Cyprinid Fishes: An Overview on the Present Status in Meghalaya, India

2020 ◽  
Vol 7 (1) ◽  
pp. 13-22
Author(s):  
Rupak Nath ◽  
◽  
S M Kharbuli
Keyword(s):  
Drainage Basin ◽  
Diversity Indices ◽  
Drainage Basins ◽  
Lower Elevation ◽  
Occasional Occurrence ◽  
Elevation Zone ◽  
Commercially Important ◽  
Cyprinid Fishes ◽  
Catch Composition ◽  
Rivers And Reservoirs

Cyprinid fishes of Meghalaya were investigated from twin drainage basins Brahmaputra and Barak-Surma-Meghna. 27 cyprinid fishes under 14 genus and 7 sub families were recorded from rivers and reservoirs of four different gradient zones. The diversity of Cyprinid fishes was highest with 49% representation of Cyprinids at lower elevation Zone IV below 500 m above MSL and bio diversity indices estimated as H: 3.05, 1-D: 0.10. In contrary lowest diversity with 7% representation of fishes was observed at elevation 1501 to 2000 m above MSL in Zone I with bio diversity indices H: 0.25, 1-D: 0.57. Distribution of commercially important cyprinids under genus Labeo, Systomus and Cirrhinus were found to be restricted to rivers of Barak-Surma-Meghna drainage basin. Catch percentage of cyprinids indicates that 70% of fishes exhibit occasional occurrence and 30% as common occurrence. High percentage of occasional occurrence, low catch composition percentage and with restricted distribution of commercially important fishes to only certain rivers of Barak-Surma-Meghna drainage is an indication of depletion of cyprinid resources in the state and requires taking multi prong conservation measures to protect cyprinid fishes in Meghalaya.

DRAINAGE BASIN AS A COMPLEX SOCIO-NATURAL HIERARCHICAL SYSTEM

2020 ◽  
Vol 42 (3) ◽  
pp. 293-303
Author(s):  
VALERIY BONDAREV
Keyword(s):  
Drainage Basin ◽  
Temporal Analysis ◽  
Large River ◽  
Hierarchical Level ◽  
Effective Management ◽  
Drainage Basins ◽  
Time Intervals ◽  
Natural Systems ◽  
Spatial And Temporal Analysis ◽  
Entire Complex

The theoretical and methodological basis of the systems hierarchical spatial and temporal analysis of a drainage basin, which addresses the problems of effective management in socio-natural systems of different ranks, is considered. It is proposed to distinguish 9 orders of forms that are relevant to the analysis of drainage basins, where the first level is represented by individual aggregates and particles, and the last - by basins of large and the largest rivers. As part of the allocation of geological, historical and modern time intervals, the specificity of the implementation of processes in basins of different scales from changing states, through functioning to evolution is demonstrated. The interrelation of conditions and factors that determine the processes occurring within the drainage basins is revealed. It is shown that a specific combination of conditions and factors that determine processes in the drainage basin is associated with the hierarchy of the objects under consideration, i.e. the choice of a spatial-temporal hierarchical level is crucial for the organization of study within drainage basins. At one hierarchical level, some phenomenon can be considered as a factor, and at another - as a condition. For example, tectonic processes can be considered as an active factor in the evolution of large river basins in the geological perspective, but for small drainage basin, this is already a conservative background condition. It is shown that at the historical time the anthropogenic factor often comes to the fore, with the appearance of which in the functioning of the drainage basin, there is a need to take into account the entire complex of socio-environmental problems that can affect the sustainable state of various territories, especially in the field of water and land use. Hierarchical levels of managing subjects are identified, which are primarily responsible for effective management at the appropriate hierarchical level of the organization of the socio-natural system within the catchment area, starting from an individual to humankind as a whole.

scholarly journals A Stepwise GIS Approach for the Delineation of River Valley Bottom within Drainage Basins Using a Cost Distance Accumulation Analysis

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 827
Author(s):  
Gasper L. Sechu ◽  
Bertel Nilsson ◽  
Bo V. Iversen ◽  
Mette B. Greve ◽  
Christen D. Børgesen ◽  
...  
Keyword(s):  
Spatial Data ◽  
Nutrient Loading ◽  
Drainage Basin ◽  
River Valley ◽  
Management Tool ◽  
Drainage Basins ◽  
Valley Bottom ◽  
Management Actions ◽  
Cost Distance ◽  
River Valleys

River valley bottoms have hydrological, geomorphological, and ecological importance and are buffers for protecting the river from upland nutrient loading coming from agriculture and other sources. They are relatively flat, low-lying areas of the terrain that are adjacent to the river and bound by increasing slopes at the transition to the uplands. These areas have under natural conditions, a groundwater table close to the soil surface. The objective of this paper is to present a stepwise GIS approach for the delineation of river valley bottom within drainage basins and use it to perform a national delineation. We developed a tool that applies a concept called cost distance accumulation with spatial data inputs consisting a river network and slope derived from a digital elevation model. We then used wetlands adjacent to rivers as a guide finding the river valley bottom boundary from the cost distance accumulation. We present results from our tool for the whole country of Denmark carrying out a validation within three selected areas. The results reveal that the tool visually performs well and delineates both confined and unconfined river valleys within the same drainage basin. We use the most common forms of wetlands (meadow and marsh) in Denmark’s river valleys known as Groundwater Dependent Ecosystems (GDE) to validate our river valley bottom delineated areas. Our delineation picks about half to two-thirds of these GDE. However, we expected this since farmers have reclaimed Denmark’s low-lying areas during the last 200 years before the first map of GDE was created. Our tool can be used as a management tool, since it can delineate an area that has been the focus of management actions to protect waterways from upland nutrient pollution.

scholarly journals Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

2016 ◽  
Vol 4 (4) ◽  
pp. 831-869 ◽  
Author(s):  
Andrew D. Wickert
Keyword(s):  
North American ◽  
Drainage Basin ◽  
Ice Sheets ◽  
Glacial Isostatic Adjustment ◽  
Drainage Basins ◽  
Last Glacial ◽  
Isostatic Adjustment ◽  
The North ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. Over the last glacial cycle, ice sheets and the resultant glacial isostatic adjustment (GIA) rearranged river systems. As these riverine threads that tied the ice sheets to the sea were stretched, severed, and restructured, they also shrank and swelled with the pulse of meltwater inputs and time-varying drainage basin areas, and sometimes delivered enough meltwater to the oceans in the right places to influence global climate. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges, by combining models of past ice sheets, glacial isostatic adjustment, and climate. The result is a time series of synthetic paleohydrographs and drainage basin maps from the Last Glacial Maximum to present for nine major drainage basins – the Mississippi, Rio Grande, Colorado, Columbia, Mackenzie, Hudson Bay, Saint Lawrence, Hudson, and Susquehanna/Chesapeake Bay. These are based on five published reconstructions of the North American ice sheets. I compare these maps with drainage reconstructions and discharge histories based on a review of observational evidence, including river deposits and terraces, isotopic records, mineral provenance markers, glacial moraine histories, and evidence of ice stream and tunnel valley flow directions. The sharp boundaries of the reconstructed past drainage basins complement the flexurally smoothed GIA signal that is more often used to validate ice-sheet reconstructions, and provide a complementary framework to reduce nonuniqueness in model reconstructions of the North American ice-sheet complex.

Peak runoff simulation in a subarctic region

1976 ◽  
Vol 3 (4) ◽  
pp. 555-562
Author(s):  
J. Penel ◽  
T. Kung
Keyword(s):  
Meteorological Parameters ◽  
Drainage Basin ◽  
Flow Simulation ◽  
Drainage Basins ◽  
Runoff Simulation ◽  
Subarctic Region ◽  
Physical Conditions ◽  
Spring Peak ◽  
Peak Runoff ◽  
Peak Discharges

Due to the lack of stream guaging stations, a peak flow simulation based on physical and meteorological parameters was established for the area along the proposed Mackenzie Valley Highway between Fort Good Hope and the Dempster Highway.Calculations based on snowmelt and rain-on-snow runoff were developed, as it was found that the snowmelt of May or early June gave the yearly spring peak discharge.Due to the gap in existing flow data, a unit hydrograph method was developed to generate additional yearly spring peak discharges. Altogether, hydrographs from four gauged watersheds of similar physical conditions with size ranging from 250 to 8 200 mi2 (648 to 21 240 km2) were used. In total, 46 yearly peak flows were generated.A regression equation of peak discharge computation was derived, using different hydrological and meteorological parameters. It was found that the most significant factors were the drainage basin area, the lake areas in the drainage basin, the water equivalent of the snow on the ground prior to melt, the rainfall in the period close to peak discharges, and the duration of snowmelt.The simulation was calibrated for drainage basins between 100 and 10 000 mi2 (250 to 25 000 km2).

scholarly journals Topographic Map Analysis of High Elevation Black Hills Through Valleys Linking Spearfish and Rapid Creek Headwaters Valleys, Lawrence County, South Dakota, USA

2017 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Eric Clausen
Keyword(s):  
South Dakota ◽  
Drainage Basin ◽  
Water Source ◽  
High Elevation ◽  
Black Hills ◽  
Topographic Map ◽  
Drainage Basins ◽  
Converging Channel ◽  
Lawrence County ◽  
Map Analysis

The Spearfish-Rapid Creek drainage extends from elevations greater than 7130 feet (2173 meters) roughly in a north direction across the northern Black Hills upland to where it becomes the Spearfish-Whitewood Creek drainage divide at an elevation of approximately 6440 feet (1963 meters) and separates north-oriented Spearfish Creek headwaters from southeast- and east-oriented Rapid Creek headwaters. This study used detailed topographic maps to investigate through valleys (and wind gaps) now crossing the Spearfish-Rapid Creek drainage divide, which is one of the Black Hills’ highest drainage divides. Through valley (or wind gap) floor elevations were determined and ranged from approximately 6150 feet (1875 meters) to approximately 7050 feet (2149 meters) and through valley (and wind gap) depths were also calculated and ranged from approximately 30 feet (9 meters) to about 290 feet (88 meters). Map evidence suggesting these through valleys (and wind gaps) originated as components of diverging and converging complexes of bedrock-walled channels is described and suggests large and prolonged southeast-oriented floods once flowed from or across the Spearfish Creek drainage basin to the Rapid Creek drainage basin. Based on today’s topography there is no upland Black Hills region capable of generating the large and prolonged floods required to erode the observed through valleys (and wind gaps) and their associated diverging and converging channel complexes so the erosion is interpreted to have taken place while the Black Hills were just beginning to emerge as the topographic high they are today. A water source could not be determined from map evidence, but large and prolonged southeast-oriented floods across the region are consistent with a recently proposed hypothesis that massive southeast-oriented (continental ice sheet) ice-marginal melt water floods eroded what are today western South Dakota and North Dakota river drainage basins. 

scholarly journals Landscape structure in the Pirapó, Paranapanema 3 and 4 Hydrographic Unit, in the state of Paraná, Brazil

2015 ◽  
Vol 75 (4 suppl 2) ◽  
pp. 107-119
Author(s):  
M. T. Nóbrega ◽  
E. Serra ◽  
H. Silveira ◽  
P. M. B. Terassi ◽  
C. M. Bonifácio
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Spatial Structure ◽  
Landscape Structure ◽  
Drainage Basin ◽  
The State ◽  
Integrated Analysis ◽  
Drainage Basins ◽  
Physical Attributes ◽  
Over Time

The aim of this study is to characterize the Pirapó, Paranapanema 3 and 4 Hydrographic Unit, emphasizing its physical attributes and processes of use and occupation, responsible for the structure of the current landscape and the state of its water resources. The recognition of the landscape’s spatial structure in the hydrographic unit and its drainage basins was obtained by integrated analysis of the main elements that compose it: geology, landforms (hypsometric and slope), soils, climate and land use. Analysis revealed that within each drainage basin several variations in the spatial structure of the landscape occur which produce an internal compartmentalization. Each compartment is defined by its own geo-ecological structure, physiognomic standards and dynamics, reflected in its potentialities and vulnerabilities and in the conditions of water resources in the wake of occupation and use over time.

scholarly journals Species composition and diversity of cast net fisheries in New Calabar River, Niger Delta, Nigeria

2018 ◽  
Vol 4 (1) ◽  
pp. 19-26 ◽  
Author(s):  
HE Dienye ◽  
OA Olopade ◽  
SA Toby
Keyword(s):  
Decapod Crustacean ◽  
Abundant Species ◽  
Diversity Indices ◽  
Fish Stock ◽  
Base Line ◽  
Fisheries Resources ◽  
Fish Samples ◽  
Catch Composition ◽  
Rivers State ◽  
Management And Conservation

A study on the catch composition and diversity of cast net fisheries was conducted between May and August, 2017 in the New Calabar River, Rivers state, using cast net of varying mesh sizes (1.5mm and 2.5mm). Fish samples were collected from three sampling stations, viz. Station1- Aluu, Station 2- Choba and Station 3- Iwofe. The fish species recorded comprised of 26 species under 11 families, and one decapod crustacean. The three most abundant species were; Coptodon guineensis (25.11%), Coptodon zilli (18.56%) both from the Cichlidae family, and Penaeus nitialis (10.90%) from the Penaeidae family, while the least abundant species was Liza grandisquamis (0.13%) from the Mugilidae family. The diversity indices showed that station 2 recorded the highest number of species (21) while station 1 recorded the lowest with (12) species. Simpson’s indexes of diversity, Simpson’s reciprocal index, Shannon- weiner index, and Pielou’s evenness index, were estimated. This study serves as a base line data which will assist relevant bodies in the management and conservation of fisheries resources in the New Calabar River. It is therefore recommended that for an improved and sustainable exploitation and management of fisheries resources of the New Calabar River, proper monitoring and management for fish stock must be done.J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(1): 19-26

Deterministic Tree Networks for River Drainage Basins

Fractals ◽  
1998 ◽  
Vol 06 (03) ◽  
pp. 245-261 ◽  
Author(s):  
M. R. Errera ◽  
A. Bejan
Keyword(s):  
Porous Medium ◽  
Flow Resistance ◽  
Drainage Basin ◽  
Drainage Basins ◽  
River Drainage ◽  
One Step ◽  
Local Properties ◽  
Flow Through ◽  
Internal Properties ◽  
Flow Medium

This paper shows that the dendritic patterns formed by low-resistance channels in a river drainage basin are reproducible and can be deduced from a single principle that acts at every step in the development of the pattern: the constrained minimization of global resistance in area-to-point flow. The river basin is modeled as a two-dimensional territory with Darcy flow through a saturated heterogeneous porous medium with uniform flow addition per unit area. From one step to the next, small elements of the porous medium are dislodged and removed in ways that minimize the global flow resistance. The removed elements are replaced by channels with lower flow resistance. The channels form a dendritic pattern that is deterministic, not random. The finest details of this structure are sensitive to internal properties and external forcing, i.e. variations in the local properties of the flow medium, and the manner in which the total area-to-point flow rate varies as the structure develops. Remarkably insensitive to such effects are the basic type and rough size of the flow structure (channels versus no channels, dendrite, number of branches) and the minimized global resistance to flow.

scholarly journals Compilation of Glacier Maps for Some Mountains (Abstract)

1986 ◽  
Vol 8 ◽  
pp. 205
Author(s):  
Gu Pei ◽  
Bu Jueying
Keyword(s):  
Drainage Basin ◽  
Aerial Photographs ◽  
List Type ◽  
Drainage Basins ◽  
Glacier Inventory ◽  
Distribution Maps ◽  
Direction Of Movement ◽  
Mountain Systems ◽  
Location Type ◽  
Base Data

Chinese Glacier Inventory is part of International Glacier Inventory, and glacier maps are important components of the glacier inventory. Since 1979, we have completed glacier maps for Qilianshan, Altaishan, Tianshan and Pamier mountain systems one after another, about 40% of the whole work. In order to improve the quality and accuracy of the maps, we fully considered the principles for the compilation of the International Glacier Inventory with due respect to the specific conditions in China as follows; 1. Materials and data. Newly published aerial topographic maps of 1:50 000 and 1:100 000 are used as basic maps with aerial photographs as supplementary data for checking and correction. 2. Scale and projection. According to the use of the glacial maps, the shape and size of the surveyed area and base data, the scale of the maps of drainage basins is fixed at 1:250 000 and 1:400 000, with Gauss projection. For the distribution maps of glaciers and their geographic landscape and characteristics, and for coding key maps, scales of 1:1 000 000 and 1:2000 000 are used, respectively, and their projection is the normal, minimum-error, conformal, conical projection, with two standard parallels. 3. Synthesis and presentational method. To show the location, type, shape, direction of movement and dependent drainage basin of glaciers is the most important task for the compilation of glacier inventory. Therefore, it is very necessary to carry out scientific summarization during compilation and to decide the acceptance or rejection of the surveyed features. In addition, the key elements of drainage basins, ridges, etc. are also given in detail. The glacier map is a basic skeleton for the glacier inventory, giving important basic data for glaciological research and exploitation, as well as the utilization of the ice-snow resources, etc.

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