不同自然降雨雨型下红壤坡地地表径流和壤中流输出特征

我国南方红壤丘陵区受降雨和土壤性状影响,洪涝灾害与季节性干旱等问题并存,研究坡地降雨过程中径流输出特征具有重要意义。为此,利用江西省水土保持生态科技园内大型土壤渗漏装置,研究了3年期间32场天然次降雨下植草覆盖、干草敷盖和裸露3种不同处理的红壤坡地径流输出特征。结果表明,小雨雨型下,研究区红壤坡地均不产生地表径流;中雨雨型下,植草覆盖、干草敷盖、裸露处理的壤中流所占地表径流和壤中流总量比例分别为58%、80%和12%;对于促进降雨入渗,干草敷盖最优。大雨及以上雨型下,植草覆盖和干草敷盖处理以壤中流为主,占比分别为63%和64%,裸露处理以地表径流为主,占比93%。在红壤坡地开发中除栽种植物加强植被覆盖外,辅以敷盖措施能起到更好的保水保墒效果。

Characteristics of Surface Runoff and Interflow Output on Red-soil Slope under Different Rainfall Patterns of Natural Rainfall Conditions

Influenced by rainfall and soil characteristics and the coexistence of floods and seasonal drought, it is significant to research the feature of runoff output in slope land in red soil area of Southern China. With the use of Drainage Lysimeter in Jiangxi Provincial Eco-Science Park of Soil and Water Conservation, runoff output characteristics on red-soil slope were analyzed in three treatments, which are Bahia grass planting, hay mulching and bare land respectively, under thirty two natural precipitation events during three years. The results show that there is no surface runoff in study area under light rain. Under moderate type rain, the proportion of the interflow in the total amount of the soil runoff of the three treatment which are grass planting, hay mulching and bare land are 58%, 80% and 12%. Hay mulching is optimal in the ability of the promotion of rainfall infiltration. Under heavy rain and heavier rain types, the main runoff is interflow in grass planting and hay mulching treatment and that in bare land treatment is surface runoff, the proportion of which are 63%, 64% and 93% respectively. In the red soil slope development, in addition to planting to enhance vegetation cover, mulching measures should be tried to assist with vegetation in order to play better water retention and better soil moisture effects.