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1.
This paper describes the spatiotemporal changes pertaining to land use land cover (LULC) and the driving forces behind these changes in Doodhganga watershed of Jhelum Basin. An integrated approach utilizing remote sensing and geographic information system (GIS) was used to extract information pertaining to LULC change. Multi-date LULC maps were generated by analyzing remotely sensed images of three dates which include LandSat TM 1992, LandSat ETM+ 2001 and IRS LISS-III 2005. The LULC information was extracted by adopting on-screen image interpretation technique in a GIS environment at 1:25,000 scale. Based on the analysis, changes were observed in the spatial extent of different LULC types over a period of 13 years. Significant changes were observed in the spatial extent of forest, horticulture, built-up and agriculture. Forest cover in the watershed has decreased by 1.47 %, Agricultural by 0.93 % while as built-up area has increased by 0.92 %. The net decrease in forest cover and agriculture land indicate the anthropogenic interference into surrounding natural ecosystems. From the study it was found that the major driving forces for these changes were population growth and changes in the stream discharge. The changes in the stream discharge were found responsible for the conversion of agricultural land into horticulture, as horticulture has increased by 1.14 % in spatial extent. It has been found that increasing human population together with decreasing stream discharge account for LULC changes in the watershed. Therefore, the existing policy framework needs to focus upon mitigating the impacts of forces responsible for LULC change so as to ensure sustainable development of land resources.  相似文献   

2.
Assessment of soil loss through Sediment Yield Index (SYI) is important for watershed planning, prioritization, and development. In the absence of measured sediment data, SYI expressing the relative sediment yield from different basins work as a basis for grading another basin to adopt erosion control measures. An attempt was made to evaluate SYI in wider scale by using cost-effective tools like remote sensing and geographical information system (GIS). SYI was calculated for Madia subwatershed, which consists of 29 microwatersheds and located in Sagar District, Madhya Pradesh (M.P.) The IRS LISS III data and Shuttle Radar Topography Mission (SRTM) digital elevation models (DEM) of 90-m resolution were used to identify land use characteristics and geomorphometric analysis. Major land use was observed as agricultural land (24.7 %), water bodies (16.7 %), forest area (10.2 %), and settlement (21.3 %). In categorization, similar overall accuracy was observed for dense forest, barren land, settlement, and water bodies. The highest SYI with a value more than 20 was observed in microwatershed Mw6, Mw7, and Mw24, which comprises 33 % of the total watershed area. It gives the information about the watershed area that requires very high priority.  相似文献   

3.
Land and water resources development plans are generally adopted at watershed level. Delineation of watersheds and their prioritization within large river basins requires host of terrain parameters to be studied and analysed. Chopan watershed in Central India has been studied for sub-watershed delineation and prioritization based on drainage morphometry, land use/land cover and sediment yield index analysis using remote sensing and GIS techniques. The watershed was demarcated into five sub-watersheds on the basis of drainage flow directions, contour value, slope, elevation. Geocoded satellite data of 1989 and 2001 on 1:50 000 scale were visually interpreted to prepare land use/land cover and drainage maps which were later digitized using Arcview/ArcGIS. Linear and shape aspects of the sub-watersheds were computed and used for prioritization. The results show widespread variation in drainage characteristics, land cover changes and sediment yield rates across sub-watersheds. On the basis of morphometric, land use/land cover change and sediment yield index, sub-watersheds were grouped into low, medium and high priority. A correlation of results show that SW1 and SW5 are common sub-watersheds falling under high and low priority based on morphometric, land use change analysis and SYI. The priority list of sub-watersheds will be crucial for decision making and implementation of land and water resource conservation projects.  相似文献   

4.
This paper mainly deals with the integrated approach of remote sensing and Geographical Information System (GIS) to delineate groundwater prospective zones in Narava basin, Visakhapatnam region. The various thematic maps generated for delineating groundwater potential zones are geomorphology, geology, lineament density, drainage density, slope and land use/land cover (LULC). Weighted index overlay (WIO) technique is used to investigate a number of choice possibilities and evaluate suitability according to the associated weight of each unit. The integrated map of the area shows different zones of groundwater prospects, viz. very good (18.9% of the area), good (26.4% of the area), moderate (17.1% of the area) and poor (37.6% of the area). The categorization of groundwater potential was in good agreement with the available water column in the basin area.  相似文献   

5.
Jaggar watershed is a constituent of the Gambhir river basin, in eastern Rajasthan and covers an area of 352.82 km2, representing arid climate. The drainage network is dendritic to sub-dendritic pattern however parallel to sub-parallel has also developed locally. The Jaggar watershed has been divided into fourteen sub-watersheds, designated as SW1 to SW14, for prioritization purpose. The prioritization of the sub-watersheds has been done on the basis of morphometric analysis and land use/land cover categories. Various morphometric parameters (linear and shape) have been determined for each sub-watershed and assigned rank on the basis of value/relationship with erodibility so as to arrive at a compound value for final ranking of the sub-watersheds. Land use/land cover mapping has been carried out using IRS LISS III data of 1998. Based on morphometric and land use/land cover analysis and their ranks, the subwatersheds have been classified into four categories as very high, high, medium and low in terms of priority for conservation and management of natural resources. The prioritization results based on morphometry reveal that only SW7 and SW10 fall under very high priority, whereas SW6, SW11 and SW13 fall under very high priority on the basis of land use/land cover analysis. However on the integration of morphometry and land use/land cover only SW14 show common priority whereas rest have little or no correlation.  相似文献   

6.
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.  相似文献   

7.
闻国静  王妍  刘云根  侯磊 《中国岩溶》2022,41(2):249-258
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。   相似文献   

8.
The valley of Kashmir is blessed with abundant water resources. However, high population growth and concentration of population at favorable locations have resulted in increased demand for water. The problem is further aggravated in Lidder catchment where unplanned tourism development has resulted in deterioration of water quality. Multi-Criteria Evaluation (MCE) approach is adopted using IRS P6 LISS III satellite data 2010, geological map published by Geological Survey of India, toposheets prepared by Survey of India, 1961 and field observation. Seven thematic layers (slope, lineament density, drainage density, soil, geology, geomorphology and land use land cover) are generated in GIS environment and weighted according to their relative relevance to groundwater occurrence. Knowledge-based weights and ranks are normalized, and a weighted linear combination technique is adopted to determine the groundwater potential (GWP). The catchment is divided into five zones of very high, high, medium, low and very low GWP. The results show that 50.22% of the total catchment area, which is uninhabited, has very low GWP. However, the densely populated southern part of the catchment has moderate to very high GWP. The study demonstrates that MCE using remote sensing and GIS technology could be efficiently employed as a very useful tool for the assessment and management of groundwater resources especially in regions where data is poor.  相似文献   

9.
The frequency in occurrence and severity of floods has increased globally. However, many regions around the globe, especially in developing countries, lack the necessary field monitoring data to characterize flood hazard risk. This paper puts forward methodology for developing flood hazard maps that define flood hazard risk, using a remote sensing and GIS-based flood hazard index (FHI), for the Nyamwamba watershed in western Uganda. The FHI was compiled using analytical hierarchy process and considered slope, flow accumulation, drainage network density, distance from drainage channel, geology, land use/cover and rainfall intensity as the flood causative factors. These factors were derived from Landsat, SRTM and PERSIANN remote sensing data products, except for geology that requires field data. The resultant composite FHI yielded a flood hazard map pointing out that over 11 and 18% of the study area was very highly and highly susceptible to flooding, respectively, while the remaining area ranged from medium to very low risk. The resulting flood hazard map was further verified using inundation area of a historical flood event in the study area. The proposed methodology was effective in producing a flood hazard map at the watershed local scale, in a data-scarce region, useful in devising flood mitigation measures.  相似文献   

10.
Delineation of Lake Karoun watershed in Egypt was carried out and various watershed parameters and environmental characteristics were extracted using geographic information system and remote sensing. Environmental characteristics including normalized vegetation index (NDVI), moisture index, land surface temperature, and land use classes were obtained from high spatial resolution images (Landsat TM). Moreover, hydrological parameters, drainage flow directions, drainage networks, and catchments from digital elevation model have been delineated using the Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) satellite images. As a result, the lake's watershed characteristics including the environmental and hydrological factors for each watershed zone were presented and analyzed. The information generated would be of immense help in hydrological modeling of watershed for prediction of runoff and sediment yield, thereby providing necessary inputs for developing suitable developmental management plans with sound scientific basis.  相似文献   

11.
通过遥感影像解译获取伊通河流域1986、1996、2005和2017年土地利用数据,采用土地利用动态模型、土地利用度和生态系统服务价值等方法,研究伊通河流域土地利用变化特征及其生态响应。研究结果表明,耕地、城镇建筑用地和林地是伊通河流域主要的土地利用类型,1986—2017年间,研究区土地利用综合动态度降低,土地利用度上升,土地利用结构趋于稳定。在31年间,生态系统服务价值整体下降33.97%,林地、草地、湿地和水域面积的减小导致生态系统服务价值显著降低。  相似文献   

12.
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.  相似文献   

13.
应用集成的遥感识别技术进行土地利用变化分析   总被引：6，自引：0，他引：6  
以厦门市为研究区域,以1988-1998年为时间跨度,利用Landsat5TM遥感数据开展土地覆盖变化识别中多种遥感数据处理方法的集成应用研究。以后分类比较法的结果为基础,运用改进的差值法定义的"变化"目标进行修正,将两种方法有机集成综合地确定土地覆盖变化。根据变化前与变化后覆盖不同但土地利用方式相同或类似的原则进行合并处理,最后得到厦门市10年间土地利用结构变化各种成因类型及其数量。结果表明,10年间厦门市因城市化引起的土地覆盖变化为590．83km2,变化强度为31.14％,引起厦门市土地利用结构发生变化主要有 8种成因机制类型,面积达351.99km2,变化强度为18.55％。  相似文献   

14.
新一轮二滩电站库区遥感调查   总被引：1，自引：0，他引：1  
新一轮二滩电站库区遥感调查是在我国前20年滑坡、泥石流遥感调查技术方法基础上的一次革新。本文介绍了革新方法的数据源、工作平台、技术流程、及人机交互与自动分类相结合的遥感解译方法，并对获得的工作区滑坡、泥石流的数量、分布、特性及它们的环境背景作简要分析。  相似文献   

15.
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.  相似文献   

16.
大兴安岭地区森林覆盖严重, 气候严寒, 交通极为不便, 野外有效工作时间短, 给区域地质矿产调查工作增加了难度, 急需遥感手段提高成果质量和效率. 在黑龙江大兴安岭洛古河等4幅1:5万区域地质矿产调查工作中, 利用SPOT7、Landsat7/8、ASTER等多种遥感数据开展地质矿产解译, 进行遥感影像分区, 建立地层、构造和侵入岩解译标志, 提取羟基和铁染蚀变异常, 结合水系沉积物测量成果划分了成矿有利区, 有效降低了地质矿产调查强度, 提高了调查效率, 增强了调查质量. 表明遥感技术在大兴安岭高植被覆盖区地质矿产调查过程中能够取得较好效果.  相似文献   

17.
Shortage of water required for drinking and agricultural uses is a subject with a vital importance in most arid and semi-arid regions. The area of this study is one of the semi-arid regions located in southwest of Urmieh lake, northwest of Iran, between N 37°00′, 37°15′ latitude and E 45°05′, 45°30′ longitude which is composed of Permian dolomitic limestone, limestone, and post-Jurassic granite with a very low primary porosity/permeability character. In order to delineate groundwater potential zones in this area, the study focused on identifying secondary porosity/permeability indicators such as lineaments, vegetation cover, lithology, drainage pattern, drainage density, etc. In this regard, a remote sensing and geographic information system-based methodology was selected. Landsat ETM, IRS (pan), SPOT data, digital elevation model, and digital image processing techniques such as filtering, false color composite, principal component analysis, band rationing and classification have been applied to reach the purposes. Information layers extracted for analysis and interpretation stage were then integrated with other data and modeled through the use of existing geographic information system (GIS) software and their related analytical functions. Finally, based on determined ground water favorability index for different sub zones, layers, weighting, and overlapping, a ground water potential index (GWPI) was defined which respectively was utilized to groundwater potential zoning and preparation of GWPI map of the region. Within the six different sub zones defined, two sub zones labeled with high and very good potential areas were highly recommended for further development and exploration purposes. Geophysical investigations in target areas confirm the labeled subzones. Based on the obtained results of the study, it can be concluded that remote sensing data are very useful tool to extract information of groundwater exploration. Also, application of geographic information systems to find target areas for groundwater exploration are effective to save time and cost.  相似文献   

18.
The present study was carried out in Singrauli area of the north India to know the water quality at selected sites. Physico-chemical parameters like pH, total dissolved solids (TDS), bicarbonate, hardness, calcium, magnesium, sodium, potassium, chloride, sulfate, copper, iron, cobalt, manganese, zinc, and chromium were analyzed in 27 water samples. Locations selected for sampling were based on the preliminary field survey carried out to understand the overall impact of mining and industrialization on the surface and groundwater resources of Singrauli. Base map, drainage map, and land use/land cover of the study area were prepared from Survey of India topographic map 63 L/12 on 1:50000 scale and satellite data of IRS P6 LISS III 4th May 2010. Land use were categorized into 15 categories out of which major area occupied by open forest covers 20.33 %, uncultivated land 20.25 %, cultivated land 12.60 %, dense forest 11.00 %, and other categories cover 35.82 %. The results obtained are compared with World Health Organisation standards for drinking water quality. The physico chemical analysis shows alkaline nature of water, soft to moderately soft, TDS and total alkalinity exceeds the desirable limit. The major ions in water like calcium, and magnesium are within desirable limits, and sulfate and potassium exceed in limit at some locations, whereas sodium and chloride show higher values. The minor ions like copper and zinc show values within desirable limits whereas iron, cobalt, and chromium show higher values than the desirable limits which deteriorate the quality of water.  相似文献   

19.
Watershed prioritization is one of the most important processes in natural resource management system especially in areas of sustainable watershed development and planning. Morphometric characteristics are the viable entity to understand the hydrological behavior of the subwatershed. For prioritization of subwatershed, morphometric analysis was utilized by using the linear, areal, and relief aspects of the drainage basin. In this context, remote sensing and GIS has been proved to be an efficient tool to identify the morphological features. The Survey of India (SOI) topographical maps, satellite data IRS-LISS III, and Cartosat DEM data were utilized to understand the drainage pattern and also for prioritization of subwatershed areas. The prioritization of subwatershed has been attempted using novel and quantitative approaches based on compound parameter ranking for soil erosion. Lower compound factors were chosen as the most feasible for soil erosion. Based on the observation, eight subwatersheds with a higher degree of the slope were severely prone to soil erosion and remaining 21 subwatersheds occur in low-lying areas that can be developed as sustainable watersheds. The identified subwatershed requires immediate soil remediation and water conservation measures for efficient watershed planning and management. The proposed study might be helpful for resource planners, government agencies, private sectors, and other stake holders to take up soil conservation measures and fixation of water-harvesting structures for better decision making.  相似文献   

20.
遥感技术已被广泛应用于生态环境调查与研究。为获取西昌市近30 a生态环境演化趋势,利用1989年、2000年、2010年的专题绘图仪(Thematic Mapper,TM)遥感影像和2018年的陆地成像仪(Operational Land Imager,OLI)遥感影像,通过图像处理、目视解译和野外验证等方法,获得了西昌市1989—2018年的土地利用/覆盖数据,并对林地、草地和湿地的动态变化特征进行了研究。结果表明: 1989—2018年,西昌市林地、湿地和草地面积持续增加,生态环境持续向好; 林地主要分布于安宁河谷和邛海盆地四周山地,在牦牛山、螺髻山一带形成主要林区; 草地主要呈星岛状分布于牦牛山、螺髻山一带林地之间; 湿地以河流湿地与湖泊湿地为主,主要沿安宁河及邛海分布。但仍存在一些问题: 森林存在针叶化现象较普遍、树种单一等问题,需要重点加强林区火灾防范; 草地多数呈零星片状分布,不具有完整的系统结构和良好的功能,多数草地承载力和生产力较低,不宜大规模开发利用,应通过封山育林促使其向森林转化; 湿地分布也比较局限,需要着力予以保护。研究成果可为西昌市生态保护修复措施的制定及经济社会可持续发展提供科学依据。  相似文献   

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