EFFECTS OF RAINFALL INTENSITY, KINETIC ENERGY AND SLOPE ANGLE TO THE UPSLOPE, DOWNSLOPE AND LATERAL
SLOPE COMPONENTS OF SPLASH EROSION IN HILLSLOPE AGRICULTURE: A CASE IN BADIANGAN, AJUY, ILOILO
A M aster o f Science Thesis presented to the
Department o f Civil Engineering University o f San Carlos
Cebu City, Philippines
In Partial Fulfillment
o f the Requirements for the Degree o f M aster o f Science in Civil Engineering
by:
SHEVANEE RUTH GANGE DELA CRUZ
N ovember 2022
UNIVERSITY of SAN CARLOS
S C ' E N H A • V I » 1 U 5 ' O E V O I . O
Civil Engineering Research Annual 2022 Volume XX
Issue XX
Department of Civil Engineering USC-TC, Talamban, Cebu City Philippines 6000
Effects o f Rainfall Intensity, K inetic Energy and Slope Angle to the Upslope, Downslope and Lateral Slope Components o f Splash Erosion in H illslope Agriculture: A Case in Badiangan, Ajuy, Iloilo
Shevanee Ruth G. dela Cruz3,5’*, Ricardo L. Fomis3
aDepartment of Civil Engineering, University of San Carlos, Talamban, Cebu City 6000, Philippines departm ent o f Civil Engineering, Central Philippine University, Jaro, Iloilo City 5000, Philippines
♦Corresponding author: Telefax +639 17 327 3680, Email: [email protected]
Abstract
This study was conducted in Barangay Badiangan, Ajuy, Iloilo City, Philippines (11°10’N, 122°58’E) to determine the effects of rainfall intensity and other rainfall-derived parameters on the directional components of splash erosion in hillslopes. There are 5 experimental set-ups with slope angles ranging from 0% to 48% under natural rainfall condition using a modified splash collector. The data collected shows that kinetic energy, slope and rainfall intensity have shown significant effects in splash erosion. The models obtained using regression analysis are Qdet = 0.0093(KE0-80) and Qtrans — 0.060(KE°,1O7)( 5 o;7OO)(/2o0'700)- The model equation performance has been validated using the Standard Error of Estimates with values of 12 and 9.4 for splash detachment and splash transport respectively. The values of the constants used for the Kinetic Energy for detachment and Slope for transport is in accordance to the research done by Quansah for sandy soil which is the soil characteristic of the research site. In addition, the rainfall intensity, especially with time duration of 20 minutes, generated the best model among the different cases as it was observed to give the least value o f SEE for all cases. Effects of surface sealing and crust formation due to the impact of continuous rain to the soil detachment process should also be considered. bla bla bla bla bla woooooooo BOYYY
Keywords: interril erosion, modelling, regression analysis
1