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• Geomorphologic analysis of drainage networks on Mars

  15-30

  Ákos Kereszturi

  Views:

  46

  Altogether 327 valleys and their 314 cross-sectional profiles were analyzed on Mars, including width, depth, length, eroded volume, drainage and spatial density, as well as the network structure. According to this systematic analysis, five possible drainage network types were identified such as (a) small valleys, (b) integrated small valleys, (c) individual, medium-sized valleys, (d) unconfined, anastomosing outflow valleys, and (e) confined outflow valleys. Measuring their various morphometric parameters, these five networks differ from each other in terms of parameters of the eroded volume, drainage density and depth values. This classification is more detailed than those described in the literature previously and correlated to several numerical parameters for the first time. These different types were probably formed during different periods of the evolution of Mars, and sprung from differently localized water sources, and they could be correlated to similar fluvial network types from the Earth.

• Quantitative Morphometric Analysis of Streams in Extreme Humid Areas: A Case Study of the Um-Mawiong River Basin, Mawsynram, Meghalaya

  59-75

  Andy T.G Lyngdoh

  Bring Blessing L Ryntathiang

  Views:

  82

  Quantitative morphometric analysis of the drainage system is essential to characterising a watershed, as all the hydrologic and geomorphic processes occur within the watershed. Consequently, this plays a crucial role in understanding the geo-hydrological attributes of a drainage basin to the terrain feature and its flow patterns, thus enabling the estimate of the incidence of infiltration and runoff and other related hydrological characteristics of a watershed, which strongly impacts natural resource conservation. The study area selected is the Um-Mawiong River basin in Mawsynram, Meghalaya. The basin shows a dendritic pattern that highlights the homogeneity in the texture of the basin. Results suggest that the stream frequency of the basin is 19.10 km², suggesting a faster surface runoff and less infiltration. In addition, it has an Elongation ratio of 0.75 indicating an elongated basin shape. The current study demonstrates that the implementations of GIS techniques are trustworthy, efficient, and capable of managing extensive databases for managing river basins. The present study tries to analyse the linear, areal and relief aspects of the basin using a GIS environment and manipulated for different calculations. The analysis reveals that the total number of stream segments and length are maximum in first-order streams and decrease as stream order increases. The drainage density exhibits a high degree of positive correlation, i.e., 0.87, with its frequency suggesting an increase in stream population concerning increasing drainage density and vice versa.

• Morphometric characteristics of a tropical river basin, central Kerala, India using geospatial techniques

  1-14

  Shabna Sherin

  Arunkumar K.S

  Views:

  228

  The Thutapuzha watershed (TW) is one among the major tributaries of Bharathapuzha – the largest west flowing river in Kerala, India. Morphometric analysis was carried out to determine the spatial variations in the drainage characteristics and to understand the prevailing geologic variation, topographic information and structural setup of TW using Survey of India topographic maps and ASTER-DEM. Geoprocessing techniques has been used for the delineation and calculation of the morphometric parameters of the watershed. The TW sprawled over 1107Km² and the study revealed that the watershed includes a sixth order stream and lower order streams mostly dominate the basin with a drianage density of 1.36 m/Km²  exhibiting highly resistant subsoil, dense vegetation, and low relief of surface nature . The study  indicate that rainfall has a significant role in the drainage development whereas the drainage pattern is controlled by structure and relief. The watershed of TW is moderate to well-drained and exhibited a geomorphic maturity in its physiographic development. The shape parameters revealed the elongated nature of TW having less prone to flood, lower erosion and sediment transport capacities and drainage network development in the watershed. This study strongly brings to light that the drainage morphometric parameters have the enormou spotentiality to unveil the hydro-morphologicalcharacteristics of the river basins. Integrating hydro-morphological characteristics with conventional watershed assessment methods would have a beneficial effect on judicious watershed management, which helped to formulate a comprehensive watershed management plan.