石羊河流域及其典型绿洲景观动态变化研究

根据1986年和2000年的TM影像数据,利用GIS技术和景观结构分析软件FRAGSTATS,分别在类型和景观两个水平上分析了石羊河流域及武威和民勤两个典型绿洲近15a来的景观结构变化.结果表明:在整个流域水平上,虽然发生了景观结构的空间变化,但总体上相对稳定.在典型绿洲区,特别是民勤绿洲景观格局的变化较大,表现为景观的破碎化,形状的简单化和景观多样性的降低,以及耕地、沙地的增加和林地、草地的显著减少,沙漠化趋势加剧.     

Dynamics of land use/cover changes and the analysis of landscape fragmentation in Dhaka Metropolitan, Bangladesh

Rapid urban expansion due to large scale land use/cover change, particularly in developing countries becomes a matter of concern since urbanization drives environmental change at multiple scales. Dhaka, the capital of Bangladesh, has been experienced break-neck urban growth in the last few decades that resulted many adverse impacts on the environment. This paper was an attempt to document spatio-temporal pattern of land use/cover changes, and to quantify the landscape structures in Dhaka Metropolitan of Bangladesh. Using multi-temporal remotely sensed data with GIS, dynamics of land use/cover changes was evaluated and a transition matrix was computed to understand the rate and pattern of land use/cover change. Derived land use statistics subsequently integrated with landscape metrics to determine the impact of land use change on landscape fragmentation. Significant changes in land use/cover were noticed in Dhaka over the study period, 1975–2005. Rapid urbanization was manifested by a large reduction of agricultural land since urban built-up area increased from 5,500?ha in 1975 to 20,549?ha in 2005. At the same time, cultivated land decreased from 12,040 to 6,236?ha in the same period. Likewise, wetland and vegetation cover reduced to about 6,027 and 2,812?ha, respectively. Consequently, sharp changes in landscape pattern and composition were observed. The landscape became highly fragmented as a result of rapid increase in the built-up areas. The analysis revealed that mean patch size decreased while the number of patches increased. Landscape diversity declined, urban dominance amplified, and the overall landscape mosaics became more continuous, homogenous and clumped. In order to devise sustainable land use planning and to determine future landscape changes for sound resource management strategies, the present study is expected to have significant implications in rapidly urbanizing cities of the world in delivering baseline information about long term land use change and its impact on landscape structure.     

典型岩溶湖泊湿地流域景观格局动态变化及趋势预测

岩溶湖泊湿地流域作为景观格局变化的热点研究区域,探讨景观格局动态变化及预测趋势,为岩溶流域生态安全研究提供科学依据。应用遥感与地理信息系统技术,结合普者黑岩溶湖泊湿地流域实际情况,分别对该地区1990、1995、2000、2005、2010、2015 年6 期遥感影像进行分类、解译,系统地获取地区景观格局状况,分析动态变化特征,并运用CA-Markov 模型对未来湿地景观格局进行模拟预测。结果表明:1990?2015年普者黑岩溶湿地流域景观格局随时间变化显著,景观破碎化程度总体呈现增加趋势,斑块数（NP）从861增加到889,景观类型的优势斑块面积在逐渐增加,而多样性指数从1.064下降到0.966;2020?2030年普者黑岩溶湿地流域建筑用地、农地和湿地景观类型面积在增加,农地和林地在减少,其中,较为突出的是建筑用地占有率由2.79%上升到2.97%,农地占有率60.12%增加到60.74%,湿地占有率6.67%上升7.02%,而林地占有率由26.70%下降到26.40%。景观格局进行预测可以发现湿地面积、建筑用地面积和农地变化幅度最大,本文相关研究和预测结果可为普者黑流域生态保护提供一定的建议和参考。      

Monitoring land use change at a small watershed scale on the Loess Plateau, China: applications of landscape metrics, remote sensing and GIS

Rapid land use change has taken place in many arid and semi-arid regions of China including the Loess Plateau. In this study, changes in land use and landscape fragmentation in the small Shanghuang watershed on the Loess Plateau were investigated by the combined use of remote sensing, GIS and landscape metrics. Land use classes were mapped and analyzed from a time series of maps and remotely sensed images that were ground truthed in 2008. Analyses of the data showed that land use had undergone substantial changes in this small watershed from 1982 to 2008, and these changes could be divided into three phases according to the change in the landscape matrix whereby the dominant land use was grassland (1982–1990), cropland (1990–2002) and forestland (2002–2008). During each phase, conversions between different land use types took place frequently, especially among cropland, orchards, grassland and forestland. Landscape fragmentation increased from 1982 to 1990 and then decreased from 1990 to 2008 as indicated by four landscape metrics. These changes in land use and landscape fragmentation in this small watershed were mainly controlled by human factors (land management, construction, population pressure, and government policy) rather than natural factors.     

50余年来岩溶山地近郊村域土地利用与景观格局演变——以贵州省清镇市王家寨地区为例

选取贵州省清镇市近郊村域王家寨地区为研究对象,在GIS支持下,利用该区域1963年、1982年、2005年、2010年和2015年5期土地利用图形数据叠加分析,提取出研究区50余年来的土地利用/覆盖信息,并结合相应的社会经济统计数据,分析了其驱动力因子,其结果表明:(1)1963—2015年间,土地覆盖类型的总体变化为高被草地和平坝旱耕地明显减少,低被草地、农村居民点、工矿用地、公路用地面积大幅增加,其中,平坝旱耕地有向经济效益更高的土地利用方式转变的趋势;（2）景观格局演变的总体趋势是:自1963年起,斑块数量、斑块密度持续增加,到2015年呈下降趋势,而最大斑块指数逐年减小,形状趋于不规则,同时,近50年景观的多样性指数持续增加;（3）区内土地利用/覆盖和景观格局呈阶段性变化,从1963年到2005年,坡地土地利用活动较强,2005年后,平地土地利用强度增加、农业逐渐转型、聚落持续扩展;（4）区内土地利用及景观格局的变化主要受经济、人口和政策因素的影响。      

1985-2014年漓江流域景观格局动态变化研究

文章以漓江流域为研究对象,应用1985年、2000年和2014年3期遥感影像,提取土地利用数据,采用土地利用动态度、土地利用转移矩阵等方法,分析1985-2014年漓江流域土地利用的演变趋势;结合Fragstats4.2景观分析工具,识别了该流域景观格局的动态变化。结果表明:1985-2014年,漓江流域土地利用整体变化幅度不大,主要表现为林地、耕地和草地面积减小,湿地、居民及城乡建设用地和未利用土地面积增加,且变化集中发生在2000-2014年。同时景观水平上破碎化和复杂化程度加剧,聚集程度和斑块连续程度有待提高;类型水平上林地景观破碎化层度增加,耕地和草地斑块面积增加,湿地和居民及城乡建设用地的聚集度较高,分布集中。     

青藏高原木里矿区及其周边土地覆被变化及景观格局脆弱性响应

矿区开发会导致周边土地覆被及景观格局发生剧烈变化, 但目前对青藏高原典型矿区及其周边土地覆被长时间序列变化缺乏动态监测, 尤其缺乏对景观格局脆弱性响应特征的深入认识, 因此无法针对矿区合理开发和生态修复等提出有效的科学指导。通过遥感技术和土地变化科学研究手段, 以及景观格局脆弱性概念, 对青藏高原北部木里矿区及周边1975 - 2016年土地覆被时空变化和景观格局脆弱性进行分析和评估。结果表明： 木里矿区在2000年后剧烈扩张, 导致周边土地覆被面积缩减, 其中高寒草甸湿地面积损失最大, 其次为其他和高寒草甸。矿区开发对周边生态系统的间接影响效应在逐渐增大, 表现为水域面积减少, 高寒草甸湿地出现退化以及矿区发生少量逆转。受矿区扩张影响, 区域景观格局脆弱性不断增强, 可能对周边生态系统服务功能产生负面影响。因此, 未来矿区的生态修复和规划过程中, 应当优化景观格局, 降低景观格局脆弱性。研究成果可为青藏高原及其他生态脆弱地区的矿区合理开发规划及生态修复等工程提供一定参考。     

大布苏地区土地利用及其景观格局变化研究

利用大布苏地区1996年和2001年两个时相的TM遥感图像,获取不同时期的土地利用信息,分析了大布苏地区土地利用时空变化,借助FRAGSTATS软件进行了景观格局变化研究。研究结果表明,土地利用变化的总趋势是水域、荒草地减少,居民用地、耕地增加,土地利用综合程度指数降低;从景观尺度上看,斑块密度、多样性指数、优势度和均匀度指数减小,最大斑块指数、景观形状指数增加。     

Geospatial modeling to identify the effects of anthropogenic processes on landscape pattern change and biodiversity

This research used geospatial data to quantify biodiversity changes and landscape pattern change to track anthropogenic impacts of such changes at the Mouteh Wildlife Refuge (MWR), Isfahan, Iran. Satellite image duration of four decades, LandSat_1-5, and IRS-P6 data were used to develop land cover classification maps for 1971, 1987, 1998, and 2011. The number and size of land cover patches, the degree of naturalness, and the diversity indices were calculated and compared for a 40-year period. The results showed an increasing concern with regard to unplanned human activities. Some improvements of the natural landscape also occurred in the core protected zone of the study area. The number and size of land cover patches, the degree of naturalness, and the diversity indices were calculated. Overall changes in natural land use between 1971 and 1998 at MWR showed that the number of patches for natural land use has increased, but it also showed a decrease in 2011. Similar changes were observed for seminatural land use. Within the artificial classes, the number and area of patches were higher and the largest patch occurred in 2011. The maximum variation of diversity is related to the year 2011. The results showed an increasing concern with regard to unplanned human activities. Some improvements of the natural landscape also occurred in the core protected zone of the study area. Remote sensing and geographic information system offers an important means of detecting and analyzing temporal changes occurring in our landscape.     

新疆喀什噶尔河流域1990-2010年土地利用/覆被及景观格局的变化特征

采用新疆喀什噶尔河流域1990、2000和2010年的Landsat-TM影像数据和中巴资源卫星数据, 结合GIS技术, 分析了喀什噶尔河流域近20 a土地利用/覆被及景观格局动态变化特征, 并对其变化原因进行探讨. 结果显示: 在1990-2010年喀什噶尔河流域耕地、建设用地、盐碱地、水域湿地、裸土地和其他未利用地面积呈不断增加趋势, 变化幅度分别为73.92%、51.44%、24.27%、10.24%、6.47%和2.98%; 林地、草地和沙地面积减少, 变化幅度分别为-4.13%、-17.16%和-0.73%; 裸石岩砾面积近20 a基本维持不变. 利用转移矩阵可知, 流域新增耕地面积主要来自于16.46%的草地和3.36%的林地; 新增建设用地主要来自于1.46%的耕地和0.22%的草地; 新增水域湿地面积主要来自于0.18%的草地; 新增盐碱地面积主要来自于0.28%的草地. 1990-2010年的20 a里喀什噶尔河流域耕地和水域湿地分布趋于集中, 景观优势度增强, 且斑块之间的联系不断增强. 林地和草地面积减少, 景观趋于破碎化, 景观优势度降低. 喀什噶尔河流域土地利用类型及景观指数的变化受人口、经济、政策和技术的多重影响, 导致流域耕地面积增加、植被退化. 因此, 合理利用流域水土资源对流域生态环境安全十分重要.     

Effects of landscape patterns on soil erosion processes in a mountain–basin system in the North China

This study was taken up to investigate the effects of landscape patterns on the soil erosion processes in a mountain–basin watershed. The revised universal soil loss equation and sediment delivery distribution models were used to estimate the soil erosion processes. The landscape patterns include the landscape metrics at the landscape level, landscape composition and configuration indicators on the basis of source–sink landscape theory. In the study area, the grassland, bare land, farmland and construction land were the sediment-source landscape; the forest and shrub were the sediment-sink landscape. The correlation analysis results showed that the soil erosion processes were significantly associated with the landscape patterns of the study area. At the landscape level, fragmentation metric was positively correlated with soil erosion; diversity metric was negatively related to soil erosion and sediment yield at the sub-basin scale. Among the source–sink landscape composition and configuration indicators, the composition indicator was positively correlated with soil erosion rate and sediment yield. In the configuration landscape indices, the shape index was negatively correlated with soil erosion rate and sediment yield; the fragmentation index was positively correlated with soil erosion rate and negatively correlated with sediment delivery rate. These results indicated that the optimization measures, such as increase in the area, connectivity and regularity of sediment-sink landscape, or decrease in the proportion, connectivity and regularity of sediment-source landscape, were favorable for soil conservation. Furthermore, the landscape indicators based on the source–sink theory could provide more information for landscape pattern optimization to reduce soil erosion.     

黔桂岩溶山区土地利用变化的社会经济因素分析

基于黔桂岩溶山区1990、2015年的土地利用数据和社会经济统计资料,利用典范对应分析方法对1990-2015年25年间的土地利用变化及社会经济驱动因素进行了实证分析。结论如下:（1）黔桂岩溶山区土地利用变化存在明显的时空分异现象;（2）贵州高原区以草地大幅减少和林地增加为主要特征;黔桂峰丛洼地区以水域面积增加和草地减少为主要特征;广西丘陵区的主要特征是耕地减少和建设用地增加。（3）贵州高原区土地利用类型变化以经济和人口因素为主要驱动力;广西丘陵区土地利用类型变化以经济因素和农业结构水平为主要驱动力;农业因素对黔桂峰丛洼地区的土地利用变化驱动作用明显。未来应提高贵州高原和黔桂峰丛洼地区岩溶山区草地生态功能重要性的认识,在加强森林植被恢复的同时加强草地资源保护;城镇化发展背景下黔桂岩溶山区应减少优质耕地占用,开发低丘缓坡土地,建设山地特色城市。      

黄土高原土壤裸露与景观格局关系——以延安市宝塔区为例

土壤裸露是水土流失具体的空间表现,同时又是导致进一步水土流失的重要因素。由人类和自然相互作用下形成的景观格局对土壤裸露具有深刻的影响。为深入探讨二者间的内部联系,文章选定位于黄土高原的延安市宝塔区为研究区,分别就景观格局的类型组成和空间结构,分析其与土壤裸露的关系。研究结果可知人为活动强度较大的区域土壤裸露程度较高,在景观类型上,表现出滩地、农村居民点、其他建设用地、低覆盖度草地及山区旱地等景观类型的土壤裸露值较高,另外,从景观组成来看,农牧组成为主的流域土壤裸露值明显高于其他流域;通过景观空间结构与土壤裸露的关系分析,可知个体单元型态、空间构型以及整体多样性等景观空间结构特征,均对土壤裸露程度具有不同大小的指示意义,其中又以景观聚集度及平均斑块面积与土壤裸露程度有强烈负相关。     

Investigation of land use changes on soil erosion process using geographical information system

Land use change quantified for the last 50 years within and near a fast growing agricultural land in Neka River Basin, using geographic information systems. Land cover and land use change was projected for the next decade using topography, geology, land use maps and remote sensing data of the study area. The study explored the relationships between agricultural land growth and landscape changes. The land use changes assessed among the different land cover classes. It is important to mention that conducting of the present study a very severe land cover changes taken place as the result of agricultural land development. These changes in land cover led to the forest degradation of the study area. Relationship between land-use changes and agricultural growth offered a more robust prediction of soil erosion in Neka watershed. This study aims to find the relationships between land use pattern, erosion and the sediment yield in the study area. The land use coefficient has applied in the model of erosion potential method to forecast the effect of the land type to reduce the erosion. The results of this study indicated that the total sediment yield of the study area has notably decreased to 89.24 % after an appropriate land use/cover alteration. The estimated special erosion for the southern Neka Basin is about 144465.1 m³/km² where after management policy is predicted 15542.9 m³/km²/y. Therefore, the total difference for the study area has estimated about 128922.2 m3/km2/y.     

Spatio-temporal patterns of agricultural expansion and its effect on watershed degradation: a case from the mountains of Nepal

Expansion of agricultural at the cost of forested land is a common cause of watershed degradation in the mountain zones of developing countries. Many studies have been conducted to demonstrate land use changes in such regions. However, current knowledge regarding the changes, driving forces and implications of such change within the context of watershed development is limited. This study analyses changes in spatial patterns of agricultural land use and their consequences for watershed degradation during the 1976–2000 period along an altitude gradient in a watershed in Nepal, by means of remote sensing, GIS and the universal soil loss equation. Estimated soil loss ranged from 589 to 620 t ha⁻¹ y⁻¹, while areas of extreme hazard severity (>100 t ha⁻¹) increased from 9 to 14.5% from 1990 to 2000. Spatial distribution of soil loss in 2000 was characterized by 88% of total soil losses being from upland agricultural areas. The study determined that without considering other forms of land degradation, only water erosion was responsible for erosion of a substantial area in a short timeframe. Areas under upland cultivation are in an extremely vulnerable state, with these areas potentially no longer cultivable within a period of 6 years. As sustainability of the watershed is dependent on forests, continued depletion of forest resources will result in poor economic returns from agriculture for local people, together with loss of ecosystem services. Thus, in order to achieve the goal of watershed development, remaining forest lands must be kept under strict protection.     

Land use and landscape pattern changes in Nenjiang River basin during 1988–2002

Based on the Landsat TM data in 1988 and 2002, the GIS technique and Fragstats software were used to calculate the land use conversion matrix and eight landscape metrics at landscape and patch class levels in upstream, midstream, and downstream regions of Nenjiang River basin. The characteristics of land use and landscape pattern changes in each region during 1988–2002 were analyzed. The results show the followings: 1) During the period from 1988 to 2002, farmland and construction land area increased, while the areas of forestland, grassland, and unutilized land decreased in all three regions. The conversion trends from forestland and grassland to farmland were obvious. The conversion from forestland to farmland mainly occurred in the upstream region, whereas the conversion from grassland to farmland primarily occurred in the midstream and downstream regions. 2) The water area in the upstream and midstream regions enlarged, mainly due to the increase of water impounded area as a result of the construction of reservoirs. Comparatively, the water area in the downstream region decreased, and it mainly occurred in the east part of downstream region with concentrated lakes and swamps. 3) The degree of landscape fragmentation increased in each region. The controlling ability of forestland was weakened, and its patch shape became more complicated. In contrast, the controlling ability of farmland was reinforced, and the connectivity among patches increased. 4) The landscape pattern shows some gradient features. From the upstream to downstream regions, the disturbance of human activities on dominant patches was intensified, and consequently, the landscape fragmentation extent and heterogeneity were enhanced.     

Spatio-temporal land cover changes in a semi-arid watershed: Central India

Land use/land cover change is a global phenomenon which reflects natural resources degradation and/or utilization. Remote sensing and GIS have been widely used to monitor such changes at watershed level. The present study evaluates the LU/LC change during 1989 - 2001 in a semi-arid watershed of central India. Geocoded satellite data of 1989 and 2001 on 1:50,000 scale, were visually interpreted to prepare thematic maps which were later digitized using ArcGIS softwares. The analysis shows that vast tracts of cultivated land have become uncultivated and at some places even converted to wasteland. However, the land under dense forest and open forest has decreased due to expansion of built-up land and other anthropogenic activities. Increase in area of uncultivated land, wasteland and decrease in cultivated land and open scrub is also supported by rainfall analysis, which shows a declining trend and a fall of 186.93 mm in average annual rainfall for 1986-2003 period. The change detection map prepared using land use/land cover of 1989 and 2001 as inputs shows that out of the total geographical area of the watershed, 25.78% of the watershed area has seen a change from one land use category to another, however rest 74.22% has remained unchanged.     

西安都市圈道路网络化对景观格局的影响

在快速城市化过程中,道路网络快速扩张对区域生态景观的分割、隔离、破坏等是导致生态景观过程与格局演变的重要原因。研究道路网络化对景观格局的影响可为快速城市化地区生态、道路建设和区域可持续发展规划提供参考。本文以西安都市圈为例,利用GIS和RS技术,基于西安都市圈TM遥感影像和Arcgis 10.1、Fragstats 4.2软件平台,通过构建道路网空间指数,定量评价了路网空间结构和景观格局变化,并从空间上分析了道路网络化对景观格局的影响。结果表明:1)1985—2015年,西安都市圈路网发育不断成熟,基本呈现以西安市区为中心、空间指数向四周递减(除杨陵区和阎良区外)且东高西低的趋势。2)随着城市化进程的不断推进,西安都市圈景观呈现多样化、复杂化和破碎化。其中:园地、林地和建设用地规模扩大,景观聚集度上升;耕地、水域及滩涂景观破碎化程度不断加深。3)30年间,高等级道路的修建、低等级道路的不断完善以及市内环路打通等,使得西安都市圈路网逐渐完善,景观优势度下降,破碎化程度上升,形状趋于规则化。此外,路网发育的程度不同对不同地类的影响各不相同:路网成熟的区域,建设用地面积较多,形状较规则,呈聚集状态,林地面积较少,且零星分布,破碎化程度较高;道路结构简单的区域,林地聚集成片,聚集度较高,耕地、水域及滩涂在路网空间指数各等级影响域内均呈现破碎化状态,且形状较不规则。     

河西内陆河流域土地利用对地表水资源影响研究

土地利用对水资源的影响,直接导致水资源空间和时间分布格局发生变化,从而对流域生态、环境以及经济发展等多方面产生深刻影响.采用多期TM等卫星影像解译土地利用/覆被变化要素,应用斑块破碎度和分段比重百分比指标等方法,研究河西内陆河流域土地利用/覆被变化;应用河川径流的溯源性和零地表水资源尺度等理论,研究土地利用对地表水资源格局的影响.结果表明:土地利用驱使地表水资源格局产生剧烈变异,地表水资源整体向河源溯进;疏勒河水资源受耕地面积扩张等影响中下游径流变化产生紊乱;黑河耕地面积10万hm2成为水资源格局变化的极值,地表水资源损耗量出现逐步减少的趋势;石羊河耕地面积的扩张对地表水资源的影响力不断减小,转化为对地下水影响的加剧.     

土地利用变化对海河流域典型区域的径流影响

为研究海河流域径流对土地利用变化的响应,以阜平流域、匡门口流域和界河铺流域为研究区,利用1970—2011年的水文气象资料,分析了不同土地利用的时空转移特征,然后结合SWAT(Soil and Water Assessment Tool)模型,设置4种土地利用情景,评价了土地利用变化对径流的影响。结果表明:模型能够较好地模拟全年及汛期月流量过程;多年径流量呈下降趋势,20世纪80年代到90年代中期呈波动性变化;不同的土地利用类型在时空上的转化呈现可逆性,主要是林地增加,草地减少,耕地略有增加;林地的增加和草地的减少会降低汛期径流量以及最大月径流量;汛期径流系数随着林地面积的增加而减小。合理地规划土地利用格局,对控制流域水文事件具有重要意义。