Investigation of mechanisms of erosion and sediment studies in Afjeh and Lavarak sub-basins using experimental models and compare them with geostatic methods

Subject Areas :

Zahra  Najm ¹ (کارشناس ارشد دانشگاه آزاد اسلامی واحد تهران شمال)
Khalil  Rezaei ² (استادیار دانشگاه خوارزمی تهران)
Seyed Hamid  Vaziri ³ (استاد دانشگاه آزاد اسلامی واحد تهران شمال)
Ali  Naeimi Nezam Abad ⁴ (استادیار دانشگاه آزاد اسلامی واحد ساوه)

Received: 2016-09-05 Accepted : 2016-09-05 Published : 2013-06-22

Keywords: Erosion, Sediment, EPM, MPSIAC, Afjeh, Lavarak, Geostatic,

Abstract :

Afjeh and Lavarak sub-basins each with area of 4651,95 and 10557,2 hectare are located at south border ofcentral Alborz at north-eastern of Tehran. Various formations basically contains Shaly, Sandstone, Conglomerateand tuff lithology, covered this region more than igneous rocks. In Afjeh sub-basin, Barout formation with theage of Cambrian and in Lavarak sub-basin, Mila formation with the age of middle and late Cambrian, are theoldest available stones and the newer stone units belong to Quaternary period in each of them. The purpose ofthis research is to compare MPSIAC and EPM models in calculation of sediments supply and soil erosion, usingGIS techniques. To achieve the goals, effects of lithology, soil texture and geological conditions on sedimentproduction were considered by sedimentological and petrographic studies. Finally with use geostatisticaloperations, two models were compared. The results show that the most values of erosion are in Shaly, Marly,weathered tuff and alluvial deposits Parts of sub watersheds correlated with sensitive formations such as Karajand Quaternary sediments. Based on map of MPSIAC model more than 75% of the total sub watersheds areawas classified at class IV of erosion category with high sedimentation. Sub-basin’s erosion were calculated as769.3 and 583.21 m2/km3 per year in Afjeh and Lavarak sub-basins by MPSIAC and 701.3 and 543.2 m2/km3 peryear by EPM models, respectively. The results of statistical compare of erosion of MPSIAC and EPM modelsshow that, there is no significant different between erosion estimate by MPSIAC model and real erosionmeasure, but the erosion estimate by EPM model have a significant different. So MPSIAC model may havebetter performance.