摘要
The aim was to further research soil erosion characteristics and accurately predict soil erosion amount in karst areas. Based on field surveys and research achievements available, yellow soils, which are widely distributed, were chosen as test soil samples and slope, rain intensity, vegetation coverage and bare-rock ratio were taken as soil erosion factors. Artificial rain simulation instruments （needle-type） were made use of to simulate correlation of rain intensity, vegetation coverage, and bare-rock ratio with soil erosion quantity. Furthermore, multiple-factor linear regression analysis, stepwise regression analysis and multiple-factor non-linear regression analy- sis were made to establish a multiple-factor formula of soil erosion modulus with dif- ferent slopes and select regression models with high correlation coefficients. The re- sults show that a non-linear regression model reached extremely significant level or significant level （0.692〈FF〈0.988） and linear regression model achieved significant lev- el （0.523〈FF〈0.634）. The effects of erosion modulus changed from decreasing to in- creasing and the erosion factors from high to low were rain intensity, vegetation cov- erage and bare-rock ratio when slope gradient was at 6~, 16~, 26~ and 36~. The mod- el is of high accuracy for predicting gentle slope and abtupt slope, which reveals correlation of erosion modulus with erosion factors in karst areas.
为了进一步认识喀斯特山区土壤侵蚀特征及准确估算土壤侵蚀量,通过对野外调查结果、已有研究成果的综合评判,选取坡度、雨强、植被覆盖度及裸岩率为主要土壤侵蚀因子,选取该区域广布的黄壤作为试验土样,采用针管式人工降雨模拟装置,模拟不同坡度条件下雨强、植被覆盖度、裸岩率与土壤侵蚀量之间的相关性,并对试验数据进行多元线性回归、逐步回归和多元非线性回归分析,建立不同坡度条件下土壤侵蚀模数的多因子方程筛选出不同坡度下复相关系数较高的回归模型,对模型精度进行了分析。结果表明:①非线性回归模型达到极显著或非常显著水平0.692<R2<0.988线性回归模型达到显著水平0.523<R2<0.634。②当坡度为6°、16°、26°、36°时,侵蚀模数的影响程度随着坡度的增大先减小后增大侵蚀因子对侵蚀模数的影响程度为雨强、植被覆盖度、裸岩率。③模型具有较好的预报精度,对缓坡、陡坡侵蚀产沙预测较准。研究初步揭示了喀斯特地区侵蚀模数与侵蚀因子的相关关系。
基金
Supported by National Science and Technology Support Program in Twelfth Five-year Plan(2012BAD05B06)
Special Funds for Excellent Young Scientific Talents in Guizhou[(2011)14]~~
