| 题名 | 黔南茂兰喀斯特森林公园峰丛洼地土壤侵蚀研究 |
| 作者 | 何永彬 |
| 学位类别 | 博士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 张信宝 |
| 关键词 | 137Cs含量 137Cs本地值 沉积剖面 草地小流域 森林小流域 泥沙堆积速率 土壤侵蚀速率 喀斯特峰丛洼地 茂兰 |
| 其他题名 | The Study on Soil Erosion in Peak-Cluster Depression of |
| 学位专业 | 自然地理学 |
| 中文摘要 | 土地资源是人类赖以生存的基础，是社会经济发展的前提条件，土壤侵蚀是当今世界重大的环境问题之一。在中国西南喀斯特山区，少土少水与富钙环境，景观异质性高，富雨地段，双层结构，地表水与地下水快速转换，干湿环境交替快，及人为因素等喀斯特土壤侵蚀环境因素的作用下，喀斯特土壤侵蚀是有包括地表流水侵蚀、重力侵蚀、土下化学溶蚀、地下流失、人为加速侵蚀等组成的混合侵蚀方式。由于喀斯特环境本身的特殊性和复杂性，有关研究已说明137Cs示踪方法不适用于非均质土壤的喀斯特坡地。但喀斯特洼地具备137Cs研究土壤侵蚀的条件。 选择了贵州普定草地和广西环江旱作稻田二个137Cs本底值样地。贵州普定草地，由于137Cs沉降初始的差异或其后各种原因引起的再分布，137Cs面积活度空间变异明显，变异系数为0.50；广西环江旱作稻田，由于犁耕混合作用，137Cs面积活度的空间分布最为均匀，变异系数(CV)最小，为0.13。研究得出贵州普定和广西环江三地的137Cs本底值，分别为805.9Bq·m-2和997.7Bq·m-2。并分析了满足一定精度要求的最少取样点数。说明在平坦草地难寻的情况下，可以选择平坦农耕地作为本地值样地。 选择黔南峰丛洼地区的茂兰自然保护区中不同生态环境条件的森林洼地与草地洼地2个典型小流域，采集洼地沉积泥沙137Cs样品，进行了洼地小流域的土壤样品137Cs剖面形态、空间分布、和堆积速率与土壤侵蚀速率的137Cs示踪研究。 (一)黔南峰丛洼地区的茂兰自然保护区中的工程碑草地洼地典型小流域。(1)草地洼地土壤剖面属于堆积土壤剖面，土壤剖面中137Cs深度分布特征反映了泥沙堆积与表层土壤侵蚀的信息，工程碑草地洼地中不同的沉积点接受了含有不同137Cs浓度的泥沙沉积，并且泥沙沉积厚度不均匀。其中洼地底部样点A-1可以作为洼地典型沉积剖面样点。(2)受岩土分布、微地形和土壤异质性的影响，137Cs初始沉降后出现不均匀再分布，面积活度的空间变化较大，变异系数为1.35，说明洼地137Cs面积活度不能表征土壤侵蚀状况。(3)根据草地洼地典型堆积农耕地土壤剖面A-1的137Cs深度分布特征，1963年以来的流域平均堆积泥沙数量是16.6T·km-2·a-1，工程碑草地洼地小流域的平均土壤侵蚀速率为45.95T·km-2·a-1，说明约占侵蚀产沙数量63.88%的泥沙以地下流失形式散失(4)利用配比法求算工程碑草地洼地小流域内地面土壤流失与地下土壤流失的相对贡献率分布是70.13%和29.87%。(5)相对于茂兰地区最大成土速率为依据推算的允许土壤侵蚀量是13.51T·km-2·a-1，工程碑草地洼地的土壤侵蚀危险程度较高。 (二)黔南峰丛洼地区的茂兰自然保护区的坡格森林洼地典型小流域。(1)坡格森林洼地低洼槽谷的土壤剖面曾受耕作扰动。典型沉积剖面B-1单一137Cs峰值浓度出现在14-16cm，高浓度137Cs均匀分布深度小于当地犁耕层厚度20cm，说明1963年以来坡格森林洼地的堆积速率接近于0。(2)受岩土分布、微地形和土壤异质性的影响，137Cs初始沉降后的再分布不均匀，137Cs面积活度变异系数为1.54。相同组成特征的地块内部样点137Cs面积活度变异系数变化为0.36～0.54，变异相对较小。但137Cs面积活度不能表征土壤侵蚀状况。 |
| 英文摘要 | Land resource is the base of human live,and is the premise of soc-economic development.But soil erosion is the vital environment problem of the world.In karst mountainous areas of southwest China, the rocky desertificational element including Carbonate rock mountain area, environment of scarce soil and water and rich in Calcium ,high landscape heterogeneous, plentiful rain region, double level structure, fast transformation of surface water and groundwater, rapid alternation of dry and wet circumstances and man-made factors, and karst soil erosion was mingled erosion mode formed by surface stream erosion, gravity erosion ,sub-soil erosion, underground soil loss, man-made accelerated erosion et al.Being the particularity and complexity of karst environment itself, the related report showed 137Cstracing technology was not suit the karst slope with non-homogeneity soil But the peak-clustr depression has the qualification to research soil erosion using 137Cs tracing technology. The paper selected two 137Cs reference sites as grassland in Puding of Guizhou and dry culture paddy in Huanjiang of Guangxi. In the reference sites of Puding in Guizhou,the spatial variability of 137Cs areal activity were evidently related to the difference of 137Cs initial deposition or redistribution for various reason, and had the coefficient of variation respectively as 0.50. The 137Cs areal activity in dry culture paddy of Huanjiang in Guangxi was the most evenly due to plowing migration ,and had the minimum coefficient of variation (CV) as 0.13.The 137Cs reference inventories in two reference sites of Puding in Guizhou and Huanjiang in Guangxi respectively as 805.9Bq•m-2 and 997.7Bq•m-2. And discussed the minimum sampling quantity to meet certain accuracy requirement. It showed that the flat cultivated land might be selected as the reference site when flat grass land were difficult to find. The research selected two typical studying depression with different ecological condition as forest depression and grassland depression in MaoLang natural reserve of peak-cluster depression area in southern Guizhou province,And collected 137Cs deposited sediment samples.At last carried the research to 137Cs characteristics of soil core profile and the spatial distribution of 137Cs concentration, and 137Cs tracing analyze to sediment accumulation and erosion of small depression basin. (一)In the typical grass depression of peak-cluster area as studying area in MaoLang natural reserve in southern Guizhou province. (1) The soil profile in grassland depression were accumulated profile, and the 137Cs depth distribution of deposited profile reflected the information of sediment accumulation and surface soil erosion. The different deposited point received sediment contained different 137Cs content, and the sediment depth were unevenly in grass depression.While A-1 core at the depression bottom might be selected as typical sediment accumulated profile.(2)Affected by earth-rock distribution, micro topography and soil heterogeneity, 137Cs spatial distribution after primary fallout was unevenly, and 137Cs inventories occurred greater spatial variation with a variation coefficient as 1.35 and showed that 137Cs inventory could not characterize the status of soil erosion.(3) Referred to 137Cs depth distribution of the typical profile A-1 core, the calculated natural erosion rate and accumulation rate in Engineering monument karst depression catchment respectively as 45.95 T•km-2•a -1 and 16.6 T•km-2•a -1.It showed that there amounted to 63.88% of eroded sediment dispersed in the way of underground loss. (4)Using matching method, we calculated relative contribution ratio of surface loss and Underground loss respectively as 70.13% and 29.87%.(5)By comparison to the utmost soil formation rate in MaoLang area as 13.51T•km-2•a -1 ,the risk of soil erosion in Engineering monument grassland depression is higher. (二)In the typical forest depression of peak-cluster area in MaoLang natural reserve in southern GuiZhou province. (1) The collected soil core profile at the depression bottom were cultivate-disturbed profile, 137Cs single peak value emerged in the depth of 14cm to 16cm in typical soil profile B-1, and higher 137Cs concentration in soil profile evenly distributed from 0cm to 16cm which was lower than the local ploughing depth 20cm.It showed that sediment accumulated rate in forest depression was nearly zero since 1963. (2)Affected by earth-rock distribution, microtopography and soil heterogeneity, 137 Cs redistribution after primary fallout was unevenly, and 137Cs inventories occurred greater spatial variation coefficient as 1.54. And the section interior with same composition showed smaller spatial variation coefficient ranged from 0.36~0.54. 137Cs inventory in soil section could not characterize the status of soil erosion. |
| 语种 | 中文 |
| 学科主题 | 水土保持学 |
| 公开日期 | 2010-10-13 |
| 分类号 | S71;S15 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2146]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 推荐引用方式 GB/T 7714 | 何永彬. 黔南茂兰喀斯特森林公园峰丛洼地土壤侵蚀研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2009. |
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