Morphological characterization of calanchi (badland) hillslope connectivity

Abstract

Calanchi, a type of Italian badlands created by a combination of water erosion processes and local geomorphological and tectonic controls, is a striking example of long‐term landscape evolution. In small temporal/spatial scales, the calanchi exhibit many of the geomorphic processes and landforms that may be observed in fluvial landscapes; hence, they may be considered as microbasins where geomorphic dynamics and landscape features can be related. The goal of this research is testing the use of simple morphometric variables for assessing sediment connectivity of calanchi landforms. In order to detect the morphological characteristics controlling the landscape connectivity of calanchi basins, 2 areas located in Sicily (Italy) were examined. The investigated features were identified on 119 calanchi basins and mapped using orthophotographs and 2‐m‐resolution digital elevation models. Application of Hack's law to the calanchi basins showed that the width/length ratio increases with the drainage area, suggesting that calanchi may have a limited connectivity of their hillslopes to the main channel. Moreover, the analysis of the drainage network composition suggested that calanchi are sediment removal systems more efficient than river basins. The empirical frequency distribution of the travel time, which is the ratio between the length and the square root of the hillslope steepness, of each cell of the calanchi digital elevation model was established. Finally, for each calanchi basin, an index of hillslope connectivity was devised. This was explored as a function of the sediment transport efficiency itself estimated by the travel time and the corresponding sediment delivery ratio of each calanco hillslope cell.

Revised SEDD (RSEDD) Model for Sediment Delivery Processes at the Basin Scale

“…The conclusions and results would need to be re-evaluated to see the extent of the impact due to the use of a new model. These studies and their contributions are as follows: the relationship between channel network parameters and the sediment transport efficiency [22], the testing and calibration of the SEDD model [8,[23][24][25][26][27][28], the assessment of sediment connectivity in dendritic and parallel Calanchi systems [29,30], sediment load impact on a reservoir [14], the estimation of the response to land use/cover change in a catchment [31], sediment yield in monocrop plantation areas, such as reafforested eucalyptus and olive orchards [13,32], the assessment of sediment delivery/soil erosion processes using Caesium-137 [23,[33][34][35][36][37], testing of the correction of the topographic factors of the RUSLE [38][39][40][41][42], soil erosion and sediment yield estimation [10,[43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58], agricultural non-point pollution …”

A New Model for Solving Hydrological Connectivity Inside Soils by Fast Field Cycling NMR Relaxometry

“…The samples "Sparacia" and "Orleans" have different grain-size distributions, an agricultural land use, and are affected by soil erosion processes. "Sampria" is a degraded soil, due to past intensive erosion processes [32], and a low organic matter content (less than 1%). Agricultural practices in "Sampria" soil are forbidden.…”

Connectivity in hydrology and sediment dynamics

“…Some studies focus on catchment scale (e.g., van der Waal and Rowntree, 2018; Yang, & Lu, 2018), while others look at smaller scale soil processes (e.g., Thomaz, 2018; Bagarello et al, 2018). There are studies looking at land‐use effects, such as grazing (Martínez‐Murillo, Hueso‐González, & Ruiz‐Sinoga, 2018), revegetation (Lizaga, Quijano, Palazón, Gaspar, & Navas, 2018), land abandonment (Calsamiglia et al, 2018), urbanization (Ferreira, Walsh, Steenhuis, ∓ Ferreira, 2018), and effects of wild fire (Martínez‐Murillo, & López‐Vicente, 2018), and others focus on characterization of specific landscape types, including alpine (Rainato et al, 2018), badlands (Moreno‐de las Herras et al, 2019; Caraballo‐Arias, Di Stefano, & Ferro, 2018), and gullies (Conoscenti, Agnesi, Cama, Caraballo‐Arias, & Rotigliano, 2018; Zegeye et al, 2018). Also, some studies address only hydrological connectivity (e.g., Laine‐Kaulio and Koivusalo, 2018) or sediment connectivity (e.g., Porto, Walling, & Callegari, 2018), while others look at both types of connectivity (Ricci, Girolamo, Abdelwahab, & Gentile, 2018).…”