贵州省大方地区石漠化现状及成因分析

发布时间：2018-05-22 16:15

本文选题：碳酸盐岩 + 石漠化　；参考：《成都理工大学》2015年硕士论文

【摘要】：本文首先依据美国陆地卫星ETM+图像数据,将其精度放至1:5万图像作为主要信息源,经过对贵州大方地区初步石漠化遥感解译,形成石漠化分布遥感解译图。再生成石漠化分布遥感解译图。结合本人参与的“贵州1:5万响水、百纳等6幅岩溶石山区地质调查”项目所得到的野外实地调查资料,绘制出研究区石漠化实际分布图,根据石漠化分级标准将研究区分为六个单元:①非石漠化区域;②无石漠化区域;③微度石漠化区域;④轻度石漠化区域;⑤中度石漠化区域;⑥重度石漠化区域。通过与石漠化遥感解译图对比,可以看出,石漠化实际分布图中石漠化主要发育区域在中部地区(盐井-羊场坝-白板),而在石漠化遥感解译图中则是南部地区(马场-牛场坡-果宝-金龙),但石漠化的总体分布情况及规律,两张图的吻合程度还是比较好的。以实际调查结果和石漠化分布现状为基础,本文从地质因素、气候因素、人为因素三个方面对区内的石漠化成因进行分析。其中地质因素包括了地貌因素、岩性因素、构造因素、坡度因素;气候因素包括了降水因素、植被因素;人为因素包括了不合理开发、不合理耕作、过渡开垦几个因素,最后对该区石漠化的形成机制进行了探讨。通过研究取得如下认识:1.研究区石漠化现状,其中非石漠化与无石漠化区域面积约2395.49km2,约占研究区总面积的87.24%;微度石漠化区域面积约91.41 km2,约占研究区总面积的3.32%;轻度石漠化区域面积约155.9 km2,约占研究区总面积的5.68%;中度石漠化区域面积约76.55 km2,约占研究区总面积的2.79%;重度石漠化区域面积约26.65 km2,约占研究区总面积的0.97%;石漠化区域面积约350.51 km2,约占研究区总面积的12.74%。通过与石漠化分布遥感解译图对比,目前石漠化发育总体程度与12年前的石漠化程度相比,石漠化情况得到了有效的控制,石漠化区域从2749 km2下降到了现在的350.51 km2,特别是牛场坡幅和沙窝幅石漠化程度有了明显的好转,主要原因是贵州省政府这几年大力治理石漠化取得了显著成效。2.地貌对于石漠化的影响:主要起到一个指示作用,通过实地调查发现,在其它因素相当的条件下,地貌类型分布区中以深切的地貌区比浅切割的地貌区更容易发生石漠化。其中以峰丛和峰林洼地地貌地区石漠化发生的概率较大,多为中-重度石漠化。地势较为平缓的盆地、丘陵地区多为无石漠化和轻度石漠化区域。3.岩性对石漠化的影响:主要在于岩性的差异风化,也是石漠化形成的本质原因,其中质地较纯且大面连续出露的碳酸盐岩区域是发育石漠化的主要区域,其中又以灰岩的连续出露为重度石漠化发育的主要区域,灰岩地区石漠化发生的程度要明显高于白云岩地区;碳酸盐岩夹碎屑岩的石漠化发生概率较小;碎屑岩区域多为无石漠化区域。4.构造对于石漠化的影响:例如羊场坝断裂构造控制了石漠化发育的展布、趋势等。中国西南部新构造运动主要表现为阶段性上升,致使早期夷平面遭受强烈切割、改造,形成现今的高原背景上的深切峡谷地貌;崎岖破碎的高原地貌及陡坡地形,提供了水土流失、土壤侵蚀的势能基础。因此,新构造阶段性抬升是影响石漠化的地质因素之一。5.坡度对于石漠化的影响在于:不同坡度对于石漠化的发育程度起着重要的决定性作用。地面坡度在0°~5°的区域,石漠化发生的概率比较小,研究区石漠化主要在坡度为5°~20°的区域内发育,坡度较高的地区特别是在10°以上的区域主要发育中度-重度石漠化,坡度在30°以上区域虽然在区域内所占比例较小且较为分散,但却极易发生石漠化,主要以重度石漠化为主。6.气候与植被因素对研究区石漠化的影响:降雨对土壤侵蚀提供了动力条件,使得岩溶石山区在暴雨的冲刷下基本留不住表层的薄层土壤,从而形成了基岩裸露的石漠化景观。而植被与石漠化发育趋势呈一个动态关系,即植被覆盖率越高,石漠化程度越低。7.人为因素对石漠化的影响:石漠化发育较为严重的地区主要集中在人口稠密、经济相对落后、人地矛盾突出的地方。特别是在人类的不合理开发以及滥砍滥伐等活动的干扰下,在很大程度上影响了石漠化的发育程度。8.石漠化形成机制:研究区多属浅覆盖或裸露型喀斯特山区,区内植被退化以及人类不合理的利用土地,使得地表土壤进一步被蚕食,在降雨或径流等运移力作用下,造成大面积的基岩裸露,加速了碳酸盐岩的风化速率,进而形成石漠化。新构造运动在研究区塑造出不同的区域地貌类型,形成不同层次的斜坡过渡界面;在地形地貌上,关岭组狮子山段地层(T2gsz),嘉陵江组一段-三段(T1j1-3)等灰岩地层为主构成的峰丛、溶丘地貌是石漠化的多发地带,在人类不合理的干扰活动下,环境进一步恶化。影响石漠化形成的因素包括自然因素和人为因素,自然因素是石漠化发生、发展的先决因素,而人为因素才是主导因素。
[Abstract]:In this paper, based on the American Landsat ETM+ image data, its accuracy is put to the 1:5 million image as the main source of information. Through remote sensing interpretation of the preliminary rocky desertification in Guizhou's generous area, the remote sensing map of rocky desertification distribution is formed. The regenerated remote sensing interpretation map of rocky desertification distribution is regenerated. The 6 karstification of "Guizhou 1:5 Wan", "Bai Na" and so on, I participated in The field survey data obtained from the project of the geological survey of the stone mountain area has drawn out the actual distribution map of the Rocky Desertification in the study area. According to the classification standard of the rocky desertification, the study is divided into six units: (1) non rocky desertification area; (2) no rocky desertification area; (3) micro rocky desertification area; (4) light rocky desertification area; 5 moderate rocky desertification area; 6 severe stone. By comparing with the remote sensing interpretation of rocky desertification, we can see that the main area of rocky desertification in the actual distribution map of rocky desertification is in the central region (the salt well - sheep field dam - white board), and in the remote sensing interpretation of rocky desertification, the southern region (the horse farm - Niu Chang Po - Guo Bao - Jinlong), but the overall distribution and law of rocky desertification, two maps On the basis of the actual survey results and the distribution status of rocky desertification, this paper analyzes the causes of rocky desertification in the area from three aspects of geological, climatic and human factors. The geological factors include geomorphic factors, lithologic factors, construction factors, slope factors, and climatic factors including precipitation causes. The human factors include irrational development, irrational tillage and transitional reclamation. Finally, the formation mechanism of rocky desertification in this area is discussed. The following understanding is made: 1. the present situation of rocky desertification in the 1. study area, of which the area of non rocky desertification and rocky desertification is about 2395.49km2, accounting for about 87.24 of the total area of the study area. %; the area of the micro rocky desertification area is about 91.41 km2, accounting for about 3.32% of the total area of the study area; the area of the mild rocky desertification area is about 155.9 km2, accounting for 5.68% of the total area of the study area; the area of moderate rocky desertification area is about 76.55 km2, accounting for 2.79% of the total area of the study area; the area of severe rocky desertification area is about 26.65 km2, accounting for about 0.97% of the total area of the study area. The area of desertification area is about 350.51 km2, which accounts for about 12.74%. of the total area of the study area. Compared with the remote sensing interpretation of rocky desertification distribution, the overall degree of rocky desertification has been effectively controlled compared with the rocky desertification degree of 12 years ago. The rocky desertification area has fallen from 2749 km2 to 350.51 km2, especially the cattle slope. The extent of rocky desertification in the amplitude and sand nest has been obviously improved, the main reason is that the Guizhou provincial government has made great efforts to control the Rocky Desertification in recent years. The effect of.2. landform on rocky desertification is the main indicator. Through field investigation, it is found that under the conditions of other factors, the geomorphic type distribution area is deeply geomorphic. The region is more prone to rocky desertification than that in shallow geomorphic areas. Among them, the probability of rocky desertification in peak shrub and peak forest low-lying land is larger, most of which are moderate to severe rocky desertification. The basin has relatively gentle terrain, and the hilly area is mostly the effect of.3. lithology on rocky desertification in the area without rocky desertification and mild rocky desertification area, mainly because of the difference weathering of lithology. It is also the essential reason for the formation of rocky desertification, of which the carbonatite area with a relatively pure and continuous exposure of the large surface is the main area for the development of rocky desertification, in which the continuous exposure of limestone is the main area of severe rocky desertification, and the degree of rocky desertification in the limestone area is obviously higher than the dolomite area; the carbonate rock clastic rocks are in the limestone area. The occurrence probability of rocky desertification is small, and the clastic rock region is mostly the effect of.4. structure on rocky desertification in the non rocky desertification area: for example, the fault structure of the Yang field dam controls the distribution and trend of rocky desertification, and the new tectonic movement in southwestern China mainly shows a stage rise, which causes the early planation plane to be strongly cut, transformed, and formed the present high. The deep cut Canyon geomorphology in the original background, the rugged plateau topography and the steep slope terrain provide the potential basis for soil erosion and soil erosion. Therefore, the stage uplift of the neotectonic is one of the geological factors affecting the rocky desertification. The influence of.5. slope on rocky desertification is that the different slopes play an important role in the development of rocky desertification. The probability of rocky desertification in the area of 0 degree ~5 degrees is relatively small. The Rocky Desertification in the study area is mainly developed in the area of 5 degree ~20 degrees. The areas with high gradient, especially in the area above 10 degrees, are mainly moderate to severe rocky desertification, and the slope in the upper region is less than that in the upper region, although the proportion is smaller and more in the region. It is easy to be dispersed, but it is very easy to have rocky desertification, mainly with severe rocky desertification as the main effect of.6. climate and vegetation factors on the rock desertification in the study area: rainfall has provided dynamic conditions for soil erosion, which makes the karst mountain area basically unable to retain the thin layer soil under the scour of the rainstorm, and form the bare rock desertification landscape of the bedrock. There is a dynamic relationship with the development trend of rocky desertification, that is, the higher the vegetation coverage and the lower the degree of rocky desertification, the influence of.7. human factors on rocky desertification: the areas with more serious development of rocky desertification are mainly concentrated in dense population, relatively backward economy, and the contradiction between human and land is outstanding. Under the interference of activity, it affects the formation mechanism of rocky desertification, to a great extent, the formation mechanism of.8. rocky desertification: the research areas are mostly shallow covered or exposed Karst mountains, the vegetation degradation in the area and the irrational use of land, which make the surface soil further encroach on, and cause large area under the action of rain or runoff and so on. The exposure of the bedrock accelerates the weathering rate of carbonate rocks and forms rocky desertification. The neotectonic movement has created different regional geomorphic types in the study area, forming a different level of slope transition interface, and in the topography and geomorphology, the Guanling formation, the lion mountain section (T2gsz), the 1st to three segment of the Jialing River group (T1j1-3) and other limestone formations The mound landform is the multiple zone of rocky desertification, and the environment is further deteriorated under the irrational human interference activities. The factors affecting the formation of rocky desertification include natural factors and human factors, and natural factors are the leading factors of rocky desertification and development, and human factors are the main factors.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171;X87

【参考文献】