Introduction

In recent years, morphometric variables are largely used for watershed prioritization using remote sensing (RS) and geographic information system (GIS) techniques (Avinash et al. 2011; Samal et al. 2015). The urban and agricultural expansion, industrial activities and climate change (Singh et al. 2014; Abboud and Nofal 2017) have shown impacts on morphometric parameters of river basins (Panda et al. 2018). Morphometric parameters define the topographical, geological and hydrological condition of a basin (Angillieri 2012; Kabite and Gessesse 2018). The study on drainage system morphometry enhances the understanding of landform formation, soil physical properties, erosion characteristics and runoff discharge (Ameri et al. 2018).

Digital elevation model (DEM) is the primary dataset for various applications in topography, geomorphology, vegetation cover studies, tsunami assessment, hydrology, morphometry and urban studies (Patel et al. 2016). DEM-based terrain visualization, processing and quantification of topographic attributes made GIS a powerful tool in morphometric studies (Kumar et al. 2017) to understand river basin structure and functions at local, regional and global scales (Thomas et al. 2011; Bali et al. 2012; Yadav et al. 2014). Geospatial studies revealed that Shuttle Radar Topography Mission digital elevation model (SRTM DEM) is much better in providing accurate data particularly for drainage morphometry and hydrological studies than Advanced Spaceborne Thermal Emission and Reflection Radiometer digital elevation model (ASTER DEM) (Kabite and Gessesse 2018). The SRTM DEM is based on the principle of interferometric SAR (InSAR), which uses phase difference measurements derived from two radar images acquired with a very small base-to-height ratio (typically 0.0002) to measure topography (SRTM project). The SRTM global data for the rest of the world other than the USA is available at 3-arc second (90 m).

Many river basins of ecological importance in the Asian countries are yet to be characterized to decipher their carrying capacity for long-term sustainability of the natural and man-made ecosystems.

Betwa River basin (BRB) is historically one of the oldest running water systems that witnessed the dawn of human civilization in the Indian subcontinent. In this study, the Betwa River basin is divided into three regions: (a) the upstream region is characterized by heavy industrialization and urbanization, (b) the midstream region stream is rural Central India and major agricultural region for the cultivation of pulses (beans, chickpeas and lentils), and (c) the downstream region is characterized by stone crushing, granite industries and thermal power plants. These man-made activities are associated with the direct discharge of mine water, wastewater, increased sedimentation, dust deposition, soil erosion and flooding. In view of this, the spatial variations in drainage and morphometric parameters (linear, aerial, drainage texture and relief aspects) were studied to describe and evaluate hydrological, geological and topographical characteristics by analyzing SRTM DEM and topographical maps of the Betwa River basin and sub-basins using GIS techniques. The yearly changes in precipitation pattern for 30 years were carried out by SWAT analysis.

Materials and methods

Study area

The Betwa is a major tributary of Yamuna River having SW to NE flow direction in the Bundelkhand region of Central India, situated between latitudes 77°15′ and 79°45′N and longitudes 23°5′ and 25°55′E, draining the total area of about 44,002 km2 of which 68.84% is in Madhya Pradesh and 32.16% in Uttar Pradesh (Fig. 1). The Dehgaon Bamori Forest Range is ecologically sensitive for the origin of Betwa River in Raisen District at an elevation of 475 m above mean sea level (msl) and joins river Yamuna near Hamirpur in Uttar Pradesh, traveling a total distance of about 564 km. The origin of major upstream tributaries mainly Kaliasot, Halali, Sagar and Bina also occurs from the Dehgaon Bamori Forest Range; the midstream tributaries are Narain, Orr and Jamni originating from Guna and Lalitpur Forest Range; Dhasan and Birma are major tributaries in downstream of Betwa River. The average annual rainfall is 1138 mm, the average annual evaporation loss is 1830 mm, and the average annual runoff is about 13,430 million cubic meters (MCM), out of which nearly 80% occurs in monsoon.

Fig. 1
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Betwa River basin: a location map and b geology of the study area

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The Betwa River basin is in saucer shape with sandstone hills around its periphery and is covered by three major group of rocks of different ages: the Bundelkhand complex (older than 2.6 billion years), the Bijawar group (2.6–2.4 billion years) and the Vindhyan Supergroup (1.4–0.9 billion years). The northern portion is covered with alluvial soils, the central part contains mixed red sandy and black soils, and the southern part has medium black soils. Bundelkhand craton comprises of granitoids, syenites, amphibolites, banded iron formation, tonalite–trondhjemite–granodiorite, gneisses, calc-silicate rocks, quartzites, pillow lavas, basaltic metasediments and giant quartz veins (Malviya et al. 2006; Pati et al. 2007). The Bijawar group is the Mesoproterozoic formations deposited over the Archean Bundelkhand craton, and it is exposed along its southeastern (Hirapur and Sonarai Basins) and northwestern (Gwalior Basin) margins. These rocks are again well exposed along the southeastern edges of the Vindhyan Syncline where they dip under the Semri Group of the Vindhyan Supergroup (Ray 2006).

Morphometric analysis

In the present study, an integrated use of DEM and survey of India topographical sheets were utilized for the generation of database and extraction of various drainage parameters. Details of data used are listed in Table 1. The following procedure was used for morphometric parameter extraction and analysis which is shown in Fig. 2:

Table 1 Data used in the present work
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Fig. 2
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Steps involved in drainage morphometry analysis

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  1. (a)

    The SOI toposheets were geometrically rectified and georeferenced by taking ground control points (GCPs) by using the Universal Transverse Mercator (UTM) projections and the World Geodetic System (WGS) 1984UTM Zone 43 datum. Further, all geocoded toposheets were mosaic using Arc GIS 10.2 software.

  2. (b)

    The catchment area of the Betwa River basin delineated from SRTM DEM and Survey of India topographical sheets of the study area using spatial analyst tool of Arc GIS by selecting AOI (area of interest).

  3. (c)

    The DEM of the catchment was extracted from Shuttle Radar Topography Mission (SRTM) data obtained with a resolution of 90 m (downloaded from the http://srtm.csi.cgiar.org). SRTM is a single pass, synthetic aperture radar interferometry (InSAR) campaign which provides unique DEM data with 90 m resolution (Rabus et al. 2003).

  4. (d)

    The SRTM DEM is utilized to prepare topographic, slope and delineation of the drainage map of the basin using the hydrology tool of Arc GIS 10.2. This extracted DEM is used to calculate morphometric parameters of the Betwa River and its tributaries.

  5. (e)

    All the extracted parameters as the number and length of streams with different stream order, drainage area, basin perimeter, total basin length and width were calculated using Arc GIS software. Drainage density, drainage texture, stream frequency, shape, circulatory ratio, elongation ratio, etc., were calculated from these parameters. The summary of methodologies adopted for the computation of morphometric parameters is given in Table 2.

    Table 2 Methodology adopted for computation of morphometric parameters
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Results and discussion

Linear aspects

The results of linear morphometric attributes of Betwa River basin and its sub-basin are given in Table 3. Stream order (U) is defined as a measure of the position of a stream, stream size and drainage area (Leopold et al. 1964; Strahler 1957). The stream number (Nu) is defined as a number of streams in each order which is inversely proportional to stream order (Horton 1945). The Betwa River identified as the sixth-order drainage basin; 75.85% and 20.70% stream number occurred in the first- and second-order streams, respectively. In upstream, Kaliyasot is the fifth order, Halali and Bina are the fourth order, and Sager is a third-order tributary; in midstream, Jamni is the sixth-order sub-basin, Narain and Orr sub-basins are fifth- and fourth-order sub-basins, respectively; and in downstream, Dashan is the fifth-order longest sub-basin and Birma is the smallest measurable fourth-order sub-basin (Fig. 3).

Table 3 Linear aspect of the Betwa River basin and sub-basins
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Fig. 3
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Drainage and stream order map of the Betwa River basin and sub-basins

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In upstream, midstream and downstream sub-basins showed a large number of the first-order stream indicates terrain complexity and compact bedrock (Vincy et al. 2012). The number of streams decreased in geometric progression as the stream order increased. It indicates that there may be a possibility of sudden flash floods after heavy rainfall in the downstreams (Chitra et al. 2011). Overall impression of a stream number and stream order revealed dendritic drainage pattern in Betwa River basin. The regression plot between a stream number and stream order showed the validity of the law of stream number for the Betwa River basin (Fig. 4).

Fig. 4
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Logarithm regression of stream number against stream order

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A stream length (Lu) states that the total length of stream segments decreases with an increase in the stream order (Horton 1945) and indicates the contributing area of the basin (Magesh et al. 2011). The Betwa River basin showed total stream length of 12,199.65 km out of which 6318.54 km was the first order. The Jamni and Dashan contributed 3630.21 km and 2981.90 km stream length in the Betwa River basin. These results showed smaller stream length and less permeable bedrocks in the Betwa River basin and sub-basins. Mean stream length (Lsm) varied from 2.12 to 9.35 km indicating gentle slopes with low gradients of drainage network and coarser texture of the contributing surface. Stream length ratio (RL) varied from 0.31 to 0.89 indicating the presence of resistant rock, low slope and topography in the terrain (Bindu et al. 2012). The RL of Orr, Sagar and Bina tributaries showed an increasing trend from lower order to higher order indicates the early mature stage of geomorphic development while the remaining sub-basins showed RL values < 2 indicating late youth stage of geomorphic development (Thomas et al. 2010; Vittala et al. 2004).

The bifurcation ratio (Rb) is defined as the ratio between the number of streams of the given order to the number of streams of the next higher orders (Strahler 1957). It is a dimensionless property and shows the degree of integration prevailing between streams of various orders in a drainage basin. In the present study, the Rb varied from 2 to 8.5, indicating quantitative variations in geological and lithological features of the catchment. The low Rb values in Betwa River basin and sub-basins indicate the flat area with rolling drainage pattern (Horton 1945). The mean bifurcation ratio (4.61) shows that the drainage pattern of the basin has not been affected by structural disturbances. Similar observation was made by many researchers on river basins originating from Vindhyan Supergroup in Central India (Singh et al. 2013).

Rho coefficient (ρ) is the important morphometric parameter which relates drainage density to physiographic development of the basin and also indicates the evaluation of storage capacity of drainage network. Hence, it is a determinant of ultimate degree of drainage development in a given watershed (Horton 1945). Rho is defined as the ratio between stream length ratio and bifurcation ratio. Rho values of Betwa River basin in the range of 0.06–0.26. The Birma sub-basin showed the highest Rho variation ranging from 0.15 to 0.38, indicating higher hydrological storage during flood periods, and it attenuates the effect of erosion during the elevated discharge (Horton 1945).

Areal aspects

The areal aspects are the two-dimensional properties of a basin, and the results are listed in Table 4. Following descending orders of areal aspects are given to understand the importance of sub-basins in the formation of Betwa River basin:

Table 4 Areal aspect of the Betwa River basin and sub-basins
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  • Length: Dashan > Jamni > Birma > Bina > Orr > Halali > Narain > Sagar > Kaliyasot.

  • Perimeter: Dashan > Jamni > Bina > Birma > Orr > Narain > Halali > Sagar > Kaliyasot.

  • Mean width: Jamni > Bina > Birma > Orr > Dashan > Narain > Halali > Sagar > Kaliyasot.

The length and perimeter showed that the downstream sub-basins (Birma, Jamni and Dashan) were contributing the maximum areal aspects to the Betwa River basin. Further, the Lemniscate’s (k) value is an important areal aspect parameter, which is used to determine the slope of the watershed. The k is defined as the ratio of the length of the watershed along the mainstream to the area of the watershed (Chorley 1957). The k value of the Betwa River basin was 4.6 while it ranged from 2.8 to 3.3, 2.8 to 3.6 and 3.6 to 6.8 in upstream, midstream and downstream sub-basins, respectively. This shows that upstream occupies the maximum area in its region of inception with a large number of streams.

Drainage texture analysis

It includes the study of drainage network properties and arrangement of stream engraved into the land surface by a drainage system. The parameters describing drainage texture of Betwa River basin and sub-basins are given in Table 5. Drainage density (Dd) value of the Betwa River basin was calculated as 0.55. However, in the upstream, midstream and downstream sub-basins, Dd varied from 0.37 to 1.64, 0.53 to 0.57 and 0.16 to 0.46, respectively. These values are less than 2, indicating very coarse texture and the presence of both highly weathered and resistant permeable material with low relief. In this study, the drainage texture (Dt) values of Betwa River basin and sub-basins were < 4, revealed occurrence of coarse texture except Kaliyasot and Narain sub-basins where drainage texture (> 10) was classified as fine textured. Stream frequency (Fs) was < 0.7, indicating permeable subsurface material and low relief except Kaliyasot and Narain. Circularity ratio (Rc) values of Betwa River basin were computed as 0.13 while it was varied from 0.14 to 0.2, 0.14 to 0.19 and 0.13 to 0.52 in upstream, midstream and downstream sub-basins, respectively. These low circularity ratios indicate the elongated shape, highly permeable homogenous geologic materials and ephemeral life cycles of the tributaries in Betwa River basin. The constant of channel maintenance (C) is measured as the reciprocal of drainage density (km2/km). The value of C for the Betwa River basin is calculated as 1.80 km2/km. The C varied from 0.61 to 2.68, 0.61 to 2.68 and 1.76 to 1.86 in upstream, midstream and downstream regions, respectively. Most of the sub-watersheds with higher values indicate the region with significantly higher infiltration rates. The infiltration number (If) values for the Betwa River basin and sub-basins showed low runoff and high infiltration capacity.

Table 5 Results of drainage texture analysis of Betwa River basin and sub-basins
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Relief characterization

Relief parameters consider as three-dimensional features of the drainage basin, generally depends on the maximum and minimum height of the basin (Table 6). The total relief of Betwa River basin was 239 m (Fig. 5). The total relief of the tributaries ranged from 80 to 164 m, 80 to 161 m and 122 to 204 m, in upstream, midstream and downstream regions, respectively. These values indicated high infiltration and low runoff conditions in the study area. Similar observations were made by Pandey and Das (2016) in Usri River basin of Chhota Nagpur Plateau in India. The relief ratio (Rh) of the Betwa River basin was 0.54, indicating large drainage areas. The Rh of upstream and midstream tributaries ranged from 1.05 to 2.04 and 1.05 to 2.15, respectively, indicating steep slope and high relief. Ruggedness number (Rn) value of Betwa River basin was 0.13 while the Rn values of tributaries ranges from 0.01 to 0.09, 0.02 to 0.21 and 0.03 to 0.04, respectively, in upstream, midstream and downstream regions. The relatively low values of Rn indicate mature river basin with long drainage density and gentle slope which resulted in less erosional susceptibility in the study area. Pandey and Das (2016) reported that homogenous lithology, gentle regional slope and lack of structural control were responsible for low values of Rn. The high Rn values were reported in the Western Ghats region indicates the structural complexity of terrain is highly susceptible to erosion (Samal et al. 2015).

Table 6 Relief characteristics of Betwa River basin and sub-basins
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Fig. 5
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Elevation map of the Betwa River basin and sub-basins

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Slope map for Betwa and sub-basins were prepared from SRTM DEM (Fig. 6). The slope classification is divided into seven classes (Table 7). The > 74.5% of the area is under < 3° slope indicates near level to gentle terrain condition. The highest mean basin slope was observed in Kaliyasot (upstream), Jamni (midstream) and Dashan (downstream), indicating that eastern region of the Betwa River basin was ecohydrologically significant for stream network generation, runoff and flooding. The midstream region was intersected by the east–west ridge of Bundelkhand granites covered with tropical deciduous forests, which alter the perennial stream flow velocity, soil erosion, sedimentation and hydrograph rise in the study area. This might be responsible for spatial variation in flooding scenario in the Betwa River basin. The aspect map derived from SRTM DEM represents the compass direction of the aspect (Fig. 7). Betwa River basin showed 37.3% NE–E–SE aspect of slope (Table 8) which is exposed to the sun during the hottest time day, consequently warmer than the aspect on other side (Al-Saady et al. 2016).

Fig. 6
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Slope map of the Betwa River basin and sub-basins

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Table 7 Slope classes in Betwa River basin according to IMSD classification
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Fig. 7
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Aspect map of the Betwa River basin and sub-basins

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Table 8 Areal extent of aspect in the Betwa River basin
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Conclusions

The morphometric analysis shows dendritic drainage patterns, coarser drainage texture, low runoff and low erosional potential in BRB. The study area is characterized with low discharge of surface runoff and highly permeable subsoil conditions. Dominant slope is east facing, gentle and laden with high moisture content and lower evaporation rate in the basin. The high moisture content in the east-facing slope may be subjected to high weathering than the dry slopes, and this condition may alter the stream channel morphology. The sub-basin morphometric analysis reveals that the northeast and central part of the Betwa River basin needs immediate attention for the watershed conservation. These regions are important perennial source of running water in Central India and middle Gangetic plain. The morphometric data can be integrated with land use/cover, landforms, geology, water level and soil in the GIS domain to identify hot-spots for soil and water conservation structures at local and regional scales. In nutshell, this study can be used in future to delineate the carrying capacity of Betwa River basin and forecast changes in the sediment transport to the Bay of Bengal through Ganga River basin.