Erodibility and runoff potential of laterite soils under simulated rainfall conditions
Loading...
Files
Date
1999
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur
Abstract
Soil erosion is one of the most serious environment degradation problems.
However reliable measurement of erosion remains limited and estimates of soil
productivity are even rarer. Assessing the extent and seriousness of erosion
therefore remains a difficult task Nevertheless, identification and assessment of
erosion problems could have an important role in influencing better land use and
conservation practices.
Rainfall simulators are considered as an effective tool in soil conservation
research. Simulators make it possible to produce predetermined storms at any
desired time and location. They make the replication of research easier and
facilitate the study of storm sequences.
Laterite soils are by far the most important soil group occurring in Kerala
and cover the largest area. The objective of this study was to estimate the
erodibility and runoff potential of laterite soils of three well defined series under
simulated rainfall conditions.
The rainfall simulator designed and fabricated by Kurien and George
(1998) was modified for better performance. The modified simulator could
produce rainfall intensities varying from 741 to 23.00 cmlh. Also uniformity of
the rainfall produced could be increased to higher values of 88.10 and 91.53 per
cent, thus giving a better performance. Intensity of rainfall increased as the
11
pressure of supply water to the simulator increased and a relationship was
established between intensity and the supply pressure of water as
1= -87.205 p2 + 108.61 P - 10.786 (R = 0.99)
Experiments were also conducted to study soil loss and runoff from three
different series of laterite soils, i.e.Mannamkulam series, Naduvattom series and
Vellanikkara series. The soil loss and runoff increased with increase in the rainfall
intensity for all slopes studied for each series of soil. A general trend of increase
In soil loss and runoff with increase in the slope was observed for all the three
series of soils.
Empirical equations were developed for estimating soil loss (E) and runoff
(0) for various intensities of rainfall and land slopes for the three series of soils
selected for the study.
The equations are:
Mannamkulam series
E = 1167.797 I + 835.109 S - 21686.07 (R = 0.90)
Q = 65.0161 + 16.747 S - 235.923 (R = 0.99)
Naduvattom series
E = 324.766 I + 112.799 S - 3912.219 (R = 0.97)
Q = 74.542 1+19.434 S - 394.323 (R = 0.99)
Vellanikkara series
E = 115.662 I + 431. 064 S - 11512.284 (R = 0.98)
Q = 58.742 I + 26.837 S - 310.019 (R = 0.99) ii1
Description
PG
Keywords
null
Citation
171537