Ruggedness Number Research Articles

Morphometric Analysis of Kajali River Basin Using Geospatial Techniques

Soil and water are the important natural resources and important input for agricultural production. The present study has been attempted to delineate and determine morphometric characteristics of Sakharpa watershed in Ratnagiri district by using Remote Sensing and GIS. The delineation of watershed was performed in QGIS 3.18.3 software. The study area was obtained from SRTM DEM with 30meter resolution after delineation. Sakharpa watershed shows a dendritic drainage pattern. The results found for morphometric parameters were Bifurcation Ratio (Rb)2-5.5, Form factor (Ff) 0.32, Elongation ratio (Re) 0.63, Circulatory ratio (Rc) 0.32, Shape index (Sw) 3.18,Drainage density (Dd)1.18km/km2, Stream frequency (Fs)1.48 km-2, Texture ratio (Rt)1.08, Drainage texture (Dt)2.24,Constant of channel maintenance (C)0.84km2/km, Length of overland flow (Lg) 0.42, Basin relief (R) 763.92 m, Relief Ratio (Rr) 0.045,Relative Relief (Rhp) 1.27,Ruggedness Number (Rn) 0.904. The study concluded that the watershed is elongated in shape, have dense vegetation and homogeneous with less structural disturbance. This morphometric analysis of drainage basin helps to planning and development of watershed also helps to understand relation between linear, areal and relief parameters of drainage basin.

Geomorphological Characteristics of a Hydrographic Basin using RS and GIS on the Example of the Venna River (Maharashtra, India)

Assessing the impact of geomorphological processes on a catchment's hydrology necessitates a quantitative analysis of its geometry. This can be effectively achieved using remote sensing (RS) and geographic information systems (GIS), which have become increasingly popular for supporting strategists and decision-makers in making precise and efficient plans and decisions. A morphometric analysis of the Venna River basin was conducted using RS and geographic information systems GIS. This study aims to assist local communities in effectively utilizing land and water resources for the sustainable development of the basin area. The drainage network was developed by digitizing Survey of India (SOI) toposheets. The Venna River basin, covering an area of 318.96 km², exhibits a dendritic drainage pattern with a 5thorder river system dominated by lower-order streams. A mean bifurcation ratio of 6.02 indicates undulating topography with structural influences on drainage. The basin's elongated shape is reflected in its circulatory ratio (0.3) and elongation ratio (0.38), while a form factor of 0.12 suggests low peak flows over extended durations. Low drainage density value of 0.6, indicates that basin has high permeability, slow surface runoff and value of constant of channel maintenance of 1.66 indicates basin has moderate slopes and effective infiltration. The relief ranges from 619 m to 1380 m, with a relief ratio of 0.015, indicating less resistant rock types. A ruggedness number of 0.46 suggests moderately rough terrain, allowing for some erosion potential while highlighting the basin's capacity for water retention, infiltration and sustainable resource management. The areal parameters, such as the form factor, circulatory ratio, elongation ratio and drainage density, suggest elongated basin geometry with high drainage intensity, implying slower runoff and moderate potential for groundwater recharge. The results of this study are valuable for effective watershed management, erosion control, and informed decision-making in land use planning and engineering projects.

Assessment of active tectonics based on GIS and statistical model: A case study of upper Alaknanda catchment (western Himalaya, India)

Due to continuing deformation of the Earth’s crust, degradation and aggradation processes, the upper part of the Alaknanda basin lying in the Garhwal Himalaya, India, is considered to be tectonically active. Active tectonics in this region made a considerable impact on the drainage system and the topographic expression. Using a digital elevation model (DEM) with a resolution of 30 m * 30 m and based on eight geomorphic indices [hypsometric integral (HI), drainage texture (Dt), asymmetry factor (AF), ruggedness number (Rd), circularity ratio (Rc), valley floor width/height ratio (Vfw), lemniscate coefficient (k) and basin shape index (Bs)], we evaluated active tectonics. Application of Index of Active Tectonic (IAT) and clustering model disclose the sub-watersheds in the southern part covering watersheds 16, 17 and near Badrinath sub-watershed 4, 9 and 8 are tectonically highly active (Class-1, 1.500-1.781). Cluster analysis defines two prominent clusters of sub-watersheds: 2, 4,14 and 15 in cluster 1; and 6, 7, 8 and 18 in cluster 2. Cluster 1 includes sub-watersheds 2, 4, 14, 15, and 16 and very high, high, and moderate IAT magnitudes. Sub-watersheds 6, 7, 8, and 18 are included in Cluster 2, which has very high and high tectonic activity

Morphometric analysis of Halda River basin, Bangladesh, using GIS and remote sensing techniques

GIS and remote sensing techniques were effectively used to analyse the morphometric parameters including linear, geometric, basin texture (aerial) and relief aspects of the Halda River Basin, Bangladesh. Along with measuring the morphometric parameters using predetermined formulas, advanced geo-computing tools of spatial analysis, cartography, math, geoprocessing and geometric analysis were employed to carry out the spatial distribution of selected parameters, especially aerial parameters. The linear aspect indicates the basin is six-order and oval-shaped. The bifurcation ratio (4.03) and relevant parameters indicate the moderate effect of geology and structural control is evident. The mean stream length (1.27) and Rho value (ranges between 0.11 and 0.20) indicate high runoff in steep areas and hydrologic storage capacity in flat areas. The stream frequency (0.83), drainage density (1.22), drainage intensity (0.68), infiltration ratio (1.02), length of the overland flow (0.41), and constant of channel maintenance (0.82) indicate the presence of moderate hard rock, less structural disturbances and moderate to high surface runoff in the basin. Basin relief (489 m), relative relief (2.02), ruggedness number (400), Melton's ruggedness number (12.43), and mean slope (9.33%) indicate the potential of high erosion and material transfer. The spatial distribution of selected aerial aspects significantly correlated to elevation and slope. The hierarchical pattern and spatial distribution of the morphometric parameters indicate areas with high slopes and lower-order streams have a high potential to be affected by soil erosion, landslides and flash floods, elsewhere, the areas with low slopes are prone to short-duration riverine floods. The research findings will help policymakers for integrated river basin management, agricultural development, and water management. In addition, researchers of morphohydrological, geological and climatological research will be beneficiary.

Hydro-morphometry of a trans-Himalayan River basin: Spatial variance, inference and significance

Subansiri is the largest tributary of the Brahmaputra River basin originated in the Tibet Autonomous Region of China. After flowing about 160 km as Chayul Chu in Tibet, it runs as Subansiri in Arunachal Pradesh state of India for about 360 km before merging into the Brahmaputra River in Assam (India). This study was carried out to understand the hydro-morphometry of the entire Subansiri Basin comprising of three sub-basins: Chayul Chu, Upper Subansiri and Lower Subansiri. Geomorphometric parameters were extracted from Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model of 30 m spatial resolution using Google Earth Engine and GIS software. On comparison, significant difference and spatial variation have been noticed in various morphometric parameters of the sub-basins. Notable differences are observed in some key morphometric parameters such as drainage density, stream frequency, constant of channel maintenance, infiltration number, drainage ratio, drainage texture, dissection index, ruggedness number, form factor ratio, elongation ratio etc. Hypsometric analysis has highlighted further the difference in geomorphic fabric, terrain maturity and hydrologic characteristics of these different sub-basins. Hydro-morphometric parameters have direct bearing on the hydrology. Thus, outcome of this study will be useful in water resources management and in finding engineering solutions to hydro-hazards for this basin and other basins worldwide.

An integrated statistical-geospatial approach for the delineation of flood-vulnerable sub-basins and identification of suitable areas for flood shelters in a tropical river basin, Kerala

Flood vulnerability assessment is crucial for developing effective flood management and mitigation strategies. The present study aims to understand the flood vulnerability of the Kallada River Basin (KRB) and identify suitable locations for safe flood sheltering facilities in the basin. As part of this, morphometric analysis of KRB was carried out by dividing the basin into fifty-eight 4th-order sub-basins to understand the sub-basin-wise terrain characteristics and the degree of vulnerability to flooding. GIS tools were used to assess various morphometrical parameters, such as drainage frequency, texture ratio, ruggedness number, basin relief, bifurcation ratio, length of overland flow, drainage density, circularity ratio and area, and geo-environmental factors such as sand percent, rainfall, and mean slope of these basins. The morphometric parameters exhibited distinct spatial trends, with higher values primarily concentrated in the east and northeast parts for certain parameters and in the western parts for others. Using hierarchical cluster analysis, the sub-basins were categorized into six clusters, revealing that 51% were vulnerable to floods, 26% moderately vulnerable, and 22% not vulnerable. Sub-basins in the central and western KRB were found to be highly vulnerable to flooding, while those in the eastern parts showed moderate vulnerability or were not vulnerable. Flood vulnerability mapping was validated using flood data of 2018 and 2019. Additionally, the weighted overlay method identified suitable areas for flood shelters in moderately vulnerable and vulnerable sub-basins and the areas were categorized into highly suitable, suitable, moderately suitable, and not suitable areas. Most areas of SB53 and SB55 were found highly suitable, emphasizing their potential for flood shelter locations. The findings of this study can be used by competent authorities to initiate flood mitigation and to develop targeted flood preparedness measures in similar river basins, particularly in the context of increasing flood events.

Assessment of Morphometric and Hypsometric Analysis of the Ruste Basin Using Remote Sensing and Geographical Information System Techniques

A basin’s characteristics and features need to be comprehended completely by conducting morphometric analysis, such as evaluating the basin’s size, form, and surface features, to estimate floods and erosion rates properly. The main objective of this investigation is to evaluate morphometric measures and hypsometric analysis of Erbil’s Ruste Basin employing remote sensing and geographical information system methods. To investigate the significant tributaries of the selected area, the hydrology tool within the Spatial Analysis Tools of ArcGIS, version 10.7, was utilized to define the basin boundaries, map the drainage networks, and obtain topographic data. The findings of the linear morphometric parameters revealed that the logarithmic relationship between stream orders and stream numbers was negative. The difference in stream order and number seen in the watershed is due to topography and bedrock influence. The results also showed a negative correlation between stream length and stream order, and a coefficient of determination of 0.972, which indicates that the basin is made of low-permeability formation and subsoil materials. Considering the areal morphometric parameters, the circularity ratio, elongation ratio, and form factor are 0.594, 0.853 and 0.572, respectively, suggested a semi-circular shape. A drainage density value of 2.259 km-1 showed that the Ruste Basin is a basin with steeply to very steeply sloping hilly terrain with varying plant covering. Furthermore, the Ruste Basin has high relief and slope with a relief ratio of 0.151 and basin relief of 2.576 km, both of which imply that it has a steep slope with high erosive force, limited infiltration, and a high runoff rate. Ruste Basin’s ruggedness number was 5.819, indicating that it has badlands topography. The average hypsometric integral was 0.467, denoting a mature basin featuring S-shaped hypsometric curves. In conclusion, the results showed that analysis of morphometric parameters and hypsometric integral and curve provides us with a notion to basin characterization and guidance to making appropriate decisions to establish effective actions to sustainable water and soil conservation and natural resources management through applying water harvesting methods, check dams, and bench terraces.

Geospatial approach in modeling linear, areal, and relief morphometric interactions in Dabus river basin ecology for sustainable water resource management

The Dabus River Basin (DRB) holds significant value within the Upper Blue Nile region yet has seen minimal exploration regarding its morphometric features. This investigation employed geospatial techniques to characterize the linear, areal, and relief morphometric properties of the DRB in the Upper Blue Nile, Ethiopia. Data sources such as the SRTM DEM, hydrological, and geological maps were utilized to comprehensively analyze the basin's morphometric aspects. In the ArcGIS environment, 26 morphometric parameters were assessed through standard statistical methodologies. The basin possesses 210,776 streams with a dendritic pattern, ranging from 1st to 9th order, reflecting lithological uniformity and structural oversight. The total stream length is 57,233 km, scattered across a basin area of 14,833.7 km2. With an average bifurcation ratio of 3, the basin displays a low degree of lithological influence and structural disturbances influencing the drainage patterns. The form factor (0.2), elongation ratio (0.5) and circulatory ratio (0.2) values suggests an elongated basin shape, resulting in poor runoff and increased erosion frequency. A high correlation can also be observed among stream frequency (14.2), drainage density (3.9), and texture ratio (54.5), which implies high basin impermeability and a heightened risk of erosion. Key relief attributes of the basin include a low to moderate relief (2641 m), an 8.8 relief ratio (erosion potential), a 10.2 ruggedness number (rugged and flood-prone terrain), and a 5.6 m/km channel gradient (steep slopes, increased runoff, erosion potential). This study aims to serve as a foundation for comprehending the DRB and facilitating the development of precise and successful land and water management strategies.

Morphometric and morphotectonic attributes of Ken basin, central India: Depicting status of soil erosion, and tectonic activities

The present study reveals the significance of the morphometric and morphotectonic parameters for the evaluation of soil erosion and tectonism in the Ken River basin of Central India. About fifty two morphometric (linear, areal and relief) and ten morphotectonic parameters were analyzed by using digital elevation model and Geographic Information System. The estimated value of bifurcation ratio (3.60 to 7) and mean bifurcation ratio (4.85) show the geological and structural control on drainage pattern. The values of drainage density (0.75), frequency, and infiltration ratio (0.23) indicate that the basin was evolved in a permeable geological and subsoil conditions with thick vegetal cover and exhibits the medium infiltration rate. The elongation ratio (0.23) and form factor (0.263) infer that the basin is elongated and show low flow peaks of longer duration. The Rho value (0.613) indicates higher hydrological storage or high discharge of water during flood period. The ruggedness number (0.35) indicates a moderately rugged basin which is less prone to soil erosion.The sinuosity index (S = 1.702) depicts the meandering nature of the river. The asymmetric and transverse asymmetric factor (T) infers that the basin was not tilted due to tectonic activities. However, the sudden drop in the elevations of the longitudinal profile of the Ken River noticed at few localities, particularly at the marginal contacts with the Yamuna envisages the influence of tectonics in the geological past. It may depict the existence of peripheral bulge tectonics along the marginal contacts of the lower reaches of the Ken basin. Our results will be helpful to researchers to explore the implications of morphometric and morphotectonic indices in the study of soil loss and tectonic activity in other cratonic rivers. This study will also assist the planners and researchers in planning the watershed management and in understanding tectonic and palaeoseismic activities.

Sub-Watershed Prioritization for Erosion Susceptibility based On Drainage Morphometric Characters

Watershed located in a Hilly-plain environment is more susceptible for soil erosion. Loss of fertile soil in agricultural land hampers the life of the farmers of the region. Identification of the vulnerable areas and devising strategies to minimize the damage caused due to soil erosion are important to address the problems faced by the agrarian society. In our current work, drainage morphometric parameters were evaluated to assess the soil erosion susceptibility of the four sub-watersheds (SW01, SW02, SW03 and SW04) of the Yagachi watershed located in the Hemavathi river basin in Karnataka State using Remote Sensing (RS) and Geographical Information System (GIS). Seventeen morphometric parameters namely Area, Stream Order, Mean Bifurcation Ratio, Drainage Density, Stream Frequency, Texture Ratio, Infiltration Number, Compactness Co-Efficient, Length of Overland Flow, Elongation Ratio, Circulatory Ratio, Form Factor, Relief Ratio, Shape Factor, Basin Relief, Dissection Index and Ruggedness Number were considered. The priority rank and category for each sub-watershed were assigned based on Compound Factor (CF) value. The sub-watersheds with the lowest CF value are most susceptible to erosion and need highest priority for the soil conservation measures. Based on CF values, the sub-watersheds were categorized into 4 priority groups: ‘Very High’ priority (<2.00), ‘High’ priority (2.01–2.50), ‘Moderate’ priority (2.51–3.00) and ‘Low’ priority (≥3). Out of 4 sub-watersheds, SW03 falls in ‘Very High’ priority category in terms of erosion susceptibility and needs appropriate soil conservation measures in order to arrest fertile soil erosion and increase agricultural produce output.

Quantitative Analysis of the Relief Aspects of Do River Basin, Southeastern Nigeria

Abstract: Morphometric analysis of a drainage basin expresses fully the state of dynamic balance that has been attained due to dealings between matter and energy. This study was carried out to analyze the relief parameters of the Do River basin. Data were obtained from the digitalized map of the basin and calculation using relevant formula. The Principle Component Analysis (PCA) was employed to determine the contributions of the parameters to the morphometry of the basin. Results showed that the basin has a relief of 340m, an average basin slope of 0 - > 40% and a ruggedness number of 0.27. Further results showed that the relief disposition, terrain configuration and variations in the slope of the basin, all have major contributions to the drainage development and erosion properties of the basin. Discussions on the findings of the relief parameters analyzed and their contributions to the basin were also undertaken.

Watershed prioritization and hydro-morphometric analysis for the potential development of Tabuk Basin, Saudi Arabia using multivariate statistical analysis and coupled RS-GIS approach

The Tabuk province of Saudi Arabia (SA) has an arid zone, few aquifers, high groundwater salinity (seawater intrusion), and accelerated population, industrial, and agricultural development. The development of Tabuk Basin is essential for the addition of new freshwater resources and the enhancement of aquifer recharge potential. The hydrological characteristics of the drainage basin aid in the identification of watersheds, enabling the protection and management of land erosion and ground/surface water resources. This study analyzed hydro-morphometric data from the eighteen sub-basins of the Tabuk Basin using multivariate statistical approaches and coupled remote sensing (RS) and geographic information systems (GIS) for water priority determination. The results show that the four principal components(PC1-4) have a variance of90.4% concerningbifurcation ratio (Rb), ruggedness number (Rn), elongation ratio (Re), drainage density (Dd), basin relief (Bh), circularity ratio (Rc), and relief ratio (Rh). The Al Ula, Thaibah, Hamd, Dama, Al Wajh, Al Ghamra, and Azlam sub-basins showed the highest priority, indicating soil erosion and the necessity for mitigating measures to reduce infrastructure damage. Mostexposed geology (67%) exhibited strong permeability and good infiltration (sedimentary cover and Quaternary sediments). The rest(23%) showed low to medium permeability(igneous, metamorphic, and carbonate rocks). The bestpromisingsitesfor building new wells can reduce surface runoff and soil erosion through aquifer infiltration and abstraction. The aquifer potentiality map was accomplished for Al Ula, Thaibah, Hamd, and Dama drainage basins. The most prospective groundwater investigation regions were identified, coincidingwith the drilled wells that confirmed and validated the results. The estimated zones of high to very high aquifer potentiality were used to add additional wells for investment reduce soil erosion, mitigate alternatives, agriculture,urbanization, etc. The other sub-basins have a medium to low priority, with less soil erosion and aquifer recharge.

Relief Morphometry of Nayaseri Watershed: A Case Study in Northern Slopes of Shimla, Himachal Pradesh, India

The study of relief elements is very significant in geography. Relief set the stage for all types of development of cultural features on the surface of the earth. To make planning regarding development of cultural landscape, for sustainable development, the study of relief is must, particularly in mountainous regions. The study of relief enlighten many characteristics of the area, like - slope, dissection of area, stability and instability of topography, erosion capacity of area, hydrological aspects and stages of sequential development of landforms etc. In the light of this need, relief morphometry of catchment has been studied. To study the Morphometry of the watershed, parameters like – relative relief, absolute relief, dissection index, slope, hypsometric integral curve, clinographic curve, relief ratio and ruggedness number, relief profile have been taken. The topographical map published by Government of India is the database of the analysis. Instruments, like- Rotameter and Planimeter have been used for various measurements. The observations per square kilometer are taken to calculate the areal coverage of absolute and relative relief, average slope and dissection index. The study reveals that the watershed has experienced tectonic incidences in the recent past. Fault, submergence, upliftment, tilt and sudden breaks of slopes are imprints of these activities on topography of the area. Indicators like - Slope, relief ratio, ruggedness number and relief profiles suggest that the watershed has Steep slopes, unstable landmass and capacity of intense erosion. Various measures of relief also imply that the area is in the youthful phase of its sequential development.

Geospatial Modeling Based-Multi-Criteria Decision-Making for Flash Flood Susceptibility Zonation in an Arid Area

Identifying areas susceptible to flash flood hazards is essential to mitigating their negative impacts, particularly in arid regions. For example, in southeastern Sinai, the Egyptian government seeks to develop its coastal areas along the Gulf of Aqaba to maximize its national economy while preserving sustainable development standards. The current study aims to map and predict flash flood prone areas utilizing a spatial analytic hierarchy process (AHP) that integrates GIS capabilities, remote sensing datasets, the NASA Giovanni web tool application, and principal component analysis (PCA). Nineteen flash flood triggering parameters were initially considered for developing the susceptibility model by conducting a detailed literature review and using our experiences in the flash food studies. Next, the PCA algorithm was utilized to reduce the subjective nature of the researchers’ judgments in selecting flash flood triggering factors. By reducing the dimensionality of the data, we eliminated ten explanatory variables, and only nine relatively less correlated factors were retained, which prevented the creation of an ill-structured model. Finally, the AHP method was utilized to determine the relative weights of the nine spatial factors based on their significance in triggering flash floods. The resulting weights were as follows: rainfall (RF = 0.310), slope (S = 0.221), drainage density (DD = 0.158), geology (G = 0.107), height above nearest drainage network (HAND = 0.074), landforms (LF = 0.051), Melton ruggedness number (MRN = 0.035), plan curvature (PnC = 0.022), and stream power index (SPI = 0.022). The current research proved that AHP, among the most dependable methods for multi-criteria decision-making (MCDM), can effectively classify the degree of flash flood risk in ungauged arid areas. The study found that 59.2% of the area assessed was at very low and low risk of a flash flood, 21% was at very high and high risk, and 19.8% was at moderate risk. Using the area under the receiver operating characteristic curve (AUC ROC) as a statistical evaluation metric, the GIS-based AHP model developed demonstrated excellent predictive accuracy, achieving a score of 91.6%.

Morphometric analysis of Hirehalla Sub-basin of Malaprabha River, Northern Karnataka using geoinformatics techniques

In the present study, basin morphometry of Hirehalla Sub-basin of Bagalkote District, Karnataka was carried out using remote sensing and geoinformatics techniques. Delineation and calculation of various morphometric parameters of the sub-basin was done in GIS environment. The study was categorized into– Linear, Aerial and Relief aspects. Result obtained from morphometric analysis confirms the highest order of fifth and showing sub-dendritic to dendritic drainage pattern. Values of shape parameters- form factor (0.16), elongation ratio (0.45) and circulatory ratio (0.38), suggests the sub-basin to be elongated in shape. Average bifurcation ratio value (Rb=3.34), indicates the influence of geomorphic features on the basin. From the values of Stream frequency (1.36) and drainage density (1.27) it indicates, permeable subsurface and low relief. Drainage texture value (1.74) suggests the basin is coarse. In addition, a low value of ruggedness number indicates the resistance of sub-basin to erosion.

Assessment of Basin Morphometric Measurements Accuracy Based on Different DEM Data, Chai Dakuk Basin, Northeast Iraq: A Case Study

Morphometric analysis is essential in evaluating the geomorphological development and hydrological characteristics of rivers and valley basins. Several studies used different DEM data to evaluate elevation accuracy or their impact on measurements of limited morphometric parameters. The current study was carried out on the Chai Dakuk River basin in the northeastern part of Iraq. The basin is bounded by latitudes 34°44'30"- 35°35'49"N and longitudes 44°17'39"- 45°28'16"E. The current study aims to evaluate the accuracy of different DEM data, i.e., ASTER-GDEM 1-arcsec, SRTM 1-arcsec, and 3- arcsec, ALOS-12.5 meters, and GMTED 7.5 arcsec data, based on reference points collected by GPS and top maps of scale 1: 20000, and to evaluate DEM resolution on the calculation accuracy of different morphometric parameters. The analysis of morphometric parameters was carried out using ArcGIS- morphometric toolbox. The results of the accuracy assessment of DEM data identified the SRTM 1arc-second is more adequate with reference measurements; based on that, the measurements of all other DEM are compared to the SRTM 1- arcsec. The results of morphometric parameters show noticeable differences in many morphometric parameters calculated from different DEM data. Numbers and lengths of stream orders; bifurcation ratios; main channel length; drainage density; stream frequency; constant of channel maintenance; compactness coefficient; drainage texture; infiltration number; basin outlet height and the maximum height of basin, total basin relief, and ruggedness number. According to the results, the study concluded that the SRTM 1- arcsec data are more suitable for morphometric analysis, followed by ASTER GDEM data.

Morphometric analysis of shel dedumal watershed using remote sensing remote sensing and GIS

Morphometric analysis is the measurements and mathematical analysis of the land surface configuration, shape and dimension of the landforms. The efficiency of the drainage network is very important for understanding the processes of landform formation, soil physical properties and erosion characteristics. The present study is focused on the evaluation of morphometric parameters for conversation of soil and water on delineated in the basin. Furthermore, morphometric analysis of watershed using geospatial data and GIS techniques and slope analysis were also utilized to propose the suitable soil and water conservation measures in the basin. The results obtained in the analysis revealed that the Shel Dedumal basin tributaries is an 5th order drainage basin which describe that the texture is homogeneous or homogeneity still exist and lack of structural control in soil strata. The relief ratio (R h ), the elevation difference (R h or H) and circularity ratio (R c ) was found to be 10.73, 222.0 and 0.42, respectively which represents the basin having moderate relief and gentle to moderately high slope. Some areas of the basin are characterized by variation in Lithology and topography. The mean values of bifurcation ratio (R b) observed as 4.52 and circularity ratio (R c ) observed as 0.42 of the entire basins shows a moderate but not strong structural control or structural disturbances. An extreme high value of ruggedness number (R n ) observed as 11.83 which indicate the structural complexity of the terrain. The Moderate drainage density (D d ) and circularity ratio (R c ) was observed as 2.63 and 0.42, respectively which indicates the basin is highly permeable subsoil and vegetative cover. The form factor (F f ), the elongation ratio (R e ) and circularity ratio (R c ) was observed as 0.39, 0.71 and 0.42 respectively which is indicating elongated basin with lower / flatter peak flows of longer duration than the average and also the elongation ratio (R e ) values indicating moderate to slightly steep ground slope in basin which is indicating possibility for soil erosion and other soil and water conservation works.

A structural equation model of land capability and related drivers: Implications for land degradation forecasting in a tropical river basin

AbstractLand degradation is a worldwide problem with natural and anthropogenic causes. An important anthropogenic cause of land degradation is land uses that deviate from land capability, which is the “natural” use. Despite the conscience of scientists about this issue, studies are lacking that set up a quantitative nexus between land capability and related drivers. This nexus is essential because it allows anticipating changes in the drivers that promote or recede degradation. In this study, a partial least squares–path model (PLS–PM) was used to help closing this gap. The pilot study occurred in seven Paraopeba River sub‐basins located in the State of Minas Gerais (Brazil), where capability is dominated by mosaics of forests and pastures. Land capability was assessed by the ruggedness number, being inversely proportional to it. Among multiple potential drivers of land capability initially included in the model, collinearity and other consistency and performance analyses indicated the percentage of latosols and (re)forested areas, annual rainfall, and water‐related processes (e.g., weathering, nutrient leaching) as prominent in the studied region. The results linked increases of latosol and forest occupation to runoff reduction [runoff = latosol × (−0.640) + forest × (−0.156) + reforestation × (−0.379)], suggesting an attenuation of erosion by these parameters, namely gully erosion that impacts on the ruggedness number and land capability in the sequel. The weathering of carbonate rocks was also related to land capability changes because the PLS–PM model exposed a relationship between the ruggedness number and products of carbonate rock dissolution: ruggedness number = alkalinity × (−0.578) + total magnesium × (0.462) + dissolved oxygen × (−0.418). In addition to highlighting processes capable of changing land capability overtime, the model equations brought attention to measures that could improve it in the region thus preventing degradation. The measures included management practices capable to raise the soil's dissolved oxygen (e.g., through aeration) or preventing soil's magnesium deficiency (e.g., through foliar sprays). The network of cause‐and‐effect relationships set up by the PLS–PM model was finally used to elucidate about potential land use changes that would bring capability in the Paraopeba River basin towards a better status, such as conversions to pasture land. Future work is expected to further elucidate about the benefits for land capability of specific land use changes, through the testing of expected socioeconomic development scenarios.

Evaluation of Morphometric Parameters Studies in Middle-West Part of Kushtia District, Bangladesh, Using Remote Sensing and GIS Techniques

This study finds 1D, 2D and 3D morphometric parameters of the middle-west part of Kushtia district, Bangladesh to implement groundwater potential. For this purpose, the SRTM (DEM) data were used to compute different parameters in GIS environment. The values of 1D parameters like stream order, stream length and mean bifurcation ratio was calculated as 6, 1774.72 km and 2.08 respectively. The computed values of drainage density (0.01 - 23.06 km/km2), stream frequency (1 - 5.64 per km2), drainage texture (0.25 - 0.70 km/km4), length of overland flow (0.02 - 45.05 km2/km), constant of channel maintenance (0.04 - 90.04 km2/km), circularity ratio (0.39 - 0.84), form factor (0.35), elongation ratio (0.62), relief ratio (0.00 - 1.81) and ruggedness number (0.04 - 214.72) disclose the morphometrical conditions of the study area. The results revealed from this study on drainage morphometry can be a great assistance for understanding the hydro-geomorphological character of the area.

Analysis of geo-morphometric and topo-hydrological indices using COP-DEM: a case study of Betwa River Basin, Central India

ABSTRACT The open source 30 m Copernicus DEM (COP-DEM) has been used to derive the geo-morphometric and topo-hydrological characteristics of Betwa River Basin. Drainage network with 7th order stream and mostly dendritic pattern has been delineated using the Strahler’s method. The drainage density, stream frequency, form factor, length of overland flow and circulatory ratio of the basin were computed as 0.38 Km/Km2, 0.08 Km−2, 0.23, 1.31, and 0.20, respectively. These outcomes suggest less available surface flow, lesser relative relief, poor drainage network, and nearly elongated shape of the basin. The mean bifurcation ratio for entire basin was calculated as 4.0 that signifies gradient dependent drainage network of the basin. The ruggedness number was computed as 0.24, which reflects the geology dominated (granite–gneiss) rocky and undulated topography of the basin. The dissection index ranges from 0.06 to 0.3, which implies less degree of dissection and mature stage of the basin. The topographic wetness index (TWI), stream power index (SPI), terrain ruggedness index (TRI), and sediment transport index (STI) ranges from 3.13 to 26.35; 0 to 6; 0 to 30; and 0 to 121.4, respectively. It implies that the lower basin is less susceptible towards erosion as compared to upper basin.