为了揭示腾格里沙漠沙层含水量和水分运移及平衡等科学问题,对甘肃民勤和宁夏中卫不同沙丘进行了含水量研究。结果显示,腾格里沙漠南缘沙层含水量空间变化明显,在垂向上分层清楚,水平方向上流动沙丘的含水量高于半固定和固定沙丘, 沙漠东南缘沙层含水量明显高于西南缘。甘肃民勤沙层含水量高值层段出现在剖面中上部;宁夏中卫毛管水带之上沙层含水量较高,指示沙层水分来自大气降水。研究区沙层水分主要以薄膜水的形式存在,在降水较多的沙漠东南缘出现了沙漠区极少出现的高含量薄膜水。该区沙层水分具正平衡特点,属于沙层水理性质决定的沙漠地区特殊的水分正平衡,这能够较好地解释极端干旱的沙漠区湖泊较多和地下水资源较为丰富的原因。论文还提出了研究区水分运移的两种模式。
In order to reveal sand moisture content, water movement and balance of the Tengger Desert, the moisture content of different types of dunes in Minqin and Zhongwei was studied. The results show that the spatial variation of sand moisture content is remarkable. The layered structure is clear in vertical direction while the moisture content of mobile dune is higher than that of half-fixed dune and fixed dune in horizontal direction, and the moisture content of southeastern edge of the desert is higher than that of southwestern. The phenomena, which the higher moisture content lies the upper part in Minqin and above capillary water sand layer in Zhongwei, indicate the sand moisture mainly comes from meteoric water. The moisture form is mainly film water in this area. There is high moisture content of film water in the southeastern edge of the Tengger Desert, which has more precipitation. The characteristic of sand moisture is special positive equilibrium, which is defined by water physical properties of sand layer. It can correctly explain why there are many lakes and abundant groundwater in the extreme dry desert. This paper also presents two modes of water movement.
[1] 冯起,程国栋.我国沙地水分分布状况及其意义[J].土壤学报,1999,36(2):225-236.
[2] 秦佳琪,托亚,叶冬梅,等.乌兰布和沙漠不同沙地类型土壤水分特征的研究[J].内蒙古农业大学学报,2004,25(2):23-27.
[3] 朱玉伟,陈启民,刘茂秀,等.古尔班通古特沙漠南缘沙丘水分的时空分布特征[J].草业科学,2008,25(12):6-12.
[4] 格日乐,张力,刘军,等.库布齐沙漠人工梭梭林地土壤水分动态规律的研究[J].干旱区资源与环境,2006,20(6):173-178.
[5] 郭柯,董学军,刘志茂.毛乌素沙地沙丘土壤含水量特点——兼论老固定沙地上油蒿衰退原因[J].植物生态报,2000,24(3):275-279.
[6] 陈荷生,康跃虎,冯今朝.腾格里沙漠沙坡头地区植物生长与水分平衡的初步研究[J].中国沙漠,1991,11(2):1-10.
[7] 冯起.半湿润沙地水分状况及动态规律研究[J].干旱地区农业研究,1995,13(1):26-30.
[8] 王锐,孙权,吴向伟.腾格里沙漠东南缘不同地形下土壤水分空间变化动态研究[J].江西农业大学学报,2009,31(4):756-769.
[9] 钱鞠,马金珠,张惠昌,等.腾格里沙漠西南缘固定沙丘水分动态与水分势能变化特征研究[J].兰州大学学报:自然科学版,1999, 35(1):218-224.
[10] 赵景波,孙桂贞,岳应利,等.关中平原人工林地的干层及其成因[J].地理研究,2007,26(4):763-772.
[11] ZHAO Jing-bo, DU Juan, CHEN Bao-qun. Dried earth layers of artificial forestland in the Loess Plateau of Shaanxi Province [J]. Journal of Geographical Sciences,2007,26(4):114-126.
[12] 赵景波,顾静,杜娟.关中平原第5层古土壤发育时的气候与土壤水环境研究[J].中国科学D辑地球科学,2008,38(3):364-374.
[13] 魏雅芬,郭柯,陈吉泉.降雨格局对库布齐沙漠土壤水分的补充效应[J].植物生态学报,2008,32(6):1346-1355.
[14] Loik M E, Breshears D D, Lauenroth W K, et al. A multi-scale perspective of water pulses in dryland ecosystems: Climatology and ecohydrology of the western USA [J]. Oecologia,2004,141:269-281.
[15] 赵从举,康慕谊,雷加强.古尔班通古特沙漠腹地水分时空分异研究[J].水土保持学报,2004,18(4):158-162.
[16] 杨文治,邵明安.黄土高原土壤水分研究[M].北京:科学出版社,2000.
