**1. Introduction**

There are numerous effects that the scientific community has managed to associate with climate change, with those related to the problem of floods being some of the most dangerous. Among the areas of the planet where these changes are forcing administrations to rethink the methodologies to address this problem are the Spanish Mediterranean regions. There, the appearance of new cold-drop phenomena called DANA (Spanish acronym for upper-level isolated atmospheric depression) has replaced the traditional flash floods associated with historical fall storm events.

In these regions, a grea<sup>t</sup> process of territorial anthropization has developed in recent decades. The Mediterranean area is undoubtedly the region in which tourism, agriculture, infrastructure expansion, etc., has experienced the greatest degree of growth in recent decades. However, it is not easy to assess how this new phenomenon of anthropization directly affects the growing problem of flooding in a territory. Phenomena of a diffuse nature and with a rather indirect impact, such as the sealing effect of the soil due to urbanization processes of the land, orographic alterations produced by changes in land use and dam micro-effects that linear communication infrastructures can generate currently do not have specific methodological approaches in the traditional scientific literature. Several

**Citation:** García-Ayllón, S. Correlation between Land Transformation and Climate Change with Flooding Vulnerability: Nature-Based Solutions (NBS) Applied in the Mar Menor Mediterranean Watershed. *Environ. Sci. Proc.* **2023**, *25*, 88. https:// doi.org/10.3390/ECWS-7-14240

Academic Editor: Athanasios Loukas

Published: 16 March 2023

**Copyright:** © 2023 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

approaches for specific case studies can be found, but comprehensive large-scale evaluation methods from a territorial point of view are still lacking.

This study raises an innovative methodological approach based on the assessment of GIS indicators using geostatistics and nature-based solutions as a mitigation strategy. This new method assesses the spatial correlation between the territorial transformation derived from anthropic procedures with the growing risk of a territory to floods. To evaluate this new framework, the proposal is applied to the Campo de Cartagena area in south-eastern Spain, experiencing devastating floods in the last decade.

### **2. Area of Study and Methodology**

### *2.1. Area of Study*

The area of study is located in the Region of Murcia, a semi-arid area in south-eastern Spain (Figure 1). This region is distinguished by limited rainfall (<300 mm/year), which mainly occurs during storm events in autumn and winter. This watershed has been extensively transformed from a relatively traditional dryland agricultural area to one of intense human activity in the last 50 years despite having significant environmental value [1].

**Figure 1.** (**a**) Wadis going to the Mar Menor lagoon (**b**) Watershed nourishing Albujon wadi.

Freshwater inputs into Mar Menor come mainly from six main ephemeral watercourses called 'wadis'. These wadis can reach lengths of over 50 km. The watershed area that nourishes some of them, the Albujon, even exceeds that of the Mar Menor Lagoon itself. These wide and shallow channels are not usually active but are able to hold huge amounts of water and sediment during the usual flood periods of autumn and winter in the Mediterranean. The torrential nature of the water supply is now worsened by the impermeable soils and scarce vegetation cover of the watershed areas, going directly to the coastal lagoon. In recent decades, there has been a grea<sup>t</sup> transformation of the territory that has coincided with a sharp increase in the damage caused by the rains, being especially relevant those produced in the years 2016, 2018, and 2019 ([2]).
