Search results for "Forestal"
showing 10 items of 1240 documents
A Comprehensive Model for Hydraulic Analysis and Wetting Patterns Simulation under Subsurface Drip Laterals
2022
In the absence of suitable specialized models to simulate the soil wetting patterns in subsurface drip irrigation systems considering the hydraulic conditions along the laterals, a new model was developed and named a “comprehensive model” in this study. This model couples the subsurface drip irrigation lateral characteristics with the soil hydraulic properties and utilizes the Hydrus-3D software as a complementary section of the model to simulate the wetting front beneath the lateral. To evaluate the model, three 16 mm drip-line pipes of 62 m length with 20, 40, and 50 cm spacing emitters and 2 to 5 L/h discharge were buried at 0.2 m depth in a soil box containing clay loamy soil. Then, the…
A model of dunnian flow at hillslope scale
2005
The development of a thin stream above the soil surface (overland flow) is associated to two mechanism of runoff generation on the hillslope: the infiltration excess (hortonian flow) and saturation excess (dunnian flow) mechanism. The first one is typical of arid and semi-arid regions, usually characterised by high rainfall intensities on soil exhibiting low permeability. The second one, firstly introduced by Hewlett and Hibbert, constitutes the main mechanism of runoff generation in humid regions, characterised by high groundwater table. In the last mechanism runoff is produced by contributing areas of restricted extent that expands with time, where near to the bottom of the hillslope a hi…
A casual alien plant new to Mediterranean Europe: Ceiba speciosa (Malvaceae) in the suburban area of Palermo (NW Sicily, Italy)
2014
The abiotic and biotic characteristics of the first sites where floss silk tree behaves as a casual alien plant in the Mediterranean Europe are described. The species was probably first planted in botanical gardens of southern France few decades before mid XIX century. It was introduced in Palermo in 1896, a city which appears to match very well its climatic requirements. According to the available information on its biology and ecology in both its original and secondary range, the floss silk tree should not become an invasive alien plant in the Mediterranean. Nevertheless, several gaps need to be filled in order to increase our understanding of future trends of Ceiba speciosa in southern E…
The green granary of the Empire? Insights into olive agroforestry in Sicily (Italy) from the Roman past and the present
2023
Groves with ancient olive trees (Olea europaea L.) could be considered remnants of old agroforestry systems. Anything but static, these agro-ecosystems have undergone drastic transformational processes in Mediterranean countries, where abandonment or intensification have been observed far more than continuity, expansion or renaissance, leading to environmental degradation of rural areas. Starting from this assumption and inspired by historical ecology and historical geography, we consider centuries-old olive trees as living archives of human-nature interactions and are thus proxies of past agroforestry. Our aim is to better understand what has driven dynamics of change and persistence, happ…
Large‐scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale
2022
Lateral saturated soil hydraulic conductivity, K-s,K-l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between K-s,K-l and hydrological connectivity at the hillslope spatial scale. K-s,K-l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluate…
Estimating field-saturated soil hydraulic conductivity by a simplified Beerkan infiltration experiment
2014
Field-saturated soil hydraulic conductivity, Kfs, is highly variable. Therefore, interpreting and simulating hydrological processes, such as rainfall excess generation, need a large number of Kfs data even at the plot scale. Simple and reasonably rapid experiments should be carried out in the field. In this investigation, a simple infiltration experiment with a ring inserted shortly into the soil and the estimation of the so-called a* parameter allowed to obtain an approximate measurement of Kfs. The theoretical approach was tested with reference to 149 sampling points established on Burundian soils. The estimated Kfs with the value of first approximation of a* for most agricultural field s…