Evaluation of spatio-temporal trends of groundwater quality in different land uses using Kendall test

2012 ◽  
Vol 16 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Dugin Kaown ◽  
Yunjung Hyun ◽  
Gwang-Ok Bae ◽  
Chang Whan Oh ◽  
Kang-Kun Lee
Keyword(s):  
Groundwater Quality ◽  
Temporal Trends ◽  
Kendall Test ◽  
Land Uses ◽  
Spatio Temporal

scholarly journals Spatio-temporal Variability and Trends in Rainfall and Temperature in Anger watershed, Southwestern Ethiopia

2021 ◽  
Vol 5 (1) ◽  
pp. 462-472
Author(s):  
Gemechu Yigezu Ofgeha ◽  
Muluneh Woldetsadik Abshire
Keyword(s):  
Temporal Trends ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Small Scale ◽  
Rainfall Trend ◽  
High Rainfall ◽  
Southwestern Ethiopia ◽  
Spatio Temporal ◽  
Small Scale Farmers ◽  
Increasing Trends

Insights to broadly argued research gap on lack of climate studies at micro-scale considering unique features of an area, this paper intended to examine agro-ecological level spatio-temporal trends and variability in rainfall and temperature in Anger watershed of southwestern Ethiopia. The gridded data managed by the Ethiopia National Meteorological Services Agency (NMSA) for 1983-2018 were used. The Mann-Kendall test for trend analysis and different variability measures were used. Questionnaire and FGD data on community perceptions gathered from 214 households and elders were analysed descriptively and qualitatively. The study reveals the consistent increasing trends in temperature; and high variability and insignificant but increasing rainfall trend. The trends and variability show spatio-temporal differences along agro-ecologies. The watershed is characterized by moderate to high rainfall coefficient of variations, significant years of high rainfall concentration, and considerable negative annual rainfall anomalies; that the variability was severe in woinadega followed by kolla agro-ecology. Although, the perceptions on trends, variability and its implications show difference across agro-ecology, the propensity to increased temperature, unclear rainfall trend and significant inter-annual and seasonal variability were witnessed. Unpredictability of rainfall time, concentrations in kiremt, and unexpected rain during harvesting was major challenges resulting multifaceted impacts on the small-scale farmers’ livelihoods.

scholarly journals Spatio-temporal analysis of Maximum temperature over Iraq

2018 ◽  
Vol 29 (1) ◽  
pp. 1
Author(s):  
Aws Ali Al Khudhairy
Keyword(s):  
Temporal Trends ◽  
Surface Air Temperature ◽  
Kendall Test ◽  
Temporal Analysis ◽  
Maximum Temperature ◽  
Positive Trend ◽  
Seasonal Temperature ◽  
The North ◽  
Four Seasons ◽  
Spatio Temporal

Monthly Maximum surface air temperature at 23 stations in Iraq were analyzed for temporal trends and spatial variation during 1980-2015.Seasonal and annual temperature was analyzed using Mann-Kendall test to detect the significant trend .The results of temporal analysis showed that during winter ,spring , summer and Autumn have a positive trend in all the parts of Iraq. A tendency has also been observed towards warmer years, with significantly warmer summer and spring periods and slightly warmer autumn and winter, The highest increase is (3.9) oC in Basrah during the summer. The results of spatial analysis using the ArcGIS showed that the seasonal temperature can be divided into two or three distinct areas with high temperature in the south and decreasing towards north, where the trend of spatial temperature were decreasing from south to the north in all the four seasons.

Spatio-temporal trends and climatology of atmospheric chlorinated hydrocarbons over Pakistan

2021 ◽  
Vol 14 (15) ◽  
Author(s):  
Ahmad Hasnain ◽  
Yong Zha ◽  
Muhammad Zaffar Hashmi ◽  
Fatima Rahim ◽  
Yufeng He ◽  
...  
Keyword(s):  
Temporal Trends ◽  
Chlorinated Hydrocarbons ◽  
Spatio Temporal

scholarly journals Spatio-temporal impacts of aerial adulticide applications on populations of West Nile virus vector mosquitoes

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Karen M. Holcomb ◽  
Robert C. Reiner ◽  
Christopher M. Barker
Keyword(s):  
West Nile Virus ◽  
Temporal Trends ◽  
Larval Habitat ◽  
Post Treatment ◽  
Additive Models ◽  
Dispersal Ability ◽  
Stochastic Variation ◽  
West Nile ◽  
Spatial Coverage ◽  
Spatio Temporal

Abstract Background Aerial applications of insecticides that target adult mosquitoes are widely used to reduce transmission of West Nile virus to humans during periods of epidemic risk. However, estimates of the reduction in abundance following these treatments typically focus on single events, rely on pre-defined, untreated control sites and can vary widely due to stochastic variation in population dynamics and trapping success unrelated to the treatment. Methods To overcome these limitations, we developed generalized additive models fitted to mosquito surveillance data collected from CO2-baited traps in Sacramento and Yolo counties, California from 2006 to 2017. The models accounted for the expected spatial and temporal trends in the abundance of adult female Culex (Cx.) tarsalis and Cx. pipiens in the absence of aerial spraying. Estimates for the magnitude of deviation from baseline abundance following aerial spray events were obtained from the models. Results At 1-week post-treatment with full spatial coverage of the trapping area by pyrethroid or pyrethrin products, Cx. pipiens abundance was reduced by a mean of 52.4% (95% confidence intrval [CI] − 65.6, − 36.5%) while the use of at least one organophosphate pesticide resulted in a mean reduction of 76.2% (95% CI − 82.8, − 67.9%). For Cx. tarsalis, at 1-week post-treatment with full coverage there was a reduction in abundance of 30.7% (95% CI − 54.5, 2.5%). Pesticide class was not a significant factor contributing to the reduction. In comparison, repetition of spraying over three to four consecutive weeks resulted in similar estimates for Cx. pipiens and estimates of somewhat smaller magnitude for Cx. tarsalis. Conclusions Aerial adulticides are effective for achieving a rapid short-term reduction of the abundance of the primary West Nile virus vectors, Cx. tarsalis and Cx. pipiens. A larger magnitude of reduction was estimated in Cx. pipiens, possibly due to the species’ focal distribution. Effects of aerial sprays on Cx. tarsalis populations are likely modulated by the species’ large dispersal ability, population sizes and vast productive larval habitat present in the study area. Our modeling approach provides a new way to estimate effects of public health pesticides on vector populations using routinely collected observational data and accounting for spatio-temporal trends and contextual factors like weather and habitat. This approach does not require pre-selected control sites and expands upon past studies that have focused on the effects of individual aerial treatment events.

scholarly journals Recessive Transition Mechanism of Arable Land Use Based on the Perspective of Coupling Coordination of Input–Output: A Case Study of 31 Provinces in China

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Yi Lou ◽  
Guanyi Yin ◽  
Yue Xin ◽  
Shuai Xie ◽  
Guanghao Li ◽  
...  
Keyword(s):  
Land Use ◽  
Evaluation Model ◽  
Arable Land ◽  
Temporal Trends ◽  
Mainland China ◽  
Input Output ◽  
Transition Mechanism ◽  
Input And Output ◽  
Spatio Temporal ◽  
Arable Land Use

In the rapid process of urbanization in China, arable land resources are faced with dual challenges in terms of quantity and quality. Starting with the change in the coupling coordination relationship between the input and output on arable land, this study applies an evaluation model of the degree of coupling coordination between the input and output (D_CCIO) on arable land and deeply analyzes the recessive transition mechanism and internal differences in arable land use modes in 31 provinces on mainland China. The results show that the total amount and the amount per unit area of the input and output on arable land in China have presented different spatio-temporal trends, along with the mismatched movement of the spatial barycenter. Although the D_CCIO on arable land increases slowly as a whole, 31 provinces show different recessive transition mechanisms of arable land use, which is hidden in the internal changes in the input–output structure. The results of this study highlight the different recessive transition patterns of arable land use in different provinces of China, which points to the outlook for higher technical input, optimized planting structure, and the coordination of human-land relationships.

Spatio-temporal trends of dust emissions triggered by desertification in China

CATENA ◽  
2021 ◽  
Vol 200 ◽  
pp. 105160
Author(s):  
Xunming Wang ◽  
Diwen Cai ◽  
Siyu Chen ◽  
Junpeng Lou ◽  
Fa Liu ◽  
...  
Keyword(s):  
Temporal Trends ◽  
Dust Emissions ◽  
Spatio Temporal

scholarly journals Historical drought patterns over Canada and their teleconnections with large-scale climate signals

2018 ◽  
Vol 22 (6) ◽  
pp. 3105-3124 ◽  
Author(s):  
Zilefac Elvis Asong ◽  
Howard Simon Wheater ◽  
Barrie Bonsal ◽  
Saman Razavi ◽  
Sopan Kurkute
Keyword(s):  
Large Scale ◽  
Southern Oscillation ◽  
Low Frequency ◽  
Kendall Test ◽  
Wavelet Coherence ◽  
Climate Indices ◽  
Data Sets ◽  
Canadian Prairies ◽  
Agriculture Industry ◽  
Spatio Temporal

Abstract. Drought is a recurring extreme climate event and among the most costly natural disasters in the world. This is particularly true over Canada, where drought is both a frequent and damaging phenomenon with impacts on regional water resources, agriculture, industry, aquatic ecosystems, and health. However, nationwide drought assessments are currently lacking and impacted by limited ground-based observations. This study provides a comprehensive analysis of historical droughts over the whole of Canada, including the role of large-scale teleconnections. Drought events are characterized by the Standardized Precipitation Evapotranspiration Index (SPEI) over various temporal scales (1, 3, 6, and 12 consecutive months, 6 months from April to September, and 12 months from October to September) applied to different gridded monthly data sets for the period 1950–2013. The Mann–Kendall test, rotated empirical orthogonal function, continuous wavelet transform, and wavelet coherence analyses are used, respectively, to investigate the trend, spatio-temporal patterns, periodicity, and teleconnectivity of drought events. Results indicate that southern (northern) parts of the country experienced significant trends towards drier (wetter) conditions although substantial variability exists. Two spatially well-defined regions with different temporal evolution of droughts were identified – the Canadian Prairies and northern central Canada. The analyses also revealed the presence of a dominant periodicity of between 8 and 32 months in the Prairie region and between 8 and 40 months in the northern central region. These cycles of low-frequency variability are found to be associated principally with the Pacific–North American (PNA) and Multivariate El Niño/Southern Oscillation Index (MEI) relative to other considered large-scale climate indices. This study is the first of its kind to identify dominant periodicities in drought variability over the whole of Canada in terms of when the drought events occur, their duration, and how often they occur.

scholarly journals Spatio‐temporal trends in caries: A study on children in Berlin‐Mitte

2020 ◽  
Author(s):  
Ae Kyung Lee ◽  
Annette Aigner ◽  
Timo Schmid ◽  
Tobias Kurth
Keyword(s):  
Temporal Trends ◽  
Spatio Temporal
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