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1.
闽江口湿地遥感时空演变应用分析   总被引:6,自引:0,他引:6  
将闽江口湿地动态变化度、湿地变化转移矩阵和景观生态学的空间格局模型相结合,横、纵向分析了1986- 1994年、1994-2000年两个时期闽江口湿地的动态演变模式。研究表明,在两个时期不同的社会政策和经济发展阶段,人类活动对闽江口湿地的干扰强度与对象不同,造成两个时期不同的湿地演变模式。在1986-1994年间景观类型动态变化,以水田面积的扩张为主导,在1994-2000年间景观类型动态变化突出表现为城乡建筑用地对水田、非湿地农业的占用。在1986-2000年间,湿地景观中,人工水域破碎度增加,破碎化速度提高,形状更加复杂化;水田破碎度和形状复杂度都由增加向减弱转变;天然水域破碎度减小,形状复杂程度由减少变为增加;滩地破碎度由减少变为增加,形状复杂化由增加转向减少。在中、小时间尺度范围内,人类活动是影响闽江口湿地演变的主要原因之一,特别是近10多年来社会经济的高速发展,城镇化进程的加速,人类活动成为影响闽江口湿地的最主要原因。  相似文献   

2.
选取8个常用的景观指数,以厦门岛土地利用格局为例,分析景观指数随粒度变化的基本规律。探讨尺度效应对景观格局的影响,为基于景观指数进行不同尺度下土地利用类型、土地利用格局变化预测、对比分析和评价等研究提供参考。结果表明:在研究区内景观类型特征和景观格局特征随粒度的增大出现了显著的变化;除面积比例对粒度变化弱敏感外,其余所选景观指数对粒度变化相对敏感,体现出一定的尺度依赖性,因而利用这些景观指数进行不同尺度下的景观格局分析时需考虑尺度效应。  相似文献   

3.
《山地科学学报》2020,17(10):2497-2511
The Diexi ancient dammed lake is in the upper reaches of the Minjiang River. Six terraces with lacustrine sediments occur at the base. These terraces are the products of the graded outburst of the Diexi ancient dammed lake. The outburst of the ancient dammed lake would certainly have had an impact on the Chengdu Plain in the lower reaches of the Minjiang River. In this paper, on-site sampling and laboratory analysis were used to analyze the sediments of the Diexi ancient dammed lake and the Jinsha site in Chengdu Plain, and the environmental indicators of each sediment layer were tested. Through a comparative analysis of the environmental indicators in the sediments at the two locations, the following results were obtained: the palaeoclimatic and palaeoenvironmental characteristics at the two locations generally show consistent changes. The most important finding is that the types and content of the major pollen taxa at the two locations are similar. The Pinus content strongly proves that the soil layers at the Jinsha site was sourced from the upper reaches of the Minjiang River. Considering that the demise of the ancient culture at the Jinsha site occurred close in time to the outburst of the ancient dammed lake, this similarity suggests that the cultural change at the Jinsha site may have been related to the outburst of the Diexi ancient dammed lake.  相似文献   

4.
The building of Shuikou Hydropower Station in the Minjiang River is the largest one in the region of east China. Its install capacity is 1.4 million kw., and its generated energy of planning is 4.95 billion kwh each year. In accordance with a comprehensive survey of the valley of the middle-lower reaches of the Minjiang River and the characteristic of hydrography and in association with the specific type of the hydrography station, we can be sure that no harm will be done to the ecological environment when a hydropower station is built at Shuikou. Not only the deposition of silt within the reservoir must not be very serious, it is also more favorable than before for the irrigation of farmland on plains in the lower reaches of the Minjiang River and inland navigation.In addition, after the completion of the power station, the ecological environment will be the same as before both at the Minjiang River estuary and beyond it.  相似文献   

5.
肖笃宁,赵羿,郭林海LANDSCAPEPATTERNCHANGESINWESTSUBURBSOFSHENYANG¥XiaoDuning;ZhaoYi;GuoLinhai(InstituteofAppliedEcology,theChineseAcad...  相似文献   

6.
The Yellow River Delta wetland is the youngest wetland ecosystem in China's warm temperate zone. To better understand how its landscape pattern has changed over time and the underlying factors responsible, this study analyzed the dynamic changes of wetlands using five Landsat series of images, namely MSS(Mulri Spectral Scanner), TM(Thematic Mapper), and OLI(Operational Land Imager) sensors in 1976, 1986, 1996, 2006, and 2016. Object-oriented classification and the combination of spatial and spectral features and both the Normalized Difference Vegetation Index(NDVI) and Normalized Difference Water Index(NDWI), as well as brightness characteristic indices, were used to classify the images in eCognition software. Landscape pattern changes in the Yellow River Delta over the past 40 years were then delineated using transition matrix and landscape index methods. Results show that: 1) from1976 to 2016, the total area of wetlands in the study area decreased from 2594.76 to 2491.79 km~2, while that of natural wetlands decreased by 954.03 km~2 whereas human-made wetlands increased by 851.06 km~2. 2) The transformation of natural wetlands was extensive: 31.34% of those covered by Suaeda heteropteras were transformed into reservoirs and ponds, and 24.71% with Phragmites australis coverage were transformed into dry farmland. Some human-made wetlands were transformed into non-wetlands types: 1.55% of reservoirs and ponds became construction land, and likewise 21.27% were transformed into dry farmland. 3) From 1976 to 2016, as the intensity of human activities increased, the number of landscape types in the study area continuously increased. Patches were scattered and more fragmented. The whole landscape became more complex. In short, over the past 40 years, the wetlands of the Yellow River Delta have been degraded, with the area of natural wetlands substantially reduced. Human activities were the dominant forces driving these changes in the Yellow River Delta.  相似文献   

7.
黄河三角洲人类干扰活动强度变化及其景观格局响应   总被引:1,自引:0,他引:1  
本研究以湿地变化较为剧烈的黄河三角洲为研究对象,基于RS技术和GIS空间分析方法,利用人为干扰度模型,结合区域人工沟渠建设情况,从区域和局地两个尺度直观揭示人类干扰强度时空分异特征,并探究区域景观格局对人类干扰活动的响应,以期为黄河三角洲滨海湿地生态保护与人类活动调控提供决策支持。结果表明:① 1995-2015年现代黄河三角洲区域人为干扰度和人工沟渠密度均明显增加,空间分布呈现从西南部向东部、北部,自内陆向沿海的扩展趋势;② 随着人类活动强度增强,研究区自然湿地面积减少,区域景观多样性和空间异质性增加,景观整体连通性减弱,景观复杂性降低;③ 景观格局对人类干扰强度变化的响应关系呈现出地区和时间差异;人类干扰活动强度相对较低的保护区受人工沟渠建设的影响,也呈现出斑块团聚程度降低、景观多样性增加和景观复杂性降低的变化趋势;④ 人为干扰度指数和人工沟渠密度指标互为补充,互相印证,可以较为全面、客观地反映黄河三角洲地区人类干扰活动强度。  相似文献   

8.
城市边缘区位于城市与乡村之间的过渡交接地带,既是城市扩张的前沿,也是城乡建设和用地置换中最具活力的地区。准确识别城市边缘区的空间范围一直是城市空间结构研究的核心问题,有助于从城乡对比的角度来衡量城市化程度。本文以城市边缘区的空间突变特征为切入点,基于格网尺度评价构建基于多源数据的城市边缘区特征识别指标,然后采用小波变换检测进行特征值突变点群的识别,并利用基于Delaunay的自动边长阈值的边界提取算法识别突变点群内外边界,从而实现了一种基于空间突变特征的城市边缘区提取方法。最后,以江阴市作为研究区进行了实证分析,并将本文方法提取结果与通过信息熵模型和土地利用程度综合指数模型提取城市边缘区的经典方法提取结果进行对比,经典方法所提取的城市边缘区结果更为混乱分散,而本文结果更为完整客观。将本文方法提取结果与使用土地利用数据与行政区划统计年鉴数据构建城市边缘区识别指标进行突变检测的不同指标方法提取结果进行对比,二者重叠度达88.03%,体现了本文方法的正确性,而从局部细节分析来看,本文结果更符合实际情况。为了更好地验证本文方法的有效性,利用景观格局指数对本文方法和不同指标方法提取的城市建成区、城市边缘区和乡村腹地的范围进行检验:从斑块类型层级指数分析, 2种方法划定的区域都具有典型的空间特征;而从景观层级指数分析,本文识别出的边缘区所计算的斑块密度、最大斑块指数、景观分离度、景观破碎化指数和香农多样性指数均高于对比方法,而蔓延度和香农均匀度均低于对比方法,说明本文识别的城市边缘区范围内景观破碎化程度和异质性更高,景观分布不均匀,社会经济条件更复杂,从而证明了本方法的有效性,尤其适合于非闭合环状的城市边缘区的提取。  相似文献   

9.
A quantitative analysis of the spatial pattern of rural settlements in the upper reaches of the Minjiang River was made with the major data sources being the relevant ETM image and the national geographical database of China (including contour line, river and road) at the scale of 1:250 000, and using image interpretation and field investigation to obtain spatial information on rural settlements. The results of the spatial analysis technique of GIS and correlation analysis showed that most settlements (78.2 %) were located in the mountain area at 1500 ∼ 2700 m altitude, and almost half in the arid valley area. More than 80.0 % of settlements had their slopes above 15°. Most settlements had good access to water resources, roads and communications, and tended to cluster close to the road network rather than the river. About half of the rural settlements in the study area were relatively concentrated, while the others were decentralized. Those with higher altitude usually had land with steep slope, inconvenient water and road accesses, and were located far apart from each other. In view of such a situation, further research should be done to make reasonable countermeasures on these settlements for better living conditions and ecosystem stability.  相似文献   

10.
目前,利用DEM衍生的地貌参数对大面积区域构造活动进行量化分析的研究相对较少。本文以岷江上游流域为例,利用ASTER GDEM数据和GIS技术,提取了该流域面积高程积分值(HI)、河长坡降指数(SL )、流域盆地不对称度(AF)、盆地形状指数(BS)、谷底宽度与谷肩高度比(VF)和水系分维数(FD)6种地貌参数,对其进行了等级划分,并量化了研究区相对构造活动强度(IAT)。结果显示:岷江上游流域有较高的SL、AF、BS值,较低的VF及FD值,中等HI值,其IAT值为1.33,分类等级为1级,表明该流域侵蚀程度强烈, 流域形态狭长, 河谷呈V型形态,受构造活动影响显著,地貌发育处于幼年期晚期,中年期早期。研究结果与区域地质背景较为吻合,该方法可为进一步探讨区域构造活动差异性提供新的手段。  相似文献   

11.
悬浮物浓度(TSM)是水生态环境评价的重要参数之一,及时掌握河流悬浮物浓度动态变化信息对于内陆水质监测、水环境治理是十分必要的。本研究基于野外实测光谱和悬浮物浓度数据,筛选与悬浮物浓度高度相关的波段组合反射率作为自变量,基于CatBoost、随机森林和多元线性回归算法构建悬浮物浓度遥感反演模型,采用带交叉验证的网格搜索法分别对CatBoost和随机森林2种机器学习模型进行超参数调优,确定模型最优参数配置,并对比不同模型反演精度,确定最优模型。基于最优模型,利用2019—2020年多时相Sentinel-2 MSI遥感影像,反演闽江下游悬浮物浓度,并分析其时空变化特征。结果表明:① b4/b3、(b6-b3)/(b6+b3)、(b4+b8)/b3、(1/b3-1/b4)×b5是MSI反演闽江下游TSM浓度的最佳波段组合反射率; ② 对比其他2种模型,基于超参数优化的CatBoost算法建立的悬浮物反演模型精度最高,其决定系数R²为0.95,均方根误差RMSE和平均绝对百分比误差MAPE分别为15.32 mg/L和19.68%; ③ 2019—2020年闽江下游悬浮物浓度分布“西低东高”,白沙至琅岐入海口呈升高趋势;④ 悬浮物浓度夏季最高,冬季和秋季次之,春季最低。本研究可为闽江下游悬浮物浓度监测及时空变化分析提供一种有效的技术手段和理论参考。  相似文献   

12.
As an important indicator of the structural and functional stability of wetland landscapes, hydrological connectivity plays an important role in maintaining the stability of wetland ecosystems. Large-scale human activities have led to significant changes in the hydrological connectivity pattern of wetlands in Naoli River Basin since 1950 s. Combined with the availability of wetland habitat and the spreading capacity of aquatic birds, hydrological connectivity indices of marsh wetlands were calculated in the studied area, and the temporal and spatial changes were analyzed from 1950 s to 2015. The results indicate that:(1) the hydrological connectivity index of the marsh wetlands shows a growth trend with increasing distance threshold. All patches of marsh wetlands linked together when the distance threshold reached 35--40 km;(2) the optimal distance of hydrological connectivity is about 10 km for marsh wetlands of whole Naoli River Basin;(3) the total hydrological connectivity of marsh wetlands decreased in the Naoli River Basin from 1950 s to 2015. Although the hydrological connectivity index increased after 2005, the fragmentation of the landscape has not been improved. The analysis of the wetland hydrological connectivity can provide a scientific basis for the ecological restoration and protection of the wetland in the Naoli River Basin.  相似文献   

13.
全面、客观地反映土地动态变化有利于正确认识对土地资源的开发和利用,能为地区产业结构调整,制定可持续发展的土地管理和土地规划提供依据。多时相遥感数据已经被成功运用于研究土地变化,评估前期政策对环境和土地利用的影响[1~5]。在遥感和GIS技术支持下,分析了岷江流域上游地区的土地利用/土地覆被状况及其1986~2000年的时空动态变化和驱动力影响。为保护该地区有限的珍贵林业资源,恢复长江上游的生态屏障作用和国土资源的有效可持续利用提供决策依据。  相似文献   

14.
In this study, remote sensing data of Wuhan City,, Hubei Province, China in 1996-2001 were selected to extract wetland landscape information. Several landscape indices were used to evaluate the changes of landscape pattern within the five years, including patch number, patch density, patch fractal dimension, landscape diversity, dominance, evenness, and fragmentation indexes. Then, transformation probabilities of wetland landscapes into non-wetland landscapes were calculated based on Markov Model, and on these grounds the relationship between changes of wetland landscape pattern and urban construction was analyzed. The results showed that fragmentation degree of all wetland types increased, lake area declined, and dominance of natural wetland decreased. The reasons for these results were mainly because of urban construction. According to the features of abundant wetland in Wuhan City, we suggested that protection of wetland landscape should cooperate with urban construction, which means wetland should become important part of urban landscape.  相似文献   

15.
山区城镇扩张受山区地形和山地灾害等因素限制,而常用的土地利用模型难以有效表达这一特征。本文通过对Dyna-CLUE(Dynamic Conversion of Land Use and its Effects Model)模型进行改进并结合系统动力学(System Dynamic,SD)模型,充分发挥这2个模型在微观土地分配,及宏观情景模拟上的优势,很好地表达了山区地形和山地灾害等因素对山区城镇扩张的限制作用,为山区城镇扩张情景模拟提供了一个有效的方法。以岷江上游地区为例,根据研究区历史统计数据构建山区城镇用地SD模型,模拟低速发展、惯性发展和高速发展3种不同发展情景下城镇用地的需求,结合Dyna-CLUE改进模型,预测了对应情景下2011-2030年的城镇用地范围,并探究其对其他土地利用类型的影响。结果表明,发展速度越快,城镇主体越快达到地理限制区域的上限,并开始沿山间平地向两端扩张。耕地受山区城镇扩张的影响要远远超出其他土地利用类型,离城镇越近受影响越大。随着城镇扩张的加剧,其对自然环境的影响也逐渐增大。模型模拟结果能为山区城镇用地规划、评估由城镇扩张造成的生态环境问题和制定相应的对策提供有效的技术支撑。  相似文献   

16.
Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats.In this study,we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province,China.The results showed landscape connectivity levels(Probability of Con-nectivity(PC)) decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation.First level roads affected landscape connectivity most significantly.At a distance of 100 m,the PC index decreased more than 50%.Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis.In addition,we conducted a graph the-ory and a least-cost modeling discussion,it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement.Network analysis offers a quantitative and simple but effective tool for ecological process assess-ment and biological conservation on large scales.  相似文献   

17.
全面准确地分析中国建设用地空间格局,是衡量城市景观的生态环境效应和制定区域发展战略的重要依据。为此,本文基于空间分辨率为12 m的2012年的全球城市足迹数据,分别在国家、经济区和城市群量化了中国建设用地空间格局。结果表明,12 m分辨率的数据能更细致和准确地刻画中国建设用地的特征。2012年中国建设用地面积为1.73×105 km2,占中国陆地总面积的1.81%。从建设用地的空间格局来看,城市群尺度的建设用地破碎度最高,其建设用地平均斑块密度分别是国家和经济区平均水平的3.66倍和1.62倍。进一步分析表明,社会经济和地形因素共同影响建设用地空间格局。今后,应针对建设用地空间格局破碎问题,因地制宜地制定合理的措施,推动中国建设用地的合理发展。  相似文献   

18.
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。  相似文献   

19.
快速城市化地区交通主干道对景观格局变化的影响   总被引:1,自引:0,他引:1  
交通主干道建设对两侧景观格局变化有着深远的影响,探索其影响机制对道路生态环境评价和区域可持续发展规划具有重要指导意义。本文以京沪高速公路(简称G2)为例,利用TM遥感影像,提取出1995、2000、2005和2010年长江三角洲地区土地利用/覆被图。同时,用缓冲区分析和景观生态学方法,分别计算不同时段和地域段G2缓冲带景观数量结构特征指数和景观格局指数变化率;并结合相关分析和非线性回归方法研究指数变化率与缓冲带距离的关系,据此判断G2对沿线景观格局变化的影响程度和范围。研究结果表明:(1)G2沿线地区景观格局变化程度与缓冲带距离呈现显著的负相关性,G2对景观格局变化的影响呈现明显的“轴带”规律;(2)G2对沿线景观格局变化的影响范围比自然生态脆弱区的道路建设更广,2000-2005年为6 km,2005-2010年扩大到9 km;(3)从整体来看,2005-2010年间的景观数量结构特征指数相关系数明显高于2000-2005年间,而景观格局指数相关系数则相反,“轴带”影响存在时间差异性;(4)从不同区域段来看,苏北和苏南段景观动态度相关系数均高于上海段,在城市化水平较低的地域段,“轴带”影响更加显著;(5)通过对比道路沿线地区不同时段、不同地域段的相关景观特征指数变化率,并结合缓冲带分析和数量统计方法,较好地评估了交通主干道对沿线景观格局变化的影响程度和范围。  相似文献   

20.
Based on literature and survery data of fish composition collected by bottom trawl investigation from 2006 to 2007 infour main estuaries of China southeastern coastal areas and their adjacent waters,changes of the taxonomic diversity across spatialand temporal scales of fish community were analyzed by taxonomic diversity indices.The results are as follows:a total number of1397 fish species(including some freshwater species),belonging to 2 classes,42 orders,186 families and 593 genera,were collected inthe studied sea areas.The species richness increased with lower latitudes,particularly so with Perciformes.There were 339 fish spe-cies in the Yangtze River Estuary and adjacent waters,belonging to 2 classes,31 orders,101 families and 231 genera.There were 535fish species in the Minjiang River Estuary and adjacent waters,belonging to 2 classes,33 orders,133 families and 323 genera.A totalnumber of 803 fish species were collected in the Jiulongjiang River Estuary and adjacent waters,which belonged to 2 classes,35 orders,155 families and 419 genera.And 1021 fish species which belonged to 2 classes,32 orders,153 families,and 466 genera were collectedin the Pearl River Estuary and adjacent waters.The numbers of orders and families of fish species from the northern to the southern wa-ters first increased and then decreased.The average variation in taxonomic distinctness(Λ+)gradually decreased with lower latitudes inthe four estuaries and adjacent waters.There were no significant differences in the average taxonomic distinctness(△+)among the fourestuaries and adjacent waters,and fish fauna were closely related with each other,and all of them belonged to the same zoogeographicalfauna(Indian-Malaysia fauna).Fish composition in the Minjiang River Estuary and adjacent waters was more similar to that in the Jiu-longjiang River Estuary and adjacent waters among the four estuaries.Compared with the historical data,the average taxonomic dis-tinctness of fish community showed a great decrease in the Minjiang River Estuary and the Jiulongjiang River Estuary and their adjacentwaters.  相似文献   

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