different rock exposed rate plots were closely related and linear regression equation was y = ax + b.（3） Based on gray correlation analysis we identified the impact of the primary and secondary factors on surface runoff coefficient. The order of the grey association about vegetation parameters was followed by the series: shrub layer leaf area index> Plant height > shrub and herb layers of leaf area index > herb layer leaf area index.（4） The three tested soil infiltration model showed that Kostiakov equation, in most cases, fitter than Philip and Horton equation to describe the soil infiltration in intermediate rock desertification, for which the accuracy of prediction of soil infiltration is high.Cumulative infiltration decreased with the increasing soil moisture at three different rock exposed rate plots .Under different conditions of soil moisture water infiltration with Hood Determination and steady infiltration rate rise with the change of soil moisture reduction.（5） The same rain runoff loss of intensity in a relatively high nutrient content in the beginning, with the rainfall over the extension of nitrogen, potassium, and total nitrogen concentration did not change significantly. Runoff loss of nutrient solution did not clearly reflects the strong correlation with the rain, light rain - have high rainfall intensity akin to the loss of concentration. In the same rainfall intensity, as the rate of increase of bare rock, nutrient runoff loss of gradually increasing the cumulative loss of nutrient runoff and loss of accumulated runoff can be used between the linear equation y = ax + b said. That the cumulative loss of nutrient runoff with the cumulative loss of accumulated runoff volume increase. In other words, with the extension of rainfall, nutrition, the loss of loss of more land productivity has been declining, thus affecting plant growth.更多还原