Vn. Sharda et al., A FINITE-ELEMENT MODEL FOR SIMULATING RUNOFF AND SOIL-EROSION FROM MECHANICALLY TREATED AGRICULTURAL LANDS .2. FIELD VALIDATION AND APPLICATIONS, Water resources research, 30(7), 1994, pp. 2299-2310
The finite element model for simulation of runoff and soil erosion as
developed by Sharda and Singh (this issue) is evaluated using data col
lected from agricultural land treated with major mechanical soil and w
ater conservation measures, namely, contour bunding, graded bunding, b
ench terracing, and conservation bench terracing. The simulated and ex
perimentally realized hydrographs and soil loss values are in reasonab
ly good agreement for various measures. Probable reasons for discrepan
cies between the predicted and observed values are discussed. The mode
l has the potential of being used on a single storm or a continuous ba
sis provided the soil, crop, and climatic parameters are precisely kno
wn or estimated for a given location and for the period under consider
ation. The model logically simulates the effects of flow, topographic,
soil, and crop parameters such as antecedent moisture level, roughnes
s coefficient, saturated hydraulic conductivity, slope, depth of impou
ndment, size of outlet, longitudinal slope of the channel, vertical in
terval, and cropping management factor. The model is found to be quite
sensitive to changes in roughness coefficient, rainfall excess rate,
and cover management factor, and hence these parameters need to be ass
essed carefully in the field. The general applicability of the model a
s a planning tool for soil conservation measures and the scope for fut
ure development are also discussed.