CONSULTATIVE RECOMMENDATIONS ON SUSTAINABLE DEVELOPMENT IN KARST AND ROCK-NAKED MOUNTAIN AREAS OF SOUTHWEST CHINA

The serious degradation of the ecological environment and the rapid expansion of stone desert have had a serious effect on the economic development of karst and rock-naked mountain areas in Southwest China. Moreover, these areas are still at the initial stage of industrialization, characterized by a greater significance of agriculture to the economy, face sharp contradictions among the population, the arable land and resources, and are suffering because of a shortage of investment. On the basis of this current situation, three recommendations are made in this article: "coordinating the relations among grain, ecology, population and economic development", "increasing the input of science and technology", and "adopting policies consistent with social equity in areas of poverty".

Spatiotemporal evolution of land transportation networks and accessibility in inland mountainous areas 1917-2017:A case study of Southwest China

Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus,mountains and hills.Its ruggedness hinders regional internal and external connections,and its poor transportation infrastructure has long constrained the socioeconomic development of Southwest China.Based on the GIS transportation database,this paper explored the spatiotemporal evolution and characteristics of the land transportation networks and the accessibility of Southwest China from 1917 to 2017.Regional accessibility in Southwest China has significantly improved,and transportation infrastructure has gradually integrated the transportation circles of the52 central cities.The transportation network has followed an evolutionary process from a"hub-spoke pattern"to a"network pattern",while the construction of a high-speed railway(HSR)has brought about significant spatial polarization.We argue that innovation in transportation technology is one of the most effective factors for promoting a significant change in regional accessibility.In addition,the spatial distribution and evolution of accessibility in Southwest China presents a verticalcharacteristic that distinguishes it from the plains,as the spillover effects of new transportation infrastructure on accessibility improvement are partly offset by the mountainous terrain.Additionally,in Southwest China,there is significant"path dependence"in the evolution of the transportation network,since a large portion of the population is concentrated along transportation corridors in mountainous areas.

Chemical characteristics of rainwater in karst rural areas,Guizhou Province, Southwest China

The chemical composition of rainwater has been studied in a karst rural area from September 2012 to August 2013 in Guizhou Province,Southwest China.The results indicated that the VWM value of p H was 5.4,varied from 4.6 to 6.9.Ca^(2+)and NH_4^+were the major cations,and SO_4^(2-)was the dominant anion.Neutralization factors show that the acid was mainly neutralized by Ca^(2+),NH_4^+and Mg^(2+).Investigations of correlation coefficients and enrichment factors revealed that Ca^(2+)and Mg^(2+)were mainly crust origins,and NH_4^+was from agriculture and livestock manure.SO_4^(2-)and NO_3^-were mainly from anthropogenic sources.

Characteristics and distributions of humic acids in two soil profiles of the southwest China Karst area

Characteristics and distributions of humic acid(HA) and soil organic matter(SOM) in a yellow soil profile and a limestone soil profile of the southwest China Karst area were systematically investigated to reveal their evolutions in different soils of the study area. The results showed that characteristics and distribution of SOM along the two soil profiles were notably different. Total organic carbon(TOC) contents of soil samples decreased just slightly along the limestone soil profile but sharply along the yellow soil profile. TOCs of the limestone soils were significantly higher than those of the corresponding yellow soils, and C/N ratios of SOMs showed a similar variation trend to that of TOCs, indicating that SOM can be better conserved in the limestone soil than in the yellow soil. The soil humic acids were exhaustively extracted and further fractionated according to their apparent molecular weights using ultrafiltration techniques to explore underlying conservation mechanisms. The result showed that C/N ratios of HAs from different limestone soil layers were relatively stable and that large molecular HA fractions predominated the bulk HA of the top soil, indicating that HA in the limestone profile was protected while bio and chemical degradations were retarded. Combined with organic elements contents and mineral contents of two soils, weconcluded that high calcium contents in limestone soils may play a key role in SOM conservation by forming complexation compounds with HAs or/and enclosing SOMs with hypergene CaCO_3 precipitation.

Study on Soil Erosion Model Under Different Slopes in Southwest Karst Mountain Area

The aim was to further research soil erosion characteristics and accurately predict soil erosion amount in karst areas. Based on field surveys and research achievements available, yellow soils, which are widely distributed, were chosen as test soil samples and slope, rain intensity, vegetation coverage and bare-rock ratio were taken as soil erosion factors. Artificial rain simulation instruments （needle-type） were made use of to simulate correlation of rain intensity, vegetation coverage, and bare-rock ratio with soil erosion quantity. Furthermore, multiple-factor linear regression analysis, stepwise regression analysis and multiple-factor non-linear regression analy- sis were made to establish a multiple-factor formula of soil erosion modulus with dif- ferent slopes and select regression models with high correlation coefficients. The re- sults show that a non-linear regression model reached extremely significant level or significant level （0.692〈FF〈0.988） and linear regression model achieved significant lev- el （0.523〈FF〈0.634）. The effects of erosion modulus changed from decreasing to in- creasing and the erosion factors from high to low were rain intensity, vegetation cov- erage and bare-rock ratio when slope gradient was at 6~, 16~, 26~ and 36~. The mod- el is of high accuracy for predicting gentle slope and abtupt slope, which reveals correlation of erosion modulus with erosion factors in karst areas.

ECOLOGICAL AND SOCIO-ECONOMIC REHABILITATION IN THE KARST OF SOUTHWEST CHINA

The Karst of Southwest China is a typical representative of poverty stricken region with impoverishment-degradation spiral. To essentially break away from this vicious circle, the local ecology, economy and society should be rehabilitated, and hence to strengthen the self-development capacity building of the localities. Two considerations are stressed in this article: (1) Poverty alleviation is a system project with great complexities. Any single approach is difficult to success and integrated measures should be taken. (2) Some typical and feasible areas should be selected to demonstrate the project of poverty alleviation and ecological, socio-economic reconstruction. Then, they can be used as a model to promote the sustainable development of the whole region. Based upon these ideals, a project entitled “Reversal of Impoverishment-Degradation Spiral in the Karst of Southwest China' was proposed and has been listed in 《Priority Programme for China's Agenda 21》.

Investigation on the Concurrent-Business Behavior of Peasant Households during the Planting Structure Adjustment in Karst Mountainous Area

Based on the survey data of 150 peasant households in typical Karst mountainous area in the year 2009, causations, characteristics and influence factors of the concurrent-business behavior of peasant households during planting structure adjustment are analyzed. Result shows that there is significant positive correlation between the concurrent-business income and the household income of farmers. And the concurrent-business behavior has the tendency to be popular among the young farmers with the characteristics of relative concentration, strong will of farmers and the significant impact of education degree on the concurrent-business income. Information, capital, skill, and market awareness are the main factors affecting the concurrent-business behavior of peasant households. Countermeasures to optimize the concurrent-business behavior of peasant households are put forward, such as strengthening the skills training for farmers to improve the cultural quality of peasant households, establishing modern rural financial service system to offer capital support for the development of peasant households, setting up information base of rural labor force to provide more information and channels for the concurrent-business behavior of peasant households, and enhancing the cultivation of farmers' market awareness to improve their ability to adapt to market economy.

ENVIRONMENTAL MIGRATION AND SUSTAINABLE DEVELOPMENT——A Case Study of Southwest China

This paper focuses on migration occurrence as a result of environmental degradation and population growth. It briefly reviews previous practices in some less developed courtries and then considers the extent to which environmental factors have been and may be significant in initiating migration. A case study of the karst region of southwest China is used to illustrate the phenomenon, including root causes, restrictive factors, nature of the migration, desires of migrants, strategies of response and optional policies. It is argued that a comprehensive approach to the prevention of environmentally caused displacement should be developed.

Emergency road network structure and planning optimization in mountainous regions in Southwest China under earthquake scenarios

Emergency road networks(ERNs),an important part of local disaster prevention systems,can provide security to residents and their property.Exploring the ERNs structure is of great significance in terms of promoting disaster prevention and establishing road safety in dangerous mountainous areas.This study considered the ERNs of the Kangding section of the Dadu River Basin as the area for a case study.Complex Network Analysis was used to examine the relationship between the four characteristic indicators of mountain roads and the degree of earthquake impacts under the Lushan,Wenchuan,and Kangding Earthquake scenarios.Based on the analysis results,the southwest mountain road network was evaluated;then,computer simulations were used to evaluate the structural changes in the road network after index changes.The network was optimized,and the corresponding emergency avoidance network was proposed to provide a reference for the establishment of the mountainous ERN.The results show that the overall completeness of the mountainous ERNs in Southwest China is poor and prone to traffic accidents.Moreover,the local stability is poor,and the network is susceptible to natural hazards.The overall structure of the road network is balanced,but that of certain road sections is not.Road sections with different attributes present a“gathering-scattering”spatial distribution,i.e,some sections are clustered together while others are far apart.Accordingly,a planning optimization strategy is proposed to better understand the complexity and systematic nature of the mountainous ERN as a whole and to provide a reference for disaster prevention and mitigation planning in mountainous regions in Southwest China.

西南山区乡村贫困地域系统时空演化格局研究——以云南省镇沅县为例

在梳理总结国内外关于贫困地理与农村多维空间贫困、乡村地域系统与贫困地域系统理论前沿研究的基础上,提出“乡村贫困地域系统”研究视角,并对乡村贫困地域系统理论内涵进行了初步探析.以云南省镇沅县109个村域为评价分析单元,构建了乡村贫困地域系统演化发展评价指标体系,设计了乡村贫困地域系统演化发展指数测度模型和基于“时空立方体—新兴时空热点分析”的时空演化模式识别方法.研究显示:(1)镇沅县2013-2021年乡村贫困地域系统演化时序阶段性特征经历了“差异波动演化(2013-2015年)—快速演化(2016-2019年)—增长滞缓趋稳(2020-2021年)”3个主要阶段.(2)镇沅县乡村贫困地域系统时空演化模式以连续热点模式为主,加强的热点模式呈零星分布,表征2013-2021年镇沅县乡村贫困地域系统整体上经历了较快且连续稳定的减贫演化过程,是减贫政策普惠作用在时空演化模式上的具体表现;连续冷点模式和持续冷点模式呈现出县域东西两端集聚分布态势.(3)多维空间贫困陷阱主要集中在和平镇、者东镇、振太镇的部分村域,相关村域脱贫稳定性相对较差、返贫风险较高.乡村发展是乡村地域系统循环累积与动态演化的结果,深入刻画分析乡村贫困地域系统时空演化格局与特征,对于科学推动脱贫地区转型发展具有重要意义.

Research on Auto-Classification Method of Remote Sensing Images in Mountainous Areas——An Application in Southwest of China

In mountainous areas, it is the undulant terrain, various types of geomorphic and land use that make the remote sensing images great metamorphism. Moreover, due to the elevation, there are many areas covered with shadow, clouds and snow that make the images more inaccurate. As a result, it would be very difficult to carry out auto-classification of RS images in these areas. The study took Southwest China as the case study area and the TM images, SPOT images as the basic information sources assisted by the auxiliary data of DEM, NDVl, topographical maps and soil maps to preprocess the images. After preprocessing by topographic correction and wiping off clouds, snow and shadows, all the image data were stacked together to form the images to be classified. Then, the research used segmentation technology and hierarchical method to extract the main types of land use in the area automatically. The results indicated that the qualitative accuracies of all types of land use extracted in Southwest China were above 90 percent, and the quantitative accuracies was above 86 percent. The goal of reducing workloads had been realized.

西南山区乡村人居环境治理:模式比较与政策启示——以4个典型村落为例

探索乡村人居环境治理的有效模式对推进乡村建设,促进乡村振兴具有重要意义。文章基于西南山区4个典型村落人居环境治理的实地调研,依据农户行为理论、公共选择理论、委托代理理论和多中心治理理论,按照治理主体力量的不同,将其划分为村民自主治理、政府治理、市场治理和多中心治理4种主要模式,并深入比较4种治理模式的实践机制。研究发现:4种模式在乡村人居环境治理中各有利弊,且适用环境不尽相同。距县城、中心镇较远,宗亲关系密切和农户较为分散的村落适宜推行村民自主治理模式;人口较为集聚且政府治理能力强的村落适宜推行政府治理模式;资源禀赋强、人文历史和交通条件好的村落适宜推行市场治理模式;村落发展较好且利益联动机制较为完善的村落,适宜推行多中心治理模式。西南山区乡村人居环境治理水平总体较低,后续治理任务依然艰巨,针对政府治理成本大、市场进出机制不完善和村民参与不积极等问题,从政府、市场和村民等视角提出了相应建议。

西南喀斯特核心分布区植被对极端气候的响应

为了探究植被变化与极端气候之间的关系,以西南喀斯特核心分布区为研究对象,基于1982~2019年NDVI数据和气象站点日气温和降雨数据,选择气候变化监测和指标专家组(ETCCDI)定义的极端气候指数,运用趋势分析法和相关分析法探讨了NDVI和极端气候时空变化及其响应机制.结果表明:1982~2019年西南喀斯特核心分布区NDVI总体(83.13%)呈显著上升趋势,仅少部分地区(0.51%)呈下降趋势.极端气候指数中,表征极端高温的指数在时间和空间上都呈显著(P<0.05)增加趋势,表征极端低温的指数在时间和空间上(P<0.05)都呈显著下降趋势,而极端降水指数变化趋势不显著(P>0.05).年尺度上,西南喀斯特核心分布区NDVI与极端降水和极端气温暖指数呈正相关,而与极端气温冷指数呈负相关;NDVI与7个具有显著关系(P<0.05)的极端气温指数(TN90P、TX90P、TNX、TXX、TN10P、TX10P、TNN)的相关性在空间上表现出明显的异质性.表征极端气温频率的TN90P、TX90P和TN10P三个指数是影响不同植被生长的主要因子.研究结果对于喀斯特地区生态保护与治理具有一定的指导意义.

中国西南山地民族传统赛马研究:回眸、困境与进路

赛马运动是栖居西南山区的诸多少数民族中比较重要的民族传统体育活动内容。回眸以往的西南山地民族传统赛马研究,可以看到这一领域迄今已形成了一批作者群和研究热点,但又面临着多方面的学术困境。当下亟需大力拓展研究视域,设立一系列新的研究议题,并引进多物种民族志、行动者网络理论、本体人类学等前沿理论和方法,以实现研究上的创新突破,从而为我国山地民族地区传统赛马运动的可持续发展提供有力的理论支撑。

产业结构演变下西南喀斯特地区产业生态效率时空演变——以贵州省为例

运用基于改进的生态足迹模型方法,分析贵州省产业结构演变下产业生态效率时空变化。研究结果显示,随着贵州省产业结构由“一二三”阶段演变到“二一三”“二三一”阶段以及“三二一”阶段,产业生态效率的增长率分别为8.2%、8.1%、14.1%,整体平均增长率为10.1%,与全国相比还有一定的差距。第一产业的生态效率平均增长率为9.4%,第二产业的生态效率平均增长率为8.2%,第三产业生态效率平均增长率为10.6%。在1986—2019年间,贵州省各市(州)产业生态效率不断增加,产业生态效率与产业生态效率增长率存在一定差距,总体差距呈现减少趋势。根据研究结果提出了新时期贵州省经济发展的相应对策。

喀斯特山区生态系统服务权衡/协同时空分异研究——以云南广南县为例

人类活动影响喀斯特山区生态系统服务功能。喀斯特山区生态系统服务权衡/协同作用及时空差异特征分析,是指导山区生态恢复及保护的重要依据。当前针对中国喀斯特山区的相关研究多以生态系统服务权衡/协同关系的时间变化为主,较少对权衡/协同关系变化的空间异质性及空间可视化进行研究,难以全面揭示各类服务间的复杂关系。本研究以云南喀斯特山区广南县为例,采用模型评估及相关分析等方法对六种生态系统服务进行评估,分析其时空变化、空间异质性和权衡/协同变化关系。结果表明:(1)2000—2018年,年均食物供给量和文化价值量呈逐年增加趋势,年均产水量、土壤保持量和固碳价值量呈先减少后增加趋势,年均生境质量呈逐年下降趋势。(2)空间上,食物供给量、文化价值量和产水量呈中部和中南部增加较多的特征,而土壤保持量与其呈大致相反的趋势,固碳价值量和生境质量空间上呈东部增加较多的趋势。(3)自相关关系上,各生态系统服务全局Moran s I指数大小为:固碳>食物供给>土壤保持>产水>文化>生境支持服务,生境支持服务在空间上呈离散化状态,而其他服务均呈集聚分布特征,且空间分异以不显著区和低-低区集群分布为主。(4)权衡/协同关系的时间变化格局上,生境支持服务-固碳释氧相关性为高度正相关,协同性系数最高,而产水-土壤保持相关性为中度负相关,权衡性系数最低;空间变化格局上,食物供给-产水、文化-固碳间空间分布均为协同关系,产水-土壤保持、固碳-产水均为权衡关系。空间格局整体以协同关系为主,权衡区与协同区空间分布有所差异。生态系统服务相关性及权衡/协同分析,有助于对研究区自然资源进行宏观调控,缓解经济发展与生态保护的矛盾。研究结果丰富了喀斯特山区生态系统恢复这一领域研究内容,有利于促进广南县资源环境的协调发展。

西南山区大型水电工程库岸滑坡InSAR早期识别与监测研究进展

我国西南山区大型水电工程大量建设于金沙江、澜沧江、雅砻江流域,但是这些流域复杂的地层、岩性、构造、水文等地质条件导致水电工程库岸滑坡灾害分布广泛,多发频发。合成孔径雷达干涉测量(InSAR)技术凭借其覆盖范围广、监测精度高、不受云雾遮挡等特点为水电工程库岸滑坡早期识别与监测带来了新的机遇,在近年来得到水电工程建设及库岸地质灾害防治相关领域的极大重视。基于此,对西南山区大型水电工程库岸滑坡InSAR早期识别与监测的应用概况进行了梳理,从研究时间、研究内容、研究对象等多角度进行了分析;对水电工程库岸滑坡InSAR早期识别与监测技术的研究现状、研究热点进行了归纳与总结,揭示了以白鹤滩水电站为里程碑,水电工程库岸滑坡早期识别与监测目前已开始进入InSAR技术应用与研究的爆发阶段;最后,探讨了水电工程全生命周期(蓄水前阶段、蓄水阶段、蓄水后阶段)对InSAR技术的不同应用需求与算法适用性。随着SAR数据质量提升与算法进步,InSAR技术必将常规化地参与到水电工程全生命周期库岸滑坡的识别与监测工作中,为水电工程库岸滑坡的早期识别、监测预警、触发机理研究及灾害防治等提供重要支撑,提升我国水电工程库岸滑坡地质灾害防治能力。

喀斯特山区不同土地利用方式对土壤微生物生物量、酶活性及其化学计量的影响

土地利用改变土壤理化性质,显著影响土壤微生物属性。在中国喀斯特地区,针对不同土地利用方式下土壤酶活性及其化学计量特征与土壤环境因子之间的关系,仍缺乏精确的定量认知,无法科学指导土地利用结构的优化与生态系统功能的维持。本文选取中国广西弄岗自然保护区4种土地利用方式(农田、草地、灌木林和森林)地块,采用土壤生物化学、酶学等方法,探讨不同土地利用方式对喀斯特土壤基本理化性质、微生物生物量、微生物熵、酶活性和酶化学计量的影响。结果表明:(1)土地利用方式显著影响土壤基础理化性质,土壤pH、有机碳(SOC)和全氮(N)含量表现为灌木林和森林显著高于农田和草地,而农田和草地土壤有效磷(AP)含量则显著高于森林和灌木林;(2)土壤微生物碳(MBC)和微生物氮(MBN)表现为灌木林>农田>森林>草地,且灌木林MBC和MBN显著高于其他土地利用方式,微生物磷(MBP)在农田土壤中最高;冗余分析(RDA)表明有效氮(AN)和pH是驱动土壤微生物生物量变化的主要环境因子;(3)微生物熵碳(qMBC)和微生物熵氮(qMBN)均表现为农田>灌木林>草地>森林,且农田土壤qMBC和qMBN显著高于森林,而不同土地利用方式土壤微生物熵磷(qMBP)无显著差异;(4)不同土地利用方式显著影响N-乙酰氨基葡萄糖苷酶(NAG)、β-葡萄糖苷酶(BG)和酚氧化酶(PHO)活性,土壤酶活性变化受土壤C∶N、SOC、pH和P含量调控;(5)不同土地利用方式对土壤酶化学计量碳氮比(eC∶N)、碳磷比(eC∶P)、氮磷比(eN∶P)和微生物资源限制程度具有显著影响,磷是喀斯特地区土壤微生物最为受限的元素,由农田、草地到灌木林,微生物碳限制逐步增加,森林土壤碳限制程度最低。喀斯特地区不同土地利用方式引起土壤理化性质的改变是土壤微生物生物量、酶活性和酶化学计量变化的主要驱动力。研究结果可为喀斯特地区土地利用的科学规划提供参考,对预测喀斯特地区土壤微生物属性如何响应全球变化背景下土地利用与覆被变化具有重要作用。

基于改进RUSLE模型的西南土石山区水土流失评价——以湖南省龙山县为例

本文基于Landsat遥感影像,引入归一化山地植被指数(NDMVI),改进RUSLE模型中的植被管理因子C,得到改进的RUSLE模型,并利用其对湖南省龙山县2000~2020年的土壤侵蚀进行估算,旨在快速、科学地评价研究区水土流失变化情况,为以龙山县为代表的西南土石山区水土流失治理提供科学依据。2000年的NDMVI数值范围较均一化植被指数(NDVI)增加了0.3158,2020年的NDMVI数值较NDVI增加了0.2076,增加幅度均较大,这说明NDMVI区分地物的能力更强,具有较强地消除复杂地形影响的能力。通过影像对比,可以看出NDMVI区分地物的能力要优于NDVI,提取城镇用地、水体等地物的精度更高,尤其在地形起伏地区以及山坡的阴影地区,能更好地反演植被覆盖管理因子。基于山地植被指数修正的植被覆盖管理因子C可以更准确地区分地物,尤其是在地形起伏和山坡阴影地区。该方法能有效地运用于西南土石山区的水土流失监测和评价,实现动态变化的快速定量监测。

山江海地域系统关键带综合分类研究——以桂西南喀斯特区-北部湾海岸带为例

为满足自然资源发展规划的需求,本文基于山江海视角,以桂西南喀斯特区-北部湾海岸带为研究对象,采用地貌类型、地质类型、土壤类型、植被类型和土地利用要素构建了山江海地域系统关键带三级分类方案,运用空间叠置法对分类要素进行叠加和制图综合分析,并进行山江海地域系统关键带区划分类、制图和环境因子分析研究。结果表明,可将桂西南喀斯特区-北部湾海岸带划分为38个一级单元、78个二级单元、111个三级单元。一级关键带分类中海拔山地-非碳酸盐岩区占据面积最大,为19.10%;二级分类中海拔山地-非碳酸盐岩区-红壤性土占据面积最大,为13.98%;三级分类中低海拔丘陵-非碳酸盐岩区-复盐基红黏土-针叶林-河渠占据面积最大,为15.21%。研究结果表明,本文所提出的关键带综合分类方案可体现区域特征中的差异和驱动因素,因此可为自然资源地表系统规划提供理论基础,同时可为国内外相关研究提供参考依据。