本文選題：三峽庫區(qū) + 面源污染�。� 參考：《西南大學學報(自然科學版)》2017年06期

【摘要】：對三峽庫區(qū)涪陵段兩個毗鄰集水域的匯水口徑流進行了持續(xù)1年的高頻(每日)采樣監(jiān)測,以對比分析稻田空間分布格局對徑流氮素質(zhì)量濃度和輸出強度的影響.所選擇的兩個集水域稻田面積比例相近,但其中一個(記為A)的稻田分布零散,破碎度高,另一個(記為B)的稻田則連片分布在其末(底)端,破碎度低.結(jié)果表明兩集水域不同作物生長季徑流氮素的輸出均以硝態(tài)氮為主(占總氮的60%~81%).對比兩個集水域,A在全年和不同作物生長季的徑流氮素平均質(zhì)量濃度都相應地高于B.同樣,集水域A的年徑流量(1 431 m3/hm2)顯著高于集水域B(840 m3/hm2),因而前者徑流總氮的年輸出通量(16.1kg/hm2)遠大于后者(5.21kg/hm2).鑒于兩個集水域的氣候、土壤類型、地形地貌和農(nóng)田耕作管理方式相同,單位土地面積的施肥量以及稻田面積比例也相近,只是稻田空間分布格局迥異,匯水口徑流氮素的質(zhì)量濃度和輸出通量的差異顯然是由于集水域末端連片分布的人工濕地—稻田比零散分布的稻田對集水域內(nèi)的徑流及隨其遷移的氮素有更佳的攔截和凈化作用所致.
[Abstract]:The high frequency (daily) sampling of two adjacent catchments in Fuling section of the three Gorges Reservoir area was carried out for one year to compare and analyze the effect of the spatial distribution pattern of paddy field on the nitrogen concentration and output intensity of runoff. The proportion of rice field area in the two collected waters was similar, but one rice field (A) was scattered and the fragmentation was high, while the other (B) rice field was distributed at the end (bottom) end of rice field with low degree of fragmentation. The results showed that the output of nitrogen in runoff of different crop growing seasons was mainly nitrate nitrogen (accounting for 60% of total nitrogen). The average nitrogen concentration in runoff of two catchment waters was higher than that of B. Similarly, the annual runoff of catchment A is 1 431 m3 / hm 2) significantly higher than that of BX 840 m 3 / hm 2, so the annual output flux of total nitrogen in runoff of the former is much higher than that of the latter (5. 21 kg / hm 2 路hm 2). In view of the same climate, soil type, landform and farmland tillage management, the fertilization amount per unit land area and the proportion of rice field area are similar, but the spatial distribution pattern of rice field is very different. The difference of mass concentration and output flux of nitrogen in the catchment is obviously due to the fact that the constructed wetland with continuous distribution at the end of the catchment water is better than the scattered paddy field in runoff and nitrogen transport in the catchment area. As a result of interception and purification.
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本文編號：1897634