赣中永阳盆地红层荒漠化特征及防治

Study on Desertification Characteristics of Red Layer in Yongyang Basin,Central Jiangxi Province

红层荒漠化是发生在红层区的土地退化灾害之一,以表土层缺失、基岩裸露和生态功能丧失为主要特征。我国南方湿润地区的红层出露广泛,人口密集,受工程经济活动、自然气候条件及岩石自身抗风化能力弱等因素的限制,红层土地退化愈趋严重。选取第四系网纹红土和白垩系红层荒漠化特征典型的吉安永阳盆地为研究对象,在野外调查的基础上,开展了红层土壤的p H值、色度、粒度、含水率及荒漠化侵蚀沟形态特征等研究,查明了其演化阶段及发育特征。结果表明,区内红层土壤分为碱性和强酸性2种,含水率较低,粒度组分以粉砂(2. 00～63. 00μm)为主,粘土(0. 01～2. 00μm)和中-细砂(> 125. 00μm)次之;其侵蚀沟形态主要受岩性、地形等因素控制,荒漠化可分为早期、中期、中晚期及晚期4个阶段。

Red layer desertification is one of the land degradation disasters that occur in the red zone, with the main features of topsoil loss, bedrock exposure and loss of ecological function. The red beds in the humid regions of southern China are widely exposed and densely populated. Due to the constraints of engineering economic activities, natural climatic conditions and the weak resistance of the rocks themselves, the red layer land degradation is becoming more and more serious. In this paper, the Ji＇an Yongyang Basin,which is characterized by the Quaternary reticulated red soil and the Cretaceous red layer desertification characteristics,is selected as the research object. Based on the field investigation, the pH value, chroma, grain size, water content and desertification of the red soil are carried out. The study on the morphological characteristics of the gully ditch and its evolutionary stages and developmental characteristics were identified. The results show that the red soil in the area is divided into alkaline and strong acid, and the water content is low. The grain size components are mainly silt （2.00-63.00 μm）,clay （0.01 -2.00 μm） and medium-fine sand （ 〉 125.00 μm） is the second;its erosion gully morphology is mainly controlled by lithology and topography, and desertification can be divided into four stages：early, middle, middle and late.