Morphometric analysis of a drainage basin using aerial photographs: A case study of Khairkuli basin,district Dehradun,U.P.

Remote sensing techniques using satellite images and aerial photographs are convenient tools in morphometric analysis of a drainage basin. In the present study morphometric parameters of Khairkuli drainage basin, district Dehradun, are worked out using aerial photographs. The parameters worked out include bifurcation ratio, stream length, form factor, circulatory ratio, elongation ratio, drainage density, constant of channel maintenance and stream frequency. Hypsometric relations of drainage basin are also presented. Relation between cumulative stream length and the stream order establishes that the ratio between cumulative stream length Σ ₁ ^u Σ ₁ ^nu Lu and the stream order u is constant throughout the. successive orders of a drainage basin suggesting that geometrical similarity is preserved in the basins of increasing order. The morphometric parameters computed suggest that the area is covered by resistant permeable rocks (with fracture and karstic porosities) and vegetative cover, the drainage network is affected by tectonic disturbances. The peak flows generated from the basin are likely to be moderately high and of short duration.     

Morphology and evolution of an alluvial fan-a case study of Kalanutala,Prakasam district,A.P.

Alluvial fans are the dominant landforms of the semi-aird and arid environments of the world. Studies on alluvial fans elsewhere suggest that there is a close relationship between the morphology of the fan and the drainage basin area; lithology, mean slope, vegetation, climatic and tectonic environments of the source area. An alluvial fan at Kalanutala village, in Prakasam district of Anthra Pradesh, has been studied in detail in order to analyse it's morphology and arrive at its geomorphic evolution. From a study of fan morphology and it's composition, it has been arrived, at the conclusion that there is a relationship between the fan and it's drainage basin (Kompayasela). Further, this study reveals that the apparent segmentation of the fan is not because of tectonic movement but due to the underlying topography of pediment. The study of fan morphology and its materials suggests that the initial deposition of fan took place in a humid climate, but gradually changed to the present arid climate.     

Distribution analysis of salt affected soils under canal and non-canal command area in a part of Etah district,U. P., using remote sensing technique

A World Bank-aided project on sodic land reclamation in Uttar Pradesh is being executed by U.P. Bhumi Sudhar Nigam, Lucknow, and Remote Sensing Applications Centre, U.P., Lucknow has the responsibility of sodic land mapping for the execution of land reclamation programme at the cadastral level. Sodic lands are mainly concentrated in the Gangetic alluvial plains but the problem of sodicity is particularly acute in the canal-irrigated areas. A study of the distribution pattern of sodic lands in canal and noncanal command areas in a reclamation site (covering 60 villages out of which sodic lands were mapped in 51 villages) of Etah district in Uttar Pradesh, indicates that 18.39 per cent area of the canal command villages was barren sodic which was 13.41 per cent of the total geographical area of the site (15417 ha), however, 11.69 per cent area was recorded to be barren sodic in the non-canal command villages which was only 3.16 per cent of the geographical area of the site. The results of soil chemical analysis indicate that barren sodic lands of canal command area are saline-sodic with higher concentration of soluble salts (pH₂ >8.5, EC₂ >4 dSm⁻¹), however, those of non-canal command area are sodic (pH₂ >8.5, EC₂ <4 dSm⁻¹). The post-monsoon ground level in the canal-irrigated areas was in the critical and semicritical zone (< 3.0 mbgl) whereas it was well below the semi-critical zone in the non-canal command area, which indicates that the high ground water level is a major factor to higher the area under sodicity.     

Study of drainage pattern through aerial data in Naugarh area of Varanasi district, U.P.

Drainage pattern of Naugarh Block of district Varanasi has been mapped. The basin characterestics have been analysed is terms of basin morphology and related parameters. The drainage system of the region is composed of 3 perennial rivers with 7 sub-basins. A total of 1223 streams. of 1st to 6th order exist, out of which 761 are of 1st order and 350 of 2nd order which hold sufficient amount of water duing the peak monsoon period Surface water resources could be enhanced in the region by constructing check dams and creating artificial recharge through effective and management.     

Land use pattern of upper tons catchment district,Uttarkashi, U. P.

Aerial Photographs of 1:50,000 scale pertaining to Tons Catchment were used for generating a land use map showing cultivated lands, forests land, grass land, barren land with rock outcrops, snow and glaciers. The area was divided into 4 altitudinal Zones. More than 81% lies above 3000 m height and should be left for natural regeneration. Cultivated land occupies 4.97% of the area and is concentrated below 3000 m altitudinal zone and lies along river courses and on river terraces. Distribution of forest lands in altitudinal zone indicates that percent area covered under forest is higher than the average distribution of forest as reported by Seth (1978). Grass and open scrub, barren Innd with rock outcrops, glaciers and snow covered areas occupy 6.8%, 18.1%, 16.5% and 28.0% respectively.     

Aerial remote sensing as an aid to engineering geologic investigation—A case study from Srinagar Hydel Project,Garhwal, U.P.

Aerial remote sensing coupled with selective field check was carried out to assess the feasibility of the Srinagar dam site, related construction works, location of Srinagar Thrust and to evaluate terrain factors that may have adverse influence on the life of the structure. The lithology of the area comprises mainly of quartzites, phyllites, basic rocks and limestones which trend WNW-ESE. The Srinagar Thrust following the regional trend passes through the centre of the area. The investigation has established the location and extension of Srinagar Thrust and other faults, and presently dormant state of Srinagar Thrust. It also links the major Kaliasaur landslide with a fault. There is a possibility that the slide would contribute a substantial amount of silt into the reservoir.     

Soil resource appraisal towards land use planning using satellite remote sensing and gis a case study in patloinala micro-watershed, district puruliya, west bengal

Visual interpretation of IRS ID LISS-III fused with PAN data (1:12,500 scale) ofPatloinala micro-watershed of Puruliya district, West Bengal was carried out for delineating the physiographic units based on the variations in image characteristics. The major physiographic units identified were upland(Tanr), medium land(Baid), and low land(Bahal andKanali). The satellite remote sensing data coupled with ground truth were translated in terms of soils using composite interpretation map as base. The abstraction level attained was phases of soil series based on Soil Taxonomy. On the basis of physiographic variation and soil or soil site characteristics such as texture, depth, slope, erosion etc. the problem areas were identified and land use plan has been suggested for the overall development of the micro-watershed.     

海道测量水位控制方法研究

将海道测量的垂直基准理论和水位改正方法综合为统一的水位控制理论与方法体系,分析比较了的时差法和最小二乘曲线比较法两种水位改正的软件实现方法的数学模型,讨论了曲线拟合参数的时变性,论证多站水位控制中垂直基准的连续线性特性,给出了水位控制的质量控制指标,得出必要的结论。     

Groundwater prospects evaluation-based on hydrogeomorphological mapping: A case study in Kancheepuram district,Tamil Nadu

Water is the most important natural resource which forms the core of the ecological system. The advent of remote sensing has opened up new vistas in groundwater prospect evaluation, exploration and management. The role of hydrogeomorphological units in tile storage of groundwater from the Kancheepuram distict has been investigated using IRS P6 LISS-III data. The Kancheepuram district exhibits diverse hydrogeomorphological conditions where the groundwater regime is controlled mainly by topography and geology. The extent of various water prospectus zones in terms of percentage includes, maximum area, particularly the north-western, and central part which is characterized by good potential occupying about 43% of total area. The moderate potential is marked by only 35%, and is scattered along the northern and southern side of the study area, the remaining 12% is of poor prospectus, which is falling in the coastal region of the study area.     

An integrated approach for ground water investigation in part of Fatehpur Sikri of district agra-a case study

The Fatehpur Sikri area infringing the western UP, Rajasthan border was investigated for its water supply crisis in respect of poor quality and quantity as well. The study has indicated presence of two parallel quartz reefs running in NE-SW direction. Geohydrological and photogeological studies have revealed the possibility of subsurface extension of quartz reefs. However, this weathered area along reefs is promising water bearing zone. Paleo channels are also marked during studies and the area found suitable for ground water exploitation. A map showing various categories is also presented.     

Visual interpretation of F.C.C. satellite data for channel migration and water logging conditions along Ghaghra and Terhi rivers in part of district Gonda and Bahraich,U.P.

The conventional visual interpretation of landsat Imagery is potentially the most useful remote sensing tool for the study of channel migration & water logging conditions at different time spans; which were earlier not easy due to non availability of suitable evidences. The present study brings out, in exact terms & the extent of the utility of the false colour and black and white landsat data. The application of the false colour scanning method is also useful remote sensing tool for the study of direct & indirect hydrogeological regime by visual interpretation technique. The spectrum are favourable for detection of surface phenomenon, which is associated with the subsurface ground water environment. An area of about 3,500 Sq.Km. of U.P. along left bank of Ghaghra river and right bank of Terhi rivers have been taken for the study. The paper was designed to evaluate the fluvial action and ground water environments with the help of repetitive landsat data in ten years. The fluvial action of Ghaghra and Terhi rivers have been mainly contributing to the development of hydrogeomorphological units which have given exact references regarding fluctuation in hydrogeomorphological units and water logging with hydrological response of the ground water environment, by using landsat data of 1975 & 1984. Further the direct relationship between remote sensing measurement and physical properties of hydrogeological environments is brought out in the maps.     

Land transformation in Punjab — A case study of Kapurthala district

The map showing the extent of salt affected and sand dune soils was prepared at 1:50,000 scale using Landsat TM data for March 1987 and compared with the soil map of Kapurthala district based on 1965 aerial photographs and semi detailed survey of the district during 1975–76. The study revealed that in a span of 22 years (1965 to 1986) the area of sand dunes decreased from 22.7 per cent to 2.3 per cent and that of salt affected soils from 20.95 per cent to 4.38 per cent respectively as a consequence of reclamation of salt affected soils and clearing and levelling of sand dunes. Salt affected soils after reclamation have been brought under paddy-wheat rotation. Whereas sand dunes after clearing and levelling, have been brought under wheat or wheat -rice/fodder/oilseed crops.     

Mapping and management of flood-affected areas through remote sensing a case study of Sirsa district,Haryana

The flood-affected areas in Siras district, Haryana, was mapped during 1993 using IRS-1A LISS-II data. Two categories of flood-affected areas viz. (i) standing water, and (ii) wet areas were identified. The flood water was standing in an area of 19676.25 ha, while wet areas covered 16773.75 ha., Silting of Ottu reservoir, mismanagement of river banks and bunds and lack of drainage system were identified, as major causes of floods. Three management practices including (i) desilting of Ottu reservoir, (ii) proper management of river banks and bands, and (iii) constructions of drains to flush out flood water have been suggested to contain the fury of floods. This study will be useful to the planners and administrators in the planning of flood-affected areas.     

Interpretation of lineaments from precambrian rocks in Madaura and Sonrai area,Lalitpur dist., U.P.

Aerial photo-interpretation of the area underlain by Bandelkhand gneisses, Bijawars and Vindhyans, around Madaura and Sonrai in Lalitpur Dist. of U.P., revealed the presence of a number of lineaments. During fieldwork the lineaments were found to represent ultrabasic, basic and acidic intrusions, faultzones, lithological contacts and foliation. The drainage of the area was found to be grossly controlled by these elements. Three major trends viz. NW-SE, NE-SW and E-W are observed in the area. The first two represent shear joint system, while the latter represent release fractures. This setup is visualised to be due to N-S phase of compression.     

Hydrogeomorphological mapping in ground water exploration using remotely sensed data — a case study in keonjhar district, orissa

Identification of fractures/lineaments and hydrogeomorphic units is prerequisite for undertaking ground water exploration and development in any terrain. Use of satellite remote sensing techniques coupled with aerial photo-interpretation greatly aid in planning ground water exploration, and pin pointing well sites In this study, airborne and space borne data was used for qualitative evaluation of ground water resources and a critical appraisal of such study in combination with hydrogeological and hydrogeophysical techniques for ground water exploration and development in Keonjhar district of Orissa. The study area has been divided into various geomorphic units based on visual interpretation of Landsat (TM) false colour composite on. 1:2,50,000 scale and the ground water potential of each of the units is qualitatively assessed. Digital image processing techniques such as principal component analysis and brightness index were used for generating classified outputs. The features like valley fills, pediments ete appeared clearly on the classified image. Directional filtering brought out minor fractures/lineaments crisply. The study has revealed the significance of different hydrogeomorptuc units and lineaments in Controlling ground water potential of the area. The findings were corroborated by resalts of drilling and resistivity soundings.     

Effect of deforestation on landslides in Nilgiris district — A case study

Landslides in the Nilgiris are mainly due to rainfall, but human intervention in the form of deforestation and plantation has turned this into a calamity. Our study in the Nilgiris district of Tamilnadu help of the Global Land Cover Facility data reveals that there is a drastic reduction in forest cover and human interventions in the form of unplanned tea estates has resulted in the loss of natural ecosystem of Nilgiris which is causing massive and frequent landslides.     

基于GIS的区域人口密度空间分布模拟——以张家界市永定区为例

人口统计数据空间化是解决统计数据与自然要素数据融合分析的有效途径。本文以张家界市永定区为研究单元,对小尺度区域的人口密度空间分布模拟进行了初步研究。文章根据2005年《永定区统计年鉴》所统计的人口数据,分析了永定区各乡镇平均人口密度与土地利用类型指数及地形指数(平均高程和平均坡度)之间的相关性。基于相关性分析,以GIS软件与SPSS统计软件为工具,运用多元回归的思想建立了人口数据空间化模型,同时生成了永定区250m×250m空间分辨率的栅格人口密度图。结果表明,模型模拟的精度较高,模拟过程具有较强的可操作性,可为县域尺度人口空间分布的应用研究提供借鉴。同时,研究结果为永定区推进城市化进程,提高人口、资源和环境的科学管理提供了理论基础。     

Procedure of geomorphological survey: a case study of Calabria,Italy

A geomorphological map of a part of Calabria, South Italy, prepared by adopting the ITC system of geomorphological survey is discussed. The approach with emphasis on form and process was found suitable to bring out the Quaternary sea level changes and associated climatic fluctuations in the form of landform distribution A brief history of the geomorphology of the area is also presented.     

Observed biases in the conterminous U.S. AVHRR satellite data set: A North Carolina case study

The USGS EROS Data Center has produced a national data set for long‐term ecological monitoring termed the “Conterminous U.S. AVHRR (Advanced Very High Resolution Radiometer) Data Set” that includes biweekly maximum‐value composite (MVC) images of NDVI (Normalized Difference Vegetation Index) values, original five channels of calibrated AVHRR satellite data, image viewing and illumination geometry, date of observation, and ancillary data sets pertaining to landcover and political boundaries (Loveland et al., 1991; Eidenshink, 1992).

The basic intent of the study was to evaluate the potential of the data set for broad‐scale, multitemporal landscape mapping by assessing the quality and sensitivity of the data set to support such applications. Potential biases existing in the data set were identified and analytical procedures suggested to deal with such biases. Results from analyses within the State of North Carolina suggest that the time series of the NDVI values is influenced by sensitivities to residual cloud contamination, preceeding climatic events, temporal and spatial scales of analyses, and the composition and spatial organization of the study area. Spatial and temporal discontinuities within and between images, irregular space‐time semivariograms, and statistical summaries of the data show the existence of biases in the data set for North Carolina. Possible adjustments to reduce this level of uncertainty include the generation of NDVI composites over longer time periods, exclusion of suspected contaminated data, or the use of spatial and temporal interpolations of contaminated values to reduce their relative impact on each composite image. Regional variations in NDVI responses to viewing and illumination geometry may also be important factors for users to consider.