福建省亚热带红壤区人为破坏的水土流失与治理定量研究

Quantitative Research on Soil and Water Loss and Countermeasures in Man-Made Distroyed Red Soil Region in Subtropical Region of Fujian Province

试验设置4种处理类型，建立6个径流小区，对松散堆积土水土流失进行定位定量观测和比较研究（其中：2小区为裸露堆积土，2小区为堆积土种草，2小区分别为原状裸露地和自然坡地对照）。研究表明：①松散堆积土与原状裸露地相比，前者土壤侵蚀模数、径流量是后者的3．0倍和1、7倍；②松散堆积土种草1年与未种草相比，水土流失量前者比后者减少了75.8%，径流深前者比后者低55．5％；③观察年的3～6月和7～9月这两个时段松散堆积土水土流失总量分别占全年的42．9％和55．3％，两者合计占98．1％，表明3～9月是亚热带红壤区水土流失主要时段。④松散堆积土种草3个月后，基本覆盖地表，土壤侵蚀量比未种草减少9．3倍。与此同时采用数理统计方法，分析水土流失量与降雨量、平均雨强、雨型等关系，同时得出4种类型的侵蚀性降雨量值。这些研究成果可为亚热带红壤区开发建设项目的水土流失防治提供科学依据。

The soil and water losses of loose cumulated-soil field was observed and compared researched based on four controling types and six runoff sections, two of these sections are bare cumulated-soil, two sections are cumulated-soil planted with grass, the others are controled intact bare field and natural slope field respectively. The results showed： （1） Compared with the intact bare field, the soil erosion modulus and the runoff amount are 3 time and 1.7 time respectively larger in loose cumulated-soil field than that in intact bare field; （2） After one year, the soil erosion in loose cumulated-soil field planted with grass reduced 75.8% compared loose cumulated-soil field without grass, and the deep of runoff in former was lower 55.5% than latter; （3） In the year of observation, the soil erosion accounted to 42.9% and 55.3X respectively in two periods which from Mar. to Jun. and from Jul. to Sept. , which added up to 98.1%. It showed that the main period of soil erosion is March to September in subtropical red soil region. （4） The grass covered surface after it had been planted three months in the loose cumulated-soil field, and the ammount of soil erosion reduced 9.3 time compared with the loose cumulated-soil field without grass. The method of mathstatistics was used to analyse the relationship between the soil erosion and rainfall, mean rainfall intensity and types of rain, 4 types of the erosion rainfall was got based on this researsh. These results would instruct the development scientifically how to control soil and water loss in subtropical red soil region.