首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 562 毫秒
1.
Physical habitat is the living space of in-stream biota which is an important factor that can affect both the quality and quantity of available habitat and the structure and composition of resident biological communities. It is a spatially and temporally dynamic entity determined by the interaction of the structural features of the channel and hydrological regime. Ganjal River is a left bank tributary of River Narmada and Morand river is the major tributary of it. At these rivers Physical Habitat Assessment was carried out using USEPA Rapid Bioassessment Protocols to know habitat suitability conditions in rivers for aquatic life thrive in. In the study habitat assessment parameters were scored according to the existing conditions for each section of the rivers and were categorised under four conditions i.e. optimal, suboptimal, marginal and poor. On the basis of result obtained from the study Habitat Suitability Map (HSM) was generated using GIS as an interface and it suggests that the habitat quality of both rivers is suitable for aquatic life.  相似文献   

2.
Habitat analysis for sambar in terms of food, cover, water, space and extent of edge in Corbett National Park using remote sensing and GIS has been attempted. Other physical parameters include climate, topography, fire history, disturbance regimes, weeds etc. IRS-IB LISS II data (FCC, hardcopy) on 1:50.000 scale was interpreted to generate vegetation cover and density map. Other maps showing drainage, water bodies, roads, human habitations and contours were prepared using Survey of India topographical maps. During evaluation of sambar habitat information regarding habitat parameters and their tolerance was collected from existing literature as well as during field observations. Twenty-two transects of one km. length were laid down in all the strata randomly to collect information regarding the structure and composition of the forest and also habitat use (direct and indirect evidences) by sambar. This was then integrated using condition-based equations in the GIS domain to generate suitability maps. Actual sightings on the ground to a large extent supported the results.  相似文献   

3.
Rivers flowing through the alluvium invariably have very low gradient forcing the river to flow slowly in a meandering and zigzag path. Nature and intensity of meandering is governed by the geological and tectonic conditions of the river basin. Barak River in tectonically active south Assam (Northeast India) exhibits intense meandering and shifting of the river course. Topographic data of two different years and satellite images of 4 different years covering a section of the Barak River have been investigated to verify the nature of changes undergone by the river through times. This study reveals active northward shift of the river and a prominent neck-cut off in the initial part of the study area. Northward shift of the river also occurred in the area west of Silchar. But, in the western part the river has shifted both towards north and south. Oscillatory shifting in the river channel has also been noticed. The river has shown a overall northward shift which is probably due to uplift of the southern part of the Barak River valley.  相似文献   

4.
据遥感影像揭示,除气象因素外,黄河与淮河洪泛形成主要受近代和现代活动构造控制。据分析,黄河下游现行河道存在一定程度隐患,部分河道稳定性较差,淮河中上游地区是现代沉降区,洪水壅滞难泻,对京九铁路及黄淮下游人民生命财产构成威胁  相似文献   

5.
建设黄河“智能大脑”服务流域生态保护和高质量发展   总被引:1,自引:0,他引:1  
本文首先介绍了黄河流域水文、地理景观和地貌特征,下游河道变迁和河口变迁历史及生态治理,流域历史水旱灾害等基本背景,分析了黄河流域生态保护和高质量发展面临的主要问题和具有的优势。然后重点论述黄河“智能大脑”如何服务流域保护和发展,提出黄河“智能大脑”三要素,即感知系统(天地一体智能感知网)、存储管理系统(资源池)和操作系统(时空大数据平台);论述了流域一体化时空大数据中心的构成及其基本功能,时空大数据平台及其目标要求,分析并提出了基于网格集成与弹性云的混合式时空大数据平台技术体制和构建技术,提出采用“共用时空大数据平台+”应用概念模型及其具体应用模式。最后讨论了时空大数据平台服务黄河流域城市数字化、网络化和智能化,加强流域上中下游7大城市群的新型智慧城市建设,推动流域生态保护和社会经济发展,提出基于流域时空大数据平台构建服务保护和发展的综合科技信息咨询服务平台,支撑流域协同创新共同体构建,增强流域整体性和协同性发展。  相似文献   

6.
Traditionally, analyses of relationships between amphibians and habitat focused on breeding environments (i.e., pond features) more than on the features of the surrounding environment. Nevertheless, for most amphibians the terrestrial phase is longer than the aquatic phase, and consequently landscape features (i.e., habitat mosaics) may have an important role for modelling amphibian distribution.There were different aims in this analysis. Firstly, we compared the effectiveness of the information provided by land cover/use (LC/LU) classes and habitat classes defined according to a new habitat taxonomy named General Habitat Category (GHC), which is based on the concept of biological forms of dominant vegetation and class naturalness. The GHC map used was obtained from a pre-existing validated LC/LU map, by integrating spectral and spatial measurements from very high resolution Earth observation data according to ecological expert rules involving concepts related to spatial and temporal relationships among LC/LU and habitat classes.Then, we investigated the importance for amphibians of the landscape surrounding ponds within the Italian Alta Murgia National Park. The work assessed whether LC/LU classes in pond surrounds are important for the presence/absence of amphibians in this area, and identified which classes are more important for amphibians. The results obtained can provide useful indications to management strategies aiming at the conservation of amphibians within the study area. An information-theoretic approach was adopted to assess whether GHC maps allow to improve the performance of species distribution models. We used the Akaike's Information Criterion (AICc) to compare the effectiveness of GHC categories versus LC/LU categories in explaining the presence/absence of pool frogs. AICc weights suggest that GHC categories can better explain the distribution of frogs, compared to LC/LU classes.  相似文献   

7.
Satellite remote sensing technique can be effectively utilised in mapping and monitoring the river course changes and associated geomorphological features. Ravi river, flowing along the Indo-Pakistan border, has been in the limelight for its repeated flood havoc during monsoon and abrupt encroachment at some places in the Indian territory, where it was not flowing earlier. This river, meandering in zig-zag fashion along the International boundary in Amritsar and Gurdaspur districts of Punjab, poses perennial threats to the nations’s economy due to extensive destruction happening every year. An attempt has been made to map the shift of this river and the associated geomorphological features along its course using the Indian Remote Sensing Satellite data (IRS-IA and IB LISS-IIFCC) of the period 1991–1993 and the Survey of India topographic sheets of the period 1972–1973. The study shows that there has been drastic changes in the course of Ravi during a span of 20 years due to human activities along its course. The river has shifted its course considerably towards India since its topography is against it. River training structures/bundhs, built by the neighbouring country, across and very near to the earlier river course has been the main reason for this drastic shifting. It is estimated that such massive structures could turn the river course towards India by atleast 1 to 5 km in the border districts of Punjab. This shifting of Ravi along international border poses a serious threat to the Nation’s defence system.  相似文献   

8.
The remote sensing technology has been widely used for mapping the vegetation types in the tropical landscapes. However, in the temperate and alpine arid regions of India very few studies have been conducted using this technique. In the mountainous temperate arid conditions the vegetation is largely confined to marsh meadows, streams courses, river valleys and moist pockets close to snowfields. The ground truth collection in these zones are physically challenging due to tough terrain and restricted mobility. The detailed mapping of vegetation and other land use classes in these areas is therefore, extremely difficult. This paper describes the use of IRS-ID LISS III sensor for deciphering land cover details Nubra Valley, northern portion of Ladakh Autonomous Hill Council, Jammu & Kashmir (India). This analysis essentially emphasizes in bringing out various vegetation classes (speciallyHippophae rhamnoides and other medicinal plant communities) along the narrow river valleys.  相似文献   

9.
度量映射方法在河流分维测算中的应用   总被引:1,自引:0,他引:1  
应用TM卫星图像数据,根据对黑龙江省阿什河约80km河段、松花江及嫩江约2300km河段的分维研究。证明了在度量数列满足持邻性和等比收敛性的条件下。可以应用度量映射方法计算随机分形集的分维。研究表明,黑龙江省阿什河河段(约80km)的分维比松花江和嫩江河段(约2300km)的分维高;曲线的分维一定要与标度的变化区间联系起来,否则分维将失去可比性;河流的分维不仅与标度有关,还与矢量化时原图像的分辨率有关。  相似文献   

10.
India has a rich repository of flora and fauna, but the rapid decline of wildlife and threat to its habitat has been a serious cause of concern. Hence, protected areas have been set up to achieve specific conservation objectives to facilitate timely and reliable information on forest types and its composition, degradation status and their suitability for different species of flora and fauna. In the present study, evaluation of tiger habitat in Corbett Tiger reserve is carried out using remote sensing, ground and other ancillary sources and is integrated using GIS using multi-criteria model. The results indicated that sal, mixed sal, miscellaneous forest, plantation, grassland, agriculture and scrub land are the major land use/land cover types and majority of the study area is covered under dense forest. Tiger habitat suitability analysis showed that large proportion of the area (51.4%) was found to be highly suitable followed by moderately suitable area (31%). Further, the correlation drawn between range-wise suitability area and actual tiger population in Corbett Tiger Reserve CTR indicated a positive correlation of 0.73. Disturbance to wildlife habitat, vegetation degradation and shrinking passage corridor are the major concern in CTR.  相似文献   

11.
Sustainable management of wetland ecosystem is necessary as it serves the important functions such as food storage, water quality maintenance and providing habitat for different species of wildlife. Hence, an inventory of wetlands in any given area is a pre-requisite for their conservation and management. A study has been carried out to delineate the wetlands of east Champaran district of Bihar, India, using IRS ID LISS III data. The data for the pre and post monsoon seasons have been analysed and the wetlands have been qualitatively characterized based on the turbidity and aquatic vegetation status. The extent of water logging problem in the study area was inferred from the seasonal variation of waterspread during both the seasons. The three categories of wetlands (ponds/lakes, water logged areas and oxbow lakes) have been identified. From the analysis, it has been observed that the inland wetlands constitute 2.7% of the study area, of which 1.8% is subjected to water logging. Thus, this study highlights the usefulness of remotely sensed data for wetland mapping, seasonal monitoring and characterization.  相似文献   

12.
黄河下游河道地貌分形分维特征研究   总被引:7,自引:2,他引:5  
黄河下游河道地貌特征是影响河流水动力地质作用和悬河稳定性的主要因素之一,本文首次采用遥感与GIS相结合的方法对黄河下游河道地貌进行了定量的分形分维研究。研究结果表明:①度量尺度由0.1km增大至100km,河床的分形弯曲度随由1.54减小为1.11,且不同河段的分形弯曲度不同;②河床浅滩数量与大小呈单对数线性相关关系,但是由1986年至2000年表现出规律性变化;③悬河的稳定性随不同河段河床分维值D值的增大而降低。  相似文献   

13.
基于ArcEngine的GIS三维功能开发技术研究   总被引:2,自引:0,他引:2  
介绍ArcEngine支持的开发平台、开发模式和它的技术内核,着重介绍了ArcEngine中三维可视化功能的实现。利用ArcEngine技术在VC 开发环境下编程实现河道整治的数字化管理为示例,探讨如何对数字河道进行分析、维护和处理,为河道整治工作提供更直观、便捷的工具。  相似文献   

14.
Geospatial presentation of habitat has become a key issue for planning conservation and management of any ecosystem. Hokersar wetland, one of the best resorts of migratory waterfowl in Kashmir, is under anthropogenic pressure and siltation due to floods. This has resulted in the degradation and change in the habitat quality of varied aquatic flora and fauna. Moreover, the seasonal changes affect the water level and land cover characteristics of the landscape. In the present study temporal mapping of the wetland has been carried out using the data sets for the autumn and spring seasons to assess the land cove/land use dynamics. The temporal change analysis, in the urban sprawl and the wetland, has been carried out to assess the rate of changes in the wetland and its environs. The wetland initially comprised of patch of marshy waterfowl habitat with some open water bodies. It has been fragmented into a large number of land uses because of anthropogenic activities. The increase in the settlement has been observed proportionate to the rate of fragmentation in the wetland. This study has created an information base, which will help to design conservation schemes for long term maintenance of the wetland.  相似文献   

15.
Ardeotis nigriceps, commonly known as Great Indian Bustard (GIB), is a Critically Endangered, Evolutionary Distinct and Globally Threatened (EDGE) and endemic species to the Indian subcontinent. GIB is under tremendous threat in its last strongholds and sliding inextricably towards extinction. The GIB sanctuary in Maharashtra (India) is one of the last refuges of the bird constituting an area of 8496 km2 spread over in seven talukas of Solapur and Ahemednagar districts. Major portion of the sanctuary (94.3 %) consists of privately owned lands under a variety of economic vocations and large number of villages and townships. In view of the legal restrictions relating to Protected Area under the Wildlife (Protection) Act of India 1972, the inhabitants of villages and townships faced a very difficult situation regarding use of their lands, development of properties and deriving benefits from planned local and regional development. This created conflict between local people and the forest department over the use of land, which necessitated the rationalization of the sanctuary. The objective of the present study was to map the suitable habitat of GIB in GIB Wildlife Sanctuary as an input for the realignment of the GIB Sanctuary by identifying areas that are important for the GIB. Main parameters considered for the habitat suitability assessments are, habit and habitat of GIB, slope, minimum patch size and disturbance sources. Based on the criteria derived for the ecological and biological requirements of GIB, binary deductive habitat suitability modeling has been done using remote sensing and GIS and prioritized the potential habitats of GIB. The net area of important suitable habitat of GIB in GIB sanctuary is 2304.99 km2 out of 8496.44 km2. The output of the present study has been used as an input by the committee (set by Honorable Supreme court of India) on rationalization of the GIB Sanctuary and the sanctuary has been rationalized with an area of 1222 km2.  相似文献   

16.
The reliability of habitat maps that have been generated using Geographic Information Systems (GIS) and image processing of remotely sensed data can be overestimated. Habitat suitability and spatially explicit population viability models are often based on these products without explicit knowledge of the effects of these mapping errors on model results. While research has considered errors in population modeling assumptions, there is no standardized method for measuring the effects of inaccuracies resulting from errors in landscape classification. Using landscape‐scale maps of existing vegetation developed for the USDA Forest Service in southern California from Landsat Thematic Mapper satellite data and GIS modeling, we performed a sensitivity analysis to estimate how mapping errors in vegetation type, forest canopy cover, and tree crown size might affect delineation of suitable habitat for the California spotted owl (Strix occidentalis occidentalis). The resulting simulated uncertainty maps showed an increase in the estimated area of suitable habitat types. Further analysis measuring the fragmentation of the additional patches showed that they were too small to be useful as habitat areas.  相似文献   

17.
The Natura 2000 network of protected sites is one of the means to enable biodiversity conservation in Europe. EU member states have to undertake surveillance of habitats and species of community interest protected under the Habitat Directive. Remote sensing techniques have been applied successfully to monitor biodiversity aspects according to Natura 2000, but many challenges remain in assessing dynamics and habitat changes outside protected sites. Grasslands are among the most threatened habitats in Europe. In this paper we tested the integration of expert knowledge into different standard classification approaches to map grassland habitats in Schleswig Holstein, Germany. Knowledge about habitat features is represented as raster information layers, and used in subsequent grassland classifications. Overall classification accuracies were highest for the maximum likelihood and support vector machine approaches using RapidEye time series, but results improved for specific grassland classes when information layers were included in the classification process.  相似文献   

18.
石振武  李驰 《测绘通报》2021,(11):106-109,114
针对建设绿色公路不可避免地对路域生存环境质量造成影响的问题,本文选用Landsat 8卫星影像、ASTER GDEM 30 m分辨率的DEM数据、2020版30 m全球地表覆盖数据,利用ENVI 5.3和ArcGIS 10.2平台协同操作,从公路的路域植被覆盖度变化、土壤侵蚀度、生存环境适宜性3个角度分析对生存环境质量的影响。研究结果表明,公路建设前后路域植被覆盖度超75%区域从2 673.8 km2降至2 389.82 km2,植被覆盖度为45%~75%的区域从997.31 km2降至767.19 km2;土壤侵蚀程度以中度侵蚀和高度侵蚀为主,中度侵蚀和高度侵蚀总计面积3 927.99 km2,占比达79.04%;生存环境适宜性方面,公路左侧呼玛河流域及附近最高,公路右侧的林区大面积图斑块次之。  相似文献   

19.
Ghagghar river in the alluvial plains of Punjab and Haryana, north-west India exhibits the phenomenon of avulsion in its middle and lower reaches. Study of aerial photographs shows that it has abandoned a 25 km long meander belt between Badshahpur and south of Jaswantpura which lies to the north of the present channel. The present channel course lies at a lower elevation on the flood plain away from the levee deposits which acted as an alluvial ridge.  相似文献   

20.
The transport of the sediment, carried in suspension by water, is central to hydrology and the ecological functioning of river floodplains and deltas. River discharge estimation is useful for demonstrating this information. In this study, we extracted MODIS reflectance values from a pixel near the river mouth after carrying out the simple atmospheric correction method, then applied single regression analysis to reflectance values and the in situ discharge of Naka River in Tokushima prefecture and Monobe River in Kochi prefecture, Japan. MODIS images and in situ data were taken from January through December, 2004. As a result, both in Naka River and Monobe River, robustly positive relationships between the discharges observed in situ and remotely sensed MODIS reflectance data in the region of river mouth were found throughout the year. In addition, we estimated monthly and annual average discharge from the MODIS reflectance with the regression formula. As a result, in situ average discharge was well estimated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号