Spatio-temporal shift of western bank of the Ganga river,Allahabad city and its implications

Ganga is one of the largest rivers of the world which supports millions of population on its banks. It is a tectonically controlled Himalayan river which also creates havoc due to perennial floods every year. Like most large river systems, it also shifts its course in the Gangetic plains in space and time. The present study measures the variable shift in a selected flood-prone stretch of the Allahabad city lying on the western bank of the Ganga river, taking into account the historical, annual to monthly data (including pre- and post-monsoon shifts) to show the ongoing changes in the river course with possible causes and futher implications. It also discusses for the first time the down stream effect of the Tehri dam on the Ganga river course after it became functional.     

SILTING AND ISLAND GROWTH IN THE ZAMBEZI NEAR LIVINGSTONE

Abstract

The Northern Rhodesia Survey Department recently carried out a series of measurements of certain cross-sections of the Zambezi in the vicinity of Livingstone. The stretch of river over which the above were made is that known as the Regatta Course and extends between the top of Loando or Long Island downstream to the mouth of the Maramba River. This stretch is about three and a half miles southwest of Livingstone and two to four miles upstream from the Victoria Falls.     

The role of multispectral imagery in elucidation of recent channel pattern changes in middle ganga plain

The mapability of Landsat images has opened up a new potentiality for study of channel pattern changes which was earlier not so easy due to nonavailability of suitable evidences at different timespans. Middle Ganga plain covering largely the northern part of Bihar and parts of eastern Uttar Pradesh is in a slate of perpetual flux due to large scale channel migration and avulsion resulting in devastating floods. Mosaic of three Landsat images has helped to study the channel changes which have occurred since 1935. The course of the river Ganga has beeh digitised along a basal line and two dimensional coordinates are taken at as many as more than fifty sample points for studying the magnitude and direction of channel changes during 1935–1975 period. The analysis shows that the main multiple channel river Ganga is under the huge hydrostatic thrust to be shifted towards south of its basin annually at a very high rate of 100 Meter per year all along the course except at its upstream near Ghazipur and at Monghyr where the shifting is towards north. The northward bend at Monghyr may be due to the presence of the Precambrian outliers here. For the multi-and single channelld tributaries of Ganga in channel behaviour is mainly in three directions—the lower water channels in the floodplain of Ganga are shifting to the south in conformity with that of their parent stream, the tributaries in Gogra-Gandak doab are shifting towards east but the shifting of the Kosi-Mahananda group of tributaries in the eastern part of the basin is towards west These channel pattern changes thus known at the interregional scale from the Landsat images may further be integrated with the study in hydrogeomorphology and their pertinent environmental impact.     

Surface and subsurface evidence of neotectonics and the aquifer disposition in central gangetic alluvial terrain of Kanpur-Unnao region in Uttar Pradesh,India

Both surface and subsurface evidences exist along the longitudinal section of the Ganga river in Kanpur-Unnao region of Central Ganga Plain indicating the effect of tectonic subsidence. While the surface evidences are discontinuous chain of high uplands with escarpments on the southern bank of the Ganga river and the wide flood plain on the northern side, the subsurface evidences are in terms of sudden deepending of the granitic basement towards north followed by deposition of coarse sand and gravel forming thick aquifers in the close vicinity of present channel of the Ganga river. The petrological examination of the aquifer material also indicates that the material has been derived from a deformation zone.     

Channel pattern transformation of the Burhi‐Gandak river,Bihar, India: A study based on multidata sets

The Burhi‐Gandak river is one of the major tributaries of the Ganga River in the middle Ganga basin. The river is i known to have an oscillatory character and has changed its course in Recent times. In the present study, a variety of remote sensing data combined with surface and subsurface data have been used to delineate the fluvial palaeofeatures of this river. The palaeofeatures of the Burhi‐Gandak indicate that the river has shifted from N to S over a distance of 30 km. Further, its is observed that Burhi‐Gandak river had a larger channel width and higher discharge on earlier times and was very active. On detailed examination, a past link between the now northerly flowing Baghmati and Burhi‐Gandak rivers is detected. Based on the above features, three distinct stages of migration of the river have been identified and a summary of fluvial palaeohistory is presented.     

NOTES ON THE BASE LINES OF THE CEYLON TRIANGULATION

Abstract

The triangulation of Ceylon depends for its scale upon two bases, each about 5½ miles long, situated at Negombo on the West Coast (latitude 7° 10′) and at Batticaloa on the East Coast (latitude 7° 40′). Both bases are in low, flat country; brick towers up to 70 feet high had to be built over the terminals to enable observations to be taken to surrounding points. These lines have recently been re-measured.     

MAPPING OUT OF CROWN LANDS IN CEYLON

Abstract

The Island of Ceylon has an extent of 25,332 square miles, and a population of nearly seven millions; the range of latitude is from 5° 55′ to 9° 50′ North and of longitude 79° 42′ to 81° 53′ East.     

SURVEYING AND MAPPING IN CANADA

Abstract

In a country of the size of Canada, the third largest in the world, comprising more than three and a half million square miles and extending through eighty degrees in longitude and a range of latitude from 42° to the North Pole, there is every variety of topography. There are the characteristic accidented regions of the Maritime Provinces and the lower St. Lawrence, vast treeless areas in the Canadian West, and park lands spreading out northwards to merge eventually into the forests, which again give way to the open northern plains that lie towards the Arctic. There are level fertile expanses, hilly areas, marshes, rocky regions of low relief, and localities that display mountainous scenery rivalling anything that exists in other parts of the world. In some places industry has taken its firm foothold with a consequent density of population. In the agricultural areas the population spreads itself out more thinly.     

应用卫星遥感探索楼兰古城消亡之谜

通过卫星遥感图像对楼兰古城区古河道分布状况进行环境地质解译，发现古城所在地上游有两处滑坡，且存在堰塞湖。基于这一发现，推测楼兰古城最终消亡原因是由于其上游发生滑坡崩塌后堵住河水，使楼兰古城因断水而被遗弃乃至消亡。     

Hydromorphology of a part of Azamgarh and Ghazipur districts,Uttar Pradesh

Hydrogeological studies in the Quaternary alluvial plain of a part of Azamgarh and Ghazipur districts, using air photos on scale 1:60,000 indicate the presence of five hydromorphic units namely, Alluvial upland, older alluvial plain of Mangat-Besu, older flood plain of Ganga—Gomti, youngest terrace of Ganga—Gomti and present flood plain of Ganga-Gomti. From the groundwater point of view older flood plain of Ganga—Gomti is the most promising hydromorphic unit. Abandoned channel of river Ganga offers favourable site for deep groundwater exploration with high potentiality. Chemical quality of shallow and deep aquifers is suitable for irrigation and other purposes.     

Changing Pattern of Channel Morphology of Alaknanda River in Srinagar Valley (Garhwal Himalaya), India

The Alaknanda River is the most significant parental river of Ganga and forms an 11.5 km long and 2.5 km wide valley, locally known as the Srinagar Valley. The purpose of the present study is to highlight the recent landform changes in the Alaknanda channel course after the Kedarnath disaster, 2013. The Kedarnath flood completely changed the channel morphology of the Alaknanda river. The river changed its course at Srikot, SSB and Sriyantra Tapu with lower terraces being silted by sands at Ranihat, SSB, Bhaktiyana and Sriyantra Tapu. A new depositional terrace also formed opposite to Sriyantra Tapu. New lateral channel bars, braided channels, back swamp, rapids, pools and river souls were identified in the channel course of the river. Shifting of the channel course at Chauras still remains a serious problem for the Garhwal University Chauras Campus. About 2–5 m silt was deposited on the lower terrace at SSB, and ITI. The Srikot river bed was appended to 4.60 m. Shifting of channel course remains a serious threat to the Srinagar valley. Urbanization, sand and boulders mining, construction of dam, hydrological canal, road and settlements are the prominent example of anthropogenic activities which affect the shifting channel.     

TIDAL OBSERVATIONS IN CEYLON

Abstract

I. IN a Report which appeared in the Empire Survey Review, vol. i, no. 5, a short account was given on pp. 227-8 of the tidal observations which had been taken in Ceylon up to that time, with special reference to the selection of a datum for the geodetic levelling of the Island. The automatic tide-gauges at Colombo and Trincomalee were maintained in action till January 1934, giving five years of simultaneous continuous records of sea-level. The resul ts of an analysis of these observations may be of interest to readers. Where necessary, statements and figures appearing in the Report mentioned above will be repeated here, to make this account complete in itself and to avoid troublesome cross- reference.     

Planform analysis of Hooghly river metamorphosis using multidate satellite data

Conventional techniques of monitoring both long-term and short-term changes in river morphology is time consuming and expensive. Remote sensing with its synoptic and temporal capability is an effective tool to study river metamorphosis. The present study is carried out in lower Ganga basin where Hooghly river is an important river contributing sediment to this vast fertile plain. A time series planform analysis is carried out between 1971 to 1991 period. Thematic maps generated from Landsat MSS and IRS-IA LLSS-I satellite data for 1986 and 1991 period respectively is compared with 1971 topographic maps. The migratory character of paleocourse of Hooghly river is deciphered through the paleochannels, oxbow takes and meander scars deciphered from satellite imagery. The shortterm river metamorphosis like cut-offs, bar migration and point bar accretion morphology are mapped and compared with 1971 topographic maps. The critical zone with respect to cut-offs and future channel migration are identified for river stabilization work.     

多时相MODIS影像水田信息提取研究

水稻种植及其分布信息是土地覆被变化、作物估产、甲烷排放、粮食安全和水资源管理分析的重要数据源。基于遥感的水田利用监测中,通常采用时序NDVI植被指数法和影像分类法分别进行AVHRR和TM影像的水田信息获取。针对8天合成MODIS陆地表面反射比数据的特点和水稻生长特征,选取水稻种植前的休耕期、秧苗移植期、秧苗生长期和成熟期等多时相MODIS地表反射率影像数据,通过归一化植被指数、增强植被指数及利用对土壤湿度和植被水分含量较敏感的短波红外波段计算得到的陆表水指数进行水田信息获取。将提取结果与基于ETM＋影像的国土资源调查水田数据,通过网格化计算处理并进行对比分析,结果表明,利用MODIS影像的8天合成地表反射率数据,进行区域甚至全国的水田利用监测是可行的。     

The solani-ganga interfluve; an application of remote sensing technique on soil resource mapping for agricultural planning

The area of the Solani-Ganga interfluve, which lies between 29°16′N to 30°15′N latitude and 77°45′E to 78°15′E longitude was undertaken for the present study using LANDSAT imagery of band 5 and 7 and the false colour composite on the scale of 1:250,000 in combination with aerial photographs (1:25,000). Major geomorphic units, e.g., Siwalik Hills. Solani-upper alluvial plain, Solani lower alluvial plain, ‘Tarai’ and Ganga alluvial plain were delineated on LANDSAT and colour composite. Sample areas selected from LANDSAT were studied on aerial photographs in details and soil physiography relationship was developed. The soils on Siwalik hills are classified as Orthents. The soils of the pledmont plain and the recent terraces of Solani river and its tributaries were Psamments, Orthents, Fluvents, Orchrepts and Aquepts. The soils of upper alluvial tract of the Ganga plain is mostly Ustalfs with inclusion of Aqualfs, while the strong hydromorphic Tarai tract consists of partly Aquepts, Ochrepts (cultivated) and partly of Aquolls, Ustolls and Ustalfs (under forest). The present study aims to pin point the nature of soil relief relationship with the help of LANDSAT imagery and aerial photographs and diagnose the intensity of the depletion of soil resources (by prevailing factors like swift run off of biykderfed torrents, fast-flow of ground water, soil creep, mass wasting) through field studies and then treat them with ecological dose of soil conservation. For agronomic development of the region, it is worked out that the present crop-combination and crop-rotation systems should be slightly modified according to its ecosystem to prevent the depletion of soil nutrients.     

Vegetation图像植被指数与实测水稻叶面积指数的关系

水稻的叶面积指数 (LAI)是水稻生长的一项重要参数 ,与水稻的生物量与产量直接相关。利用 1999年在江苏省江宁县实测的水稻叶面积指数与同期Vegetation/SPOT的植被指数作了对比分析 ,结果发现同期的LAI与植被指数表现相近的变化特征 ,两者具有良好的相关关系。     

伶仃洋遥感动态监测

水利部珠江水利委员会以卫星遥感资料为信息源对珠江河口湾──伶仃洋进行动态监测已有13a的历史, 积累的资料有:1973年至1992年25个时相的各种潮情及水情的卫星影像资料。该动态监测研究主要是进行河口湾水体悬浮泥沙含量及其分布特征研究; 岸线和近岸浅滩地形及其动态变化研究; 流场特征研究; 河(海)岸及近岸工程的现状与变化及其对河口的水动力影响等研究。采用的主要技术方法是综合运用计算机和光学图像处理技术对卫星遥感图像进行处理, 并据河口水动力学与地学理论进行分析。分析成果为伶仃洋河口治理开发规划与工程实施、滩涂资源的合理开发、航道开发与治理等提供了新的科学依据。其中一些合理建议已为生产部门所采纳。发挥了很好的经济效益和社会效益。     

MAP REPRODUCTION IN THE TROPICS

Abstract

The useful paper on “Map Printing in Ceylon” which was written by Mr. W. S. Maddams of the Ceylon Survey Department for the 1935 Conference of Empire Survey Officers has been read with interest in the Gold Coast. The writer of the present note was not present at the Conference but has read the report of the discussion on that paper. It appears to him that Mr. Maddams makes certain generalizations, based on his own, experience in Ceylon, regarding map reproduction in the Tropics and, however true these statements may be as regards Ceylon, they certainly do not apply to the Gold Coast and probably not to some other tropical countries. As it is possible that another Colony, when starting a map-printing establishment of its own, might be led, on the strength of the paper read at the Conference, to believe that less expensive (though less elaborate) methods than those used in Ceylon are not possible in a tropical country, the following notes on the methods used and found successful in the Gold Coast may be of some value. They are not intended to be a criticism of Mr. Maddams' paper but only to supplement it with a record of experience obtained in another part of the world.     

稻田光谱与水稻长势及产量结构要素关系的研究

本文通过对水稻不同生育期的稻田光谱与水稻长势和产量结构的相关分析得出以下几点结论:(1)稻田光谱与水稻长势的相关性较好,特别是在水稻生长后期;(2)抽穗期,稻田光谱与决定水稻产量的各结构要素之间相关系数较高;(3)在水稻灌浆期,稻田光谱与水稻理论产量的相关性较好,特别是800nm的反射光谱值:(4)水稻估产模型是:Y=6.65PVI_D+8.19PVI_H+4.48PVI_Mt+4.36PVI_Ms-0.3,其中:Y-水稻产量;PVI-垂直植被指数,D,H,Mt,Ms,分别代表分化期、抽搐期、灌浆期及乳熟期。     

Estimation of discharges at river mouth with MODIS image

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.