delineation of groundwater potential zone in chhatna block bankura district west bengal india using remote sensing and gis techniques groundwater is one of the most valuable natural resources which is an immensely important and dependable source of water supply in all climatic regions over the world groundwater is in demand in areas where surface water supply is inadequate and nonsexist in the chhatna block bankura district and is located on the eastern slope of chotonagpur plateau which is mapped on 73 i 15 73 i 16 and 73 m 3 and falls between latitude 23 10 23 30 n and longitude 86 47 87 02 e it represents plain land and gentle slope which is responsible for infiltration and groundwater recharge the groundwater in this region is confined within the fracture zones and weathered residuum the present investigation is therefore undertaken to delineate potential zones for groundwater development with the help of a remote sensing study irs liss iii data along with other data sets e g existing toposheets and field observation data have been utilized to extract information on the hydrogeomorphic features which include valley fills buried pediment moderate buried pediment shallow and structural hills lineament density contour and slope map of this hard rock terrain the target of this study is to delineate the groundwater potential zones in chhatna block bankura district west bengal satellite imagery along with other data sets has been utilized to extract information on the groundwater controlling features of this study area three features hydrogeomorphology slope and lineaments that influence groundwater occurrences were analyzed and integrated all the information layers have been integrated through gis analysis and the groundwater potential zones have been delineated the weighted index overlay method has been followed to delineate groundwater potential zones the results indicate that good to excellent groundwater potential zones are available in almost the entire block the results show that there is good agreement between the predicted groundwater potential map and the existing groundwater borehole databases the area is characterized by hard rock terrain still due to the presence of planation surface along valley fills it became the prospective zone the area has been categorized into four distinct zones excellent good fair and poor excellent groundwater potential zones constitute 30 35 of the total block area good groundwater potential zones occupy a majority of the block covering approximately 55 60 and the fair potential zones occupy about 10 15 of the total block poor potential zones occupy a very insignificant portion less than 1

coseismic deformation from earthquake faulting on a layered spherical earth summary a method for calculating the static displacement field following earthquake faulting in a layered spherical earth is presented at shallow levels the earth s layering is characterized by sharp jumps in bulk and shear moduli at the conrad discontinuity and the moho and is therefore important to consider when evaluating crustal deformation the solution to the equations of static equilibrium is represented as a superposition of spheroidal and toroidal components that each depend on spherical harmonic degree and the moment tensor a method that has recently been applied to the problem of wave propagation on a layered spherical earth is here applied to the static deformation field by representing the point source in terms of discontinuities in the displacement stress vector the green s function for a particular source geometry is derived directly numerical tests are presented to verify the accuracy of the method and to illustrate the effects of sphericity and layering on the calculated deformation fields the effect of sphericity is generally less than about 2 per cent of maximum deformation within 100 km of an earthquake source at crustal depths comparisons between the deformation calculated on a spherical homogeneous earth and spherical layered earth show that up to 20 per cent errors would be introduced if the earth s layered structure were ignored the effect of layering is strongest for sources with a strong horizontal slip component

remote sensing technology and geographic information system modeling an integrated approach towards the mapping of groundwater potential zones in hardrock terrain mamundiyar basin in this paper remote sensing evaluation of digital elevation models dem geographic information systems gis and fieldwork techniques were combined to study the groundwater conditions in mamundiyar basin tamilnadu several digital image processing techniques including standard color composites intensity hue saturation ihs transformation and decorrelation stretch ds were applied to map rock types remote sensing data were interpreted to produce lithological and lineament maps dem was used for lineament and geomorphologic mapping all thematic layers were integrated and analyzed in a gis the overall results demonstrate that the use of remote sensing and gis provide potentially powerful tools to study groundwater resources and design a suitable exploration plan

groundwater potential index in a crystalline terrain using remote sensing data demand for groundwater for drinking agricultural and industrial purposes has increased due to uncertainty in the surface water supply agriculture is the main occupation of the rural people in guntur district andhra pradesh india development of groundwater in the district is very less indicating a lot of scope for further development of groundwater resources however assessment of groundwater conditions particularly in a crystalline terrain is a complex task because of variations in weathering and fracturing zones from place to place systematic studies for evaluation of groundwater potential zones have been carried out in a crystalline terrain of the district information on soils geological formations and groundwater conditions is collected during the hydrogeological survey topographical and drainage conditions are derived from the survey of india topographical maps geomorphological units and associated landform features inferred and delineated from the indian remote sensing satellite imagery irs id liss iii fcc are moderately buried pediplain bpm shallow buried pediplain bps valley fills vf structural hill sh residual hills rh lineaments and land use land cover a groundwater potential index gpi is computed for relative evaluation of groundwater potential zones in the study area by integrating all the related factors of occurrence and movement of groundwater resources accordingly the landforms bpm bps vf sh and rh of the area are categorized as very good groundwater potential zone good to moderate groundwater potential zone moderate to poor groundwater potential zone poor to very poor groundwater potential zone and very poor groundwater potential zone respectively for development and utilization of both groundwater and surface water resources for eliminating water scarcity this study could help to improve the agrarian economy for better living conditions of the rural people taking the total weight score of the gpi into account a generalized classification of groundwater potential zones is evaluated for a quick assessment of the occurrence of groundwater resources on regional scale

drainage morphometry of himalayan glacio fluvial basin india hydrologic and neotectonic implications morphometric analysis being widely used to assess the drainage characteristics of the river basins has been found to be a useful tool to delineate the glacial till covered overburden material as well as to identify areas prone to flash floods in present studies a number of parameters including the stream frequency drainage density and drainage texture suggest that the unconsolidated unstratified and highly permeable glacially deposited overburden till material facilitates the infiltration of snowmelt and rainwater in the pindari glacio fluvial basin eastern kumaun himalaya india likewise other till overburden covered glacial and proglacial areas of higher himalayan regions have been contributing to the groundwater budget the shape parameters further suggest that the sub basins with higher form factor are more prone to flash floods besides this the anomalies in the morphometric parameters have been found to be a useful tool to delineate zones of active tectonics in such areas

geophysical and geomorphological approach for locating groundwater potential zones in sukinda chromite mining area the impact of mining causes deterioration of environment and decline of groundwater level in the adjoining mining areas which influences groundwater source for domestic and agriculture purposes this necessitated locating and exploiting of new groundwater source a fast cost effective and economical way of locating and exploration is to study and analyze remote sensing data interpreted remote sensing data were used to select sites for carrying out surface geophysical investigations various geomorphologic units were demarcated and the lineaments were identified by interpretation of false color composite satellite imageries the potential for occurrence of groundwater in the sukinda valley was classified as very good good moderate and poor by interpreting the images sub surface geophysical investigations namely vertical electrical soundings were carried out to delineate and demarcate potential water bearing zones integrated studies of interpretation of geomorphologic lineaments and geophysical data aquifer thickness were used to prepare groundwater potential map the studies reveal that the groundwater potential of shallow aquifers is due to geomorphologic features and the potential of deeper aquifers is determined by lineaments and degree of weathering

quantitative analysis of morphometric parameters of kali river basin southern india using bearing azimuth and drainage bad calculator and gis this study deals with the application of visual basic program bearing azimuth and drainage bad calculator which employs a new and easy methodology for extraction of watershed morphometric parameters using bad calculator morphometric analysis was carried out for the kali river basin of southwest coast of india the basin forms a part of the western ghats which is an important mountain range of the indian sub continent and runs nearly parallel to the coast spatial maps of six morphometric parameters have been prepared from the results obtained various linear areal shape and relief morphometric parameters of fifth and sixth order basins have been calculated and interpreted majority of the sub basins show less uniform values 3 to 4 of rbm which indicate the uniform and systematic branching pattern of streams high dd zones are found in the western ghats region whereas low dd zones are observed in the eastern part of the basin and near the estuary the eastern part of the basin shows low fs values whereas nw and sw parts of the basin show high fs values compared to manual measurement bad calculator requires minimal time to quantify the morphometric parameters experimental results show that the software is effective in calculating drainage parameters such as drainage density frequency bifurcation ratio etc using the text file of esri shapefile

a regionalized upper mantle rum seismic model seismic velocity heterogeneity in the earth s mantle is strongly concentrated near its top the shallow heterogeneity of the mantle correlates strongly with surface tectonics we use these observations as constraints of a tomographic experiment aimed at building a regionalized upper mantle rum reference model we use a select set of teleseismic travel times to minimize the mapping of mislocation into structure the data selection emphasizes the robustness of individual picks the form of the rum model is a set of velocity profiles as functions of depth through the upper mantle for each of the different tectonic provinces of earth together the profiles constitute a three dimensional model which incorporates considerable structural detail but is described by only 90 parameters and has only about 22 degrees of freedom this is achieved by irregularly sampling a detailed regionalization of the globe by detailed mapping of subducted lithosphere in the mantle as defined by seismicity and by combining these structures in an irregular grid in which bookkeeping is efficiently handled the resulting rum model includes subducting slabs as sharp fast features in the upper mantle old continents are fast young oceans are slow models have been derived for both compressional and shear velocity the rum model is designed to represent as much of upper mantle heterogeneity as seen by body wave travel times as possible with a simple model it can be useful as a reference model for individual tectonic regions travel times are efficiently generated for the rum model mislocations of explosions of known location are significantly reduced when corrections for the rum model are applied to travel time residuals for a spherically symmetrical earth model

shoreline changes and morphology of spits along southern karnataka west coast of india a remote sensing and statistics based approach abstract the changes in shoreline positions and morphology of spits along the karnataka coast western india are investigated for the period from 1910 to 2005 using multi dated satellite images and topomaps the study area has been divided into four littoral cells and each cell into a number of transects at uniform intervals the rate of change in shoreline position has been estimated using the statistical linear regression method and cross validated with regression coefficient r 2 and root mean square error rmse methods past and future shoreline positions have been demarcated and future positions of shoreline are estimated for time periods of 10 and 24 years the study reveals that i about 57 of transects exhibit 10 m rmse values indicating better agreement between the estimated and satellite based shoreline positions and ii transects closer to the cell boundaries exhibit about 50 uncertainties in shoreline change rate estimations based on rmse values the influence of natural processes and anthropogenic factors on shoreline changes has been evaluated the cells transects dominated by natural processes reveal low rmse values whereas the cells transects influenced by anthropogenic activities such as sand mining construction of coastal structures exhibit higher rmse values however the variation in rmse values is not significant if the total number of transects is considered significant changes in morphology of spits have been recorded spits demonstrate variations in areal extent i e length and area if 1910 and 1967 are considered separately as base years the present study demonstrates that combined use of satellite imagery and statistical techniques such as linear regression and rmses can be very useful in quantifying shoreline changes and spit morphology

seismology speed and size of the sumatra earthquake we now have a clearer picture of the seismic features of last year s gigantic event our seismological results reveal that indonesia s devastating sumatra andaman earthquake on 26 december 2004 was 2 5 times larger than initial reports suggested second only to the 1960 chilean earthquake in recorded magnitude they indicate that it slowly released its energy by slip along a 1 200 km fault generating a long rupture that contributed to the subsequent tsunami now that the entire rupture zone has slipped the strain accumulated from the subduction of the indian plate beneath the burma microplate has been released and there is no immediate danger of a similar tsunami being generated on this part of the plate boundary although large earthquakes on segments to the south still present a threat

integrated remote sensing and gis based approach for deciphering groundwater potential zones in the central region of saudi arabia the scarcity of fresh water resources is a major challenge facing saudi arabia groundwater is the major conventional water source in saudi arabia therefore it is important to identify areas having groundwater potential however the current methods of groundwater exploration consume a lot of time and money alternatively this paper introduces a methodology to identify groundwater potential zones in the central part of saudi arabia using remote sensing and gis based decision support system dss and fuzzy logic based spatial model the dss model generated suitability maps for groundwater potential gwp zones with five suitability classes i e excellent very good good poor and very poor based on the integration of nine thematic maps soil type land cover and land use slope lithology rainfall geological structure geomorphology lineament density and drainage density using a hierarchical process analysis ahp the spatial distribution of the gwp zones by ahp dss and fuzzy logic model showed that excellent suitable areas for gwp were concentrated in the main wadi channels within the central northeastern and southeastern parts of the study area the ahp dss model showed that 1 47 5608 5 km2 and 4 15 15 787 3 km2 of the study area was classified as excellent and very good respectively while 12 59 47 911 1 km2 74 82 284 670 9 km2 and 6 97 26 519 9 km2 of the area were classified as good poor and very poor respectively on the other hand integrating thematic layers using fuzzy logics indicates that 2 8 10 739 km2 8 8 33 587 km2 7 9 30 106 km2 60 228 361 km2 and 20 4 77 705 km2 of the entire study area is considered as excellent very good good poor and very poor areas for groundwater potential respectively the majority of the areas with excellent to very good suitability had slopes between 0 and 3 and were in intensively cultivated fields the major soil type in the excellent to very good zones was arenosols and lithosols the rainfall ranged from 125 to 226 mm year while the main lithological structures are alluvial deposits carbonate rocks and mixed sedimentary consolidated rocks these areas are mainly located in the carbonate sulfate formations which extend from the lower jurassic to the lower cretaceous and the sandstone aquifers moreover they have lineament density ranged from 4 75 to 8 34 km km2 and drainage density ranged from 1 to 1 83 km km2 furthermore the study revealed that lineament density is closely related to groundwater occurrence and yield and is essential to groundwater surveys development and management validation of the two models employed depends on comparing existing groundwater well locations with the suitability map generated using the proximity analysis tools of arcgis 10 2 the results obtained from ahp dss approach and fuzzy model were verified with field survey and were found to be in very good and good agreement respectively the validation results showed that the database and methodology used for developing the suitability model for gwp zones including the suitability levels of the criteria and the criteria s relative importance weights to have yielded accurate results

integration of hydrological factors and demarcation of groundwater prospect zones insights from remote sensing and gis techniques the study demonstrates the potential of geographical information system and statistical based approaches to identify the hydrological processes and demarcate the groundwater prospect zones of the gangolli basin karnataka state india the basin is situated in humid tropical climate and influenced by three major rivers viz kollur 6th order stream chakra 6th order stream and haladi 7th order stream which cover an area of 1 512 km2 and cumulative length of 84 km various thematic maps drainage geomorphology geology slope soil lineament and lineament density were prepared using survey of india topographic maps indian remote sensing irs p6 images and other published maps hydrogeomorphologic characteristics were correlated with different morphometric parameters to identify the hydrological processes and demarcate the groundwater potential zones of the basin all the hydrological units and morphometric parameters were assigned suitable weightages according to their relative importance to groundwater potentiality to identify the most deficit surplus zones of groundwater based on hydrological characteristics integrated thematic maps reveal that 14 217 km2 of basin area falls under very good 32 486 km2 under good 23 353 km2 under moderate and 30 443 km2 under poor zones for groundwater potential from the sub basin wise prioritisation it has been inferred that sb iii scored highest groundwater potential followed by sb x result of morphometric analyses with the hydrologic parameters indicates that 99 area of sb iii and sb x are under very good to moderate groundwater potential zone this study clearly demonstrates that hydrological parameters in relation with morphometric analyses are useful to demarcate the prospect zones of groundwater

lagrangian simulation of transport pathways and residence times along the western antarctic peninsula abstract the relative contribution of ocean circulation in producing areas where marine mammals and other predators concentrate to produce biological hot spots along the continental shelf of the western antarctic peninsula wap was investigated with numerical lagrangian particle tracking simulations circulation distributions used in the lagrangian simulations were obtained from the regional ocean modeling system roms configured for the wap region with a horizontal resolution of 4 km and a vertical resolution of 24 sigma layers to determine release points for the floats the simulated circulation fields were first analyzed to estimate scales of temporal variability the temporal decorrelation scales of the simulated surface flow over most of the wap shelf were 2 3 days however decorrelation scales of about 40 days were found for the surface flow in the southern part of marguerite bay temporal decorrelation scales for the flow below the permanent pycnocline at the depth of circumpolar deep water cdw intrusions below 250 m were between 40 and 70 days along the northern flank of marguerite trough and extending into marguerite bay near adelaide island anvers island and the offshore side of alexander island the velocity decorrelation scales varied between 40 and 60 days floats were released in the wap simulated circulation fields along the outer and mid shelf at a range of depths in different seasons the simulated particle trajectories showed preferred sites for across shelf transport with marguerite trough being a primary pathway for movement of floats into marguerite bay crystal sound and the inner shelf region the three primary biological hot spots crystal sound laubeuf fjord and off alexander island were sites with the longest particle residence times being 18 27 days for alexander island and crystal sound to almost 35 days for laubeuf fjord however the source regions and circulation processes that provided the input of particles differed for each site the lagrangian particle tracking results showed the importance of the circulation in developing localized biological hot spots along the wap perhaps by facilitating aggregation of planktonic prey

groundwater potential mapping using remote sensing techniques and weights of evidence gis model a case study from wadi yalamlam basin makkah province western saudi arabia in the present study remote sensing techniques gis models and field measurements are integrated to identify and map groundwater potential zones at wadi yalamlam sa diyah basin makkah province western saudi arabia the study area is located in the arabian shield heterogeneous basement terrain it is characterized by insignificant primary porosity and permeability and is mainly covered by massive and altered gneissose granites diorite and gabbro and metamorphosed basalts lithology rainfall lineament density drainage density slope steepness and landuse landcover are the main hydrogeological parameters defined to be related to the groundwater storage in the study area they are prepared using the processed satellite data and integrated using weights of evidence and index overlay gis models to generate groundwater potential zones map within the gis model those parameters are assigned values of 30 20 15 15 10 and 10 respectively as score values the resulting groundwater potential zone map for wadi yalamlam basin is categorized into three main classes high moderate and low groundwater potential zones based on pixel values the results of this study indicate that the lower parts of the wadi yalamlam basin is the most promising area for groundwater occurrences and contains both high and moderate potential zones high groundwater potential zones are located to the north of the main dyke area around abu helal farm they are characterized by loose wadi deposits flat areas gentle slope ranges between 0 and 5 degrees low drainage density 100 d 30 km2 and shallow water table water table is 7 m from the ground surface the present study proved 1 the usefulness of the processed remote sensing satellite imageries for generating several indirect groundwater parameters 2 the usefulness of weights of evidence and index overlay gis models for the integration process and the production of groundwater potential zone map along the study area

the significance of morphometric analysis for obtaining groundwater potential zones in a structurally controlled terrain watershed development and management plans are more important for harnessing surface water and groundwater resources in arid and semi arid regions to prepare a comprehensive watershed development plan it becomes necessary to understand the topography erosion status and drainage patterns of the region this study was undertaken to determine the drainage characteristics of pageru river basin using topographical maps on a scale of 1 50 000 the total area of the pageru river basin is 480 km2 it was divided into x sub basins for analysis the drainage patterns of the basin are dendritic and include a sixth order stream the quantitative analysis of various aspects of a river basin drainage network characteristics reveals complex morphometric attributes the streams of lower orders mostly dominate the basin the development of stream segments in the basin area is more or less affected by rainfall the elongated shape of the basin is mainly due to the guiding effect of thrusting and faulting the erosional processes of fluvial origin have been predominately influenced by the subsurface lithology of the basin

groundwater recharge and exploitative potential zone mapping using gis and god techniques two thirds of the total area of taiwan is mountainous terrain which is the main groundwater recharge source of the plains region this study assesses groundwater recharge and exploitative potential zone in the central division of the mountain areas of taiwan the middle reaches of the jhuoshuei river basin basic information from remote sensing and a satellite phantom is collected to set up the basic data maps using elevation formosa ii images the normalized difference vegetation index drainage distribution slope aspect ratio lineament distribution and land cover a geographical information system is used to integrate five contributing factors namely lithology land cover land use drainage slope and lineaments the criteria for the recharge potential assessment are established to demarcate the potential groundwater recharge zone finally the god rating system is adopted to evaluate the potential exploitation zone three main parameters are considered the groundwater occurrence the lithology of the overlying layers and the depth to groundwater the results show that the middle reaches of the chenyuland river have large potential exploitation zones due to its high rainfall recharge capacity regions west of the jhuoshuei river and the downstream regions of the chingshui river are medium potential exploitation zones because of their high infiltration rates and shallow groundwater levels

morphometrical analysis of two tropical mountain river basins of contrasting environmental settings the southern western ghats india the morphometric analysis of river basins represents a simple procedure to describe hydrologic and geomorphic processes operating on a basin scale a morphometric analysis was carried out to evaluate the drainage characteristics of two adjoining mountain river basins of the southern western ghats india muthirapuzha river basin mrb in the western slopes and pambar river basin prb in the eastern slopes the basins forming a part of the proterozoic high grade southern granulite terrain of the peninsular india are carved out of a terrain dominantly made of granite and hornblende biotite gneisses the western ghats forming the basin divide significantly influences the regional climate i e humid climate in mrb while semi arid in prb the survey of india topographic maps 1 50 000 and shuttle radar topographic mission digital elevation data were used as the base for delineation and analysis both river basins are of 6th order and comparable in basin geometry the drainage patterns and linear alignment of the drainage networks suggest the influence of structural elements the rb of either basins failed to highlight the structural controls on drainage organization which might be a result of the elongated basin shape the irregular trends in rb between various stream orders suggest the influence of geology and relief on drainage branching the dd values designate the basins as moderate to well drained with lower infiltration rates the overall increasing trend of rl between successive stream orders suggests a geomorphic maturity of either basins and confirmed by the characteristic i hyp values the re values imply an elongate shape for both mrb and prb and subsequently lower vulnerability to flash floods and hence easier flood management the relatively higher rr of prb is an indicative of comparatively steeply sloping terrain and consequently higher intensity of erosion processes further the derivatives of digital elevation data slope aspect topographic wetness index and stream power index showing significant differences between mrb and prb are useful in soil conservation plans the study highlighted the variation in morphometric parameters with respect to the dissimilarities in topography and climate

tectonics and history of the andaman sea region abstract the andaman sea is an active backarc basin lying above and behind the sunda subduction zone where convergence between the overriding southeast asian plate and the subducting australian plate is highly oblique the effect of the oblique convergence has been formation of a sliver plate between the subduction zone and a complex right lateral fault system the late paleocene collision of greater india and asia with approximately normal convergence started clockwise rotation and bending of the northern and western sunda arc the initial sliver fault which probably started in the eocene extended through the outer arc ridge offshore from sumatra through the present region of the andaman sea into the sagaing fault with more oblique convergence due to the rotation the rate of strike slip motion increased and a series of extensional basins opened obliquely by the combination of backarc extension and the strike slip motion these basins in sequence are the mergui basin starting at 32 ma the conjoined alcock and sewell rises starting at 23 ma east basin separating the rises from the foot of the continental slope starting at 15 ma and finally at 4 ma the present plate edge was formed alcock and sewell rises were separated by formation of the central andaman basin and the faulting moved onshore from the mentawai fault to the sumatra fault system bisecting sumatra

coseismic slip distributions of the 26 december 2004 sumatra andaman and 28 march 2005 nias earthquakes from gps static offsets static offsets produced by the 26 december 2004 m 9 sumatra andaman earthquake as measured by global positioning system gps reveal a large amount of slip along the entire 1300 km long rupture most seismic slip inversions place little slip on the andaman segment whereas both near field and far field gps offsets demand large slip on the andaman segment we compile available datasets of the static offset to render a more detailed picture of the static slip distribution we construct geodetic offsets such that postearthquake positions of continuous gps sites are reckoned to a time 1 day after the earthquake and campaign gps sites are similarly corrected for postseismic motions the newly revised slip distribution m w 9 22 reveals substantial segmentation of slip along the andaman islands with the southern quarter slipping 15 m in unison with the adjacent nicobar and northern sumatran segments of length 700 km we infer a small excess of geodetic moment relative to the seismic moment a similar compilation of gps offsets from the 28 march 2005 nias earthquake is well explained with dip slip averaging several meters mw 8 66 distributed primarily at depths greater than 20 km online material offset estimation procedure comparison of results to other stud ies and simpler solutions and tables of coseismic offsets

prioritization of malesari mini watersheds through morphometric analysis a remote sensing and gis perspective geographical information system and remote sensing are proven to be an efficient tool for locating water harvesting structures by prioritization of mini watersheds through morphometric analysis in this study the morphometric analysis and prioritization of ten mini watersheds of malesari watershed situated in bhavnagar district of saurashtra region of gujarat state india are studied for prioritization of mini watersheds morphometric analysis is utilized by using the linear parameters such as bifurcation ratio drainage density stream frequency texture ratio and length of overland flow and shape parameters such as form factor shape factor elongation ratio compactness constant and circularity ratio the different prioritization ranks are assigned after evaluation of the compound factor digital elevation model from shuttle radar topography mission digitized contour and other thematic layers like drainage order drainage density and geology are created and analyzed over arcgis 9 1 platform combining all thematic layers with soil and slope map the best feasibility of positioning check dams in mini watershed has been proposed after validating the sites through the field surveys

evolution of swarna estuary and its impact on braided islands and estuarine banks southwest coast of india qualitative and quantitative evolution of the swarna estuary during the past 38 years 1967 2005 has been analysed by integrating the results of field surveys satellite images hydrodynamic modelling and topographic data in gis context significant changes in erosion accretion patterns of the estuarine banks inlet configuration and adjacent spits and origin morphology orientation and areal extent of fifteen braided islands have been estimated hydrodynamics of the region is studied through modelling and probable flow pattern that is responsible for morphological changes is discussed the simulated flow patterns indicate that current speeds are of the order of 10 20 cm s inside the estuary and of the order of 40 cm s at the mouth the right bank rb of the estuary is subject to net erosion and the left bank lb is subject to net accretion on an average 20 30 of the area of all braided islands would be flooded if the water level rises by 0 7 to 1 0 m islands of this estuary are morphologically very dynamic migrating towards north northeast and southwest directions and subject to net accretion whereas only one island i e the padu has lost its major portion of landmass a conceptual inverse distance weighted idw interpolation model has been generated and evaluated possible flooding on the estuarine shoals and braided islands due to heavy rainfall and or sea level rise the model reveals that the possibility of flooding will be higher for those islands which are located close to the rb than those close to the lb

application of gis techniques to determine areas most suitable for artificial groundwater recharge in a coastal aquifer in southern iran abstract special attention has been paid to artificial groundwater recharge in water resource management in arid and semi arid regions parameters considered in the selection of groundwater artificial recharge locations are diverse and complex in this study factors such as slope infiltration rate depth to groundwater quality of alluvial sediments and land use are considered to determine the areas most suitable for groundwater recharge in a coastal aquifer in the gavbandi drainage basin in the southern part of iran thematic layers for the above parameters were prepared classified weighted and integrated in a gis environment by the means of boolean and fuzzy logic to determine the relationships between geomorphological units and the appropriate sites for groundwater artificial recharge land use and geomorphological maps were developed from satellite images the results of the study indicate that about 12 of the study area is considered as appropriate and 8 moderately appropriate sites for artificial groundwater recharge the relationship between geomorphology and appropriate areas for groundwater recharge indicate that the majority of these areas are located on alluvial fans and pediment units at the reconnaissance stage these geomorphological units can be considered as appropriate sites for artificial recharge in regions with similar characteristics

morphometric evaluation of papanasam and manimuthar watersheds parts of western ghats tirunelveli district tamil nadu india a gis approach a morphometric analysis was carried out to describe the topography and drainage characteristics of papanasam and manimuthar watersheds these watersheds are part of western ghats which is an ecologically sensitive region the drainage areas of papanasam and manimuthar watersheds are 163 and 211 km2 respectively and they show patterns of dendritic to sub dendritic drainage the slope of both watersheds varied from 0 to 59 and 0 to 55 respectively moreover the slope variation is chiefly controlled by the local geology and erosion cycles each watershed was classified as a fifth order drainage basin the stream order of the basin was predominantly controlled by physiographic and structural conditions the increase in 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 size and duration of the sumatra andaman earthquake from far field static offsets the 26 december 2004 sumatra earthquake produced static offsets at continuously operating gps stations at distances of up to 4500 kilometers from the epicenter we used these displacements to model the earthquake and include consideration of the earth s shape and depth varying rigidity the results imply that the average slip was 5 meters along the full length of the rupture including the approximately 650 kilometer long andaman segment comparison of the source derived from the far field static offsets with seismically derived estimates suggests that 25 to 35 of the total moment release occurred at periods greater than 1 hour taking into consideration the strong dip dependence of moment estimates the magnitude of the earthquake did not exceed mw 9 2