Geodaysit 2023

The agricultural sector has benefitted over the last century from several factors that have led to an exponential increase in its productive efficiency. The increasing use of new materials, such as plastics, has been one of the most important factors, as they have allowed for increased production in a simpler and more economical way. Various polymer types are used in different phases of the agricultural production cycle, but when their use is incorrectly managed, it can lead to serious environmental impacts. Plastic pollution, largely perceived by the public as a major risk factor that strongly impacts sea life and preservation, has an even higher negative impact on terrestrial ecosystems. Indeed, quantitative data about plastic contamination on agricultural soils are progressively emerging in alarming ways. One of the main contributors to this pollution involves the mismanagement of Agricultural Plastic Waste (APW), i.e., the residues from plastic material used to improve the productivity of agricultural crops - such as: greenhouse covers, mulching films, irrigation pipes, etc. Indeed, a wrong management of agricultural plastics during and after their working lives, may pollute the agricultural soil and aquifers by releasing macro-, micro-, and nano-plastics, which could also enter into the human food chain.
In this study, an applied and simplified methodology to quantify and manage agricultural plastics is proposed. The techniques used are based on a deductive approach, based on the quantification through the use of different remote-sensed datasets (orthophotos and satellite images) of the areas covered by plastics used for crop protection. Additionally, through an inductive approach, based on statistical data from the agricultural census of the administrative areas of the Italian provinces, an agricultural plastic coefficient (APC) has been proposed, implemented, and spatialized in a GIS environment, to produce a database of APW for each type of crop.
The study area chosen for the analysis here presented is a part of the Ionian Coast of Southern Italy, which includes the most important municipalities of the Basilicata Region as for fruit and vegetable production. The use of geographical techniques and observation methodologies, developed in an open-source GIS environment, enabled an accurate location of about 2000 hectares of agricultural land covered by plastics, as well as the identification of areas most susceptible to the accumulation of plastic waste. The proposed methodology can be exported to other countries, since it represents valuable support that could realize, in integration with other tools, a database of agricultural plastics use, which may be a starting point to plan strategies and actions targeted to the reduction of the plastic footprint of agriculture. The techniques and the model implemented, due to its simplicity of use and reliability, can be applied by different local authorities, in order to create an atlas of agricultural plastics, which would be applied for their continuous monitoring, thereby enabling to upscale future social and ecological impact assessments, identification of new policy impacts, market searches, etc. as well.

The setting up of a general framework for the environmental and landscape planning of a protected area, requires a basic detailed survey of this area and its vegetation, accompanied by a monitoring of the latter, so that a specific maintenance plan can be implemented accordingly. With reference to an area of high environmental, landscape and archaeological value, such as the 'Pulo di Molfetta' (Municipality of Molfetta – Southern Italy), some georeferenced floristic surveys have been carried out, with relative mapping and monitoring of the vegetation growth. In this way, it has been possible to draw up some detailed management measures for the vegetation, as well as to plan suitable interventions of ecological engineering, aimed at determining the most appropriate conditions for the recovery, use and sustainable management of this study area, even for tourism purposes. These activities have been conducted through the construction of a basic model, which has been implemented in a Geographical Information System (GIS), structured on the basis of some Free and Open-Source geographic data, integrated with a geo-localized 3D survey of the geomorphology, architectural structures and the flora-vegetation habitat. The survey, georeferencing and 3D model formation operations have been conducted by means of:
1) a photogrammetric survey at ultra-low height – variable, according to the orography - carried out with Unmanned Aerial Vehicles (UAVs), to obtain a 3D digital modelling, having a readable resolution of at least 2 cm/pixel;
2) coverage with a block of frames with nadiral and sub-horizontal orientation, for a readability optimized to the analysis of both the geomorphology and the existing medium and tall vegetation;
3) creation of a framing and support network, materialized with high-contrast photographic targets, measured with RTK methodologies of GNSS satellite positioning and accuracy ≤ 3 cm, georeferenced in the RDN2008 Reference Coordinate System - as per Italian regulations;
4) restitution of a 3D digital model, obtained with SfM (Structure from Motion) technologies, formed by a resolution of 1-2 cm, point clouds, triangular mesh and photographic texture;
5) formation of a very-high resolution ortho-photomosaic, with GSD (Ground Sampling Distance) ≤ 15 mm, and of an adequate number of radial sections, with two views, each one orthogonal to the section plane;
6) georeferenced identification of the individual floristic-vegetational elements and help for the construction of a database containing the agreed attributes defined and aimed at planning the vegetation layers present.
The metric analyses have been conducted with commercial instruments, such as UAVs systems, GNSS and photogrammetric processing software, in order to test a very widespread, low-cost operational chain in the dimensional and qualitative survey of medium-small extensions, affected by great biodiversity and an important altimetric variation such as a karst sinkhole.
In conclusion, the results thus obtained have allowed for the inclusion of the geo-localized 3D model in a GIS base for the knowledge of the flora-vegetation habitat, thanks to which it will be possible to provide support for the decision-making of planning choices for the territory, landscape and environment of the study area, as well as its close surroundings, so as to safeguard its biodiversity and ecosystem relations.