摘要
通过对乌兰布和沙漠流动沙丘的不同部位沙土含水量的测定研究,结果表明:(1) 乌兰布和沙漠流动沙丘3个不同部位的水分垂直变化趋势是一致的,0～60 cm含水量变化幅度大,60～100 cm变化幅度小,含水量最大值出现在20～60 cm,降雨主要影响60 cm以上的沙土水分;(2) 3种部位在时间变化上都表现为4～5月含水量最小,从6月开始含水量升高;(3)迎风坡含水量较其他部位大0.65%～0.9%,较背风坡大1.8%～2.5%,其他部位较背风坡大1%～1.7%,且3种地貌部位20～ 60 cm处较80 cm和100 cm处有较大差异,同时迎风坡的变化幅度最大.
The Study area （40°30′N, 106°50′E）, the Ulanbuh Desert, is located in Dengkou County, Inner Mongolia Autonomous Region, and its area is 200 km^2, in which the area of mobile-dune regions is 150 km^2. According to the morphological and vegetation conditions, the study area can be divided into three main units, i. e. , the mobile sandland, semi-fixed sandland and fixed sandland. The dunes are generally 3～7 m in height, the groundwater depth varies in a range of 7～15 m, and the soils are dominated by desert calcic soil and aeolian sand soil. It belongs to the temperate desert climate, the annual temperature and monthly temperatures in July and January are 7.6 ℃, 23.8 ℃ and - 10.8℃ respectively, the annual accumulated temperature ≥10 ℃ is 3 222.2 ℃, and the annual sunshine duration is over 3 000 hours. The annual average wind speed and the maximum wind speed are 3.7 m/s and 15 m/s respectively, the annual precipitation and evaporation are 142.7 mm and 2 351.9 mm respectively, the annual average relative humidity is 47%, the frost-free period is 168 days, and the aridity index is 〉4. In this paper, the soil moisture contents on the windward and leeward slopes and at the different sites of mobile dunes in the Ulanbuh Desert are measured, and their dynamic change is researched, The results are as follows. （1） The trends of soil moisture contents are accordant on the windward and leeward slopes and at the atypical sites. The change of soil moisture content is significant at soil depth of 0 ～60 cm, but it is not so obvious at soil depth of 60～100 cm, the highest soil moisture content occurs at depth of 20～60 cm. Rainfall affects soil moisture content mainly at soil depth upper 60 cm; （2） Temporally, the soil moisture contents on the windward and leeward slopes and at the atypical sites of mobiles dunes are minimum during the period from April to May, and it begins to be increased from June; （3） Soil moisture contents at the different soil depths on windward slopes are 0.65% ～0.9 % higher than that at the atypical sites, and they are 1.8 % ～2.5 % higher than that on leeward slopes. The soil moisture contentsat the atypical sites are 1.0 % ～ 1.7% higher than that on leeward slopes. The difference of soil moisture content at soil depth of 20～60 cm is more significant than that at soil depth of 80～100 cm, and the change extent of soil moisture content is the highest on windward slopes.
出处
《干旱区研究》
CSCD
北大核心
2005年第3期367-370,共4页
Arid Zone Research
基金
国家自然科学基金重点项目(30230290)资助
关键词
乌兰布和沙漠
流动沙丘
土壤水分
内蒙古
Ulanbuh Desert
mobile dune
dynamic change of soil moisture content.
