喀斯特地区不同土地利用方式下包气带土壤水分动态特征  

DYNAMIC VARIATION CHARACTERISTICS OF SOIL WATER IN AN UNSATURATED ZONES UNDER DIFFERENT LAND USES IN A KARST ZONE

作　　者：劳文科[1] 吴孔运[1] 

机构地区：[1]中国地质科学院岩溶地质研究所,广西桂林541004

出　　处：《地球与环境》2008年第2期119-124,共6页Earth and Environment

基　　金：国家自然科学基金(40572151)

摘　　要：为了揭示喀斯特峰林平原区旱地土壤水的特征,在广西来宾市附近选取了地膜覆盖玉米地、露地玉米地和撂荒地等三处地块,从2006年3月至2007年4月,用中子仪和负压计观测了土壤剖面0cm至450cm处土壤含水量和土壤水势,结果显示:包气带土壤含水量在10cm处变动强烈,而在100cm和450cm处变弱。从时间上看,土壤含水量及其动态具有明显的季节性,2006年3月-4月,土壤平均含水量36.7%,为年内平均最大含水量,这一时期土壤水分含量普遍较大且呈现逐渐增高的趋势。在5月-8月,土壤平均含水量34.1%,且年内最大含水量与最小含水量都出现在这一时期。在9月-11月,土壤平均含水量32.6%,包气带水分含量在此期间以逐步下降为主。在12月-次年2月,土壤平均含水量31.4%,为年度内最低。包气带土壤水零通量面在一个年度内存在时间共338天,11月至次年2月ZFP(零通量面)的发育深度为170 cm,其它月份大多低于100cm。整个观测模拟期内,土壤水的蒸发总量为865.66 mm,占同期降雨总量的88.5%,下渗总量为145.47mm,占同期降雨总量的11.5%,田间持水量为30.3%。In order to research soil water of a peak-forest karst plain in Laibin, Guangxil, a corn field with plastic mulching, a corn field without plastic mulching and a abandoned land were chosen, and from March 2006 to April 2007, soil water contents and potential of soil water at the depths ranging from 0cm to 450cm in soil profiles had been observed by means of tensionmeters and neutron moisture meters. Results showed that soil water contents of the unsaturated zone sharply varied at 10-cm depth, but slightly at 100cm and 450cm. On the other hand, soil water contents and its dynamic variation showed seasonal features, From March to April 2006, the average soil water content was 36.7%, which was the biggest value in one year. The soil water contents in this period, in general, were very high and tend to increase progressively. From May to August, the average soil water content was 34.1%, and the maximum and minimum soil water contents both appeared in this period of time. From September to November, the average soil water content was 32.6%,and the soil water contents tend to decrease progressively during this period of time. From December 2006 to February 2007, the average soil water content was 31.4%, the lowest in one year. The ZFP Of soil water in the unsaturated zone emerged 338 days in one year. Depth of ZFP, from November 2006 to February 2007, was 170cm, and in the other months, it was less than 100cm. In all observation time, evapotranspiration of soil water was 865.66mm, and infiltration 145.47. The average soil field water-holding capacity was 30.3%.

关 键 词：包气带 土壤水 零通量面 田间持水量 广西来宾 

分 类 号：P641.131[天文地球—地质矿产勘探]