Inductive pattern-based land use/cover change models: A comparison of four software packages

International audienceLand use/cover change (LUCC), as an important factor in global change, is a topic that has recently received considerable attention in the prospective modeling domain. There are many approaches and software packages for modeling LUCC, many of them are empirical approaches based on past LUCC such as CLUES , DINAMICA EGO, CA_MARKOV and Land Change Modeler (both available in IDRISI). This study reviews the possibilities and the limits of these four modeling software packages. First, a revision of the methods and tools available for each model was performed, taking into account how the models carry out the different procedures involved in the modeling process: quantity of change estimate, change potential evaluation, spatial allocation of change, reproduction of temporal and spatial patterns, model evaluation and advanced modeling options. Additional considerations, such as flexibility and user friendliness were also taken into account. Then, the four models were applied to a virtual case study to illustrate the previous descriptions with a typical LUCC scenario that consists of four processes of change (conversion of forest to two different types of crops, crop abandonment and urban sprawl) that follow different spatial patterns and are conditioned by different drivers. The outputs were compared to assess the quantity of change estimates, the change potential and the simulated prospective maps. Finally, we discussed some basic criteria to define a " good " model

Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was-0.42 \ub1 1.72 and 0.03 \ub1 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between-5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 \ub1 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively. Technical improvements such as using an aerial platform and/or placing artificial targets could significantly improve the results but run the risk of being more demanding in terms of costs and logistics

Proceedings Of The 18th Annual Meeting Of The Asia Oceania Geosciences Society (Aogs 2021)

The 18th Annual Meeting of the Asia Oceania Geosciences Society (AOGS 2021) was held from 1st to 6th August 2021. This proceedings volume includes selected extended abstracts from a challenging array of presentations at this conference. The AOGS Annual Meeting is a leading venue for professional interaction among researchers and practitioners, covering diverse disciplines of geosciences

An open and extensible framework for spatially explicit land use change modelling in R: the lulccR package (0.1.0)

Land use change has important consequences for biodiversity and the sustainability of ecosystem services, as well as for global environmental change. Spatially explicit land use change models improve our understanding of the processes driving change and make predictions about the quantity and location of future and past change. Here we present the lulccR package, an object-oriented framework for land use change modelling written in the R programming language. The contribution of the work is to resolve the following limitations associated with the current land use change modelling paradigm: (1) the source code for model implementations is frequently unavailable, severely compromising the reproducibility of scientific results and making it impossible for members of the community to improve or adapt models for their own purposes; (2) ensemble experiments to capture model structural uncertainty are difficult because of fundamental differences between implementations of different models; (3) different aspects of the modelling procedure must be performed in different environments because existing applications usually only perform the spatial allocation of change. The package includes a stochastic ordered allocation procedure as well as an implementation of the widely used CLUE-S algorithm. We demonstrate its functionality by simulating land use change at the Plum Island Ecosystems site, using a dataset included with the package. It is envisaged that lulccR will enable future model development and comparison within an open environment

Landscape domains and information surfaces: Data collection, recording and citation using decimal latitude‐longitude geolocation via the FAIR principles

There is a need for geomorphology to integrate better with related disciplines, especially in Critical Zone science. To help satisfy this integration, geomorphology's knowledge-base should extend into biotic as well as geological processes via ‘open data’. To aid information exchange between disciplines, the use of decimal latitude-longitude (dLL) topographic geo-referencing is advocated to identify locations of investigations, images and data in accord with the FAIR principles for data: findability, accessibility, interoperability and reusability. While local place names (toponyms) have their uses, they do not provide good location information. Identification of detailed locations using dLL referencing should be used in written, especially published, reports of investigations. Author-date citations are traditionally used to identify geomorphic knowledge, which can be enhanced when linked to dLL-specified locations and data such as sample sites and laboratory data. Ways in which dLL specifications might be used in geomorphology and associated disciplines are explored and some geomorphological problems associated with ‘steepland’ landscape domains are presented. Examples show how dLL data can be incorporated into the literature, whereby authors can help provide and develop geomorphic ‘information surfaces’ by using geo-referencing to enhance ‘open’ science via the FAIR principles

Integrative assessment of Badland erosion dynamics in the Oltrepo area

The present work is the result of three years of investigations on soil erosion forms and features in the Oltrepo Pavese, Northern Apennines, Italy. The aim of the work is to review from a modern and scientific point of view the badlands which crop out in the study area as well as to improve methodologies to study the sediment dynamics in badland areas. Badlands are the result of a complex interaction between sub-surface and surface runoff soil erosion processes and are a hotspot for biodiversity and geodiversity. In addition, badlands have always been a fundamental environment for soil erosion investigations. This work is based on the following four principal steps: i) the geological and structural characterisation of the study area, ii) the description of badland forms and features, iii) a probabilistic approach to determine soil erosion susceptible areas in the Oltrepo Pavese and iv) the assessment of suspended sediment dynamics at catchment scale. This study highlights a complex geological and structural sector of the Northern Apennines characterised by soft sedimentary bedrock materials that are prone to be eroded by running water. Initially, a litho-structural map was assembled, and the geological formations of the study area were grouped according to their lithology. The map represents a homogeneous base of information to classify from lithological point of view the badlands of the study area and will become a raster-base for spatial multilayer analysis. Subsequently, a geological, geomorphological and morphometrical classification of the badlands which crop out in the study area was performed though field survey and detailed terrain analysis based on Digital Terrain Models (DTM). The Oltrepo Pavese badlands were classified in type A and B according to their morphology and vegetation conditions. The badlands show high heterogeneity and can be closely related with melange bedrock, claystone and interstratified rocks. Furthermore, the badlands show the typical characteristics of Apennine badlands even if certain morphological differences were noted. This study also highlights the importance of the rainfall characteristics and land use changes playing an important role in the development and stabilisation of the badland forms and features. The land use change induced by planting operations (afforestation) and the reduction of agricultural activities in the area, as well as the reduction of the precipitation amount leads to a shrinking of badlands. Though a detailed terrain analysis and the application of the Maximum Entropy model (MaxEnt) three susceptibility maps were generated for the badland and rill-interrill erosion forms. The predictor analysis has highlighted that the more important predictors (i.e. lithology, land use, elevation) can significantly explain the diversity between calanchi type A and B. However, less significant predictors e.g. Vertical Distance to Channel Network, Valley Depth and Catchment Area are fundamental to understand the development of the two morphotypes. Finally, the study reveals for the first time, the dynamics between precipitation, discharge and suspended sediment transport in a small watershed basin sited in the Northern Apennines. A laser diffraction instrument was installed at the outlet of a small watershed basin deeply interested by aquatic erosion and the sediment diameter and concentration was evaluated with respect to rainfall. The initial moisture condition, hydrophobicity, vegetation cover, and physical conditions of the basin play a fundamental role in the assessment of sediment dynamics. Finally, the study reveals the importance of a correct land management to reduce badland erosion in the Apennine region.The present work is the result of three years of investigations on soil erosion forms and features in the Oltrepo Pavese, Northern Apennines, Italy. The aim of the work is to review from a modern and scientific point of view the badlands which crop out in the study area as well as to improve methodologies to study the sediment dynamics in badland areas. Badlands are the result of a complex interaction between sub-surface and surface runoff soil erosion processes and are a hotspot for biodiversity and geodiversity. In addition, badlands have always been a fundamental environment for soil erosion investigations. This work is based on the following four principal steps: i) the geological and structural characterisation of the study area, ii) the description of badland forms and features, iii) a probabilistic approach to determine soil erosion susceptible areas in the Oltrepo Pavese and iv) the assessment of suspended sediment dynamics at catchment scale. This study highlights a complex geological and structural sector of the Northern Apennines characterised by soft sedimentary bedrock materials that are prone to be eroded by running water. Initially, a litho-structural map was assembled, and the geological formations of the study area were grouped according to their lithology. The map represents a homogeneous base of information to classify from lithological point of view the badlands of the study area and will become a raster-base for spatial multilayer analysis. Subsequently, a geological, geomorphological and morphometrical classification of the badlands which crop out in the study area was performed though field survey and detailed terrain analysis based on Digital Terrain Models (DTM). The Oltrepo Pavese badlands were classified in type A and B according to their morphology and vegetation conditions. The badlands show high heterogeneity and can be closely related with melange bedrock, claystone and interstratified rocks. Furthermore, the badlands show the typical characteristics of Apennine badlands even if certain morphological differences were noted. This study also highlights the importance of the rainfall characteristics and land use changes playing an important role in the development and stabilisation of the badland forms and features. The land use change induced by planting operations (afforestation) and the reduction of agricultural activities in the area, as well as the reduction of the precipitation amount leads to a shrinking of badlands. Though a detailed terrain analysis and the application of the Maximum Entropy model (MaxEnt) three susceptibility maps were generated for the badland and rill-interrill erosion forms. The predictor analysis has highlighted that the more important predictors (i.e. lithology, land use, elevation) can significantly explain the diversity between calanchi type A and B. However, less significant predictors e.g. Vertical Distance to Channel Network, Valley Depth and Catchment Area are fundamental to understand the development of the two morphotypes. Finally, the study reveals for the first time, the dynamics between precipitation, discharge and suspended sediment transport in a small watershed basin sited in the Northern Apennines. A laser diffraction instrument was installed at the outlet of a small watershed basin deeply interested by aquatic erosion and the sediment diameter and concentration was evaluated with respect to rainfall. The initial moisture condition, hydrophobicity, vegetation cover, and physical conditions of the basin play a fundamental role in the assessment of sediment dynamics. Finally, the study reveals the importance of a correct land management to reduce badland erosion in the Apennine region

SINKHOLES OF THE FRIULI VENEZIA GIULIA REGION: CHARACTERIZATION, DATA COLLECTION AND HAZARD DEFINITION

Il dottorato di ricerca si è focalizzato sull’identificazione, la caratterizzazione e l’analisi dei fenomeni di sinkhole (subsidence sinkhole sensu Gutiérrez et al., 2014) al fine di calcolare le distanze di rispetto e di sviluppare un protocollo informatico in grado di assegnare automaticamente a ciascun fenomeno la sua pericolosità. La regione Friuli Venezia Giulia (FVG) è stata scelta come area studio in quanto assieme al Carso Classico rappresenta un’area ricca di fenomeni di sprofondamento verificatisi in diversi contesti geologici. Un vasto censimento dei fenomeni presenti sul territorio regionale è stato fatto negli anni grazie ai diversi Accordi di ricerca tra il Servizio Geologico della regione e il Dipartimento di Matematica e Geoscienze dell'Università di Trieste al fine di implementare, con i fenomeni naturali, il geodatabase già esistente a livello nazionale. Il primo lavoro svolto all’interno del dottorato è stato quello di revisionare la struttura della banca dati, aggiornare le informazioni al suo interno e censire nuovi fenomeni in diversi contesti geomorfologici e litologici (inizialmente il censimento riguardava solo l’ambiente evaporitico). Tutto questo è stato possibile grazie agli innumerevoli sopralluoghi che hanno contribuito alla riduzione dei fenomeni "non definiti" (da 446 nel 2020 a 262 nel 2023), alla compilazione e/o all’aggiornamento di alcuni campi come la classificazione e, quando possibile, lo stato di attività e i parametri morfometrici, e all’aggiunta di 159 nuovi fenomeni. Il censimento si è concentrato in particolare sui carbonati a partire dal Carso Classico, e successivamente l'analisi è stata estesa a tutto il territorio regionale. La presenza di numerose grotte i cui ingressi possono essere riconducibili a dei collassi ha determinato la scelta di analizzare il catasto speleologico della regione FVG (CSR), esaminando un totale di 8004 grotte e definendo un protocollo metodologico per l’identificazione dei sinkhole in questo contesto. Parallelamente a quanto descritto, sono stati effettuati degli studi approfonditi su diverse aree test (es. abitati di Quinis e Baus (UD)) che hanno permesso di definire la miglior metodologia per caratterizzare questi fenomeni in diversi contesti geologico/geomorfologici. L'applicazione di diverse metodologie, come la combinazione di analisi di dati interferometrici e di livellamento, indagini geofisiche ecc., si è dimostrata fondamentale, non solo per la caratterizzazione tridimensionale di alcune forme, ma anche per l’analisi della loro evoluzione nel tempo evidenziando l'importanza del monitoraggio in continuo al fine di evitare danni ad abitazioni ed infrastrutture. Nell'area di Quinis sono state inoltre effettuate indagini di dettaglio tramite lo scavo di una trincea attraversando un sinkhole attivo. Questo studio, effettuato per la prima volta in Italia, ha permesso di descrivere e caratterizzare tridimensionalmente il fenomeno e l’area circostante. Tutte le attività svolte hanno portato allo sviluppo di un approccio metodologico in grado di definire automaticamente le distanze di rispetto dai sinkhole. Nella letteratura non esiste un metodo specifico per calcolarne il valore. Nel caso della regione FVG, è stato deciso di applicare una metodologia quantitativa basata sui dati disponibili raccolti nel geodatabase. In base allo stato di attività, alla classificazione e alla litologia, criteri specifici basati sul calcolo trigonometrico e sulle caratteristiche intrinseche del materiale coinvolto, hanno portato al calcolo di un buffer e all'assegnazione di una pericolosità a ciascuna area individuata. La metodologia è stata successivamente importata in ambiente GIS sviluppando un tool ad hoc applicabile ai fenomeni legati all'ambiente evaporitico per creare una mappa di pericolosità

Earthquake-triggered landslide susceptibility in Italy by means of Artificial Neural Network

The use of Artificial Neural Network (ANN) approaches has gained a significant role over the last decade in the field of predicting the distribution of effects triggered by natural forcing, this being particularly relevant for the development of adequate risk mitigation strategies. Among the most critical features of these approaches, there are the accurate geolocation of the available data as well as their numerosity and spatial distribution. The use of an ANN has never been tested at a national scale in Italy, especially in estimating earthquake-triggered landslides susceptibility. The CEDIT catalogue, the most up-to-date national inventory of earthquake-induced ground effects, was adopted to evaluate the efficiency of an ANN to explain the distribution of landslides over the Italian territory. An ex-post evaluation of the ANN-based susceptibility model was also performed, using a sub-dataset of historical data with lower geolocation precision. The ANN training highly performed in terms of spatial prediction, by partitioning the Italian landscape into slope units. The obtained results returned a distribution of potentially unstable slope units with maximum concentrations primarily distributed in the central Apennines and secondarily in the southern and northern Apennines. Moreover, the Alpine sector clearly appeared to be divided into two areas, a western one with relatively low susceptibility to earthquake-triggered landslides and the eastern sector with higher susceptibility. Our work clearly demonstrates that if funds for risk mitigation were allocated only on the basis of rainfall-induced landslide distribution, large areas highly susceptible to earthquake-triggered landslides would be completely ignored by mitigation plans.</p