【摘要】：溝谷地貌作為黃土高原上廣泛分布的基本地貌類型,既兼具一定的生態(tài)功能,也可引發(fā)土壤侵蝕惡性循環(huán),分析礦區(qū)周圍的溝谷地貌特征及其影響,對(duì)提高土地復(fù)墾與生態(tài)修復(fù)的工程效果具有重要意義。本文以平朔礦區(qū)及其周邊的溝谷系統(tǒng)為研究對(duì)象,提取溝谷線的形態(tài)、地貌特征,討論各地類中溝谷的坡度變化與溝道侵蝕相互作用,分析平朔礦區(qū)周圍溝谷系統(tǒng)的時(shí)空演變。主要研究結(jié)論如下:(1)量化了溝谷形態(tài)特征。選取溝谷線高差、坡降等形態(tài)特征指標(biāo),分析研究區(qū)內(nèi)溝谷形態(tài)特征的變化后發(fā)現(xiàn),小于5km的溝谷變化頻繁,溝谷長度與數(shù)量呈總體增加趨勢(shì)。研究區(qū)內(nèi)大部分溝谷線高差在0-100m之間,負(fù)高差溝谷線長度與數(shù)量增加。溝谷線的坡降平均值總體降低,溝谷線溝頭處坡降較高,土壤侵蝕量大。溝谷的寬深比隨發(fā)育時(shí)間的累積而增加,溝谷主要由切溝、沖溝、坳溝組成。(2)統(tǒng)計(jì)了排土場區(qū)、露天礦區(qū)、井工礦區(qū)、工業(yè)場地、原地貌溝谷周圍的坡度特征。自然狀態(tài)下的溝谷地貌以5°-10°的微陡地勢(shì)為主。露天礦區(qū)、井工礦區(qū)、工業(yè)場地、排土場區(qū)的坡度主要集中于0°-10°之間,極陡地形持續(xù)增加。礦坑工作幫邊坡與內(nèi)排土場邊坡坡度大于15°,外排土場邊坡坡度在20°-35°之間。堆狀排土法塑造出的外排土場以小于10°的平坦、微陡地形為主,工業(yè)場地區(qū)地勢(shì)較低,溝谷線多分布于此。(3)分析了采礦擾動(dòng)后的溝谷地貌時(shí)空變化。1986至2013年平朔及周圍地區(qū)溝谷系統(tǒng)的流域面積主要影響因素是露天礦坑與排土場,溝谷因礦坑延長,溝道因排土場而縮短。溝谷線呈現(xiàn)單線異向和單線相向的匯流特征,礦坑平臺(tái)處出現(xiàn)平行溝谷線。(4)明確了溝谷系統(tǒng)的組成特點(diǎn)與生態(tài)效應(yīng)。平朔礦區(qū)及其周圍地區(qū)溝谷系統(tǒng)由細(xì)溝、淺溝、切溝、沖溝、坳溝組成。其中,細(xì)溝、淺溝以及切溝的土壤侵蝕量大,多不利影響,而沖溝、坳溝內(nèi)存在多樣化的生鏡,具有提高生物多樣性的生態(tài)效應(yīng)。
[Abstract]:As a basic geomorphic type widely distributed on the Loess Plateau, gully geomorphology can not only have certain ecological functions, but also cause a vicious circle of soil erosion. The characteristics and effects of gully geomorphology around the mining area are analyzed. It is of great significance to improve the engineering effect of land reclamation and ecological restoration. This paper takes the gully system of Pingshuo mining area and its surrounding area as the research object, extracts the shape and geomorphological characteristics of the gully line, discusses the interaction between the slope change of the gully and the channel erosion in various areas, and analyzes the space-time evolution of the gully system around the Pingshuo mining area. The main conclusions are as follows: (1) the morphological characteristics of the valley are quantified. After analyzing the variation of the morphological characteristics of the valley in the study area, it was found that the valley with less than 5km changed frequently, and the length and quantity of the gully showed a general increasing trend. The height difference of most valley lines in the study area ranges from 0 to 100 m, and the length and number of negative valley lines increase. The average slope gradient of the valley line was decreased generally, and the slope at the gully line head was higher, and the soil erosion was larger than that at the end of the gully line. The width-depth ratio of the gully increases with the accumulation of development time. The gully is mainly composed of cutting trench, gully and depression. (2) the slope characteristics of dump area, open-pit area, well industry area, industrial site and original geomorphologic gully are analyzed. The gully landforms in the natural state are mainly slightly steep terrain of 5 擄- 10 擄. The slope of opencast mine area, well mining area, industrial site and dump area is mainly between 0 擄-10 擄, and the extremely steep terrain continues to increase. The slope of the working side slope of the pit and the slope of the internal dump slope is more than 15 擄, and the slope of the external dump slope is between 20 擄-35 擄. The external dump shaped by the pile drainage method is flat with less than 10 擄, slightly steep terrain, and low topography in the industrial area. (3) the temporal and spatial variation of gully geomorphology after mining disturbance is analyzed. The main influencing factors of valley area in Pingshuo and surrounding areas from 1986 to 2013 are opencast pit and dump. The ditch was shortened by the dump. The trench line presents the confluence characteristics of unidirectional and single-line opposite direction, and the parallel valley line appears at the platform of mine pit. (4) the composition characteristics and ecological effect of the gully system are clarified. The gully system of Pingshuo mining area and its surrounding area is composed of fine gully, shallow gully, cutting ditch, gully and depression. Among them, the amount of soil erosion in gully, shallow ditch and cut ditch is large, and there are many adverse effects on soil erosion. However, there is a variety of mirror in gully and depression, which has the ecological effect of improving biodiversity.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TD15;TD88
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本文編號(hào)：2293211