International Journal of Geosciences, 2013, 4, 461-470
http://dx.doi.org/10.4236/ijg.2013.42043 Published Online March 2013 (http://www.scirp.org/journal/ijg)
Assessment of Factors Affecting Ephemeral Gully
Development in Badland Topography: A Case Study at
Garbheta Badland (Pashchim Medinipur,
West Bengal, India)
Pravat Kumar Shit1*, Gouri Sankar Bhunia2, Ramkrishna Maiti1
1Department of Geography & Environment Management, Vidyasagar University, Medinipur, India
2Rajendra Memorial Research Institutes of Medical Sciences (ICMR), Patna, Bihar, India
Received October 11, 2012; revised December 5, 2012; accepted January 4, 2013
ABSTRACT
Gully erosion in the Paschim Medinipur district of West Bengal, India has been an issue of anxiety, formed by the am-
putation of soil from narrow channels through the accretion of surface runoff. Here, we attempted to investigate the
erosion variability of gully in a micro catchment area, and also scrutinized the gully cross-sectional areas as distinct
components of gully volumes. Twelve gullies were randomly selected in different slopes. To determine the geometric
growth of the gully dimensions and soil loss, the initial length of gully, the width of the gully and depth of respective
gullies was monitored in different seasons. Univariate analysis was conducted to measure the association between gully
head retreat and vegetation coverage, slope, rainfall volume and runoff contributing area. We found strong and signifi-
cant relation between the slope of gully head and linear retreat in the pre monsoon (p < 0.008) and post monsoon (p <
0.024) season respectively. Conversely, rainfall volume and gully head retreat showed a strong relationship in the pre
monsoon (r = 0.80), monsoon (r = 0.66) and post-monsoon period (r = 0.94); while meager relationship was observed
with rainfall intensity (r = 0.06). Results also illustrated that the overall retreat of gully head had very strong and posi-
tive relationship with the runoff contributing area (r = 0.89, p < 0.001), and maximum gully erosion was observed in the
monsoon period (55.67%). These results indicate that slope, rainfall and runoff contributing area have a strong positive
influence on gully erosion in Paschim Medinipur district, since the initiation of the gully.
Keywords: Gully Erosion; Gully Heads; Rainfall; Runoff Contributing Area; Sediment Yield
1. Introduction
Studies of soil erosion on local scales such as the indi-
vidual gully system are an imperative subject of land
degradation. Gully head morphology as the key factor of
gully enlargement has also been well studied in world-
wide [1,2]. Gully erosion is primarily caused and has-
tened by overland flow, influenced by runoff occurrence
upslope. However, it is very tricky to gather compre-
hend- sive information incessantly, especially given the
spatial condition and limited financial resources of a de-
veloping country. Previous studies [3-5] signified that
gully erosion is often the key cause of sediment produc-
tion.
Gully erosion has been an issue of anxiety in the
Paschim Medinipur district of West Bengal, India. Gul-
lies are formed by the amputation of soil from narrow
channels through the accretion of surface runoff, tends to
fabricate more sediment loss than other forms of soil
erosion such as overland flow [6-9]. Today, it is re-
nowned as a major land degradation issue, causing both
impacts on-site, through direct soil loss and off-site,
through sediment deposition in downstream environ-
ments. The network of the gully has been developed by
gully-head erosion [10,11], and it is a complex process
with interactions and feedback mechanisms that are only
conceptually and qualitatively understood [12,13]. Ear-
lier researchers suggested that the gully-head retreat and
gully development include upslope movement of the
gully-head [14-16]. Though, previous workers reported
that the mechanism of gully head erosion with more em-
phasis on the hydraulic shear by overland flow on the rim
and on the vertical walls [11], the impact of splash from
a plunge pool at the foot of a headcut [17], and mass
wasting of walls [18]. However, the quantification of
these processes is very difficult to attain and approxi-
mation in their predictions of where gullies begin and
*Corresponding author.
C
opyright © 2013 SciRes. IJG

P. K. SHIT ET AL. 462
end are not well established. An additional problem in
attempting to link short and long-term headcut erosion is
the possibility of gully head bifurcation, which is a com-
mon process that can dramatically change the retreat
process. Erosion problems crop up mainly from natural
causes but their degree and severity are progressively
more being attributed to man’s unawareness and invo-
luntary action [7]. However, long-term retreat rates often
show negative-exponential trends [19], and linear ones
have also been reported by Imeson and Kwaad [20].
Nevertheless, there is a need for short-term predictions of
sediment yield, especially where gully heads retreat into
agricultural fields. Recent soil erosion models, like
WEPP [21], LISEM [22] and EUROSEM [23] predict
the sediment yield from fields or catchments using
event-based data considering the gully erosion.
In spite of technological advancement, gully erosion
still remains a major problem in India. The yearly heavy
rainfall has an enormous impact on developing landscape
intensively eroded and dissected. Such landforms are
creating deep gullies that cut into the soil. The gullies are
spread and grow, until the soil is removed from the
sloping ground. In the present study, we attempted to
investigate the erosion variability of gully at Ganganir
Danga, a micro catchment area of Paschim Medinipur
district of West Bengal in India (Figure 1). We also
scrutinized the gully cross-sectional areas as distinct
components of gully volumes. Here, we focused, mainly
on the headward erosion of the gully heads (gully
headcut retreat). The field observations were carried out
in the gully area during pre monsoon, monsoon and post
monsoon season to depict the gullying patterns and to
estimate the erosional activity of the same.
2. Material and Method
2.1. Study Area
The study work was conducted at Ganganir Danga of
Garbheta block in Paschim Medinnipur district in West
Bengal, India (lies between 22˚51'18''N - 22˚51'30''N
Figure 1. Location of the study area.

P. K. SHIT ET AL. 463
latitude and 87˚20'20'' E to 87˚20'28'' E longitude). The
area is covered by 3.5 km2 of Pleistocene lateritic upland,
and is noted for spectacular ravine development on the
concave right (northern) bank of river Silai [24] (Figure
1). The climate is tropical i.e., characterized by hot sum-
mer (maximum temperature > 39 degree Celsius), cold
winter (minimum < 10 degree Celsius), abundant rainfall
(1450 - 1560 mm/year) and humidity and the land sur-
face of the study site is characterized by hard rock up-
lands, barren lateritic covered area and non-arable lands.
Cross beddings and parallel beddings, composed of
varied size grains and also shows possible fluctuation in
erosional environment [25]. However, Geomorpho- logi-
cally, the study area is a part of the Chotonagpur flank
and hills and is exemplified with mounds and rolling
lands. The formation of Pali (~1000 m) is portrayed by
pebbly to coarse-grained micaceous sandstones medium
to fine grained sandstones, and red and green coloured
mudstones in the study area (Figure 2). The groundwater
expansions and judicious organization of the surface
water are imperative factors for endorsing current
agriculture through high yielding and remunerative crops
in the study site:
http://www.indianetzone.co m/46/paschimmed inipur_dist
rict.htm.
2.2. Field Measurement and Monitoring
In the present research, twelve gullies were randomly
selected, four gullies in higher slope (above 50˚), four
gullies in middle slope (40˚ to 50˚) and four gullies in
lower slope (below 40˚) respectively. Measuring tapes
and clinometers were used to determine length parame-
ters and slope of the soil surface (immediately above and
below the gully head) and of the channel bed below the
gully head respectively (Figure 3). The drainage area
was determined in the field by demarcating the area from
where runoff could reach the gully head.
To determine the geometric growth of the gully di-
mensions and soil loss, initial length of gully, width of
the gully and depth of respective gullies were noted.
Subsequently, incremental changes of basic morphomet-
ric properties of gullies were measured (Figure 4).
However, these properties were calculated at weekly
intervals for 2010 and 2011 using a 30 m linen tape. Lo-
cally built ranging poles and 6 cm × 24 cm pegs were
used to compute the length, bed width and depth of the
gullies, followed by the proposed method of Michael and
Ojha, [26]. The gully top width, depths and bed width
were monitored at the gully mouth, and gully head.
Depths and width were measured repeatedly at 1 m spac-
ing interval, along the incised length of the gully. A tape
was extended out across the gully to determine the top
width at each interval to assess the length. Gully depth
was measured vertically, e.g., from the tightly held tape
to the gully bed via ranging pole. Rainfall within the
catchment area was calculated by self recording rain
gauge station during the pre monsoon, monsoon and post
monsoon period.
Gully erosion is occurring due to hydraulic action of
running water and it initiates with rills. Initially, the an-
nual gully retreat rate was calculated, and subsequently
the retreat of gully by individual storm events was as-
sessed. Subsequently, the changes in the plans and di-
mensions of the gully heads have been used to estimate
the amount of sediment volume eroded and the surface
area affected (Figure 5).
Descriptive statistics were calculated of the study
variables and univariate analysis was performed to de-
lineate the statistical relationship between the variables in
relation to gully head retreats. Simple linear regression
analysis was done to measure the association between
gully head retreat and each variable (e.g., rainfall, slope,
and runoff contributing area) affecting the gully erosion
in the study site. All the analysis was estimated at <0.05
significance level.
(a) (b)
Figure 2. (a) Extensive red mudstone units; (b) Multistoried channel sandstones (at Garbheta, P asc him Medinipur).

P. K. SHIT ET AL. 464
Figure 3. Gully erosion at Gang anir Danga. (a) Location of 1 2 gully headcut under study; (b) Details topographic information;
and stratigraphic information (c) Plan view; (d) Cross section view of the main (G7) gully complex.
(a) (b) (c)
(d) (e) (f)
Figure 4. Gully head erosion. (a) Gully head and earth pillar; (b) Gully head undercutting due to seepage erosion; (c) Gullies
head and wall measurement; (d) Gully head slumping; (e) Gullies head and length measurement; and (f) Gully head area
easurement. m

P. K. SHIT ET AL. 465
3. Result and Discussion centration and flows at a velocity adequate to disengage
and transport soil particles. While peak flows from ex-
treme rainfall causes substantial gully erosion, the pro-
tracted low flows resulting from a comprehensive wet
period can also generate problems. In the present study,
we estimated the relationship between linear retreat of
gully head and rainfall volume in each gully area during
the pre monsoon, monsoon and post monsoon period
(Table 1(b) and Figure 7). During the pre monsoon
3.1. Slope and Gully Erosion
The progression of gully-head and gully enlargement
comprise upslope movement of the gully-head by over-
land flow on the rim and on the vertical walls. Though,
earlier researcher studied the Relation between degree of
gully erosion and slope gradient in worldwide [9,27-29].
However, in our study we measured the linear retreat of
gully in respect to slope during the pre-monsoon, mon-
soon and post monsoon period (Table 1(a) and Figure 6).
In the pre monsoon season the slope of the gully head
varied from 30˚ to 70˚. The average slope of twelve of
gully areas was 48.08˚, with a standard deviation of
±13.80. In the monsoon and post monsoon season, the
slope of the gully head is ranged from 45˚ - 72˚ (mean ±
standard deviation 57.75 ± 9.57) and 36˚ - 62˚ (mean ±
standard deviation 47.83 ± 8.62) respectively. However,
in our study area, we found strong and positive relation
between the slope of gully head and linear retreat in the
pre monsoon (r = 0.46, p < 0.008) and post monsoon (r =
0.39, p < 0.024) season respectively. Conversely, moder-
ate relationship was observed in the monsoon season (r =
0.30, p < 0.046).
Figure 5. Collapsing the successively top bed rock in the
gully head wall due to loss of cohesive force and under lay-
ing support, with the adding of moisture c ontent.
3.2. Rainfall and Gully Erosion
Gully erosion in this area is occurring due to runoff con-
Table 1. (a) Descriptive characteristics of twelve gully heads and their erosional parameters during different periods of time;
(b) Descriptive characteristics of twelve gullies and their erosional parameters during different periods of time.
(a)
Descriptive characteristics Area (sq. m) Slope (Degree) % of vegetation cover
Pre
Monsoon Monsoon Post Monsoon
Pre
Monsoon Monsoon Post Monsoon
Pre
Monsoon Monsoon Post Monsoon
Mean 279.71 280.88 282.49 48.08 57.75 47.83 3.21 4.92 7.73
Standard error 22.02 22.15 22.12 3.98 2.76 2.49 0.33 0.48 0.57
Standard deviation 76.27 76.72 76.62 13.80 9.57 8.62 1.14 1.68 1.97
Kurtosis −0.42 −0.40 −0.42 −0.94 −1.55 −1.01 −1.14 −0.80 −0.41
Skewness 0.58 0.60 0.60 0.66 0.14 0.27 0.60 0.69 0.96
95% CI 178.5 - 428.9 179.5 - 431.42181.35 - 432.4530 - 7045 - 7236 - 622 - 5 3 - 8 5.5 - 11.3
(b)
Descriptive characteristics Rainfall volume (mm) Linear retreat
Pre Monsoon Monsoon Post Monsoon Pre Monsoon Monsoon Post Monsoon
Mean 18983.273 88761.918 46432.609 37.67 82.00 27.67
Standard error 1494.229 6998.748 3635.588 6.35 4.65 4.23
Standard deviation 5176.161 24244.373 12594.046 21.99 16.10 14.65
Kurtosis −0.042 −0.040 −0.042 −0.30 0.08 −1.06
Skewness 0.058 0.060 0.060 0.95 −0.48 0.37
95% CI 29108.8 - 12114.53 136334.2 - 56582.0871081.39 - 29808.3212 - 80 49 - 105 7 - 52

P. K. SHIT ET AL. 466
(a)
(b)
(c)
Figure 6. Correlations of linear gully head retreat and slope
gradient. (a) Pre-monsoon; (b) Monsoon; (c) Post-monsoon
period.
period the rainfall volume is ranged from 12114.528 cm3
to 29108.802 cm3 (18983.273 ± 5176.161), in the mon-
soon period it is ranged from 56582.078 cm3 to
136334.209 cm3 (88761.917 ± 24244.372), and the rain-
fall volume is varied from 29808.324 cm3 to 71081.389
cm3 (46432.608 ± 12594.045) in the post monsoon period.
Furthermore, the average linear retreats of gully head in
the study area are 37.67 cm, 82.00 cm and 27.67cm re-
spectively. The results also illustrated that maximum
linear retreat was found during the monsoon period, be-
cause of high volume of rainfall intensity. Earlier report
also suggested that raindrop impact initiates detachment
of soil particles and causes crust formation which sills
the surface and limits the infiltration [30,31].
(a)
(b)
(c)
Figure 7. Correlations of linear gully head retreat and rain-
fall. (a) Pre-monsoon; (b) Monsoon; (c) Post-monsoon pe-
riod.
However, a simple linear relationship was calculated
between the rainfall volume and gully head retreat, which
showed strong positive and significant relationship in the
pre monsoon (r = 0.80, p < 0.001), monsoon (r = 0.66, p
< 0.001), and post monsoon period (r = 0.94, p < 0.001).
Carey (2006) suggested that both intense rainfall and low
flow under protracted wet soil may prompt troubles of
gully growth that may generate spoil to drainage lines if
not secluded. Hence, gully development is a function of
numerous factors out of which rainfall is a prime reason.
Furthermore, a comparison has been made between the
cumulative gully head retreat and rainfall intensity in the
study area (Table 1(b) and Figure 8). Rainfall intensity
as calculated by collecting the rainfall within each w

P. K. SHIT ET AL. 467
Figure 8. Relation between rainfall and cumulative linear gully head retreat.
gully area for 30 minutes. Result of the analysis showed
that rainfall intensity was maximum in monsoon period
in relation to pre monsoon and post monsoon period.
Results also illustrated that due to increase in rainfall
intensity, subsidence and slumping occurred in the
mid-monsoon (7th August, 2011) and end of the monsoon
period (26th August, 2011) in the study area. Conversely,
no any significant relationship was established between
the rainfall intensity and gully head retreat (r = 0.06),
suggested that the influence of rainfall intensity is not
affected by the gully erosion. It may be due to the reason
of duration rainfall that may affect the shear stress be-
tween the soil particles, and finally the runoff has taken
place and aids to detach the soil. The ephemeral gully
formation results from accelerated erosion, and therefore
unhinged landscape.
3.3. Vegetation Coverage vs. Gully Head Retreat
In the study area, attention has also been focused on the
possessions of below ground biomass on gully erosion,
since conventionally all the studies on vegetation cover
put importance on above-ground biomass [32,33]. Dur-
ing the pre-monsoon, monsoon and post-monsoon the
average percentages of vegetation cover were 3.21%,
4.92% and 7.73% respectively (Table 1(a)). However,
the correlation coefficient between the linear retreat of
gully head and percent of vegetation cover is illustrated
the weak relationship in pre-monsoon (r = 0.17), in
monsoon (r = 0.14), and in the post-monsoon season (r =
0.19) respectively. It may be due to the reason of more
important roles played by high rainfall, and steep slope in
gully head retreat in this particular area.
3.4. Gully Head Erosion vs. Runoff-Contributing
Area (RCA)
In the present work, a correlation was drawn between the
RCA and linear retreat of gully head. Like previous
analysis, the relationship was drawn separately in the
pre-monsoon, monsoon and post-monsoon period (Fig-
ure 9). Gully head morphology is the key factor of gully
head erosion. However, the morphological characteristics
of gully heads and its area are shown in Table 2. More-
over, the relationship is much stronger in the pre mon-
soon (r = 0.80, p < 0.001) and post monsoon period (r =
0.94, p < 0.001) in respect to the monsoon period (r =
0.66, p < 0.001). We also observed that the overall retreat
of gully head had very strong and positive relationship
with the RCA (r = 0.89, p < 0.001). The result is also
corroborated with the previous study [34-36]. It may be
due to the effect of huge volume of soil loss from these
gully slopes be prejudiced by the upslope contribution of
runoff and sediment.
3.5. Seasonal Influence of Gully Head Retreat
The gully head retreat in different season is shown in
Figure 10. In the study area, maximum gully erosion is
observed in the monsoon period (55.67%). It may be due
to the high rainfall input. However, the minimum gully
erosion is examined in the post-monsoon season (18.78%).
In the pre-monsoon season, the gully head retreat ranges
from 12 - 80 cm, in monsoon period it is varied from 49 -
105 cm, and in the post-monsoon period, the value of
etreat is varied from 7 - 52 cm. r

P. K. SHIT ET AL. 468
(a) (b)
(c)
Figure 9. Correlations linear gully head retreat and runoff contributing area (RCA). (a) Pre-monsoon; (b) Monsoon; (c)
Post-monsoon period.
Table 2. Morphological characteristics of gully heads, catchments area and gully head retreat.
Gully heads Major gullying process Runoff contributing
Area (m2)
Mean slope
(degree)
Total gully head retreat
during January-Oct., 2011 (cm)
G-1 Overland flow 270.63 49.33 120
G-2 Overland flow, undercutting 292.95 46.33 144
G-3 Overland flow, undercutting 195.3 61.00 139
G-4 Overland flow, undercutting, landsliding 362.7 63.00 226
G-5 Overland flow, undercutting, landsliding and Piping 432.45 68.00 229
G-6 Overland flow 368.28 46.33 201
G-7 Overland flow, undercutting, subsidence 326.43 43.66 161
G-8 Overland flow, undercutting 242.73 46.66 128
G-9 Overland flow, undercutting 265.08 40.30 113
G-10 Overland flow, undercutting and piping 228.78 50.50 87
G-11 Overland flow 181.35 52.60 109
G-12 Overland flow 223.2 47.00 111

P. K. SHIT ET AL. 469
Figure 10. Gully head erosion during pre-monsoon, mon-
soon and post monsoon periods.
4. Conclusion
Gully head progression is conceived as current danger
for land degradation. Therefore, monitoring the growth
rate of gullies and understanding the factors for gully
extension are important for land resource managers.
Field observations showed geomorphic differences be-
tween the gully channels. The favourable environment
for gully and rill development arises when soil is un-
guarded by vegetation and crusting. Taking account of
fluvial development of gully channels, the linear shaped
gullies are measured to have been preferentially formed
by knickpoint movement escorted by a lowering process,
and this can be a swaying cause for the hasty headcut
retreat. Retreat of gully head is maximum in the mon-
soon season. Our analysis also showed that the slope,
rainfall and runoff contributing area have a strong a posi-
tive relationship with the gully erosion in Paschim
Medinipur district. Under extreme concentrated rainfall,
gully erosion is the foremost cause of sediment at the
catchment scale.
5. Acknowledgements
We express our profound heartfelt thanks to M. M. Maiti,
R. K. Bhattachryay, N. Sar, R. Sahoo, R. K. Ghosh ,K.
Risi, P. Maiti, M. K. Jana, A. K. Jana, S. Jana, C. Kandar,
S. Mandal, D. Mandal, K. K. Das, T. K. Ghosh, D. Patra,
U. Palui, M. Das, S. Mondal, S. Pal, P. Sarkar, S. Ghosh,
for their constant help and cooperation during the field
study.
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