西南喀斯特地区不同石漠化阶段土壤有效磷变异研究

为了探索西南喀斯特地区土壤有效磷的变异规律,采用野外采样与实验室分析相结合的方法,对贵州省荔波县及普定县不同石漠化阶段典型土壤的有效磷含量进行了研究.结果表明:①非石漠化土壤与轻度石漠化土壤有效磷质量分数呈显著差异,非石漠化的黑色石灰土有效磷质量分数高达9.29×10-6,随着石漠化程度的加深,土壤有效磷含量逐渐减少;②土壤剖面中有效磷质量分数均表现为表土层高于心土层,且随着石漠化的发展,有效磷质量分数在剖面中减少得越慢;③土壤有效磷质量分数随时间有显著变化,有效磷从5月开始积累,7月后出现下降趋势,9月或11月又逐渐升高,到翌年1月达到峰值;④土壤有效磷与有机质和黏粒质量分数均呈极显著线性相关,相关系数分别为0.901 7和-0.777 2.这说明增加有机质的积累可提高土壤有效磷质量分数,对防治石漠化具有重要意义.     

西南喀斯特地区不同石漠化阶段土壤黏土矿物组成及其含量变异研究

为了探索西南喀斯特地区土壤中黏土矿物组成及其含量的变异规律,以贵州省普定县和荔波县不同石漠化阶段典型土壤的黏土矿物为例,采用X-射线衍射仪图谱分析方法,计算得到黏土矿物组成及其含量,探讨不同石漠化阶段黏土矿物组成变化规律及其含量之间的线性关系.结果表明:不同石漠化阶段黏土矿物的组成是相同的,均为高岭石、蒙脱石和伊利石;在未石漠化、轻度石漠化、中度石漠化阶段,蒙脱石在剖面表层的质量分数分别为27.82％、29.34％、58.32％,高岭石分别为21.39％、31.81％、36.93％,伊利石分别为50.79％、38.85％、4.75％;在西南喀斯特地区,各石漠化阶段伊利石与蒙脱石的含量之间以及伊利石和高岭石的含量之间都呈显著的线性相关,相关系数分别为-0.970 3、-0.945 6;西南喀斯特地区土壤相似的成土作用和成土环境造成了黏土矿物相同的组成,而黏土矿物含量的差异说明各成土作用的程度或阶段是不同的;粉粒中的黏土矿物主要为石英和白云母,而砂砾中的黏土矿物主要为石英.     

成都平原典型Cd污染区稻米Cd、Zn含量特征及其健康风险探讨

摘 要:在成都平原选取了2个镉污染程度不同的区域,测定了污染区内稻米样本中的Cd、Zn质量分数,分析了这些元素含量随污染程度的变化,探讨了农民就地消费稻米的安全性。结果表明,中度( Ⅲ类土)、重度( 超Ⅲ类土)Cd污染区稻米Cd质量分数超标严重,超标率分别达75％和100％ ,而且重度污染区稻米中的Cd含量是中度污染区的近5倍,但Zn含量差异很小,表明随着土壤Cd含量的增加,会加剧稻米Cd累积和Zn的相对缺乏,从而进一步降低食品的安全性;中度Cd污染区65％、重度Cd污染区92％的稻米样品Cd/Zn比值超过了食物Cd/Zn的健康临界值0.015。分别参照WHO和USEPA推荐的成人RFD(Cd)值和当地居民习惯食物消费结构,分析表明对于农民就地消费稻米来说均存在较大程度的潜在Cd暴露风险,特别是重度污染区。因此,对于成都平原Cd污染区,研究相应的控制Cd污染技术并采取适宜的膳食结构做调节,来确保每日饮食中Cd的安全含量显得尤为迫切。?      

广西黑水河流域岩溶石漠化分布及治理对策

文章以广西黑水河流域为研究单元,对该区石漠化分布现状、成因进行了分析,并按石漠化程度进行了分区。石漠化主要集中在北西和北东部地区,中部及南部地区石漠化程度低且分布较稀少,重度石漠化主要分布在流域中上游,与中度石漠化分布面积相当,轻度石漠化占比较大的面积。在分析石漠化产生的原因基础上,提出了综合治理的一些对策措施。     

湛江地区辣椒地土壤的养分状况及其调节

对湛江地区辣椒地土壤取样,测定了容重pH、及有机质、全氮、碱解氮、速效磷、速效钾含量。结果表明,辣椒地土壤肥力比甘蔗地土壤有明显改善,且随年限延长呈提高的趋势;与甘蔗地土壤比较,辣椒地土壤速效钾含量呈降低趋势。     

基于无人机航摄影像的喀斯特地区裸岩信息提取及景观格局分析

喀斯特地区不同石漠化等级的结构和格局是实现区域石漠化治理的重要基础信息,受技术手段的限制,目前这方面的研究进展仍非常缓慢。随着无人机技术的快速发展,高精度的地表信息获取越来越方便、且成本较低。本研究利用无人机影像,对比了基于像元的非监督和监督分类方法以及面向对象的分类方法在裸岩信息提取中的表现,发现面向对象分类结果具有更高精度。基于获得的裸岩分布信息的研究结果表明：① 岩石平均斑块面积与裸岩率呈负相关的关系,岩石斑块个数与裸岩率呈正相关关系;② 通过对比不同裸岩率（11%、20%、29%和48%）基质的景观斑块指数、景观形状指数和景观破碎度指数对不同裸岩率的景观分布的影响,从而表明了在不同的石漠化地区随着裸岩率的增加,岩石形状指数与岩石破碎度指数均逐渐增加,进而表明石漠化程度越严重;③ 裸岩率不同的地区表现不同的分布形态和斑块特征,裸岩率越高,岩石越破碎,斑块分布较为分散。小尺度斑块景观格局与区域的生态过程有着重要关系,开展小尺度景观格局的研究会深化区域尺度石漠化发展过程的理解。石漠化地区的小尺度斑块景观格局变化影响区域的生态过程,对以后的石漠化过程以及未来石漠化演变的发展有重要的启示作用。     

赣南地区水稻－根系土系统中硒含量影响因素分析

硒是人体必需微量元素之一,而水稻作为我国第一大主粮,其硒含量的高低与人体健康关系密切,因此研 究水稻－根系土体系中硒含量的影响因素,可为富硒地区水稻种植及开发富硒农业提供科学理论依据.以赣南 为研究区,采集１３８组水稻籽实及配套根系土样品进行了测试分析,探究赣南地区土壤理化条件对硒在水稻及其 根系土中的实际影响效应,对富硒水稻及土壤进行质量综合评价,并构建富硒水稻地球化学适生模型.结果表 明:赣南地区水稻根系土Se平均质量分数为０．２９mg/kg,Se水平主要为足硒水平,富硒土壤仅占１４．５％;有效硒 (Sebio)质量分数平均为４６．０μg/kg,占总硒质量分数的１６．４４％;水稻的Se平均质量分数为０．０５mg/kg,无重金属 元素超标的安全富硒水稻率达到４５％,富硒水稻对 Cd,Zn,Cu的生物富集能力较强.相关分析表明,根系土中Se 质量分数与 TFe２O３,MnO,MgO,有机碳(Corg)质量分数呈极显著正相关,与主要重金属元素存在一定程度的伴 生关系.水稻Se质量分数与根系土Se,Sebio,SiO２ 质量分数和pH 值呈极显著正相关,与 Al２O３,有机碳(Corg)质 量分数呈极显著负相关.单项污染指数表明研究区根系土中重金属元素基本属于清洁和尚清洁水平,Cd,Pb, As,Hg,Cu存在一些样品超标,其中 Cd超标率最高;内÷罗综合污染指数表征７７．０％的样品属于安全等级;富硒 土壤综合评估显示研究区主要为良级富硒土壤,优级富硒土壤仅占８．７％.通过最佳子集回归分析最终选取了根 系土总Se、有机质、pH 值为自变量构建富硒水稻地球化学适生模型,拟合的模型可以解释水稻中 Se３０．６％的变 异.      

泰莱盆地土壤有机质含量及pH值对微量元素有效性的影响分析

土壤微量元素有效性,对农作物的生长及农产品的品质特征有重要的影响作用。该文首先阐述了泰莱盆地土壤微量元素有效性情况,分析探讨了土壤有机质含量及pH值对泰莱盆地土壤微量养分的有效性影响。结果表明：有效铜、硼和锌的含量有随着土壤中有机质含量增加而增大的趋势;有效硼的含量有随着土壤pH值升高而增大的趋势,有效铁、锰和钼的含量随着pH值的升高逐渐降低。     

基于ArcObjects的喀斯特石漠化动态监测与驱动诊断信息系统开发研究

本文主要介绍了喀斯特石漠化动态监测与驱动诊断信息系统(KRD.DMDM.IS)的研制。文章论述了该系统应用的ArcObjects技术及其二次开发层次、一般开发步骤和应用的部分接口,采用了Geodatabase数据模型建立数据库,并将支持C/S体系结构的空间数据库管理器(ArcSDE)集成于系统中来,较好地解决了对空间和非空间数据进行高效率操作的数据库接口;构建了马尔柯夫模型和驱动诊断模型,对广西都安瑶族自治县的石漠化动态变化、演变趋势和形成机制进行了深入分析,从而为该地区的喀斯特石漠化综合治理工作提供有益的帮助。     

基于小波与包络线的土壤有机质高光谱估测

以陕西省横山县为研究区,对小波分析法与包络线去除法融合应用于土壤有机质高光谱估测的有效性进行了探究。利用陕西省横山县84个土壤样本的光谱反射率和有机质含量数据,采用小波分析法去除了部分噪声,通过光谱一阶微分变换,提高光谱反射率与有机质的相关性,采用包络线去除法提取建模因子,减少数据冗余后最终采用回归分析法建立土壤有机质的估测模型。结果表明,与未采用小波分析法建立的模型比较,建模因子的相关性提高了0.1~0.25,模型的判定系数可达0.932,提高了0.207,检验样本的均方根误差RMSE为0.107,减小了0.116。总体而言,小波分析与包络线去除法联合应用于土壤有机质高光谱估测是有效的且所建模型精度较高,但数据质量对模型精度有重要影响。     

典型石漠化峰丛洼地土壤重金属的空间分异特征及其影响因素

研究石漠化峰丛洼地土壤重金属空间分异特征及其影响因素, 对推动区域土壤重金属污染防治、石漠化综合治理具有重要的指导意义和实践价值。以广西平果市典型石漠化峰丛洼地土壤为研究对象, 通过调查采样分析以及综合运用地统计学、地质累积指数、潜在生态危害指数和地理探测器等方法, 分析探讨土壤重金属的空间分异特征及其影响因素。结果表明, 研究区8种重金属元素的空间分布总体呈东北向西南降低的变化格局, 研究区东北部和东南部为重金属高值叠加区的集中分布区, Cr,Cd元素呈现中等的空间相关性, 其他6个重金属元素表现为强空间相关性;研究区受Cd,As,Cr,Cu,Zn等元素不同污染程度的影响, 且以Cd的影响尤为突出, 其地质累积指数和潜在生态危害指数分别高达1.34和107.73;pH、地层、Fe₂O₃、土地利用、P、CaO、Mn、到断层距离、石漠化程度是影响研究区土壤重金属空间分异的主要因子, 而且不同因子组对土壤重金属空间分异的交互作用以双因子增强型和非线性增强为主。因此认为不同因子对石漠化峰丛洼地土壤不同重金属元素空间分异特征的影响程度存在差异, Cd是石漠化峰丛洼地土壤污染程度和潜在生态危害程度最严重的重金属元素, 地层、Mn、CaO、岩性、到断层距离、P是影响Cd空间分异的关键因子。      

Human driving forces: Analysis of rocky desertification in karst region in Guanling County,Guizhou Province

Karst rocky desertification is one of the major ecological and environmental problems that threaten the sustainable development of southwestern China. It is caused by irrational and intensive land-use patterns in karst geo-ecological environment. Therefore, it is vital to identify how human forces work on this degraded environment. Based on the soil erosion information in 2000 and remote sensing images of Guanling County collected in 2000 and 2007, four grades of karst rocky desertification data in 14 villages of Guanling County were extracted. Impacts of population, affluence, and other human forces on karst rocky desertification were analyzed using STIRPAT model. The results show that: 1) Factors of population and affluence had strong influence on karst rocky desertification. In the STIRPAT model analysis, the population and affluence coefficients were positive, indicating that the increase in population and affluence would lead to more serious desertification. 2) Factors of farmer correlated with karst rocky desertification negatively, especially the way of viewing the relationship between people and nature, and the level of knowledge about rocky desertification. Government behavior was not a significant factor in this analysis. 3) The findings provide evidence that STIRPAT model can be used to analyze the relationship between human driving forces and rocky desertification.     

遥感石漠化信息的提取

石漠化信息提取是多种信息综合分析、反馈的过程。通过分析当前石漠化分级体系,对比喀斯特地区与石漠化范围、土地利用与石漠化关系,并结合当前石漠化信息提取关键技术研究认为:目前的石漠化分级体系在划分级别、分级指标、分级区域等方面存在巨大差异,将尺度划分引入石漠化等级体系是统一石漠化等级划分差异的有力途径;充分利用基于内容的特征识别算法进行喀斯区的圈定可以有效提高石漠化信息提取精度;利用已有的土地利用矢量数据,通过合理转换进行石漠化信息提取是重要研究思路;传统的建立石漠化解译标志、改进植被指数模型以及建立波谱关系模型等石漠化信息提取方法无法很好融合石漠化综合指征,提出基于遥感的石漠化综合指标度进行石漠化信息的提取方法。     

Human Driving Forces:Analysis of Rocky Desertification in Karst Region in Guanling County,Guizhou Province

Karst rocky desertification is one of the major ecological and environmental problems that threaten the sustainable development of southwestern China. It is caused by irrational and intensive land-use patterns in karst geo-ecological environment. Therefore, it is vital to identify how human forces work on this degraded environment. Based on the soil erosion information in 2000 and remote sensing images of Guanling County collected in 2000 and 2007, four grades of karst rocky desertification data in 14 villa...     

Rocky Desertification Risk Zone Delineation in Karst Plateau Area： A Case Study in Puding County, Guizhou Province

Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantified with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about 50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.     

Rocky land desertification and its driving forces in the karst areas of rural Guangxi,Southwest China

With a subtropical climate, Guangxi Zhuang Autonomous Region has a typical karst landscape. Rocky desertification has become a serious environmental issue due to its high vulnerability caused by the joint effect of natural settings and human activities, because of which its eco- environment has been deteriorated in recent years, and farmland has been disappearing sharply at the same time. This, in turn, has exacerbated the poverty level in the rural areas of the region. In this study, we monitored the spatial distribution of rocky land desertification and its temporal evolution using Landsat TM/ETM images of 1985, 1995, 2000 and 2005. We also analyzed the driving forces of the desertification and its expansion. Through constructing regression models by using all the relevant variables and considering the lagged effects as well as fixed effects, we quantified the exact role of different factors causing rocky land desertification in the study area with some new findings. The new findings in this study are greatly helpful for preserving, restoring and reconstructing the degraded mountain environment in Guangxi and other karst areas in Southwest China, and also for alleviating poverty in the rural areas in the future.     

DESIGN AND APPLICATION OF DYNAMIC MONITORING AND VISUALIZATION MANAGEMENT INFORMATION SYSTEM OF KARST LAND ROCKY DESERTIFICATION

In order to study the spatial-temporal change and environmental management of regional karst LUCC (land use and land cover change) and its causative environmental effect-rocky dcsertification by integrating qualitative analysis and quantitative analysis, and relying on RS, GIS and GPS (3S) techniques, karst land rocky derification dynamic monitoring and visualization management information system (KLRD.DMVM.IS) is framed, which includes design aim and structure model, function design, database design and model system design. The model system design gives priority to dynamic monitoring, drive force diagnosis, comprehensive evaluation and decision support of karst rocky desertification. From the viewpoint of model type, mathematic expression and its meaning, the dynamic monitoring models are concretely devised to reflect the spatial and temporal changing features and the trend of karst LUCC and rocky desertification. Taking Du‘an Yao Autonomic County of Guangxi as an example, the KLRD.DMVM.1S is systematically analyzed in the application of the process and trend of karst LUCC and rocky desertiflcation in Du‘an County, and it provides the technical support for the study on karst land rocky desertification.     

ECO-ENVIRONMENT CHANGE AND SOIL EROSION PROCESS IN THE RECLAIMED FORESTLAND OF THE LOESS PLATEAU

1INTRODUCTIONSerioussoilerosionhasmadetheeco-environmentfragileintheLoessPlateau.InthemodernsoilerosionoftheLoessPlateau,theman-madeerosionwasthedominanterosionpattern (TANGetal.,1993a,1993b).Manyhumanactivitiesacceleratesoilerosion,butthemostinfluentialactivitiesaretodestroyforestandgrass,eventodestroyallvegetation.Reclamationbydestroyingforestlandandgrasslandartificiallycouldrapidlyincreasesoilerosionintensityinshorttimeandenlargeerosionspacegradually,evenchangeerosiondirectionandwor…     

白岩脚煤矿环境水文地质问题及防治对策

对白岩脚煤矿含水层特征、地下水赋存、转化与排泄等水文地质条件分析的基础上,对区内水土流失、石漠化、内涝、地下水污染等原生的和煤炭开采可能引发的环境水文地质问题进行梳理,并提出对策建议,为矿井设计和矿山环境保护与恢复治理提供参考。