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 quantifed 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.

Dynamic Change and Simulation and Prediction of the Karst Rocky Desertification Sensitivity in Guizhou Province

Sensitivity evaluation of rocky desertification is to recognize the areas prone to be rock-deserted,so as to assess the sensitivity degree of rocky desertification to human activities.To perform the sensitivity evaluation of rocky desertification,we should be on the basis of the mechanism of rocky desertification formation for analyzing its regional distribution difference in the sensitivity and further for finding out the rocky desertification-susceptive areas and their possible degrees.Employing remote sensing and geological information system techniques,we regarded the 1∶ 50 000 topographic map and the TM image in 2000 of Guizhou Province,together with the hydrologic map,soil map,geologic map,rock formation map,administrative map and other geological information as data sources to generate the degree data of rocky desertification sensitivity of Guizhou Province in 1962 and 2000,based on which we determined the corresponding degree transfer matrix and adopted Markov model to simulate the dynamic change process of rocky desertification sensitivity and its future evolution trend.In various sensitivity types of rocky desertification in Guizhou Province,only the insensitive type showed a declined acreage,from the proportion of total land acreage of 61.35% in 1962 to 55.55% in 2000.Various sensitivity types inter-conversed,resultantly the acreage of mildly sensitive type increased most.The prediction results showed that the acreage of insensitive type of rocky desertification in Guizhou Province will assume a remarkable decline trend,of mildly sensitive type will present a remarkably increasing trend and of slightly sensitive type basically will maintain a stable level in the future tens of years.Acreages of both highly sensitive and extremely sensitive type of rocky desertification expanded to some extent,suggesting that the rocky desertification risk in Guizhou Province is in an aggravating process.

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.

Study on the Driving Forces of Rocky Desertification in Guizhou Province Based on Variation Coefficient Method

[Objective] The aim was to study the driving forces of rocky desertification in Guizhou Province. [Method] Based on GIS and RS technology, the main driving forces of rocky desertification in Guizhou Province were analyzed by means of correlation analysis and variation coefficient method, and then the distribution of rocky desertification in Guizhou Province was assessed synthetically. [Result] The main driving forces of rocky desertification in Guizhou Province were vegetation cover, rainfall, peasant income and gradient which were obviously correlative with rocky desertification; from theoretical distribution, rocky desertification was the most serious in Bijie, southwest Guizhou, southern Guizhou and northeastern Guizhou, and the theoretical distribution of rocky desertification in Bijie was severer than its current situation, which showed that construction of ecological function area in Bijie restrained the development of rocky desertification effectively; the good consistency between theoretical and current distribution of rocky desertification revealed that the study method was feasible. [Conclusion] The study could provide theoretical references for the practical control of rocky desertification.

Ecological Restoration Technology and Benefit Assessment of Karst Rocky Desertification Mountains in Xixiu District of Anshun City

Ecological restoration refers to the containment of soil erosion,restoration of water conservation,climate regulation,maintenance of ecological functions of biodiversity,and improvement of ecological environment and landscape pattern based on self-repairing capacity of the nature and combined with appropriate artificial measures. Since the natural restoration process of karst desertification mountain is very long,it needs to be supplemented by artificial vegetation restoration. This paper introduced the ecological restoration technologies implemented in karst rocky desertification mountains in Xixiu District,Anshun City of Guizhou Province,and also introduced the afforestation tending management measures. It assessed the ecological benefits of the ecological restoration project from five aspects: mountain community characteristics,vegetation coverage,species diversity,afforestation survival rate and landscape effect.

中国典型石漠化地区土地利用与石漠化的关系

定量研究了贵州省盘县中南部峰丛洼地典型石漠化地区不同岩性的土地利用分布规律和不同土地利用类型的石漠化发生率。结果表明,难利用的、岩石裸露的石旮旯地在连续性石灰岩、石灰岩夹碎屑岩和石灰岩与白云岩互层分布区的比例很高。不同等级石漠化与不同土地利用类型和岩石类型存在着相关性,如坡耕地中以连续性石灰岩发生轻度石漠化的比例最高,其次是石灰岩碎屑岩互层分布区;研究区的轻度石漠化中,土地覆被以灌丛所占的比例最高,坡耕地占11.67%;中度石漠化中,土地覆被以中覆盖度草地所占比例最高;强度以上石漠化中,土地覆被以难利用地的石漠化比例最高。从1995到2000年,中覆盖度草地和难利用地中强度和极强度石漠化比例有所增加。基于上述研究,对研究区的石漠化土地覆被作了进一步的分类,指出了研究区的石漠化的形成过程和治理重点。

贵州土地石漠化的形成原因及其治理对策

贵州省境内土地石漠化现象严重。结合贵州省岩溶生态环境分析表明 :贵州省土地石漠化形成的地质背景是地壳的持续隆升运动和沿断裂破碎带的深切作用 ,使正、负地形高差对比越来越不平衡 ,碳酸盐岩广布为石漠化的广泛发育奠定了物质基础 ;支离破碎的地形地貌给土壤侵蚀提供了有利条件 ,导致严重的水土流失和石漠化 ,独特的气候条件是石漠化发育的主要外营力 ;不合理的人类活动加速了石漠化的进程。

贵州省喀斯特山区生态环境脆弱性研究

贵州省喀斯特山区生态脆弱 ,主要表现为敏感度高、环境容量低、抗干扰能力弱和稳定性差。地球内动力机制奠定了其脆弱的生态环境背景 ,如地貌类型复杂、碳酸盐岩广泛分布、山高坡陡、土层薄而不连续等。季风活动和人口压力是喀斯特生态系统扰动的外动力机制 ,大气环流决定了贵州省阴湿多雨的气候特点 ,为岩溶发育提供了重要的侵蚀营力 ;社会经济压力超过了其生态系统的承载力 ,加剧了生态环境的恶化。

贵州喀斯特山地的“石漠化”及防治对策

贵州是一个碳酸盐岩分布广泛、生态环境脆弱、“石漠化”严重的山区省份。本文在综合大量实地考察资料的基础上着重阐述了贵州喀斯特地区的山地“石漠化”现状及危害，探讨了“石漠化”过程的成因，指出不合理的人类活动是近期贵州喀斯特山地“石漠化”过程加快的主导因素，并据此提出了相应的防治对策。

喀斯特山区石漠化成因的差异性定量研究——以贵州省盘县典型石漠化地区为例

珠东区的轻中度石漠化主要由人为因素引起,强度以上石漠化则由人为因素和恶劣的自然条件共同造成;保基区的轻中度石漠化主要是人为因素引起,强度以上石漠化则由自然因素造成;红果区的自然条件好于其它两个研究区,石漠化尤其是强度石漠化主要是土地利用强度大造成的,坡耕地发生中度甚至极强度石漠化。喀斯特石漠化土地的成因类型与恢复治理模式密切相关,在确定石漠化土地的治理恢复模式和治理重点时,有必要考虑石漠化土地的土地利用成因和成因的地域差异性。

土地石漠化的生态地质环境背景及其驱动机制——以贵州省喀斯特山区为例

在分析贵州省喀斯特山区的土地石漠化的生态地质环境背景基础上 ,探讨了土地石漠化内、外动力驱动机制。认为地质构造运动塑造了陡峻而破碎的喀斯特地貌景观 ,由此产生的较大地表切割度和地形坡度 ,为水土流失提供了动力潜能 ;古环境演化为喀斯特石漠化提供了广泛分布的碳酸盐物质。温暖潮湿的季风气候为喀斯特地貌的强烈发育提供了必要的溶蚀条件 ,超载的社会经济压力则是导致喀斯特山区土地石漠化最重要的驱动力。

喀斯特石漠化地区土壤含水量变化影响因素分析——以贵州省普定县为例

主要对普定典型喀斯特石漠化地区土壤含水量变化的影响因素进行了研究和探讨,简要分析了气象、石漠化、坡度、植被、土壤性状等因素对土壤水分的影响。研究结果表明:降水量是土壤含水量的主要控制因子;土壤含水率与湿度呈正相关,与气温呈负相关;不同发育程度的石漠化样地的土壤含水量大小顺序依次为:潜在石漠化>轻度石漠化>中度石漠化;植被覆盖度与土壤含水量呈正相关;土壤含水量随坡度的增加而减小;土壤含水率与土壤厚度呈正相关;土壤质地对土壤水分入渗能力有一定的影响,但土壤化学性质对土壤含水量影响较小。

基于RBFN模型的贵州省石漠化危险度评价

西南喀斯特山区石漠化已成为当地发展的重大障碍,国内诸多学者对此做了大量研究工作。本文在前人研究成果的基础上,选取影响喀斯特石漠化演化的相关指标,运用GIS技术提取各指标数据,建立RBFN模型(RadialBasisFunctionNetwork,径向基函数网络模型),根据不同石漠化危险程度标准,选取12个市县相关数据进行训练,确定网络模型参数,进而对贵州省82个市、县(自治州)的喀斯特石漠化危险度进行了评价,结果显示:贵州省西南部的西南—东北沿线为喀斯特石漠化发生的极强危险区、整个西南部为强危险区,北部地区为中度危险区,而东南部地区为轻度危险区,并利用他人研究成果进行了对比验证,发现结果较为理想。

贵州省喀斯特石漠化与水土流失空间相关分析

喀斯特地区石漠化现象的产生与水土流失之间存在不可分割的关系。为进一步分析石漠化与水土流失之间的关系,以贵州省2010年的水土流失及石漠化解译数据为基础,运用地图代数原理,通过水土流失与石漠化转移矩阵的计算,从而得出不同水土流失等级的石漠化分布以及不同石漠化等级的水土流失分布情况。结果表明:贵州省石漠化主要发生在水土流失轻度侵蚀与中度侵蚀区,其发生率分别为24.31%,24.09%,而水土流失主要发生在轻度石漠化与潜在石漠化区,其发生率分别为35.70%,34.16%;水土流失或石漠化等级的变化并不一定呈现相应等级的石漠化或水土流失等级的变化,石漠化的发生与生态恢复存在滞后性。

降雨因子对喀斯特石漠化发生发展的影响研究

石漠化的形成有其深刻的自然背景与社会背景,研究石漠化发生发展的驱动机制是喀斯特脆弱生态系统恢复与重建的必要条件。为了定量研究气候要素对石漠化发生发展的影响,综合选取地理要素、气候要素、人口要素、社会经济要素、人地关系要素中对石漠化具有驱动作用的因子。用这些驱动因子与石漠化指数进行相关性分析,并选取显著相关的部分驱动因子进行偏最小二乘回归分析。利用变量投影重要性指标(VIP)来定量衡量各驱动因子对石漠化影响的重要性,从而定位气候要素对石漠化发生发展影响的作用。分析认为石漠化的发生发展主要是由自然地理因子决定的,自然气候要素特别是暴雨为石漠化的发生发展提供了直接的驱动力,并随着雨量级的增加其对石漠化的驱动作用越强。

贵州北盘江镇喀斯特峡谷石漠化地区生态经济治理模式及效益分析

石漠化地区是造林的困难地带和生态治理的重点地区。为了加快石漠化的综合治理 ,以喀斯特石漠化发育典型的北盘江镇花江大峡谷右岸的顶坛片区为例 ,在阐述顶坛片区的自然环境条件及石漠化现状的基础上 ,分析目前正在实施的几种石漠化治理模式 :如“花椒—养猪—沼气”模式、“砂仁—养猪—沼气”模式、“传统粮食经济作物 (如玉米、花生等 )—砂仁、花椒”套种模式等 ,对这几种发展模式的生态经济效益、发展潜力、存在的问题等进行对比研究 ,查明第 1种和第 2种模式经济效益好 ,而第 3种模式有更好的生态效益 ,并针对存在的问题 ,提出了对策。

喀斯特石漠化景观及其土地生态效应——以贵州贞丰县为例

利用喀斯特石漠化生态脆弱区贵州贞丰县2004年的A STER遥感影像,解译了全县的喀斯特石漠化现状,并从景观生态学的角度指出轻、中、强、极度石漠化存在不同的空间分布格局。与此同时,作者还把石漠化的景观格局和其土地生态价值的分布频率结合起来,并从生态系统服务功能的角度定量计算了相应喀斯特石漠化土地的相对生态价值,评价了研究区石漠化土地的生态效应。结果表明,贞丰县270个村的生态价值整体偏低,全县极大值为1.016,极小值为0.286;不同区域之间的总体生态价值差异较大,生态价值相对较好的地区主要集中在非喀斯特地带,而在中度、强度、极强度石漠化地区生态价值很低。

岩溶山区石漠化生态治理的生态效应研究

以贵州省花江峡谷石漠化治理示范区为研究单元,对比分析了小流域2005和2009年生态治理下的土壤理化性质与植物数量特征的变化。结果发现,该区土壤理化性质的变异系数值降低,说明土壤理化性质的空间变异程度降低;土壤总孔隙度略微降低,非毛管孔隙度明显增加,毛管孔隙度明显下降,土壤毛管持水量明显降低,土壤田间持水量明显提高,表明土壤的孔隙结构更加合理,土壤持水能力与通气透水性能增强;土壤有机质含量变化不明显,全氮、全磷含量明显增加,全钾营养元素含量降低,土壤pH值略微降低;植物的高度、基径、冠幅、均匀度等数量特征呈明显增长趋势,土壤质量与植物群落的生态效应具有较好的一致性。经过石漠化生态治理的土壤、植被生态效应改善与提高,逐步改善岩溶山区石漠化生态环境。

岩溶山区石漠化生态治理的植物多样性动态响应——以贵州省花江示范区顶坛小流域为例

以贵州省花江示范区顶坛小流域2005、2007、2010年治理区为研究对象,根据石漠化等级及植被演替特征,选择强、中、轻和潜4个等级的石漠化样地进行调查,研究其植物多样性变化。结果表明:1)在人为干扰作用下,植物数量特征的空间变异程度较高,但植物的高度、地径、冠幅、生物量均呈较明显增长趋势;2)植物种群特征中优势种较为突出,除强度石漠化区外,花椒(Zanthoxylum bungeanum)群落2005、2007、2010年在中度石漠化群落中占16.5%、16.5%、16.8%,在轻度石漠化群落中占26%、25.9%、29.2%,在潜在石漠化群落中占37.9%、39.2%、51.3%,呈现逐年增长趋势;3)在群落分类上以禾本科(Gramineae)、菊科(Compositae)、大戟科(Euphorbiaceae)、桑科(Moraceae)和凤尾蕨科(Pteridaceae)为主;4)植物物种多样性特征上,表现出随石漠化等级的降低而降低的趋势。上述结论表明,不同等级石漠化区植被生长、群落分布及多样性特征均不尽相同,应采取相应的恢复措施。

贵州省喀斯特石漠化历史演变过程研究及其意义

针对贵州省喀斯特石漠化历史演变过程研究不足的现状,从人口数量、粮食需求、坡耕地开垦、石漠化发生发展的角度,并结合石漠化发生的地质背景等因素,对其历史时期人地关系、人地矛盾和喀斯特石漠化历史演变过程进行了研究。结果表明,贵州省石漠化发生发展经历了一个长期的、渐进、从量变到质变的过程,人口数量增长是这一过程的关键控制因素;其实质是人口与土地资源之间承载能力的不协调。同时,其演变同生产方式的转变和生产关系的变化是密切联系的;而国家对该区的宏观战略定位也间接影响了贵州省的生态环境质量。严控人口数量和提高人口素质、提高农业生产力、调整产业布局和政策是解决石漠化问题的基本途径,而建立和实行区域间的生态补偿制度对该问题的解决大有裨益。