Improved Estimation of Aboveground Biomass of Disturbed Grassland through Including Bare Ground and Grazing Intensity

Accurate approaches to aboveground biomass (AGB) estimation are required to support appraisal of the effectiveness of land use measures, which seek to protect grazing-adapted grasslands atop the Qinghai-Tibet Plateau (QTP). This methodological study assesses the effectiveness of one commonly used visible band vegetation index, Red Green Blue Vegetation Index (RGBVI), obtained from unmanned aerial vehicle (UAV), in estimating AGB timely and accurately at the local scale, seeking to improve the estimation accuracy by taking into account in situ collected information on disturbed grassland. Particular emphasis is placed upon the mapping and quantification of areas disturbed by grazing (simulated via mowing) and plateau pika (Ochotona curzoniae) that have led to the emergence of bare ground. The initial model involving only RGBVI performed poorly in AGB estimation by underestimating high AGB by around 10% and overestimating low AGB by about 10%. The estimation model was modified by the mowing intensity ratio and bare ground metrics. The former almost doubled the estimation accuracy from R2 = 0.44 to 0.81. However, this modification caused the bare ground AGB to be overestimated by about 38 and 19 g m−2 for 2018 and 2019, respectively. Although further modification of the model by bare ground metrics improved the accuracy slightly to 0.88, it markedly reduced the overestimation of low AGB values. It is recommended that grazing intensity be incorporated into the micro-scale estimation of AGB, together with the bare ground modification metrics, especially for severely disturbed meadows with a sizable portion of bare ground.

NUMERICAL STUDY ON DEFORMATION CHARACTERISTICS OF FIBRE REINFORCED LOAD TRANSFER PLATFORM AND COLUMNS SUPPORTED EMBANKMENTS

In this investigation, a ground modification technique utilising fibre-reinforced-load-transfer-platform (FRLTP) and column-supported (CS) embankment constructed on multilayered soft soils is proposed and investigated. After validating the proposed model with published data in the literature, numerical analysis was firstly conducted on the two-dimensional finite element model of a CS embankment without or with FRLTP to examine the influence of the FRLTP inclusion into the CS embankment system. Secondly, an extensive parametric study was performed to further investigate the effects of the FRLTP essential parameters including platform thickness, shear strength and tensile strength properties, and deformation modulus on the embankment performance during the construction and post-construction stages. Additionally, the influence of the embankment design parameters such as column spacing, column length and diameter was also examined. The numerical results reveal that the FRLTP inclusion can be effective in enhancing the CS embankment behaviour. It is also found that when increasing the platform thickness, the shear strength properties of FRLTP plays a significant role in improving the overall performance of a column-embankment with FRLTP.

Impact of Brownfield Sites on Local Energy Production as Resilient Response to Land Contamination: A Case Study in Italy

The decentralization of the production sector crisis following industries in the suburbs have generated a multitude of empty containers in the medium-large Italian cities, which are abandoned, unsafe, and often dangerous for the community. From this arises the need to recover them and transform them into something else. This is not always possible or interesting for the subjects involved in the transformation. When the abandoned space is (even if only partially) polluted, then any hypothesis of transformation is stopped due to the high impact of decontamination costs, which greatly compromise the profitability of the investment. This paper deals with this issue focusing on a complex case study involving the abandoned area and the buildings of a former paint mill in the center of a typical city in the Turin metropolitan area. The suggested hypothesis is to act only on building components and external areas without any ground modification because of its contamination. Moreover, the new planned use (energy production from renewable sources to supply part of the public administration’s needs) does not foresee neither a stable presence of people nor a further consumption of land. The technical analysis of community energy needs and the subsequent economic and financial study lead to a financial sustainability over a period of about 25 years.