Geoinformatics in morphological study of River Paglia, Tiber River basin, Central Italy

A GIS-Based Tool for Automatic Bankfull Detection from Airborne High Resolution Dem

“…Determining bankfull dimensions in the fields may be difficult for streams that are in disequilibrium or rather for riverbeds that are recently carved or are still under a linear incision process. Most geomorphological studies require the detection of bankfull dimensions and often data collected in the field have to be interpreted and combined with remotely sensed data [19,20]. Disequilibrium channels are typically hydrologically disconnected from their active-floodplain with a development of in-channel morphological feature (i.e., benches and incipient floodplain) [21,22].…”

“…In this case, the algorithm identifies the bankfull mean depth reading the slope change from the opposite side, where the bank is located not close to the active alluvial plain but close to the river terrace. This poor result is linked to the disequilibrium condition affecting the river [19].…”

Short-Term GIS Analysis for the Assessment of the Recent Active-Channel Planform Adjustments in a Widening, Highly Altered River: The Scrivia River, Italy

“…These morphological dynamics have been more or less pronounced both at reach scale and over time. The extreme floods occurred in the investigated period can be considered the most important triggering factor of the active-channel planform changes, most probably together with an increase of the reach-scale unit stream power due to changes in the channel geometry occurred over the 20th century.Water 2020, 12, 514 2 of 22 literature focus on riverbed adjustments occurred in historical time, that is over the past few centuries, at the so-called medium-term temporal scale [11,21]. However, aiming to precisely define the ongoing morphological dynamics, the most suited time span to consider for analyzing the riverbed adjustments ranges from the present-day to approximately 10-25 years ago [11,22,23].Previous studies concerning the morphological evolution of Italian rivers outlined their main morphological tendencies over the last two centuries, that is substantially before the occurrence of the most intense and widespread anthropic interventions on fluvial systems.…”

“…However, aiming to precisely define the ongoing morphological dynamics, the most suited time span to consider for analyzing the riverbed adjustments ranges from the present-day to approximately 10-25 years ago [11,22,23].Previous studies concerning the morphological evolution of Italian rivers outlined their main morphological tendencies over the last two centuries, that is substantially before the occurrence of the most intense and widespread anthropic interventions on fluvial systems. As reported by several authors [18,[24][25][26][27][28], three evolutionary phases can be recognized: (i) the first one, from the last decades of the 19th century to the 1950s, is generally characterized by gentle narrowing and incision albeit, in some cases, no large-scale dominant processes are recognizable up to the beginning of the 20th century [18]; (ii) the second one, from the 1950s to the 1990s, presents the most relevant channel adjustments related to fast, severe and generalized narrowing and incision processes, coupled with a reduction in braiding degree and with an increase of sinuosity; (iii) the third one, from the 1990s onwards, shows a reversal trend since it is characterized by active-channel widening and by an overall slight aggradation or bed-level stability; however, this latter phase is documented only along some rivers [25,29,30].The causes behind the 20th century channel changes are now widely documented [18,21] and have been recognized in the reduction of the sediment budget due to in-channel quarrying activity [19,31], occupation of areas of fluvial pertinence [21,32], channelization [19,33,34], land-use changes at catchment scale [16,30,[35][36][37][38] and building of cross works such as weirs and dams [39][40][41]. On the contrary, the triggering factors of the most recent phase are still quite debated in the scientific literature…”

Multi-Temporal Image Analysis for Fluvial Morphological Characterization with Application to Albanian Rivers

“…Hence, the identification of an applicable procedure for the extraction of geometrical features of rivers, such as the active channel, is not straightforward. In fact, many studies are based on manual digitalization of geometrical features of interest [23,24]. Manual operations are however particularly costly, especially for broad study areas to be analyzed over time.…”