JWSS - Journal of Water and Soil Science

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Purple coneflower (Echinaceae purpurea (L.) Mnch) is one of the most important medicinal plants used by pharmaceutical industries in industrialized countries. The active substances of this plant are antiviral and are used as human immunostimulant. The plant of purple coneflower is not included in the Iranian flora. Therefore, the main aim of this study was to evaluate the adaptability of the plant to the conditions in the north of Tehran (Zardband region). The results from this research should contribute to large-scale production as a raw material for Iranian pharmaceutical industries. Comparison of means of the different characteristics was carried out using t-test at 5% level. Results showed that purple coneflower is adaptable to the climatic conditions in the north of Tehran and can be produced on a large scale. The suitable time for transplanting the seedling in the field was from 5 August to 5 September. Maintaining the purple coneflower until its fourth vegetative period is economical. Transplanting after this date produces woody stems and reduces both the herb yield and the quality of its active substances.

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The objective of the current research was to prioritize effective factors in landslide occurrence and its susceptibility zonation using Shannon’s entropy index in North of Tehran metropolitan. To this end, 528 landslide locations were identified using satellite images such as Geoeye (2011-2012), SPOT-5 (2010), and field surveys, and then landslide inventory map was created for the study area in ArcGIS environment. Data layers such as slope degree, slope aspect, plan curvature, altitude, lithology, land use, distance of road, distance of fault, distance of drainage, drainage density, road density, sediment transport index (STI), stream power index (SPI), topographic wetness index (TWI), normalized difference vegetation index (NDVI), surface area ratio (SAR) and topographic position index (TPI) were created and the mentioned maps were digitized in GIS environment. Prioritization of effective factors by Shannon’s entropy index showed that the layers such as land use, lithology, slope degree, stream power index, and NDVI had the most effect on landslide occurrence. However, factors of topographic position index and plan curvature had the least effect. Also, landslide susceptibility zoning by the mentioned model and its accuracy assessment using relative operating characteristics (ROC) curve and 30 percent of landslide locations showed an accuracy of 82.83% with a standard error of 0.0233 in the study area.