【摘要】：隨著經(jīng)濟的迅猛發(fā)展和人民生活水平的逐步提高,亞熱帶農業(yè)小流域的面源污染日趨嚴峻,惡化的水體環(huán)境質量已經(jīng)成為該區(qū)域可持續(xù)發(fā)展和生態(tài)文明建設的重要障礙.基流過程對流域生態(tài)水文過程有重要影響,因此本研究選取湖南省長沙縣的脫甲和澗山兩個農業(yè)小流域作為調查對象,通過流域觀測和模型估算方法,對比分析2011年1月至2013年12月間流域基流過程對總氮(TN)輸出的貢獻.結果表明,在較高強度水稻種植的脫甲流域的月平均基流流量、平均基流TN流量加權濃度和平均基流對TN輸出貢獻[15.2 mm·month~(-1)、4.14 mg·L~(-1)和0.54 kg·(hm~2·month)~(-1)],均大于較低強度水稻種植的澗山流域[11.4 mm·month~(-1)、1.72 mg·L~(-1)和0.20 kg·(hm2·month)~(-1)].基流對TN輸出貢獻呈現(xiàn)明顯的季節(jié)性變化,如在水稻生長季,脫甲和澗山流域基流對TN輸出貢獻分別為23.2%和18.6%,均低于休耕季的46.9%和40.0%,表明水稻種植會提高休耕季的流域基流過程對TN輸出的貢獻.因此,為緩解農業(yè)小流域水體面源污染,應當在農業(yè)小流域中實施合理的稻田管理措施來降低基流對TN輸出的貢獻.
[Abstract]:With the rapid development of economy and the gradual improvement of people's living standard, the non-point source pollution of subtropical agricultural small watershed is becoming more and more serious. The deteriorating water environment quality has become an important obstacle to the sustainable development and ecological civilization construction in this region. The basic flow process has an important effect on the eco-hydrological process of the watershed. Therefore, two agricultural small watersheds in Changsha County, Hunan Province are selected as the investigation objects, and the watershed observation and model estimation methods are adopted. The contribution of base flow process to total nitrogen (TN) output from January 2011 to December 2013 was compared and analyzed. The results showed that the average basal flow, the weighted concentration of average basal flow TN flux and the contribution of average basal flow to TN output [15.2 mm month~ (-1)] were obtained in the denuded basin with high intensity rice cultivation. 4.14 mg L ~ (-1) and 0.54 kg (hm~2 month) ~ (-1) were larger than those in Jianshan watershed with low intensity rice cultivation [11.4 mm month~ (-1)]. 1.72 mg L ~ (-1) and 0.20 kg (hm2 month) ~ (-1)]. The contribution of basal flow to TN output showed obvious seasonal variation. For example, in rice growing season, the contribution of base stream to TN output was 23.2% and 18.6% in rice growing season, respectively, which was lower than that in fallow season (46.9% and 40.0%). The results showed that rice cultivation could increase the contribution of base-flow process to TN output in fallow season. Therefore, in order to alleviate the water non-point source pollution in agricultural small watershed, reasonable rice field management measures should be implemented in order to reduce the contribution of base flow to TN output.
【作者單位】： 中國科學院亞熱帶農業(yè)生態(tài)研究所亞熱帶農業(yè)生態(tài)過程重點實驗室;中國科學院長沙農業(yè)環(huán)境觀測研究站;中國科學院大學;長沙縣氣象局;
【基金】：國家重點基礎研究發(fā)展規(guī)劃(973)項目(2012CB417105) 國家自然科學基金青年科學基金項目(41301202)
【分類號】：X52;X71
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本文編號：2344729