Change of biological soil quality in organic and conventional farming systems of the DOK trial

The DOK trial has started in the 1970ies, when first reports warned us on the consequences of our actions and the limits to growth. Even though farmers and a huge research community know better, we are still not managing our soils in a sustainable way. It seems inevitable that the mainstream agriculture wants to go beyond natural frontiers. Soils have an enormous buffering capacity, but this ends, when ecosystems are collapsing not only at the local, but also at the global level

in advective–dispersive systems: 1. Generalized reservoir theory

which should be used for any reference to this wor

Empirical model for estimating groundwater flow into tunnel in discontinuous rock masses

The high volume of water inflow into tunnel plays a significant role in the design of drainage systems and exerts bio-environmental effects. In engineering practice, analytical and empirical methods that are commonly used to estimate water inflow in sedimentary rock masses, lack sufficient accuracy. The geostructural anisotropy in a fractured rock has a great impact on water inflow. In discontinuous media, anisotropy and heterogeneity of the fractured rock masses are highlited. Hence, these methods are not efficient to calculate water inflow to tunnel in such media, due to the assumed isotropic hydraulic coefficient. In this regard, an empirical formula is developed in this study for hydraulic conductivity in the fractured rock masses for analytical methods, alternately used to predict water inflow. To achieve this, a discrete network flow model was performed. The simulation resulted in a dataset that is helpful in developing hydraulic conductivity empirical formula for well-known Goodman equation. The geostructural parameters, such as the joint orientation, aperture, spacing and joint interconnectivity were included to determine this formula. The acquired empirical equation was utilized in the evaluation of groundwater inflow to middle-depth Amirkabir tunnel in north of Iran. In comparison to the observerd flow, analytical methods resulted in higher overestimation, especially in the sites with high anisotropy. However, empirical model led to a better estimation of water inflow to tunnel