摘要
使用吹填土进行围海造地是当前拓展沿海地区土地空间的主要方法。河北曹妃甸陆面基本上为吹填土围海造陆而成,针对该地区地下水埋深较浅和矿化度高、土质单一等特点,通过室内土柱模拟试验,研究了稳定蒸发条件下,不同地下水埋深脱盐土柱剖面的含水量变化规律、地下水通过土壤毛管上升作用的返盐规律、主要盐分离子的迁移行为以及土壤碱化问题。研究结果表明,地下水埋深50cm(B1)和100cm(B2)分别在15天和51天时达到埋深30cm处0.3%的设定含盐量,B1表层返盐速率高于B2;试验中土柱B1表面和B2埋深为5cm处出现盐壳,且B1和B2地下水累计消耗量随时间线性变化;试验结束时B1和B2的平均含水量为18.8%和20.1%,B1和B2的平均含盐量为0.5%和0.4%;在返盐过程中B1和B2的阳离子迁移速度均为Na+>Ca2+>Mg2+,阴离子为Cl->HCO3->SO42-,且试验结束时土柱中未出现碱化现象,说明了土体能提供给植物生长一个良好的生境。该研究结果为曹妃甸以及类似地区进行生态建设和发展农业生产等方面提供吹填土的改良、盐分控制等方面的依据。
Hebei Caofeidian region was formed by reclaiming dredger fill,and here has a single coarse sand soil-profile,and other features which are disadvantage to ecumenical plant.Based on soil column simulation experiment in door,changes of water content of soil column profile and laws of salt accumulation when groundwater rose through capillary,the migration of salt ions,as well as the problem of soil alkalization had been analyzed under the condition of evaporation and different groundwater levels.Studies had shown that when groundwater level were 50 cm and 100 cm,the tests had continued for 15 d and 51 d,and the ion migration speed is Na^＋〉Ca^2＋〉Mg^2＋,Cl^-〉HCO3^-〉SO4^2-.Soil water content,wastage of groundwater and soil salt content were researched.Studied also showed that soil can supplied plant a good habitat at the end of tests.The results can sever as a reference for ecological construction and afforestation of land which is made from dredger fill.
出处
《水土保持学报》
CSCD
北大核心
2010年第2期87-91,共5页
Journal of Soil and Water Conservation
基金
国家科技支撑计划项目(2007BAD67B03)
国家自然科学基金(50869006)
关键词
吹填土
蒸发
水盐动态
碱化
dredger fill
evaporation
water and salt transport
alkalization
