基于Hydrus-1D模型的太湖流域农田系统水分渗漏和氮磷淋失特征分析  

FEATURE ANALYSIS OF SOIL WATER LEAKAGE AND LEACHING OF NITROGEN AND PHOSPHORUS IN THE TYPICAL FARMLAND OF TAIHU LAKE BASIN BASED ON HYDRUS-1D MODEL

作　　者：赖晓明[1,2] 廖凯华[1] 朱青[1] 吕立刚[1,3] 徐飞[1,2] 

机构地区：[1]中国科学院南京地理与湖泊研究所,流域地理学重点实验室,江苏南京210008 [2]中国科学院大学,北京100049 [3]南京大学地理与海洋科学学院,江苏南京210046

出　　处：《长江流域资源与环境》2015年第9期1491-1498,共8页Resources and Environment in the Yangtze Basin

基　　金：江苏省自然科学基金(BK2012502);中国科学院南京地理与湖泊研究所“一三五”重点项目(NIGLAS2012135005)

摘　　要：在土壤水分长期定位观测基础上,应用Hydrus-1D模型对太湖流域典型稻麦轮作农田土壤水分渗漏进行动态模拟,并结合深层土壤溶液取样及氮磷浓度测定,分析了当前耕作方式下农田水分渗漏和氮磷淋失特征。结果表明,土壤水渗漏与降雨、灌溉及前期土壤含水率有关;麦季深层渗漏量小但持续时间长,而稻季单次渗漏量大却持续时间短。模拟时段内铵态氮和可溶解性总磷的淋失主要发生在稻季,淋失量分别为2.62、0.49kg/hm2,分别占稻麦轮作期总淋失量的96.0%、96.0%,而硝态氮淋失主要发生在麦季,淋失量为57.97kg/hm2,占总淋失量的80.2%;无机氮淋失的主要形态为硝态氮,其淋失量占总淋失量的96.4%。综合看来,硝态氮应作为主要阻控对象,以减少农田面源污染对地下水及太湖水体的污染风险。此外,氮磷淋失在6、7月份即休耕期和水稻生长早期容易达到峰值,应得到重视。Taihu Lake Basin is one of the most serious polluted areas in China,while the eutrophication is the main environmental problem,which is mainly caused by the agricultural non-point source pollution as commonly considered.Therefore,an in-depth study of the agricultural leaching of nitrogen and phosphorus under rice-wheat rotation in Taihu Lake Basin is necessary.In order to get the data of leaching nitrogen and phosphorus,the concentration of the nitrogen and phosphorus in soil water sample should be tested and the leakage of soil water should be acquired.Traditional methods on that have many limitations in practical applications and generally the time-continuous leaching of nitrogen and phosphorus can＇t be obtained.While in this study,based on long-term measurement of soil water content,the farmland soil water leakage under rice-wheat rotation was simulated using the Hydrus-1Dmodel.Combining simulation results and measurements of soil water nitrogen and phosphorus concentrations at the depth of 60 cm,the leaching of nitrogen and phosphorus were obtained.Comparing to the traditional methods,this method can calculate the data of the leaching of nitrogen and phosphorus by less measurement data.Results showed that the Hyrus-1D model can well simulate the leakage of soil water in the farmlands of Taihu Lake Basin.The soil water leakage was influenced by precipitation,irrigation and antecedent soil water content.The leakage amount was little and the time of duration was long during wheat growing season;while during rice growing season,the leakage amount was large and the time of duration was short.The leaching of ammonium nitrogen and dissolved phosphorus mainly occur during the rice growing season.The leaching of ammonium nitrogen during this period（2.62kg/hm^2）accounted for 96.0% of the total leaching during the whole study period.The leaching of dissolved phosphorus（0.49kg/hm^2）accounted for 96.0% of the total leaching.However,the leaching of nitrate nitrogen mainly occurred during the wheat growing season.

关 键 词：土壤水分 稻麦轮作 富营养化 氮磷淋失 

分 类 号：X171[环境科学与工程—环境科学]