Spatiotemporal Variation of Frost within Growing Periods

Moeletsi, Mokhele Edmond; Tongwane, Mphethe Isaac

doi:10.1155/2017/5472869

Cited by 8 publications

(6 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The probability of frost, expressed as the percentage of years with frost (Table 2), showed great differences between the weather stations sampled in agreement with Moletisi et al [63]. Although, the vast majority of them had high or very high values.…”

Section: Probability Of Frostsupporting

confidence: 87%

Spatiotemporal Analysis of the Frost Regime in the Iberian Peninsula in the Context of Climate Change (1975–2018)

et al. 2021

View full text Add to dashboard Cite

Climate change is having many effects in the agricultural sector, which are being studied worldwide. Undoubtedly, warmer winters and earlier springs produce changes in frost regimes and severity that will affect the sustainability of agricultural production in the area. The Mediterranean region and the Iberian Peninsula (IP) are among the areas where the greatest impact of climate change is expected. Daily data from 68 weather stations of the IP belonging to the European Climate Assessment and Dataset (1975–2018) were used to conduct a spatiotemporal study of the frost regime. The variables calculated include the probability of three frost types according to their severity, frost day, mean absolute minimum yearly temperature, first frost day, last frost day, and frost-free period. These variables were integrated into a geographic information system, which allowed the graphical visualization of their patterns using of geostatistical interpolation techniques (kriging). Changes in frost variables were investigated using the Mann–Kendall test and Sen’s slope estimator. A general reduction in the number of frosts per year is observed (values between −0.04- and −0.8-day frosts per year), as well as an increase in the mean absolute minimum temperature (values between 0.04 and 0.10 °C per year), with very high significant trends throughout the territory. The reduction in the number of frosts is more pronounced at a higher elevation. Frost dates vary greatly due to the orographic characteristics of the IP. The generalized trend is of a significant delay of the autumn frosts (values between 0.4 and 1.06 days/year), as well as early spring frosts (between −0.429 and −1.29 days/year), and as a consequence a longer frost-free period, all changes were much stronger than those found in other regions of the world. These effects of climate change must be mitigated by modifying species, varieties, and cultivation techniques to guarantee sustainable agriculture.

show abstract

Section: Probability Of Frostsupporting

confidence: 87%

Spatiotemporal Analysis of the Frost Regime in the Iberian Peninsula in the Context of Climate Change (1975–2018)

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Classification methods classify an input case into frost or no frost events for a future period of time, whereas regression methods predict the minimum temperature of a future period of time. As weather conditions could vary due to small spatial variations [8], [35], spatial resolution is essential for frost prediction. Also, realtime prediction and high temporal resolution prediction are both important to save the protection cost.…”

Section: Frost Prediction Methodsmentioning

confidence: 99%

Frost Monitoring Cyber–Physical System: A Survey on Prediction and Active Protection Methods

Zhou

Lipman

Shariati

et al. 2020

IEEE Internet Things J.

View full text Add to dashboard Cite

Frost damage in broadacre cropping and horticulture (including viticulture) results in substantial economic losses to producers and may also disrupt associated product value chains. Frost risk windows are changing in timing, frequency, and duration. Faced with the increasing cost of mitigation infrastructure and competition for resources (e.g. water and energy), multi-peril insurance, and the need for supply chain certainty, producers are under pressure to innovate in order to manage and mitigate risk. Frost protection systems are cyber-physical systems comprising of sensors (event detection), intelligence (prediction), and actuators (active protection methods). The Internet of Things communication protocols joining the cyber-physical system components are also evaluated. In this context, this paper introduces and reviews existing methods of frost management. This paper focuses on active protection methods because of their potential for real-time deployment during frost events. For integrated frost prediction and active protection systems, prediction method, sensor types, and integration architecture are assessed, research gaps are identified and future research directions proposed.

show abstract

“…Mean monthly temperatures range from 16 o C to 26 o C while low temperatures range from -1.0 o C to 12.8 o C (Figure 2). During winter months, temperatures can reach below freezing point resulting in frost and snowfall (Moeletsi and Tongwane, 2017).…”

Section: Study Areamentioning

confidence: 99%

Introduction of household biogas digesters in rural farming households of the Maluti-a-Phofung municipality, South Africa

Nape

Magama

Moeletsi

et al. 2019

J. energy South. Afr.

Self Cite

View full text Add to dashboard Cite

The study aimed to introduce biogas as an alternative source of energy for rural cattle farmers in the Malutia-Phofung municipality in the Free State Province, South Africa. To augment the rural farming community's adoption of the biodigester technology the following initiatives were undertaken: (i) a situational analysis (or diagnostic survey); (ii) training on biogas production in an integrated crop-livestock-bioenergy system; (iii) installation of the biodigesters; and (iv) monitoring and evaluation of the biogas production. Results on the diagnostic survey showed that the main source of energy for cooking was wood in all the farms and availability of water was not a constraint. Prefabricated biodigesters of 6m 3 -12m 3 were installed in all the households and, after continual feeding of the units with cattle dung, the production of biogas increased gradually. Monitoring of biogas production showed that, in two-thirds of the households, 80% of their cooking needs were met in summer, while in winter biogas production was minimal due to extremely cold weather. Challenges faced included non-adherence to a feeding regime -resulting in a blockage of the biodigesterand lack of feeding. Generally, farmers in the study area showed a high appreciation of the biodigester technology. ; M.I. Tongwane https://orcid.org/0000-0002-8003-909X; P.M. Nakana https://orcid.org/0000-0003-4521-7310; V.K. Mliswa https://orcid.org/0000-0003-3651-1366; M.I. Motsepe https://orcid.org/0000- 0002-1950-9320; S. Madikiza https://orcid.org/0000-0002-7610-5381

show abstract

Spatiotemporal Variation of Frost within Growing Periods

Cited by 8 publications

References 25 publications

Spatiotemporal Analysis of the Frost Regime in the Iberian Peninsula in the Context of Climate Change (1975–2018)

Spatiotemporal Analysis of the Frost Regime in the Iberian Peninsula in the Context of Climate Change (1975–2018)

Frost Monitoring Cyber–Physical System: A Survey on Prediction and Active Protection Methods

Introduction of household biogas digesters in rural farming households of the Maluti-a-Phofung municipality, South Africa

Contact Info

Product

Resources

About