An Investigation of Parent Distributions and Long-Term Trends of Average Maximum and Minimum Temperature in the Limpopo Province of South Africa

2021 ◽  
Vol 10 (1) ◽  
pp. 17-33
Keyword(s):  
South Africa ◽  
Minimum Temperature ◽  
Limpopo Province ◽  
Average Maximum ◽  
Long Term Trends

Long-term trends in the competitive shore fishery along the KwaZulu-Natal coast, South Africa

2007 ◽  
Vol 42 (2) ◽  
pp. 216-236 ◽  
Author(s):  
P. Pradervand ◽  
B. Q. Mann ◽  
M. F. Bellis
Keyword(s):  
South Africa ◽  
Kwazulu Natal ◽  
Long Term Trends

scholarly journals Vertical Differences in the Long-Term Trends and Breakpoints of NDVI and Climate Factors in Taiwan

2021 ◽  
Vol 13 (22) ◽  
pp. 4707
Author(s):  
Hui Ping Tsai ◽  
Geng-Gui Wang ◽  
Zhong-Han Zhuang
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Maximum Temperature ◽  
Climatic Data ◽  
Positive Effects ◽  
Central Regions ◽  
Long Term Trends

This study explored the long-term trends and breakpoints of vegetation, rainfall, and temperature in Taiwan from overall and regional perspectives in terms of vertical differences from 1982 to 2012. With time-series Advanced Very-High-Resolution Radiometer (AVHRR) normalized difference vegetation index (NDVI) data and Taiwan Climate Change Estimate and Information Platform (TCCIP) gridded monthly climatic data, their vertical dynamics were investigated by employing the Breaks for Additive Seasonal and Trend (BFAST) algorithm, Pearson’s correlation analysis, and the Durbin–Watson test. The vertical differences in NDVI values presented three breakpoints and a consistent trend from positive (1982 to 1989) to negative at varied rates, and then gradually increased after 2000. In addition, a positive rainfall trend was discovered. Average and maximum temperature had similar increasing trends, while minimum temperature showed variations, especially at higher altitudes. In terms of regional variations, the vegetation growth was stable in the north but worse in the central region. Higher elevations revealed larger variations in the NDVI and temperature datasets. NDVI, along with average and minimum temperature, showed their largest changes earlier in higher altitude areas. Specifically, the increasing minimum temperature direction was more prominent in the mid-to-high-altitude areas in the eastern and central regions. Seasonal variations were observed for each region. The difference between the dry and wet seasons is becoming larger, with the smallest difference in the northern region and the largest difference in the southern region. Taiwan’s NDVI and climatic factors have a significant negative correlation (p < 0.05), but the maximum and minimum temperatures have significant positive effects at low altitudes below 500 m. The northern and central regions reveal similar responses, while the south and east display different feedbacks. The results illuminate climate change evidence from assessment of the long-term dynamics of vegetation and climatic factors, providing valuable references for establishing correspondent climate-adaptive strategies in Taiwan.

scholarly journals Measurement report: Statistical modelling of long-term atmospheric inorganic gaseous species trends within proximity of the pollution hotspot in South Africa

2020 ◽  
Author(s):  
Jan-Stefan Swartz ◽  
Pieter G. Van Zyl ◽  
Johan P. Beukes ◽  
Corinne Galy-Lacaux ◽  
Avishkar Ramandh ◽  
...  
Keyword(s):  
South Africa ◽  
Source Region ◽  
Statistical Modelling ◽  
Atmospheric Pollutants ◽  
Solar Irradiation ◽  
Substantial Contribution ◽  
North Eastern ◽  
Long Term Trends ◽  
Global Parameters

Abstract. South Africa is considered an important source region of atmospheric pollutants, which is compounded by high population- and industrial growth. However, this region is understudied, especially with regard to evaluating long-term trends of atmospheric pollutants. The aim of this study was to perform statistical modelling of SO2, NO2 and O3 long-term trends based on 21-, 19- and 16-year passive sampling datasets available for three South African INDAAF (International network to study Atmospheric Chemistry and Deposition in Africa) sites located within proximity of the pollution hotspot in the industrialised north-eastern interior in South Africa. The interdependencies between local, regional and global parameters on variances in SO2, NO2 and O3 levels were investigated in the model. Long-term temporal trends indicated seasonal and inter-annual variability at all three sites, which could be ascribed to changes in meteorological conditions and/or variances in source contribution. Local, regional and global parameters contributed to SO2 variability, with total solar irradiation (TSI) being the most significant factor at the regional background site, Louis Trichardt (LT). Temperature (T) was the most important factor at Skukuza (SK), located in the Kruger National Park, while population growth (P) made the most substantial contribution at the industrially impacted Amersfoort (AF) site. Air masses passing over the source region also contributed to SO2 levels at SK and LT. Local and regional factors made more substantial contributions to modelled NO2 levels, with P being the most significant factor explaining NO2 variability at all three sites, while relative humidity (RH) was the most important local and regional meteorological factor. The important contribution of P on modelled SO2 and NO2 concentrations was indicative of the impact of increased anthropogenic activities and energy demand in the north-eastern interior of South Africa. Higher SO2 concentrations, associated with lower temperatures, as well as the negative correlation of NO2 levels to RH, reflected the influence of pollution build-up and increased household combustion during winter. ENSO made a significant contribution to modelled O3 levels at all three sites, while the influence of local and regional meteorological factors was also evident. Trend lines for SO2 and NO2 at AF indicated an increase in SO2 and NO2 concentrations over the 19-year sampling period, while an upward trend in NO2 levels at SK signified the influence of growing rural communities. Marginal trends were observed for SO2 at SK, as well as SO2 and NO2 at LT, while O3 remained relatively constant at all three sites. SO2 and NO2 concentrations were higher at AF, while the regional O3 problem was evident at all three sites.

scholarly journals Measurement report: Statistical modelling of long-term trends of atmospheric inorganic gaseous species within proximity of the pollution hotspot in South Africa

2020 ◽  
Vol 20 (17) ◽  
pp. 10637-10665
Author(s):  
Jan-Stefan Swartz ◽  
Pieter G. van Zyl ◽  
Johan P. Beukes ◽  
Corinne Galy-Lacaux ◽  
Avishkar Ramandh ◽  
...  
Keyword(s):  
South Africa ◽  
Source Region ◽  
Statistical Modelling ◽  
Atmospheric Pollutants ◽  
Solar Irradiation ◽  
Substantial Contribution ◽  
North Eastern ◽  
Long Term Trends ◽  
Global Parameters

Abstract. South Africa is considered an important source region of atmospheric pollutants, which is compounded by high population and industrial growth. However, this region is understudied, especially with regard to evaluating long-term trends of atmospheric pollutants. The aim of this study was to perform statistical modelling of SO2, NO2 and O3 long-term trends based on 21-, 19- and 16-year passive sampling datasets available for three South African INDAAF (International Network to study Deposition and Atmospheric Chemistry in Africa) sites located within proximity of the pollution hotspot in the industrialized north-eastern interior in South Africa. The interdependencies between local, regional and global parameters on variances in SO2, NO2 and O3 levels were investigated in the model. Average monthly SO2 concentrations at Amersfoort (AF), Louis Trichardt (LT) and Skukuza (SK) were 9.91, 1.70 and 2.07 µg m−3, respectively, while respective mean monthly NO2 concentrations at each of these sites were 6.56, 1.46 and 2.54 µg m−3. Average monthly O3 concentrations were 50.77, 58.44 and 43.36 µg m−3 at AF, LT and SK, respectively. Long-term temporal trends indicated seasonal and inter-annual variability at all three sites, which could be ascribed to changes in meteorological conditions and/or variances in source contribution. Local, regional and global parameters contributed to SO2 variability, with total solar irradiation (TSI) being the most significant factor at the regional background site LT. Temperature (T) was the most important factor at SK, located in the Kruger National Park, while population growth (P) made the most substantial contribution at the industrially impacted AF site. Air masses passing over the source region also contributed to SO2 levels at SK and LT. Local and regional factors made more substantial contributions to modelled NO2 levels, with P being the most significant factor explaining NO2 variability at all three sites, while relative humidity (RH) was the most important local and regional meteorological factor. The important contribution of P on modelled SO2 and NO2 concentrations was indicative of the impact of increased anthropogenic activities and energy demand in the north-eastern interior of South Africa. Higher SO2 concentrations, associated with lower temperatures, as well as the negative correlation of NO2 levels to RH, reflected the influence of pollution build-up and increased household combustion during winter. The El Niño–Southern Oscillation (ENSO) made a significant contribution to modelled O3 levels at all three sites, while the influence of local and regional meteorological factors was also evident. Trend lines for SO2 and NO2 at AF indicated an increase in SO2 and NO2 concentrations over the 19-year sampling period, while an upward trend in NO2 levels at SK signified the influence of growing rural communities. Marginal trends were observed for SO2 at SK, as well as SO2 and NO2 at LT, while O3 remained relatively constant at all three sites. SO2 and NO2 concentrations were higher at AF, while the regional O3 problem was evident at all three sites.

Sign in / Sign up

Export Citation Format

Share Document