scholarly journals Morphometrical Analysis and Peak Runoff Estimation for the Sub-Lower Niger River Basin, Nigeria

2016 ◽  
Vol 24 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Adebayo Wahab Salami ◽  
Oseni Taiwo Amoo ◽  
Joshiah Adetayo Adeyemo ◽  
Abdulrasaq Apalando Mohammed ◽  
Adeniyi Ganiyu Adeogun

AbstractThis study utilized Spatial Information Technology (SIT) such as Remote Sensing (RS), a Geographical Information System (GIS), the Global Positioning System (GPS) and a high-resolution Digital Elevation Model (DEM) for a morphometrical analysis of five sub-basins within the Lower Niger River Basin, Nigeria. Morpho-metrical parameters, such as the total relief, relative relief, relief ratio, ruggedness number, texture ratio, elongation ratio, circularity ratio, form factor ratio, drainage density, stream frequency, sinuosity factor and bifurcation ratio, have been computed and analyzed. The study revealed that the contribution of the morphometric parameters to flooding suggest catchment No. 1 has the least concentration time and the highest runoff depth. Catchment No. 4 has the highest circularity ratio (0.35) as the most hazardous site where floods could reach a great volume over a small area.

2019 ◽  
Vol 4 (4) ◽  
pp. 70
Author(s):  
Iau-Teh Wang

The evaluation of portal locations for mountain tunnels is among the most crucial considerations during route selection and structural layout planning. The development of spatial information technology has provided a more objective approach for assessing the slope stability of potential portal sites. The simulations in such studies have been performed to evaluate potential hazards and slope stability. However, potential instabilities resulting from excavation are seldom considered in these studies. Therefore, a method based on spatial information technology was developed in this study for considering the potential impact of the direction and depth of excavations on portal stability. An analysis method for an infinite slope was integrated into the geographical information system for evaluating the stability of critical wedges. The proposed method provides a reasonable estimation comparable with that provided by the conventional slice method. The results of applying this method to six mountain tunnel portals where slope instability occurred during construction indicate that the actual outcomes agreed with the predicted outcomes. For potential portal site evaluation, the proposed method facilitates the rapid estimation of safety factors for various slope designations, which is useful for site selection.


Agropedology ◽  
2019 ◽  
Vol 29 (1) ◽  
Author(s):  
A. P. Bowlekar ◽  

In present study Kansa watershed in Satara district of Maharashtra was characterized for watershed parameters. Geographical Information Systems (GIS) and a high-resolution Digital Elevation Model (DEM) has been utilized for the estimation of morphological parameters. Several morphometric parameters have been computed and analyzed viz. linear aspects such as stream order, stream number, stream length, mean stream length, stream length ratio; areal aspects such as drainage density, stream frequency, drainage texture, elongation ratio, circularity ratio, form factor, constant of channel maintenance; relief aspects such as relief, relief ratio, relative relief, ruggedness number, length of overland flow. Impacts of morphometric parameters on flash flood characteristics have also been investigated. The presence of the maximum number of the first order segments shows that the basin is subjected to erosion and also that some areas of the basin are characterized by variations in lithology and topography. The form factor is 0.21, and the circulatory ratio is 0.42, which suggests an elongated type of catchment. Elongation ratio is 0.52, which indicates that watershed has high relief and steep slope. The estimated catchment characteristics may be useful to stimulate hydrological responses of the catchment.


Author(s):  
Rajnish Yadav ◽  
Mohammad Iqbal Bhat ◽  
Faisul-Ur- Rasool ◽  
Shabir Ahmed Bangroo ◽  
Roheela Ahmad ◽  
...  

Morphometric analysis is of vital importance in any hydrological research and is inevitable in development and management of watershed. Using the watershed as the main unit of morphometric characterization is the most logical choice, as well as geomorphological and hydrological processes take place within the drainage basin. A critical assessment and evaluation of morphometric parameters of Khag micro-watershed was accomplished through measurement of relief, linear and aerial aspects using Geographical Information System (GIS). The watershed boundaries, aspect, slope, digital elevation model (DEM), profile graph of topography, drainage order and drainage density mapswere generated for detailed study of micro-watershed using Shuttle Radar Topographic Mission (SRTM) data. The study area was designated as fourth order basin with the drainage area of 34.32 km2 and shows dendritic drainage pattern. The total length, drainage density and mean bifurcation ratio (Rb) were found to be 38.84 km, 1.13km/km2 and 1.73, respectively. The Khag micro-watershed showed the greater Rb value, which directs a strong structural control in the runoff pattern. A decrease in the stream frequency of flow was also observed with an increase in the order of flow. The shape parameters such as circulatory ratio, elongation ratio, length of over land flow, form factor and drainage texture of Khag micro-watershed were 0.42, 0.56, 0.43 km, 0.24 and 1.66, respectively. The Khag micro-watershed is elongated in shape and dendritic in drainage pattern. This can be attributed to the fact that the lithology and structural controls are more or less uniform. Relative relief and ruggedness number were 0.065 and 2.39 and are likely to subject the micro watershed to maximum soil erosion that demands, instantaneous soil conservation measure to be taken by watershed managers for its stability and sustainability. These studies area advantageous for the planning of rainwater harvesting and the management of the catchment area.


2015 ◽  
Vol 72 (7) ◽  
pp. 1168-1175 ◽  
Author(s):  
Manoj Kumar ◽  
Rohitashw Kumar ◽  
P. K. Singh ◽  
Manjeet Singh ◽  
K. K. Yadav ◽  
...  

The geographical information system (GIS) has emerged as an efficient tool in delineation of drainage patterns of watershed planning and management. The morphometric parameters of basins can address linear, areal and relief aspects. The study deals with the integrated watershed management of Baliya micro-watersheds, located in the Udaipur district of Rajasthan, India. Morphometric analysis in hydrological investigation is an important aspect and it is inevitable in the development and management of drainage basins. The determination of linear, areal and relief parameters indicate fairly good significance. The low value of the bifurcation ratio of 4.19 revealed that the drainage pattern has not been distorted by structural disturbance. The high value of the elongation ratio (0.68) compared to the circulatory ratio (0.27) indicates an elongated shape of the watershed. The high value of drainage density (5.39 km/km2) and stream frequency (12.32) shows that the region has impermeable subsoil material under poor vegetative cover with a low relief factor. The morphometric parameters of relief ratio (0.041) and relative relief (0.99%) show that the watershed can be treated using GIS techniques to determine the morphometric presence of dendritic drainage pattern, with a view to selecting the soil and water conservation measures and water harvesting.


Author(s):  
Ikpong Sunday Umo ◽  
M. C. Ike ◽  
Ifeanyi G. Ukwe

This study evaluates the relationships between dimensionless basin geomorphometry and discharge in the Ikpa River. The basin was stratified into seven sub-units using [1] scheme. Geospatial tools were used in generating data for the digital elevation model, while dimensionless geomorphometric parameters were generated from topographic maps (sheet 322 NE; sheet 322 SE; sheet 323 SW; and sheet 331 NW) of the basin area drawn on a scale of 1.50,000. The sampled sub-basins were gauged and discharge measured by a surface float. Graphical analysis of discharge revealed wide variations between months and in seasons across sub-basins with the rainy season attracting highest volume of discharge and the corresponding fluvial processes. The regression analysis yields a coefficient of multiple determination (R) of 0.937, signifying a very high effect expressed by 87.8 of the proportion of variance in dimensionless geomorphometric parameters on discharge in Ikpa River Basin. Also, the computed F value yields 1.439, while the Table value tested at (0.05)5/2 confident level offers 19.30. The result led to the conclusion that variations in relief ratio, average bifurcation ratio, circularity ratio, elongation ratio and form factor have a significant effect on discharge in Ikpa River Basin. This paper recommends for prompt installations of state of the art river gauging and monitoring facilities to provide the needed information to the government, researchers, and individuals for the sustainable land and watershed development options (dam and irrigation) in the coastal plain of Ikpa River basin.  


2021 ◽  
Vol 10 (4) ◽  
pp. 247
Author(s):  
Til Prasad Pangali Sharma ◽  
Jiahua Zhang ◽  
Narendra Raj Khanal ◽  
Foyez Ahmed Prodhan ◽  
Lkhagvadorj Nanzad ◽  
...  

Basin geomorphology is a complete system of landforms and topographic features that play a crucial role in the basin-scale flood risk evaluation. Nepal is a country characterized by several rivers and under the influence of frequent floods. Therefore, identifying flood risk areas is of paramount importance. The East Rapti River, a tributary of the Ganga River, is one of the flood-affected basins, where two major cities are located, making it crucial to assess and mitigate flood risk in this river basin. A morphometric calculation was made based on the Shuttle Radar Topographic Mission (SRTM) 30-m Digital Elevation Model (DEM) in the Geographic Information System (GIS) environment. The watershed, covering 3037.29 km2 of the area has 14 sub-basins (named as basin A up to N), where twenty morphometric parameters were used to identify flash flood potential sub-basins. The resulting flash flood potential maps were categorized into five classes ranging from very low to very high-risk. The result shows that the drainage density, topographic relief, and rainfall intensity have mainly contributed to flash floods in the study area. Hence, flood risk was analyzed pixel-wise based on slope, drainage density, and precipitation. Existing landcover types extracted from the potential risk area indicated that flash flood is more frequent along the major Tribhuvan Rajpath highway. The landcover data shows that human activities are highly concentrated along the west (Eastern part of Bharatpur) and the east (Hetauda) sections. The study concludes that the high human concentrated sub-basin “B” has been categorized as a high flood risk sub-basin; hence, a flood-resilient city planning should be prioritized in the basin.


Hydrological analysis and for the integrated development of the watershed, it is essential to do geomorphometric analysis. A comprehensive study of drainage pattern, topography, and most essential erosion status can be analyzed through morphometric analysis. Prioritization of sub-watersheds according to the capacity of the water table of Nashik district watershed was evaluated by linear, aerial and relief aspects. The morphometric analysis has been used for the prioritization of seven sub-watersheds of the Godavari river basin in the Nashik district, Maharashtra. Using the Digital Elevation Model, the sub-watersheds were delineated in ArcMap 10.4 and also few extraction works were done in Erdas Imagine. Drains and their corresponding characteristics including stream length, stream order, stream frequency, circulatory ratio, texture ratio, compactness coefficient, elongation ratio, form factor, drainage density, bifurcation ratio is analyzed and their value has evaluated for each sub-watershed by using the Remotely Sensed-data and geospatial techniques. Finally based on morphometric behavior the priority has been given to each sub-watershed & rank has assigned to them, the most sensitive sub-watershed is identified. The reveled analysis says stream order ranges from 1 to 6. The overall stream segments of all order are 1,115 in the watershed. On the account of morphometric analysis prioritization of watershed is done. Resulting prioritization rank assigned to each watershed based upon the evaluated compound parameter given to them. Those Sub-watersheds having least compound parameter value has assigned the highest priority. Further, sub watersheds accordingly categorized into three type i.e. high (3.4-3.8), medium (4.0-4.2) and low (4.4) priority based on their maximum priority score (4.5) and minimum score (3.4).


2021 ◽  
Vol 11 (9) ◽  
Author(s):  
W. R. Singh ◽  
S. Barman ◽  
G. Tirkey

AbstractMorphologic parameters of a watershed could help in segregating critical sub-watersheds for taking up conservation practices and mitigation interventions. Determination of critical watersheds or prioritization of sub-watersheds is inevitable for efficient and sustainable watershed management programs and allocation of its natural resources. The traditional methods of determination of morphologic parameters are time consuming, expensive and requires huge labor. However, the process becomes easier, cheaper and faster with the advent of Geographical Information System (GIS) and remote sensing technologies. In the present study, a combined approach of using toposheet, remotely sensed digital elevation model and morphometric ArcGIS toolbox has been adopted to determine morphometric parameters in Dudhnai river basin, a sub-basin of river Brahmaputra which is prone to both erosion and sedimentation. Seven sub-watersheds of Dudhnai have been prioritized by using the morphometric parameters and ranked them according to its vulnerability to soil erosion. The results of bifurcation ratio, drainage density, drainage intensity and constant of channel maintenance showed that Dudhnai watershed is a well-dissected watershed with less risk to flooding and soil erosion. However, significantly high values of infiltration number and ruggedness number obtained are indicative of very low infiltration which may result in high surface runoff and soil erosion. The study also revealed that channel erosion is stronger than sheet erosion in the basin. The prioritization of the sub-watersheds implied that Chil sub-watershed is the most susceptible sub-watershed that needs greater attention for soil and water conservation measures. The results of the present study could aid various stakeholders who are involved in the watershed development and management programs.


2021 ◽  
Vol 54 (2D) ◽  
pp. 138-154
Author(s):  
Mohammed S. Shamkhi

Modern technologies are used for watershed management to cope with drought risks in arid and semi-arid regions. The study aimed to conduct a morphometric analysis and know potential groundwater recharge areas in the eastern region of Wasit Province. Remote sensing and GIS data were used for morphometric analysis. The morphometric analysis results adopted the Digital Elevation Model. The results of the analysis were verified by matching the results with what exists in reality. The area of the first basin was 1482.017, as it is the largest basin from the area, with a percent of 51.228% of the total area of all basins. The percentage of first-degree flows reached 83.37% in the first basin, 74.14% percent in the second basin, 75.51% in the third basin, and 75.75% in the fourth basin from all streams in each basin. The bifurcation rate (3.135-4.233), Stream frequency range values (0.543-0.332), drainage texture coarse, low drainage density that ranged between 0.986-1.14 km/km2 elongation ratio ranging from 0.348-0.624 form factor (0.095-0.316). The basins' circularity (0.105-0.238) relief value (951-112) m infiltration number value (0.369-0.535). All basins have a longitudinal shape and lead to the formation of floods and rapid currents, which exposes the region to rapid seasonal floods and the creation of flash floods that cause soil erosion and analyses the drainage intensity results. It was low, and this is an indication that the ground has high permeability. The flow frequency results indicate that the area is semi-arid and exposed to small amounts of rain and coarse drainage texture by comparing the result parameters from morphometric analysis results for each basin. The potential recharge areas of groundwater in the study area can be known, n as the analysis results showed that recharge potential occurs in all basins. The highest groundwater recharge is possible in the third basin and the lowest in the first basin. Morphometric analysis was performed by ARC-GIS(Arc-map10.4).


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