基于遥感(RS)和地理信息系统(GIS)技术，以1978年-2007年的Landsat MSS/TM/ETM影像为数据源，综合运用数理统计和景观生态学理论和方法，对渭河流域关中地区1978年-2007年生态景观格局动态变化进行了研究。结果表明：渭河流域关中地区各景观类型都发生了不同程度的消长变化，耕地斑块面积减少，但分离度和破碎度增加；草地和林地斑块面积增加，破碎度和分离度减小；居民工矿建设用地面积显著增加；未利用土地斑块面积有所减少。从景观格局变化来看，渭河流域关中地区景观斑块分布趋于破碎化，破碎度指数从0.9127下降为 0.8755；景观多样性指数和景观均匀度指数均在20世纪90年代有所增加，分别增长了2.72%和2.71%，之后锐减，2000年达到最低后逐渐有所回升；景观优势度也在20世纪90年代有所增加，后逐渐减小。说明近期研究区生态景观的异质性有所改进，生态景观格局处于快速调整并趋于稳定发展阶段。

Analysis of changes in ecological landscape patterns is one of key issues in landscape ecology. Studying the dynamic changes in landscape patterns can reveal the interactions between landscape patterns and ecosystems, providing important reference for utilizing natural resources. Remote sensing techniques can be useful in examining ecological landscape patterns, especially in the study of distribution characteristics, evolution rules, spatial relationships of landscape phenomena, and in simulation of ecological landscape patterns. The Weihe River is the largest tributary of the Yellow River. In recent years, land use and ecological landscape changes in the Weihe River basin have received much attention. The Guanzhong part of the Weihe River basin was investigated in this study. Landsat Multispectral Scanner System (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper Plus (ETM+) imageries covering the Guanzhong part of Weihe river basin acquired in vegetation/crop growing season in the early 1980s, early 1990s, 2000, 2005 and 2007 were obtained. Landscape ecology theory was used to examine the dynamic changes in landscape patterns across the study area from 1978 to 2007. First, satellite images were geometrically and atmospherically processed. Training classes/sites of ecological landscape types for imagery interpretation by visual interpretation were determined. Thematic maps of ecological landscape types were made. Then, topological analysis was performed. Finally, ecological landscape indices were calculated and compared to examine the characteristics of changes in ecological landscape patterns. It was concluded that all types of landscapes over the area of interest changed to some extent. The area of farmland decreased, but its fragmentation and separation increased. Grassland and woodland areas increased, but their fragmentation and separation decreased. The area of construction land increased significantly. Unused land area decreased. The landscape over the study area became increasingly dispersed, demonstrated by its fragmentation index decreasing from 0.9127 to 0.8755. The landscape diversity index and evenness index increased by 2.72% and 2.71% in the 1990s, respectively. Landscape dominance also increased in the 1990s, and then gradually decreased. These results indicate improvements in ecological landscape heterogeneity. Ecological landscape patterns changed rapidly, but showed a gradually stabilized trend.

草地是重要的陆地生态系统类型,草地生态系统健康评价是干旱区草地健康研究的重要组成部分。新疆位于中亚干旱区,典型的“山盆”地形结构孕育的天然草地具有鲜明的垂直地带性,又因水热组合差异形成了丰富多样的草地类型,这使得新疆草地生态系统健康评价成为一项系统的复杂工作,急需构建适用于新疆的草地生态系统健康评价体系。本研究以新疆草地生态系统为研究对象,构建新疆草地生态系统健康评价总体框架,从数据来源与评价方法阐述了新疆草地生态系统健康评价体系。基于草地样方、生物气象与多源遥感数据建立草地生态系统基础数据库,针对草地健康评价方法,明确评价目标,确定评价区域与参照系统,进而筛选评价指标,最后通过选择评价方法开展草地健康评价,采用四分法将评价结果划分为健康、亚健康、警戒与崩溃。采用该体系在新疆和田地区民丰县开展草地生态系统健康评价,结果显示围栏内的温性荒漠类草地处于健康状态,围栏外的温性荒漠类草地为亚健康状态。通过构建新疆草地生态系统健康评价体系,能够为基层草原部门开展草地生态健康评价提供参考,促进草地可持续发展。

The evaluation of the health of grasslands (an important terrestrial ecosystem) is a crucial part of grassland health research, especially in arid regions. The grasslands of Xinjiang, an arid region in Central Asia, show a distinct variation in vertical zonality because of its special geographical environment. Particularly, the differences in hydrothermal combination at each geographical location (latitude, longitude, and altitude) have resulted in a rich variety of grasslands. Therefore, assessing the health of Xinjiang grasslands is a systematic and complex task. In this study, we constructed an overall framework, including data sources and evaluation methods, for evaluating the ecosystem health of Xinjiang grasslands. An ecological geographic database of these grassland ecosystems was designed based on grassland quadrats, biometeorology, and multi-source remote sensing data that together form the data basis for grassland health evaluation. The steps in the grassland health evaluation method are as follows: Defining the evaluation objective, determining the evaluation area and reference system, filtering evaluation indicators, and finally selecting the specific method for performing grassland health evaluation. The objective of evaluation contains biological and non-biological components, as well as ecosystem services of grassland ecosystem. The evaluation area is often based on administrative divisions, grassland types, and grassland divisions. The reference system is a stable state achieved by maintaining balance with the local climate. The recommended evaluation methods include the analytic hierarchy process, vigor-organization-resilience, condition-organization-vigor-resilience, and pressure-state-response. The evaluation results were divided into health, sub-health, vigilance, and collapse based on the quarter method. This grassland health evaluation was validated in Minfeng County, Hotan Prefecture, Xinjiang. The research area, Minfeng County, is located at the northern foot of the Kunlun Mountains and the southern edge of the Taklimakan Desert. The temperate desert grassland of Minfeng County primarily contains Seriphidium rhodanthum, Ceratoides latens, Reaumuria soongarica, and Ephedra intermedia. The objective of evaluation was based on the biological components of grassland ecosystems. Our results showed that the temperate desert grasslands within the fenced area were in a healthy state, but those outside the exclosure were in sub-healthy state. Thus, we gave a further explanation for healthy and sub-healthy state in the verification area. By constructing this grassland ecosystem health evaluation system for Xinjiang, we hope to provide a reference for the local management of grasslands, with the goal of fostering ecological health of these systems and promoting the sustainable development of grassland areas in Xinjiang.

Peatland is one type of ecosystems with the strongest carbon sequestration capacity on earth, the stability maintenance of which is of great significance to the enhancement of wetland carbon sequestration capacity. We examined the stability of Jinchuan peatland, a typical peatland in Longwan National Nature Reserve, Jilin Province. The evaluation index of ecosystem stability was screened by frequency analysis and ecosystem structure-function index method. Based on analytic hierarchy process (AHP), a peatland ecosystem stability evaluation index system was established, and then was used to assess the stability of the Jinchuan peatland. The results showed that: (1) 20 indicators reflecting wetland structure, wetland function, and external environmental spatiotemporal changes were screened to construct an evaluation index system for wetland ecosystem stability. (2) The value of stability index of Jinchuan peatland was 0.84, indicating that the wetland is in a stable state. The fluctuation of wetland hydrological process caused by climate change and agricultural production was the constraint factor affecting stability. (3) The health status index of Jinchuan peatland was 63.59, indicating a sub-healthy status. In order to maintain the stability of Jinchuan peatland and keep healthy, it is suggested to implement land reclamation for returning the surrounding drylands to wetlands, or adjust the agricultural planting structure, transforming drylands into paddy fields or planting aquatic economic crops. Meanwhile, linear drainage ditches should be filled up to improve the drainage rhythm of wetlands.<br><div> <br></div>

随着社会的发展和技术的进步,自然环境受到来自人类影响的范围和强度都在不断加大,由此引起的生态环境问题日益严重。区域生态环境敏感性分析对于制定生态环境保护规划和指导区域生态建设等工作具有重要意义。在RS与GIS 技术的支持下,以三峡库区巫山—奉节段为研究对象,结合研究区实际情况,选取地质灾害、石漠化、土壤侵蚀3个生态因素作为评价指标,建立各单因素生态敏感性评价模型,然后运用层次分析法确定各单因素在整个指标体系中的权重,通过加权求和得到该区域生态敏感性综合评价结果,并将生态敏感性空间分布图与研究区乡镇行政区划图进行空间叠加及统计分析。研究结果表明研究区域内不敏感区、轻度敏感区、中度敏感区、高度敏感区和极敏感区分别占巫山—奉节段区域总面积的7.55%,40.75%,45.21%,6.31%,0.18%,其中高度敏感区和极敏感区主要分布在康坪乡、永安镇、巫峡镇、康乐镇、大溪乡、朱衣镇和鹤峰乡。这些乡镇生态敏感性高,当受到人类不合理活动影响时,容易产生生态环境问题,应该是生态环境保护和恢复建设的重点。

As society and technology develop, the impact of human activity on natural environment has widened and intensified, resulting in severe eco-environmental problems. Sensitivity analysis for regional eco-environment is of significance to planning eco-environmental protection and guiding regional ecological construction work. With the segment from Wushan to Fengjie in Three Gorges Reservoir Area as study area, the sensitivity evaluation models of single factor, namely geological disaster, rocky desertification, and soil erosion, were established. The weight of each factor was determined through analytic hierarchical process, and the comprehensive evaluation results of ecological sensitivity were further obtained through weighted summation. With the support of RS and GIS technology, the spatial distribution of ecological sensitivity was superposed on the administrative map of the study area for statistical analysis. Results revealed that insensitive areas, slightly sensitive areas, moderately sensitive areas, highly sensitive areas and extremely sensitive areas comprise 7.55%, 40.75%, 45.21%, 6.31% and 0.18% of the whole research region, respectively. Highly sensitive areas and extremely sensitive areas mainly distributed in Kangping town, Yong’an town, Wuxia town, Kangle town, Daxi town, Zhuyi town and Hefeng town. These towns are easily subjected to eco-environmental problems when affected by improper human activities, and hence should be the focuses of eco-environmental protection and restoration.

青藏高原作为全球最大的关键生态热点区域,具有丰富的生态系统服务,但其广阔而独特的高寒生态系统正受到如土地利用集约化等日益严重的人为干扰。本研究旨在探讨1980—2020年青藏高原土地利用规模、时空格局及其变化过程,分析其对主要生态系统服务的影响。采用生态系统服务与权衡综合评价模型模拟研究了生境质量、碳储存、产水量3种生态系统服务的时空变化趋势,分析了土地利用演变对生态系统服务的影响。结果表明: 1980—2020年间,研究区土地利用格局较为稳定,以高寒草地和荒漠为主。生境质量整体提高,碳储量和产水量先升高后降低。3种服务整体呈现从西北向东南逐渐提升的空间格局,与土地利用由荒漠、草地到林地过渡的空间格局相对应。土地利用强度与生态系统服务的相关性呈现明显的空间分异特征,受土地利用强度影响较大的县域主要集中在青藏高原中西部、南部和中东部等区域。本研究结果对制定土地利用政策、调控青藏高原独特的高寒生态系统土地利用格局具有一定的指导意义。

滇南山区土壤侵蚀时空演变研究对于水土保持规划及世界文化遗产区的生态保护具有重要意义。本研究基于RUSLE模型和GIS/RS空间信息技术,分析元阳县2005—2015年间土壤侵蚀状况的时空变化趋势,以及其侵蚀成因和影响机理。结果表明: 研究期间,元阳县土壤侵蚀空间分异显著,流失区主要集中于县域东南部、西南部,藤条江沿岸区域侵蚀广泛,极强度和剧烈侵蚀呈点状分布。元阳县2005—2015年平均土壤侵蚀模数为11.06 t·hm^-2·a^-1,微度和轻度侵蚀所占面积比例近80%,而轻度和中度侵蚀则构成了近50%的全年土壤侵蚀总量,是县域水土流失治理的重点侵蚀级别。研究期间,随着森林覆盖率的提高,县域水土流失有减缓趋势。元阳县地形复杂多变,土壤侵蚀分布与海拔、坡度有很大的相关性,这种分布格局的形成受自然和人为因素的共同影响,海拔500 m以下、1500 m以上且坡度25°～45°的山地区是水土防护治理的重点区域。

It is of great significance to understand the spatial-temporal change of soil erosion in the Southern Yunnan Mountainous Area, especially for soil and water conservation planning and ecolo-gical protection in the world cultural heritage area. Based on the RUSLE model and GIS/RS space information technology, we examined the spatial-temporal variation of soil erosion and its relationship with environmental factors in Yuanyang County from 2005 to 2015. The results showed that, during the study period, the spatial differentiation of soil erosion in Yuanyang County was substantial. The soil erosion area was concentrated on the southeast and southwest region. Erosion widely distributed among both sides of Tengtiao River. Extreme and severe erosion presented a point distribution pattern. The average soil erosion modulus was 11.06 t·hm^-2·a^-1 from 2005 to 2015. The erosion level was basically slight and mild, accounting 80% of the total. Mild and moderate erosion contributed nearly 50% of total annual soil erosion, which was the key level of soil erosion control. During the study period, soil erosion had been slowed down with the improvement of forest cover. The terrain was complicated and changeable in Yuanyang County, and soil erosion distribution had a prominent correlation with altitude and slope. The formation of this distribution pattern was driven by numerous natural and human factors. The key area of soil and water protective governance were below 500 m, above 1500 m and slope located at 25°-45°.

On the basis of remotely sensed land use data in 1980,1995 and 2000, we quantitatively analyzed the characteristics of the spatio-temporal distribution of land use/cover changes (LUCC) in the Jialingjiang River Basin by using GIS technical platform and establishing index model. Furthermore, we analyzed the driving forces of the LUCC in detail. Results show that farmland, forest and grassland were major land covers in the studied area, and the conversion among the three was the major pattern of land use change. During the period from 1980 to 2000, farmland and forest decreased initially and increased afterwards; grassland increased initially and then decreased; land for construction showed an ever-increasing trend; other land use types were in small change. The analysis showed that natural factor, economy, population, macro-policy and large-scale projects were the main driving forces of LUCC in the studied area. All the factors restricted each other and then affected the land use patterns.

The environment in the Dongjiang River basin has received much attention in recent years due to its role in providing freshwater to cities including Heyuan, Huizhou, Dongguan, ShenZhen, and in part Hong Kong. It is widely recognized that land use change is a major cause of environmental changes. The Dongjiang River basin has undergone rapid urbanization along with growing economy during the recent two decades, which, in turn, has led to great regional land use changes over space and time. In this paper, the spatial-temporal characteristics of the land use change in the basin from 1990 to 2009 were quantified and comprehensively analyzed through performing change detection on the basis of interpretation of Landsat TM/ETM+ imageries acquired in 1990, 2000, and 2009. Some quantitative indexes were adopted, involving land use net change, annual change rate, and transition matrix. Results show that: 1) significant land use changes have taken place in the basin during the period 1990-2009, implying that the region has been experiencing processes of rapid urbanization and a prominent adjustment of the land use structure, which were demonstrated by increases in human-related land use, e.g., the urban built-up areas and decreases in natural land use types, e.g., woodland, brushwood, and grassland; 2) there existed obvious regional differentiation in land use change across the basin during the study period, which can be further divided into two phrases. For the first phrase, 1990-2000, the annual growth rate of the urban build-up land varied over the basin, showing the rate in the middle reaches > the upper reaches > the lower reaches. For the second phrase, 2000-2009, this rate in a decreasing order was the upper reaches > the middle reaches > the lower reaches, showing a slightly different magnitude of the change for the two phrases. Meanwhile, the decreasing extent of the natural land use types shows a trend as the lower reaches > the upper reaches > the middle reaches; 3) comparing with the period 1990-2000, the period 2000-2009 exhibited a more marked decrease in the amount of land use change and a decrease in the annual change rate; and 4) population growth, rapid economic development, and regional development strategies and policies are probably three major drivers for the spatial-temporal land use changes occurring in the basin. In the end, several measures for sustainable land use, encompassing natural vegetation conservation, land-use planning and management, restoration of wetlands, arable land protection, and ecological and environmental protection were given.