Terrain characteristics and longitudinal,land use and land cover profiles behavior—a case study from Vamanapuram river basin,southern Kerala,India

The morphology of Vamanapuram river basin (VRB), southern Kerala, India has been studied by preparing longitudinal profiles from the source of VRB at Chemmunji Mottai (1,717 m) to its mouth at Muthalapallipozhy (Lakshadweep Sea). Survey of India topographical maps, Geocoded Satellite Imageries, Microsoft Excel and GIS software ILWIS 2.1 are used in this study. The morphometric analysis reveals that there are 1,489, 347, 79, 21, 6, 2 and 1 first-, second-, third-, fourth-, fifth-, sixth- and seventh-order streams, respectively, in VRB, which are responsible for the present-day landform genesis. The mean bifurcation value of VRB is 3.49. The Ponmudi hills receive the highest rainfall in VRB in the Western Ghats Region and Attingal, the lowest in the Coastal Strand Plain. The six land use and land cover profile sections show the distribution of land use–land cover with respect to elevation and depth to water level. The study reveals that mid and high lands generally occupy lower order streams up to fourth order and generally originate from linear ridge, hill crest, rocky slope (scarp face), side slope (S3)/slope 10–15° and hilly terrain.     

Response of Sedimentary Nucleic Acids to Benthic Disturbance in the Central Indian Basin

Information on the response of nucleic acids (i.e., DNA and RNA) to simulated benthic disturbance was obtained from samples collected from eight sediment cores (0–10 cm) located in the Central Indian Basin (CIB). In general the total sedimentary DNA (DNA) increased with depth (from 380.09 to 408.99 μg·g^?1), while total sedimentary RNA (RNA) decreased (from 878.13 to 484.16 μg·g^?1). Following the simulated benthic disturbance brought about by the benthic hydraulic disturber, DNA decreased by 10% along the disturbed track while the RNA increased by around 75%. The RNA/DNA ratio decreased nearly 10%. However, the ratio doubled along the disturbed track suggesting that the activity was stimulated at molecular level following artif icial disturbance. The nucleic acid ratio thus shows that the CIB sediments are metabolically active, and with disturbance the activity tends to increase further.     

Tidal Constituents in the Shallow Waters of the Southwest Indian Coast

A two-dimensional hydrodynamic model was set up and validated for the west coast of India. The spatio-temporal variation of the tidal constituents for a 110 km stretch of the southwest coast of India was then studied by setting up a fine grid model. The study brings out variability in the shallow water constituents and their selective amplification. Within the Cochin estuary, the amplitudes of almost all the major tidal constituents show a gradual reduction upstream compared to other locations. The shallow water constituents show significant amplification and Z0, the constituent related to mean sea level shows five-fold amplification within the estuary.     

关于我国东部夏季风进退的定义

使用１９８３年至１９９６年美国国家环境预测中心１４年逐日平均２．５°＊２．５°再分析的网格点资料对我国东部夏季风进退进行了 细胞研究,并对夏季风进退作了新的定义。它既考虑了西南风的强度亦考虑了其暖湿程度。     

On the structure of sea-breeze fronts observed near the coastline of Thumba,India

An investigation has been made of the structure of sea-breeze fronts observed at Thumba mostly during the months of December to April using data from a Doppler SODAR and in situ measurements of wind components, humidity and temperature. The study shows that the vertical wind structure observed in the SODAR height range provides a distinct signature of the passage of a front and that the intensity of the front is decided by the intensity and direction of the prevailing winds as well as the amount of rotation of the wind vector during the onset of the sea-breeze. Spectral analyses of vertical winds during the passage of the front reveal a dominant periodicity of about 6 min for strong sea-breeze fronts.