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

Abstract

Noor H., Fazli S., Alibakhshi S.M. (2013) Suspended sediment (SS) resulted from distributed soil erosions facilitates soil organic matter and phosphorus (P) transportation and influences soil depletion and water quality. Organic matter (OM) in soil is the most important indicator of soil quality and productivity. P is one of the major nutrients controlling eutrophication of surface water. Irregular contaminant load pulsed by heavy rainfall may damage the ecological quality of downstream waters. Evaluation of OM and P, depleted by erosion processes in watershed scale, is necessary for better understanding the watershed system and should lead to appropriate management approaches. On the other hand, different behaviours of soil erosion as well as the necessity of regional studies have been proved. The present study was conducted in the Kojour watershed, Iran in order to (1) get some ideas about the storm-wise OM and P load in river, (2) evaluate the relationship between the peak of OM and P concentration and discharge during individual rainfall events, and (3) assess the applicability of rainfall and runoff variables of ten storm events in the prediction of storm-wise OM and P loss. The results showed that most of the OM and P peaks preceded the peak discharge, following a clockwise hysteretic loop that exhibited hysteresis with a greater OM and P concentration for a given discharge occurring on the rising limb rather than on the falling limb. The results also showed that regression models had good efficiency in estimation of storm-wise OM and P loss with coefficient of determination of 0.96 and 0.93, respectively.

Sediment yield modelling using SDR and MUSLE with high resolution satellite precipitation dataset in an ungauged basin

“…While the word "soil erosion" often refers to erosion that takes place inside a watershed, "sediment yield" refers to the amount of soil that the watershed has left over.Sediment Yields (SY) from catchment restricts the sustainable utilization of natural resources. Predicting the SY is crucial because it influences the factors like reservoir storage, watershed characteristics, and channel shape, as well as watershed health and efficacy of watershed management practices (Sadeghi et al 2007, Noor et al 2013. The hydrometric station (gauging station) is provided at the outlet of the watershed to monitor the daily SY and discharge of water.…”

Soil Erosion Assessment With Invest Model: Case Study in Wee-Oya Watershed in Sri Lanka

“…Soil erosion is the main factor of deterioration in the quality of surface water. Low levels of oxygen, eutrophication, and high concentrations of nutrients and organic matter in water bodies are associated with the pollution of sediment-associated water (Noor et al, 2013). Water turbidity occurred by sedimentation becomes a barrier to the penetration of light into the water and prevents the productivity of aquatic ecosystems.…”

“…Water turbidity occurred by sedimentation becomes a barrier to the penetration of light into the water and prevents the productivity of aquatic ecosystems. Sediment accumulation also disrupts ecological processes and degrades fish spawning habitats and habitats in aquatic environments (Noor et al, 2013).…”

Modelling of Soil Erosion Processes and Runoff for Sustainable Watershed Management: Case Study Oued El Abid Watershed, Morocco

“…Soil erosion is one of the most important causes of land degradation and one of the key global environmental hazards; especially for developing countries (Eswaran et al, 2001), affecting all natural and human-managed ecosystems (Kalibová et al, 2016;Gholami et al, 2013). Soil erosion by water affects 1,094 million hectares of arable land worldwide (Noor et al, 2013).…”