Large scale transport events are studied using two different 3-Dsimulation codes related to resistive ballooning and ion temperature gradientturbulence. The turbulence is driven by a constant incoming flux. In the caseof resistive ballooning simulations, the underlying structures are found to beradially elongated on the low field side and distorted by magnetic shear inthe parallel direction (streamers). The non-linear character of these structures isemphasized. Bursty transport is investigated in the presence of zonal flows andinternal transport barriers generated either by a strong shear flow or with amagnetic shear reversal. In deriving a low dimensional model that captures themain features of bursty transport dynamics, it is found that E × B shear flow isnecessary to trigger the bursts.