Connectivity assessment in Mediterranean vineyards using improved stock unearthing method, LiDAR and soil erosion field surveys

Abstract

The interaction between processes and landforms is accelerated in vineyards due to bare tilled soils that enhance splash, runoff, and erosion. Traditionally, in order to assess these processes, the stock unearthing method (SUM) is considered a useful methodology that uses the graft union of the vine plant as passive bio-indicator of the topsoil level changes. However, SUM assumes that the topography between the rows is planar when development of a model of the current micro-topography is performed. Thus, we consider that there is a need to develop a new methodology (ISUM: improved SUM) that, by adding new measurements in the inter-row areas (at least 3), allows inclusion of the absent micro-topographical information of SUM. In this way, the main aim of this research was to estimate the micro-topographical changes and soil transport at three different slope positions (upper, middle and lower parts) in a 25-years-old vineyard in eastern Spain. LiDAR data were used to compare the connectivity processes at the catchment with the pedon scale. We obtained maps that showed topsoil level changes and detected soil depletion and accumulation signals. We estimated soil displacement rates of -1.6 Mg ha yr -1 (depletion), +2.8 Mg ha yr -1 and +13.3 Mg ha yr -1 (accumulation) at upper, middle and lower slope positions, respectively. The total average soil erosion rates in the inter-rows were -5.7 Mg ha -1 yr -1 . In the row areas, deposition of +10.5 Mg ha yr -1 was measured. Field erosion marks surveyed after each rainfall event gave insights to the connectivity at the inter-row and the slope scale. It was found that at the row scale there were sinks of sediments underneath the vines and sources in the inter-row parts, although they are the highest and lowest local topographical terrain, respectively. This is due to tillage erosion that redistributed the sediments. At the slope scale, the lower part of the slope collected sediments from the upper slope positions, which were transported along the middle part of the slope, as the measurement of ISUM and the field survey after intense rainfall events demonstrated. Connectivity of the flows along the whole slope were rare (twice), and along individual slope parts connectivity was found eight times, and 19 at the inter-row scale after 8 years of field observations.

A review of nature-based solutions for urban water management in European circular cities: a critical assessment based on case studies and literature

“…Planning infrastructures to manage flood risk is related to connectivity (Parson et al 2015), circularity (Kirchherr et al 2017;Comino et al 2018;Keesstra et al 2018) and finding a balance between natural and urban elements (Gaines 2016). Moreover, in a fast developing city, the loss of circularity is often associated with the altered hydrological cycle, implying that water is not a natural, valuable resource, but rather a threat to the urban environment, when it flows at rates different from those of natural paths, from/toward locations that are functional to the development of human activity rather than to the environmental dynamics, through man-managed (often fast) connections, with quality standards far from those provided by natural water bodies (EPA 2005).…”

Estimation of Soil Erosion in the Chaohu Lake Basin through Modified Soil Erodibility Combined with Gravel Content in the RUSLE Model

“…Rainfall erosivity is the potential possibility of soil erosion induced by rainfall, which is the most important external driving force and the dynamic indicator of soil separation and transportation [45,46]. Many of the existing classic and straightforward algorithms for estimating this factor are mainly based on annual rainfall, monthly, daily, or hourly rainfall [47][48][49].…”

Estimating Non-Sustainable Soil Erosion Rates in the Tierra de Barros Vineyards (Extremadura, Spain) Using an ISUM Update

“…In addition, there is a doubt about how this strategy affects the final result. It is accepted and demonstrated that soil erosion is different at different locations and slope positions such as what Rodrigo-Comino et al [32] found. However, how different the erosion rate will be in the same hillslope position and soil type from one inter-row to the nearest one is still unclear.…”