Multidecadal Land-Use Changes and Implications on Soil Protection in the Calore River Basin Landscape (Southern Italy)

Abstract

In Southern Italy, studies dealing with the analysis of multidecadal land-use changes at the basin scale are scarce. This is an important gap, considering the deep interrelationships between land-use changes, soil erosion, and river dynamics, and hazards at the basin scale and the proneness of Southern Italy to desertification. This study provides a contribution in filling this gap by analyzing the land-use changes occurring in an inner area of Southern Italy, i.e., the Calore River basin, between 1960 and 2018. Working to this aim, we conducted a GIS-aided comparison and analysis of three land-use maps of the study area from 1960, 1990, and 2018, respectively. We analyzed land-use changes at the basin, physiographic unit, and land-use class scale. We also interpreted the results in terms of variations in soil protection against erosion. Most of the detected land-use changes occurred between 1960 and 1990 and mainly consisted of the afforestation of agricultural lands. The latter was mainly concentrated in the alluvial plains and, to a lesser extent, on mountainous reliefs. In contrast, between 1990 and 2018, the land-use remained unchanged in more than 90% of the studied landscape. Artificial surfaces increased by about six times over a period of ~60 years; notwithstanding, they currently occupy about 4% of the basin area. The detected changes led to an overall increase in soil protection against erosion at the basin scale.

Assessing the Morphological Quality of the Calore River (Southern Italy)

“…Most of the land-use changes in the study area occurred between the 1960s and the 1990s, followed by a period of substantial stability. This likely led to a decrease in soil erosion and sediment supply to the rivers between 1960 and 1990 [42], which is confirmed by recent studies dealing with short-term river channel adjustments [4,5,43], followed by a phase of overall stability since the 1990s [42].…”

“…The land-use in the Calore River basin [42] is dominated by agricultural lands (64% of the total area) and, subordinately, by forests (23%). In the last 60 years, the studied basin experienced an increase in forested areas at the expense of agricultural lands.…”

Changes in Land-Cover/Land-Use Pattern in the Fortore River Basin (Southern Italy) and Morphodynamic Implications

“…This harmonization was possible only at the third level of the Corine land cover, due to the differences in scope, years, and methods of production between CNR-TC and CLC maps (Table 1). According to Magliulo et al [24,25], the differences in the responses of the LULC classes to soil-erosion processes, widely accepted in the literature ( [38,39], and references therein), were used as additional harmonization criteria. The harmonization also took into account the suggestion by Falcucci et al [40] to reduce the former number of classes and define a few new classes that represent markedly distinct LULC types.…”

“…The results consisted of digital maps in which each polygon represented areas that experienced LULC changes or persistence. Each polygon, i.e., each LULC change or persistence, was classified according to Di Gennaro et al [37] and Magliulo et al [24,25] (Figure 3). Finally, the extension of each polygon was automatically calculated by means of the "Calculate Geometry" ArcGIS ® tool.…”

“…Notwithstanding this observation, previous research on this topic in a geomorphologically dynamic and vulnerable territory such as southern Italy is extremely scarce. Only very recently, two studies [24,25] focused on LULC changes over a period of about six decades in two large-sized river basins in southern Italy (i.e., the Calore River and the Sele River basins), also exploring the implications of the detected changes in terms of soil erosion and/or protection. However, we are currently very far from providing an exhaustive framework of the multidecadal LULC dynamics at the basin scale in southern Italy, as most of the river basins in this area still remain uninvestigated from this point of view.…”