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1.
The Diyung river descends in Nagaon district of Assam. After its confluence with main channel Kopili it causes enormous losses to life and property due to floods. Appropriate watershed treatment measures are, therefore, required for moderating the flood damage. In the present study landscape information viz., the hypsometric integral has been analysed. The Diyung watershed has been subdivided into 23 sub-watersheds for hypsometric analysis. The hypsometric integral for the entire Diyung watershed ranged from 0.14 to 0.56. According to the present study there are two stages of geologic/geomorphologic development, namely equilibrium stage and monadnock stage. The hypsometric integral indicates that surface runoff is the dominant process. Although static, the topographic characteristics indicate response of watershed to various natural phenomenon and dominant processes such as runoff and erosion. Based on the intensity of the processes sub-watershed can be prioritized for taking up appropriate conservation measures. The study also highlights the use of hypsometric integral for prioritizing watershed for planning engineering measures to mitigate the impact.  相似文献   

2.
Sediment discharge due to soil and rock erosion within the watersheds is the major cause of siltation in water reservoirs. Siltation in reservoirs reduces the capacity for power production, irrigation water supply, and other domestic purposes. Hypsometric analysis has widely been used to identifying the geomorphic development stages (stabilized, equilibrium, and un-stable) to assess the erosion proneness of watersheds. In this study, watershed of Kurram Tangi Dam and its four sub-watersheds (SWs) were considered to determine their sediment discharge capacity through hypsometric analysis. The boundaries of watershed and sub-watersheds were delineated from Digital Elevation Model (DEM). The hypsometric parameters i.e., hypsometric integral (HI) and curves were generated using Geographic Information System (GIS) techniques. The HI values of SW-1 (0.41) and SW-2 (0.36) indicated that these two SWs were relatively more prone to erosion and contributed higher sediment discharge in Dam siltation. The results were validated through sampling the main drainage channel (Kurram River) to determine the sediment concentration at 12 sites during summer, winter, and spring seasons. Comparison of HI and sediment concentration of SWs presented high correlation (R2?=?0.87). The results emphasized the effective watershed management, extensive afforestation, and construction of silt-control structures at appropriate locations in sub-watersheds. This will ultimately maintain the water and power generation capacity as well as extending the life span of the Dam.  相似文献   

3.
An integrated morphometric and hypsometric analysis coupled with asymmetric factor used as a proxy for the landscape evolution of the catchment of Karuvannur River. The present study area is a sixth order tropical river in the central Kerala which supplies water and sediments to the Vembanad-Kol Ramsar site. The Karuvannur River Basin (KRB) has been divided into six sub-watersheds (SW). Morphometric parameters (areal, linear, and relief) and hypsometric and asymmetric factors are measured for the delineation of morphotectonic evolution of the area. High values of drainage density, texture, ruggedness number, and hypsometric integral with relatively high volume of leftover rocks in the basin in SW-II and SW-III compared to the entire basin of KRB imply that these two sub-watersheds have been influenced by the tectonic activities. Further, detailed asymmetric data indicated that these two watersheds are tilted in opposite direction. It may be the result of reactivation of Precambrian fault/lineament in recent past. This has been supported by recent tremors and neotectonic studies in Kerala. Moreover, detailed field evidence along with google imagery revealed that the entire basin is a part of regional anticline associated with PCSZ. Geomorphic response to disturbance will produce a sensible, recognizable response; it can be well studied in rivers through detailed study of their sensitivity or behavioral changes. Rivers have an enormous capacity to absorb perturbation and these types of studies are essential for identifying/measuring tectonic activities, sediment diffusion, surface runoff in a drainage basin, and as an important tool for target oriented micro watershed management.  相似文献   

4.
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   

5.
Bago River is an important river in Myanmar. Although shorter than other rivers, it has its own river system, and people along the river rely heavily on it for their daily lives. The upper part of the watershed has changed rapidly from closed forest to open forest land in the 1990s. Since the recent degradation of the forest environment, annual flooding has become worse during the rainy season in Bago City. This paper aims at determining soil conservation prioritization of watershed based on soil loss due to erosion and morphometric analysis in the Bago Watershed by integrating remote sensing and geographic information system (GIS) techniques. In this study, soil erosion of the Bago watershed was determined using the Universal Soil Loss Equation. Such factormaps as rainfall, soil erodibility, slope length gradient, and crop management were compiled as input parameters for the modeling; and the soil loss from 26 sub-watersheds were estimated. Then, the soil erosion maps of the Bago watershed for 2005 were developed. The resulting Soil Loss Tolerance Map could be utilized in developing watershed management planning, forestry management planning, etc.  相似文献   

6.
In this present study, Remote Sensing (RS) and Geographical Information System (GIS) techniques were used to update drainage and surface water bodies and to evaluate linear, relief and aerial morphometric parameters of the two sub-watersheds viz. Jilugumilli and Regulapadu in the northern part of West Godavari District, Andhra Pradesh. The area of Jilugumilli and Regulapadu watersheds spread over about 110 & 80 sq. km respectively. The morphometric analysis of the drainage networks of Regulapadu and Jilugumilli sub-watersheds exhibit sub-dendritic and sub parallel drainage pattern. The variation in stream length ratio changes due to change in slope and topography. It was inferred from the study that the streams are in a mature stage in Regulapadu and Jilugumilli watersheds, which indicated the geomorphic development. The variations in bifurcation ratio values among the sub-watersheds are described with respect to topography and geometric development. The stream frequencies for both sub-watersheds exhibit positive correlation with the drainage density, indicating increase in stream population with respect to increase in drainage density. The Jilugumilli watershed has a coarse drainage texture and Regulapadu sub-watershed is a fine drainage texture in nature. In the present study an attempt has been made to analyse the morphometric analysis of two sub-watersheds under different physiographic conditions. Morphometric analysis is one of the essential analyses required for development and management of watershed.  相似文献   

7.
The integration of Remote Sensing (RS) and Geographic Information Systems (GIS) constitutes a powerful tool for the evaluation of watershed morphometric parameters. The benefits of this integration include saving time and effort as well as improving the accuracy of the analysis. Moreover, this technique is appropriate for describing the watershed and its streams. In this study, a detailed morphometric analysis of the Wadi Baish catchment area has been performed using the Shuttle Radar Topography Mission (SRTM). The performed morphometric analysis includes linear, areal, and relief aspects. The results of the morphometric analysis reveal that the catchment can be described as of eighth stream order and consists of an area of 4741.07 km2. Additionally, the basin is characterized by a relatively high mean value of bifurcation (4.012), indicative of the scarcity of permeable rocks with high slope in the area. This value of bifurcation ratio is consistent with the high drainage density value of 2.064 km/km2 and confirms the impermeability of the subsurface material and mountainous relief. The hypsometric integral of the catchment is 47.4%, and the erosion integral of the catchment is 52.6%, both were indications of a mature catchment area.  相似文献   

8.
利用数字高程模型(DEM)数据、地形图、地质图数据结合实地踏勘,分析并计算了张家界地貌主要分布区溹水流域河谷形态特征和侵蚀积分值(HI),探讨了流域地貌侵蚀发育阶段特征。研究发现:溹水干流比降沿程基本上逐渐减小,纵剖面呈上凹形,凹度值约为0.70;主要支流比降明显大于干流,凹度值介于0.12～0.98;溹水干流河谷宽度和宽深比沿程向下表现出上升趋势、深度表现出下降趋势;溹水河谷横剖面凹度值上游较低,中游较高,近河口又降低,平均值约为0.63,都大于0.5;上中游主要支流河谷相对窄深,下游支流河谷相对宽浅;支流河谷横剖面的凹度值变化范围较大,平均值大于0.50。说明这一地区在地壳迅速抬升之间有较长时间地壳相对稳定,横向侵蚀形成一定宽度的河漫滩,河谷为U型谷,地貌发育处于壮年期或壮年期的中晚期。河谷侧蚀,河谷凹度值大于0.5,是张家界地貌独立峰柱得以形成的重要条件;溹水流域上游下段和中游HI值较高,下游HI值较低,最高值出现在天子山周围;没有发现地势和基岩特性对溹水流域HI值分布存在显著影响;张家界砂岩峰林地貌发育地区集中于溹水上游下段和中游上段的泥盆系砂岩分布区,这一地区HI平均值为0.46,处于地貌侵蚀旋回的壮年期。  相似文献   

9.
Spatial pattern of geomorphometric parameters of two sub-watersheds in the Attapady valley, Kerala, is evaluated using the Geographical Information System. Both the aspatial and spatial morphometric and hypsometric measurements of the sub-watershed are compared. The analysis of geomorphometric parameters coupled with DEM and GIS suggests that the two sub-watersheds are structurally complex with high relief and the denuded hills are undergoing severe soil erosion. Terrain analysis enables evaluation of landform changes in the two sub-watersheds which indicate differences in the denudational history of adjoining watersheds. It is demonstrated that the domainal variations in the lithology and structural complexity are reflected in differences in the denudational history which in turn is manifested in the geomorphic parameters. The study also helps in developing functional relationships between geomorphometric parameters and hydrological variables.  相似文献   

10.
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   

11.
姜勇彪  郭福生  黎广荣  李蓉  楼法生  汪震  陈留勤  郄海满  闫罗彬  李益朝  凡秀君 《地质论评》2023,69(5):2023050014-2023050014
晚白垩世至古近纪期间,江西省内沿区域性断裂构造发育30余个断陷盆地,沉积了巨厚的红色陆相碎屑岩,为丹霞地貌的形成提供了物质基础。已发现的228处丹霞地貌点主要分布于江西东部武夷山北麓和西麓的红层盆地内。利用面积—高程积分法,对江西省9个盆地的丹霞地貌演化阶段进行了定量分析,结果表明省内丹霞地貌景区的面积—高程HI为0.17~0.52,平均为0.38,即其演化阶段处于壮年晚期至老年早期,在空间分布上具有由南向北,由壮年期转为老年期的趋势。该趋势可能与武夷山的构造隆升有关。构造分析显示,节理与武夷山的隆升对江西丹霞地貌演化起控制作用,具体表现为：① 龙虎山、九仙湖、仙岩、蛤蟆坞、赭亭山、龟峰等地发育的崖壁、一线天、巷谷、石墙、石寨、峰丛、峰林等丹霞典型景观均与节理有关。② 流水侵蚀等外营力的作用对丹霞地貌的剥露、削平起重要作用,统计表明距离武夷山越近,丹霞地貌山峰越密集、崖壁越陡峻,指示武夷山的隆升与丹霞地貌的发育有直接关系。总体来看,江西省内的红层为丹霞地貌的发育提供了物质基础,武夷山的隆升控制了丹霞地貌的分布。值得注意的是,丹霞地貌区的节理构造是否与武夷山的隆升存在直接因果关系还需进一步研究。  相似文献   

12.
DEM是目前用于流域地形分析的主要数据,基于DEM的水文模拟技术,在流域地形分析及水系构建等方面已形成了比较成熟的算法,给传统的水文模拟技术带来了根本性的变化。以蒲石河流域山区为例,借助流域水文软件WMS,结合ARCVIEW和SURFER软件,计算了流域的面积、周长、坡度与形状因子等参数。在生成山区数字高程模型的基础上,采用WMS嵌入的HEC-1模型对一场降雨进行了降雨径流模拟研究。  相似文献   

13.
Land degradation is still a very common problem in the mountains of Asia because of inappropriate land use practice in steep topography. Many studies have been carried out to map shifting cultivation and areas susceptible to soil erosion. Mostly, estimated soil loss is taken as the basis to classify the level of soil loss susceptibility of area. Factors that influence soil erosion are: rainfall erosivity, soil erodibility, slope length and steepness, crop management and conservation practices. Thus the reliability of estimated soil loss is based on how accurately the different factors were estimated or prepared. As each and every small pixel of our earth surface is different from one area to another, the manner in which the study area was discretized into smaller homogenous sizes and how the most accurate and efficient technique were adopted to estimate the soil loss are very important. The purpose of this study is to produce erosion susceptibility maps for an area that has suffered because of shifting cultivation located in the mountainous regions of Northern Thailand. For this purpose, an integrated approach using RS and GIS-based methods is proposed. Data from the Upper Nam Wa Watershed, a mountainous area of the Northern Thailand were used. An Earth Resources Data Analysis System (ERDAS) imagine image processor has been used for the digital analysis of satellite data and topographical analysis of the contour data for deriving the land use/land cover and the topographical data of the watershed, respectively. ARCInfo and ARCView have been used for carrying out geographical data analysis. The watershed was discretized into hydrologically, topographically, and geographically homogeneous grid cells to capture the watershed heterogeneity. The soil erosion in each cell was calculated using the universal soil loss equation (USLE) by carefully determining its various parameters and classifying the watershed into different levels of soil erosion severity. Results show that during the time of this study most of the areas under shifting cultivation fell in the highest severity class of susceptibility.  相似文献   

14.
GIS/RS是流域水文过程分布式模拟的重要技术支撑。结合泾河流域的实例研究,探讨了GIS支持下,基于栅格DEM流域水文特征的获取,降水、气温等资料的空间插值,以及土壤、植被等下垫面信息在水文模拟单元上的耦合。在此基础上,应用分布式水文模型对泾河流域的水文过程进行模拟。结果表明:所建模型结构上是合理的,在产流计算中泾河25个子流域在水量平衡方面误差均小于5%。潜在蒸发的模拟在趋势上与实测过程基本一致。径流模拟在4个检验站点上与实测过程的相关系数达到0.84～0.93。模型基本能够满足水资源规划与管理的需要。  相似文献   

15.
研究区主要包括北京东部的通州、平谷、顺义、燕郊、大厂和三河,位于华北沉降带北部、阴山东西向构造带南缘。该区地势总体上西北略高,东南略低,为大型缓倾斜平原,地形不仅受本区内北东向断裂的影响,还受北西向断裂的影响。资源三号卫星立体影像(ZY3)DEM和NASA航天飞机雷达地形任务(SRTM)DEM在北京地区地貌特征研究中显示出了许多优于其他DEM的优势。文章利用包括水系偏转、河长坡降指标(SL)、面积-高程积分值(HI)、等值线分级色彩显示和地形粗糙度等几种地形参数,分析了地形特征与断层构造活动性的关系。水系的右旋偏转证实了该区北东向断裂的右旋走滑活动,如夏垫断裂和其他相邻断裂。SL指数表明,河床纵剖面在横跨断层处均是陡坡;HI的高值主要集中在南口-孙河断裂与该区其他北东向断裂的交汇处,夏垫断裂的中段,以及香河县西北部,反映了该区强烈的构造活动,同时也反映出可能存在隐伏断层。另外,研究表明,面积、高程积分值的高值区与低值区相邻衔接处,往往是地震危险性较大的地方。此外,平原区相同值域的面积-高程积分所反映的构造活动强度应该与山区不同,因此地貌演化阶段划分标准也应与山区有所不同。等值线分级色彩显示对地形变化非常敏感,当与已识别的断层重叠时,大部分地形突变的地方都与断层活动有关。地形粗糙度分析显示不同断裂带的地形粗糙度与断裂活动强度呈正相关关系。  相似文献   

16.
Assessment of erosion status of a watershed is an essential prerequisite for integrated watershed management. It not only assists in chalking out suitable soil and water conservation measures to arrest erosion and conserve water but also helps in devising best management practices to enhance biomass production in watersheds. Keeping this in view, the present study has been undertaken by involving geospatial-statistical techniques to determine the critical and priority areas for soil and water conservation in Suketi watershed of the lower Himachal Himalayan region. A novel weighted sum analysis technique was used for ranking each of hydrological unit by obtaining the weightages from various morphometric parameters. This technique offers dynamic, effective and sustainable approach over traditional prioritization methods in which significance of each parameter were considered equally. Considering this approach, sub-watersheds were delineated into low, medium and high priority zones. The results illustrate that about 52 % of sub-watersheds of Suketi watershed are in moderate to high erosion and runoff susceptible zones. Therefore, these potential areas can be considered for preferential soil and water conservation planning. The results obtained from the study will be useful for various stakeholders such as agriculturists, water resource managers, conservation measures planners and decision policy makers for better management practices and decision making. The geospatial-statistical technique can be used for effective estimation of erosion status of watersheds leading to watershed prioritization for taking up soil and water conservation measures in watershed systems. Finally, this technique can be very useful in remote, rugged and inaccessible watersheds with absence of soil erosion and runoff monitoring.  相似文献   

17.
Vembanad lake system (VLS) is a Ramsar wetland of premier importance along the south west coast of India. This system spread over 13098 km2 accounts for 33.7% of total geographic area of Kerala state. VLS sustains by the input of six main river systems of Kerala viz., Achankovil, Pampa, Manimala, Meenachil, Muvattupuzha and Periyar. Central focus of this study is to find out the influence of morphometric variables on hydrological processes using geo-informatics and correlation analysis and to analyse the scale dependence of basin hypsometry in steady state topography and hydrology. The study also examines the contribution of each river in making the entities of this wetland system by portraying the morphometric and hypsometric parameters of its watershed. The results of this analysis reveals that the Manimala river basin has survived with rapid denudation activities and run off mechanism, while Periyar and Pampa river basins have culminating stage of development and are tectonically active. This study immensely contributes to the knowledge on the influence of morphometric variables on hydrological process and scale dependence of basin hypsometry in steady state topography including hydrology of VLS. The results will shed some light on hydrologic makeup of inflow rivers and will be beneficial for the sustainable management of India’s one of the premier wetlands.  相似文献   

18.
Neotectonic activity in Mahe (Mayyazhi) river basin and its implication in landform development and stream characteristics were investigated with the help of the digital elevation model-derived geomorphic indices. The analysis is based on the commonly used geomorphic indices such as hypsometric curve and integral, drainage basin asymmetry, transverse topographic symmetric factor (T), stream length (SL) gradient index and longitudinal profiles of the stream. Hypsometric integrals indicate that the basin has reached the base level and lesser amount of material remains for erosion and transportation. The basin is asymmetric and has a south-south-east directional tilt, but with a probable spin caused due to the presence of major strike slip fracture, the mouth portion of the Mahe river has been tilted towards north-north-west. The SL index with sudden and non-uniform variations supports the finding and indicates the relative tectonic activity and its influence over the river networks in the area. Longitudinal profile of the stream also reveals gradational changes in the profile with the presence of knick points. Cross comparison of the analysed geomorphic indices points towards neotectonic activity in the basin, which modified the river basin to the present morphology and is reflected in the characteristics of the river and the basin as a whole.  相似文献   

19.
In this paper, the hypsometric curves and integrals of four neighboring micro-watersheds draining into Patiala-Ki-Rao stream which is situated in the Shivalik foothills of district SAS Nagar in the Punjab state (India) has been presented to access and compare the erosion regimes under different management practices. Area-elevation ratio method has been used to compute hypsometric curve and integral values for each micro-watershed through ArcGIS 10.3 and Microsoft Excel. The 9-year data of runoff and sediment yield for all these micro-watersheds under different management practices has been analyzed for their effect on land cover and soil quality. Thus, the results of present study are very useful for comparing, planning, implementing, and controlling soil erosion in similar watersheds.  相似文献   

20.
GIS and Remote Sensing have proved to be an indispensible tool in morphometric analysis. The identification of morphometric properties based on a geographic information system (GIS) was carried out in two watersheds in the Thrissur district of Kerala, India. These watersheds are parts of Western Ghats, which is an ecologically sensitive area. Quantitative geomorphometric analysis was carried out for the Chimmini and Mupily watersheds independently by estimating their (a) linear aspects like stream number, stream order, stream length, mean stream length, stream length ratio, bifurcation ratio, length of overland flow, drainage pattern (b) aerial aspects like circulatory ratio, elongation ratio, drainage density and (c) relief aspects like basin relief, relief ratio, relative relief and ruggedness number. The drainage areas of Chimmini and Mupily watersheds are 140 and 122 km2 respectively and show patterns of dendritic to sub-dendritic drainage. The Chimmini watershed was classified as a sixth order drainage basin, whereas Mupily watershed was classified as a fifth order basin. The stream order of the basin was predominantly controlled by physiographic and structural conditions. The increase in the stream length ratio from lower to higher order suggests that the study area has reached a mature geomorphic stage. The development of stream segments is affected by rainfall and local lithology of the watersheds. The slope of both watersheds varied from 0° to 50° and 0° to 42° respectively and the slope variation is chiefly controlled by the local geology and erosion cycles. Moreover, these studies are useful for planning rain water harvesting and watershed management.  相似文献   

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