Application of MUSLE for the prediction of phosphorus losses

Abstract

Soil erosion in forestlands affects not only land productivity but also the water body down stream. The Universal Soil Loss Equation (USLE) has been applied broadly for the prediction of soil loss from upland fields. However, there are few reports concerning the prediction of nutrient (P) losses based on the USLE and its versions. The present study was conducted to evaluate the applicability of the deterministic model Modified Universal Soil Loss Equation (MUSLE) to estimation of phosphorus losses in the Kojor forest watershed, northern Iran. The model was tested and calibrated using accurate continuous P loss data collected during seven storm events in 2008. Results of the original model simulations for storm-wise P loss did not match the observed data, while the revised version of the model could imitate the observed values well. The results of the study approved the efficient application of the revised MUSLE in estimating storm-wise P losses in the study area with a high level of agreement of beyond 93%, an acceptable estimation error of some 35%.

Evaluation of the relationships between runoff-rainfall-sediment related nutrient loss (A case study: Kojour Watershed, Iran)

“…Phosphorus (P) is one of the major plant nutrients and also one of the major nutrients controlling eutrophication of surface waters (McDowell et al 2001;Blanco & Lal 2008;Noor et al 2010). Many soil scientists advocate the conservation of OM because of the modifying effects it has on soil properties.…”

“…The most P and OM losses from watersheds are exported during rainfall events resulting in rapid temporal variations in their loads. This makes it difficult to accurately estimate the P and OM loads because of the need for intensive water sampling during periods of highly fluctuating discharge (Hatch et al 1999;Ide et al 2008;Noor et al 2010).…”

Storm-wise sediment yield prediction using hillslope erosion model in semi-arid abundant lands

“…Sediment yield also provides an important index of land degradation, severity and trends, and also reflects the characteristics of a watershed, its history, development, use and management. Therefore, the estimation of sediment yield is needed because it not only affects reservoir capacity, sediment transport to the oceans, stream water quality and quantity, aquatic life, stream habitat, channel morphology and in brief environmental health impact assessment but also it is a good indicator for the effectiveness of watershed management conditions (Sadeghi et al 2008;Noor et al 2010Noor et al , 2012.…”

“…Computational models are generally used to simulate the amount of sediment yield from watersheds (Sadeghi et al 2008;Noor 2010). These models vary from complex procedures requiring a range of input parameters, e.g.…”

“…Soil erosion and sediment yield models can assist in the development of suitable policies and regulations for agricultural, rangeland and forestry practices. Some models, in spite of their strong theoretical base, may not be very suitable in the context of developing country situations such as those in Iran, where the detailed rainfall, topographic and other input data are not often available or are difficult to collect due to resource constraints (Sadeghi et al 2008;Noor et al 2010Noor et al , 2012.…”