【摘要】：受全球氣候變化影響,內蒙古東部草原地區(qū)河流干涸、濕地萎縮等干旱缺水問題突出,草原沙化退化加劇,人類活動對草原流域水文過程造成強烈擾動,徑流量發(fā)生顯著變化,制約流域社會經(jīng)濟發(fā)展,直接影響草原生態(tài)環(huán)境�；髯鳛閺搅鞯闹匾M分,在維持水量平衡和評價管理水資源中起著重要作用。在此背景下,定量分析氣候變化和人類活動對基流的影響,對維持流域良性水文循環(huán)和草原生態(tài)環(huán)境可持續(xù)發(fā)展等方面具有重大意義。本文選擇寒旱區(qū)典型草原流域—錫林河流域為研究對象,開展流域基流對氣候變化與人類活動的響應研究。取得的主要成果如下：(1)評價數(shù)字濾波法、HYSEP分割法、平滑最小值法和加里寧試算法4類共9種自動基流分割方法在錫林河流域的適用性,結果表明：采用3次迭代數(shù)字濾波法(F1法、β=0.85)估算的基流穩(wěn)定性良好,驗證結果可靠性高,適用性最佳。(2)分析各氣象要素變化特征,揭示流域基流演變規(guī)律。氣溫整體顯著上升(0.426℃/10a),蒸發(fā)量顯著增加(4.322mm/a),溫度越高,蒸發(fā)量越大；降水量下降不顯著(-0.446 mm/a),呈“單峰型”分布。基流年內分配極不均勻,完全依賴冰雪融水和降水混合補給,“雙峰型”明顯。多年平均基流深為2.24mm,基流整體下降顯著(-0.025mm/a),60-70年代增幅較小,80-90年代先減少后增加直至最大；21世紀以后下降明顯。存在22～32年,6-13年和3-5年的3種尺度的周期震蕩規(guī)律。在大時間尺度上共出現(xiàn)5次枯-豐交替變換,預測基流有轉向增加的趨勢。(3)定性研究基流對氣候變化和人類活動的響應過程。降水與基流呈極顯著相關,蒸發(fā)與基流呈顯著負相關,氣溫通過對蒸發(fā)產(chǎn)生作用間接影響基流。徑流相對降水、基流相對徑流均具有滯后效應,不同水文年的滯后時長存在以下關系：豐水年枯水年平水年�？菟诘乇韽搅髁肯鄬邓康臏笮蓉S水期明顯,枯水期基流量相對地表徑流滯后的時間比豐水期略短。城市擴張與過度放牧、地下水不合理開發(fā)利用、煤礦開采及水土保持活動等多種人類活動共同影響基流。(4)定量分解氣候和人類活動對基流變化的貢獻率。以拐點年份1979、1991和1998年為界,將1963-2012年劃分為基準期(T1)和措施期(T2-T4),在措施期氣候變化對基流的貢獻率分別為54.15%、30.24%和43.76%,人類活動對基流的貢獻率分別為45.85%、69.76%和56.24%,T2階段氣候變化是基流量縮減的主要驅動因素,T3與T4階段人類活動是引起基流變化的主要原因。
[Abstract]:Under the influence of global climate change, the problems of drought and water shortage, such as river drying up and wetland atrophy in eastern Inner Mongolia, are prominent, the degradation of grassland desertification has intensified, and human activities have caused strong disturbance to the hydrological process of steppe basins, resulting in significant changes in runoff. Restrict the social and economic development of the basin, directly affect the grassland ecological environment. As an important component of runoff, base flow plays an important role in maintaining water balance and evaluating and managing water resources. In this context, the quantitative analysis of the effects of climate change and human activities on the basic flow is of great significance in maintaining the benign hydrological cycle of the watershed and the sustainable development of the grassland ecological environment. In this paper, a typical steppe basin in cold and arid region, Xilin River Basin, is selected as the research object, and the response of the watershed base flow to climate change and human activities is studied. The main achievements are as follows: (1) the applicability of 9 kinds of automatic base-current segmentation methods, including digital filtering, HYSEP segmentation, smooth minimum method and Kalinen trial algorithm, in the Xilin River Basin is evaluated. The results show that the base flow estimated by the three times iterative digital filtering method (F1 method, 尾 = 0.85) has good stability, high reliability and optimum applicability. (2) the variation characteristics of various meteorological elements are analyzed and the evolution law of the basic flow in the basin is revealed. The temperature increased significantly (0.426 鈩，

本文編號：2350538