Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2007.388.392MahmoudzadehA. 32007103To obtain, characteristics and behaviors of soil erosion phenomena, to
control its harms and reduce its risks, realistic data from soil erosion
rates are necessary. Mean while, measuring soil erosion rates particularly
in large scale is a time consuming and expensive task. Moreover, spatial
and temporal changes of soil erosion increase this problem. Therefore,
to find out a certain way of creating capable methods which easily and
quickly be able to estimate soil erosion rate, is quite logical. So, different
models are widely used, but, may be the most important consideration with
this regard is that, these models should be previously, tested and adopted
to defined areas to stop probability of causing some huge and meaningful
errors. Therefore, to achieve the above mentioned aim, different methods
are used. Anyway, conditions which resulted to create a suitable model,
should be considered in a defined area where, model is applied, unless,
model application can leads to huge risks. This study is an attempt with
this refer, that is, with comparing measured soil loss rates and predicted
soil erosion rates from a defined catchment area, created a reasonable
relationship between them and achieved the main aim of the study. That
is, one of the small upland catchments of Emam kandi of Urmia with 75
ha area which is part of the Urmia lake catchment area and under layned
by calcareous parent material, is selected as a study site. Selected catchment
has natural pasture and has closured during the recent years. To calculate
sediment yield the following processes were done: first, estimating the
volume of trapped sediments, then, surveying the catchment area, for calculating
sediment yield. Measured sediment yield is 6.19 t ha-1 year-1
which leads to soil loss rate of 13.76 t ha-1 year-1
by using Sediment Delivery Ratio (SDR). Also, inside the measurement of
sediment yields and calculation of soil loss rates, two models of MUSLE
and PSIAC were used respectively after exclosure and before exclosure
to predict soil loss rates. Predicted soil loss rates by MUSLE and PSIAC
respectively are 12.80 and 26.5 t ha-1 year-1. Finally,
Comparisons and statistical analysis and scientific discussions were made.]]>Edward, K.,198819136140Freebairn, M.D. and H.G. Wockner,198624135158Graham, O.P. et al.,1989Kardowani, P.,1988Mahmoudzadeh, A.,19971997Mctainsh, G.H. and W.C. Boughton,1993Neil, D.T. and R.W. Galloway,198924651Sanders, D.,199254650De Vente, J., J. Poesen and G. Verstraeten,20053056386Walling, D.E.,198365209237Wilson, L.,1973273335349Jihad Sazandagi of Western Azarbaijan,19971997