9 resultados para alternative land use
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
In genere, negli studi di vocazionalità delle colture, vengono presi in considerazione solo variabili ambientali pedo-climatiche. La coltivazione di una coltura comporta anche un impatto ambientale derivante dalle pratiche agronomiche ed il territorio può essere più o meno sensibile a questi impatti in base alla sua vulnerabilità. In questo studio si vuole sviluppare una metodologia per relazionare spazialmente l’impatto delle colture con le caratteristiche sito specifiche del territorio in modo da considerare anche questo aspetto nell’allocazione negli studi di vocazionalità. LCA è stato utilizzato per quantificare diversi impatti di alcune colture erbacee alimentari e da energia, relazionati a mappe di vulnerabilità costruite con l’utilizzo di GIS, attraverso il calcolo di coefficienti di rischio di allocazione per ogni combinazione coltura-area vulnerabile. Le colture energetiche sono state considerate come un uso alternativo del suolo per diminuire l’impatto ambientale. Il caso studio ha mostrato che l’allocazione delle colture può essere diversa in base al tipo e al numero di impatti considerati. Il risultato sono delle mappe in cui sono riportate le distribuzioni ottimali delle colture al fine di minimizzare gli impatti, rispetto a mais e grano, due colture alimentari importanti nell’area di studio. Le colture con l’impatto più alto dovrebbero essere coltivate nelle aree a vulnerabilità bassa, e viceversa. Se il rischio ambientale è la priorità, mais, colza, grano, girasole, e sorgo da fibra dovrebbero essere coltivate solo nelle aree a vulnerabilità bassa o moderata, mentre, le colture energetiche erbacee perenni, come il panico, potrebbero essere coltivate anche nelle aree a vulnerabilità alta, rappresentando cosi una opportunità per aumentare la sostenibilità di uso del suolo rurale. Lo strumento LCA-GIS inoltre, integrato con mappe di uso attuale del suolo, può aiutare a valutarne il suo grado di sostenibilità ambientale.
Resumo:
Throughout the alpine domain, shallow landslides represent a serious geologic hazard, often causing severe damages to infrastructures, private properties, natural resources and in the most catastrophic events, threatening human lives. Landslides are a major factor of landscape evolution in mountainous and hilly regions and represent a critical issue for mountainous land management, since they cause loss of pastoral lands. In several alpine contexts, shallow landsliding distribution is strictly connected to the presence and condition of vegetation on the slopes. With the aid of high-resolution satellite images, it's possible to divide automatically the mountainous territory in land cover classes, which contribute with different magnitude to the stability of the slopes. The aim of this research is to combine EO (Earth Observation) land cover maps with ground-based measurements of the land cover properties. In order to achieve this goal, a new procedure has been developed to automatically detect grass mantle degradation patterns from satellite images. Moreover, innovative surveying techniques and instruments are tested to measure in situ the shear strength of grass mantle and the geomechanical and geotechnical properties of these alpine soils. Shallow landsliding distribution is assessed with the aid of physically based models, which use the EO-based map to distribute the resistance parameters across the landscape.
Resumo:
Studies on soil organic carbon (SOC) sequestration in perennial energy crops are available for North-Central Europe, while there is insufficient information for Southern Europe. This research was conducted in the Po Valley, a Mediterranean-temperate zone characterised by low SOC levels, due to intensive management. The aim was to assess the factors influencing SOC sequestration and its distribution through depth and within soil fractions, after a 9-year old conversion from two annual systems to Miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax). The 13C natural abundance was used to evaluate the amount of SOC in annual and perennial species, and determine the percentage of carbon derived from perennial crops. SOC was significantly higher under perennial species, especially in the topsoil (0-0.15 m). After 9 years, the amount of C derived from Miscanthus was 18.7 Mg ha-1, mostly stored at 0-0.15 m, whereas the amount of C derived from giant reed was 34.7 Mg ha-1, evenly distributed through layers. Physical soil fractionation was combined with 13C abundance analysis. C derived from perennial crops was mainly found in macroaggregates. Under giant reed, more newly derived-carbon was stored in microaggregates and mineral fraction than under Miscanthus. A molecular approach based on denaturing gradient gel electrophoresis (DGGE) allowed to evaluate changes on microbial community, after the introduction of perennial crops. Functional aspects were investigated by determining relevant soil enzymes (β-glucosidase, urease, alkaline phosphatase). Perennial crops positively stimulated these enzymes, especially in the topsoil. DGGE profiles revealed that community richness was higher in perennial crops; Shannon index of diversity was influenced only by depth. In conclusion, Miscanthus and giant reed represent a sustainable choice for the recovery of soils exhausted by intensive management, also in Mediterranean conditions and this is relevant mainly because this geographical area is notoriously characterised by a rapid turnover of SOC.
Resumo:
Landslide hazard and risk are growing as a consequence of climate change and demographic pressure. Land‐use planning represents a powerful tool to manage this socio‐economic problem and build sustainable and landslide resilient communities. Landslide inventory maps are a cornerstone of land‐use planning and, consequently, their quality assessment represents a burning issue. This work aimed to define the quality parameters of a landslide inventory and assess its spatial and temporal accuracy with regard to its possible applications to land‐use planning. In this sense, I proceeded according to a two‐steps approach. An overall assessment of the accuracy of data geographic positioning was performed on four case study sites located in the Italian Northern Apennines. The quantification of the overall spatial and temporal accuracy, instead, focused on the Dorgola Valley (Province of Reggio Emilia). The assessment of spatial accuracy involved a comparison between remotely sensed and field survey data, as well as an innovative fuzzylike analysis of a multi‐temporal landslide inventory map. Conversely, long‐ and short‐term landslide temporal persistence was appraised over a period of 60 years with the aid of 18 remotely sensed image sets. These results were eventually compared with the current Territorial Plan for Provincial Coordination (PTCP) of the Province of Reggio Emilia. The outcome of this work suggested that geomorphologically detected and mapped landslides are a significant approximation of a more complex reality. In order to convey to the end‐users this intrinsic uncertainty, a new form of cartographic representation is needed. In this sense, a fuzzy raster landslide map may be an option. With regard to land‐use planning, landslide inventory maps, if appropriately updated, confirmed to be essential decision‐support tools. This research, however, proved that their spatial and temporal uncertainty discourages any direct use as zoning maps, especially when zoning itself is associated to statutory or advisory regulations.
Resumo:
La dissertazione ha riguardato l’analisi di sostenibilità di un sistema agronomico per la produzione di olio vegetale a fini energetici in terreni resi marginali dall’infestazione di nematodi. Il processo indagato ha previsto il sovescio di una coltura con proprietà biofumiganti (brassicacea) coltivata in precessione alla specie oleosa (soia e tabacco) al fine di contrastare il proliferare dell’infestazione nel terreno. Tale sistema agronomico è stato confrontato attraverso una analisi di ciclo di vita (LCA) ad uno scenario di coltivazione della stessa specie oleosa senza precessione di brassica ma con l’utilizzo di 1-3-dicloropropene come sistema di lotta ai nematodi. Allo scopo di completare l’analisi LCA con una valutazione dell’impatto sull’uso del suolo (Land use Impact) generato dai due scenari a confronto, sono stati costruiti due modelli nel software per il calcolo del Soil Conditioning Index (SCI), un indicatore quali-quantitativo della qualità del terreno definito dal Dipartimento per l’Agricoltura degli Stati Uniti d’America (USDA).
Resumo:
The abandonment of less productive fields and agro-forest activities has occured in the last decades, interesting large mountain areas in all mediterranean basin. Until the fifties, agricultural practices dealt mainly with soil surface and surface runoff control systems. However, the apparent sustainability of soil use results often in contrast with historical documents, witnessing heavy hydrogeological instability, in naturally fragile areas. The research focused on the dynamics and effects of post-coltural land abandonment in a critical mountain area of the Reno River. The Reno River rappresents a typical Tuscan-Emilian Apennines Watershed where soil erosion occurs under very different conditions depending on interactions between land use, climate, geomorphology and lithology. Landslides are largely rappresented, due to the diffusion of clay hill slopes. Recent researches suggest that climatic variability will increase as a consequence of global climate change, resulting in greater frequency and intensity of extreme weather events, which could increase rates of erosion, landslides reactivations and diffusion of calanchive basins. As far as hill slopes are concerned, instability is today basically due to intrinsic factors, as the Apennine range is a rather young formation, in geological terms, and is mainly formed by sedimentary rocks with high occurrence of clays. Therefore landslides and rockfalls are very frequent, while surface soil erosion is generally low and anyway concentrated in the low Apennine, where intensive farming is still economically worth. The study, supported by GIS use, analyses the main fisical characteristics of the area and the historical changes of land use, and focalizes the dynamics of spontaneous reafforestation. Futhermore, the research studies the results of soil bioengineering and surface water control solutions for the restablishment of landslides occured in the last period. Infact soil bioengineering has been recently used in different situations in order to consolidate slopes and hillsides and prevent erosion; when applied, it gave good results, both in terms of engineering efficiency and vegetational development, expecially if combined with a good hydraulic control, thus proving to be an actual alternative to other techniques with heavier environmental impacts. Research into the specific site features and the use of proper plant species is vital to the success of bioengineering works.
Resumo:
One of the main problems recognized in sustainable development goals and sustainable agricultural objectives is Climate change. Farming contributes significantly to the overall Greenhouse gases (GHG) in the atmosphere, which is approximately 10-12 percent of total GHG emissions, but when taking in consideration also land-use change, including deforestation driven by agricultural expansion for food, fiber and fuel the number rises to approximately 30 percent (Smith et. al., 2007). There are two distinct methodological approaches for environmental impact assessment; Life Cycle Assessment (a bottom up approach) and Input-Output Analysis (a top down approach). The two methodologies differ significantly but there is not an immediate choice between them if the scope of the study is on a sectorial level. Instead, as an alternative, hybrid approaches which combine these two approaches have emerged. The aim of this study is to analyze in a greater detail the agricultural sectors contribution to Climate change caused by the consumption of food products. Hence, to identify the food products that have the greatest impact through their life cycle, identifying their hotspots and evaluating the mitigation possibilities for the same. At the same time evaluating methodological possibilities and models to be applied for this purpose both on a EU level and on a country level (Italy).
Resumo:
This doctoral thesis focuses on the study of historical shallow landslide activity over time in response to anthropogenic forcing on land use, through the compilation of multi-temporal landslide inventories. The study areas, located in contrasting settings and characterized by different history of land-cover changes, include the Sillaro River basin (Italy) and the Tsitika and Eve River basins (coastal British Columbia). The Sillaro River basin belongs to clay-dominated settings, characterized by extensive badland development, and dominated by earth slides and earthflows. Here, forest removal began in the Roman period and has been followed by agricultural land abandonment and natural revegetation in recent time. By contrast, the Tsitika-Eve River basins are characterized by granitic and basaltic lithologies, and dominated by debris slides, debris flows and debris avalanches. In this setting, anthropogenic impacts started in 1960’s and have involved logging operation. The thesis begins with an introductory chapter, followed by a methodological section, where a multi-temporal mapping approach is proposed and tested at four landslide sites of the Sillaro River basin. Results, in terms of inventory completeness in time and space, are compared against the existing region-wide Emilia-Romagna inventory. This approach is then applied at the Sillaro River basin scale, where the multi-temporal inventory obtained is used to investigate the landslide activity in relation to historical land cover changes across geologic domains and in relation to hydro-meteorological forcing. Then, the impact of timber harvesting and road construction on landslide activity and sediment transfer in the Tsitika-Eve River basins is investigated, with a focus on the controls that interactions between landscape morphometry and cutblock location may have on landslide size-frequency relations. The thesis ends with a summary of the main findings and discusses advantages and limitations associated with the compilation of multi-temporal inventories in the two settings during different periods of human-driven, land-cover dynamics.
Resumo:
The First Cataract region (Egypt) has always played a crucial role as a border area and a crossroads for cultures and people living in adjacent landscapes. The region has its central point in the modern city of Aswan, but it extends up to the Kom Ombo Plain in the north and reaches the Bab el-Kalabsha in the south. Its eastern and western limits cannot be defined with the same precision, given that they are located in deserts. This research focused on the landscape analysis of the region intended as a complex entanglement of archaeological evidence in a geographical and natural environment whose changes impacted and, simultaneously, were influenced by human activities. Settlement patterns and land use can give interesting information on how these relationships worked from a diachronic perspective and how they shaped the region’s characteristics. To understand the links between the human presence and its evidence and the landscape of the First Cataract region, the integration of various datasets was needed, from historical and archaeological ones to the remote sensing observation of large areas. An area corresponding to ca. 18.000 km2 has been selected for this research. The chronological framework has been chosen to cover a considerable period, from the beginning of the 5th millennium BCE to the 7th century AD. Multi-temporality and multifunctionality appear as two essential aspects when the archaeological evidence of the First Cataract region is considered in its geographical and topographical setting as a general context for settlement patterns and resource exploitation analyses. A combination of remote sensing data and topographical materials has been integrated with archaeological evidence to obtain information about resource exploitation strategies and settlement adaptation from a diachronic perspective.