Rainfall estimates from opportunistic sensors in Germany across spatio-temporal scales – Geostatistical interpolation framework

Precipitation - highly variable in space and time - is the most important input for many hydrological models. As these models become more and more detailed in space and time, high-resolution input data are required. Especially for modeling and prediction in fast reacting catchments, such as urban catchment areas, a higher space-time resolution is needed than the current ground measurement networks operated by national weather services usually provide. With the increasing number and availability of opportunistic sensors such as commercial microwave links (CMLs) and personal weather stations (PWS) in recent years, new opportunities for measuring meteorological data are emerging.We developed a geostatistical interpolation framework which allows a combination of different opportunistic sensors and their specific features and geometric properties, e.g. point and line information. In this framework, a combined kriging approach is introduced, taking into account not only the point information of a reliable primary network, e.g., from national weather services, but also the higher uncertainty of the PWS- and CML-based precipitation. The path-averaged information of the CMLs is included through a block kriging-type approach.The methodology was applied for two 7-months periods in Germany using an hourly temporal and a 1x1 km spatial resolution. By incorporating CMLs and PWS, the Pearson correlation could be increased from 0.56 to 0.73 compared to using only primary network for interpolation. The resulting precipitation maps also provided good agreement compared to gauge adjusted radar products.

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Advanced Graphical–Analytical Method of Pipe Tank Design Integrated with Sensitivity Analysis for Sustainable Stormwater Management in Urbanized Catchments

Water ◽

10.3390/w13081035 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1035

Author(s):

Bartosz Szeląg ◽

Adam Kiczko ◽

Anna Musz-Pomorska ◽

Marcin K. Widomski ◽

Jacek Zaburko ◽

...

Keyword(s):

Sensitivity Analysis ◽

Analytical Method ◽

Design Method ◽

Accurate Method ◽

Urban Catchment ◽

Storm Water Management Model ◽

Catchment Areas ◽

Calculation Methodology ◽

Tank Design ◽

Spatial Plan

Pipe tanks represent important runoff retention elements of urban stormwater systems. They enable us to reduce and retain runoff as well as to mitigate peak flows in the network. Pipe tanks are often taken into account while designing the spatial plan of urban catchment areas. Hence, there is a need to develop a relatively quick and accurate method for pipe tank dimensioning. A graphical–analytical method of designing a pipe tank is presented in the paper. In the assumed methodology, the possibility of employing machine learning for obtaining a more precise error prediction of the proposed pipe tank design method (compared with the tank volume simulations using the storm water management model (SWMM)) are considered. Thus far, this aspect has not been discussed in the literature. In the adopted calculation methodology, sensitivity analysis constitutes an important element, enabling us to assess the influence of the input data assumed for tank design on the dimensions of the outflow devices and the length of the retention chamber.

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The features of the coastal fronts in the Eastern Guangdong coastal waters during the downwelling-favorable wind period

Scientific Reports ◽

10.1038/s41598-021-89649-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chaoyu Yang ◽

Haibin Ye

Keyword(s):

Coastal Waters ◽

Meteorological Data ◽

Pearson Correlation ◽

Ocean Model ◽

Ekman Pumping ◽

Zonal Distribution ◽

Factors Affecting ◽

China Sea ◽

Hybrid Coordinate Ocean Model ◽

The Mean

AbstractA coastal front was detected in the eastern Guangdong (EGD) coastal waters during a downwelling-favorable wind period by using the diffuse attenuation coefficient at 490 nm (Kd(490)). Long-term satellite data, meteorological data and hydrographic data collected from 2003 to 2017 were jointly utilized to analyze the environmental factors affecting coastal fronts. The intensities of the coastal fronts were found to be associated with the downwelling intensity. The monthly mean Kd(490) anomalies in shallow coastal waters less than 25 m deep along the EGD coast and the monthly mean Ekman pumping velocities retrieved by the ERA5 dataset were negatively correlated, with a Pearson correlation of − 0.71. The fronts started in October, became weaker and gradually disappeared after January, extending southwestward from the southeastern coast of Guangdong Province to the Wanshan Archipelago in the South China Sea (SCS). The cross-frontal differences in the mean Kd(490) values could reach 3.7 m−1. Noticeable peaks were found in the meridional distribution of the mean Kd(490) values at 22.5°N and 22.2°N and in the zonal distribution of the mean Kd(490) values at 114.7°E and 114.4°E. The peaks tended to narrow as the latitude increased. The average coastal surface currents obtained from the global Hybrid Coordinate Ocean Model (HYCOM) showed that waters with high nutrient and sediment contents in the Fujian and Zhejiang coastal areas in the southern part of the East China Sea could flow into the SCS. The directions and lengths of the fronts were found to be associated with the flow advection.

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The COVID-19 Pandemic Situation in Malaysia: Lessons Learned from the Perspective of Population Density

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18126566 ◽

2021 ◽

Vol 18 (12) ◽

pp. 6566

Author(s):

Siew Bee Aw ◽

Bor Tsong Teh ◽

Gabriel Hoh Teck Ling ◽

Pau Chung Leng ◽

Weng Howe Chan ◽

...

Keyword(s):

Population Density ◽

Pearson Correlation ◽

Strong Relationship ◽

Lessons Learned ◽

P Value ◽

Population Census ◽

Infection Rates ◽

Health Official ◽

Contagious Diseases ◽

Spatio Temporal

This paper attempts to ascertain the impacts of population density on the spread and severity of COVID-19 in Malaysia. Besides describing the spatio-temporal contagion risk of the virus, ultimately, it seeks to test the hypothesis that higher population density results in exacerbated COVID-19 virulence in the community. The population density of 143 districts in Malaysia, as per data from Malaysia’s 2010 population census, was plotted against cumulative COVID-19 cases and infection rates of COVID-19 cases, which were obtained from Malaysia’s Ministry of Health official website. The data of these three variables were collected between 19 January 2020 and 31 December 2020. Based on the observations, districts that have high population densities and are highly inter-connected with neighbouring districts, whether geographically, socio-economically, or infrastructurally, tend to experience spikes in COVID-19 cases within weeks of each other. Using a parametric approach of the Pearson correlation, population density was found to have a moderately strong relationship to cumulative COVID-19 cases (p-value of 0.000 and R2 of 0.415) and a weak relationship to COVID-19 infection rates (p-value of 0.005 and R2 of 0.047). Consequently, we provide several non-pharmaceutical lessons, including urban planning strategies, as passive containment measures that may better support disease interventions against future contagious diseases.

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Impact of Large-Scale Climate Indices on Meteorological Drought of Coastal Ghana

Advances in Meteorology ◽

10.1155/2021/8899645 ◽

2021 ◽

Vol 2021 ◽

pp. 1-17

Author(s):

Martin Addi ◽

Kofi Asare ◽

Samuel Kofi Fosuhene ◽

Theophilus Ansah-Narh ◽

Kenneth Aidoo ◽

...

Keyword(s):

Water Resource Management ◽

Stepwise Regression ◽

Pearson Correlation ◽

Standardized Precipitation Index ◽

Climate Indices ◽

Severe Drought ◽

Time Lags ◽

Drought Prediction ◽

Catchment Areas ◽

Dry Seasons

The devastating effects of drought on agriculture, water resources, and other socioeconomic activities have severe consequences on food security and water resource management. Understanding the mechanism that drives drought and predicting its variability is important for enhancing early warning and disaster risk management. In this study, meteorological droughts over six coastal synoptic stations were investigated using three-month Standardized Precipitation Index (SPI). The dry seasons of November-December-January (NDJ), December-January-February (DJF), and January-February-March (JFM) were the focal seasons for the study. Trends of dry seasons SPIs were evaluated using seasonal Mann–Kendall test. The relationship between drought SPI and ocean-atmosphere climate indices and their predictive ability were assessed using Pearson correlation and Akaike Information Criterion (AIC) stepwise regression method to select best climate indices at lagged timestep that fit the SPI. The SPI exhibited moderate to severe drought during the dry seasons. Accra exhibited a significant increasing SPI trend in JFM, NDJ, and DJF seasons. Besides, Saltpond during DJF, Tema, and Axim in NDJ season showed significant increasing trend of SPI. In recent years, SPIs in dry seasons are increasing, an indication of weak drought intensity, and the catchment areas are becoming wetter in the traditional dry seasons. Direct (inverse) relationship was established between dry seasons SPIs and Atlantic (equatorial Pacific) ocean's climate indices. The significant climate indices modulating drought SPIs at different time lags are a combination of either Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, or AMO for a given station. The AIC stepwise regression model explained up to 48% of the variance in the drought SPI and indicates Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, and AMO have great potential for seasonal drought prediction over Coastal Ghana.

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Sediment Transport Dynamism in the Confluence Area of Two Rivers Transporting Mainly Suspended Sediment Based on Sentinel-2 Satellite Images

Water ◽

10.3390/w13213132 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3132

Author(s):

Ahmed Mohsen ◽

Ferenc Kovács ◽

Gábor Mezősi ◽

Tímea Kiss

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

Temporal Dynamics ◽

Pearson Correlation ◽

Unsupervised Classification ◽

Mixing Process ◽

Hydrological Parameters ◽

Flow And Sediment Transport ◽

Spatio Temporal ◽

Sentinel 2

Downstream of the confluence of rivers, complex hydrological and morphological processes control the flow and sediment transport. This study aimed to analyze the spatio-temporal dynamics of suspended sediment in the confluence area of the Tisza and its main tributary Maros River using Sentinel-2 images and to reveal the correlation between the hydrological parameters and the mixing process through a relatively long period (2015–2021). The surficial suspended sediment dynamism was analyzed by applying K-means unsupervised classification algorithm on 143 images. The percentages of the Tisza (TW) and Maros (MW) waters and their mixture (MIX) were calculated and compared with the hydrological parameters in both rivers. The main results revealed that the areal, lateral, and longitudinal extensions of TW and MIX have a better correlation with the hydrological parameters than the MW. The Pearson correlation matrix revealed that the discharge ratio between the rivers controls the mixing process significantly. Altogether, 11 mixing patterns were identified in the confluence area throughout the studied period. The TW usually dominates the confluence in November and January, MW in June and July, and MIX in August and September. Predictive equations for the areal distribution of the three classes were derived to support future water sampling in the confluence area.

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The effect of air temperature on forest fire risk in the municipality of Negotin

Glasnik srpskog geografskog drustva ◽

10.2298/gsgd1504067z ◽

2015 ◽

Vol 95 (4) ◽

pp. 67-76

Author(s):

Stanimir Zivanovic ◽

Milena Gocic ◽

Radomir Ivanovic ◽

Natasa Martic-Bursac

Keyword(s):

Air Temperature ◽

Forest Fires ◽

Meteorological Data ◽

Pearson Correlation ◽

Correlation Coefficients ◽

Fire Risk ◽

Annual Number ◽

Absolute Maximum ◽

Maximum Air Temperature ◽

Forest Fire Risk

Fires in nature are caused by moisture content in the burning material, which is dependent on the values of the climatic elements. The occurrence of these fires in Serbia is becoming more common, depending on the intensity and duration have a major impact on the state of vegetation. The aim of this study was to determine the association between changes in air temperature and the dynamics of the appearance of forest fires. To study the association of these properties were used Pearson correlation coefficients. The analysis is based on meteorological data obtained from meteorological station in Negotin for the period 1991-2010. Research has found that the annual number of fires, correlating with an average annual air temperature (p = 0.317, ? = 0.21). Also, it was found that the annual number of fires positive, medium intensity, correlate with the absolute maximum air temperature (p = 0.578, ? = 0.26), but not statistically significant (p> 0.05).

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Estimation and Comparative Analysis of Daily Reference Evapotranspiration Based on Different Input Combinations and Different Models

10.21203/rs.3.rs-636505/v1 ◽

2021 ◽

Author(s):

Chaojie Niu ◽

Xiang Li ◽

Chengshuai Liu ◽

Shan-e-hyder Soomro ◽

Caihong Hu

Keyword(s):

Reference Evapotranspiration ◽

Meteorological Factors ◽

Meteorological Data ◽

Pearson Correlation ◽

Back Propagation ◽

Maximum Temperature ◽

Least Squares Regression ◽

Simulation Performance ◽

Bp Model ◽

Plsr Model

Abstract Daily reference evapotranspiration (ET0) is the most crucial link in estimating crop water demand. In this study, Levenberg-Marquardt (L-M), Genetic Algorithm-Back Propagation (GA-BP) and Partial Least Squares Regression (PLSR) models were introduced to calculate the ET0 values, Based on the Pearson Correlation analysis method, five meteorological factors were obtained, which were combined into six different input scenarios. Compared with the values that calculated by the the Penman Monteith (PM) formula. Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Nash-Sutcliffe Efficiency (NSE), and Scatter Index (SI) were used to evaluate the simulation performance of the models. The results showed that the simulation effect of the L-M model is better than that of the GA-BP model and PLSR model in all scenarios. PLSR model has the worst performance. The SI index of L-M6 was 46.69% lower than that of GA-BP6 and 65.78% lower than that of PLSR6. When the input factors are 3, the simulation effect of the input wind speed, the maximum temperature and the minimum temperature is the best. L-M model and GA-BP model can predict the ET0 in the region with a lack of meteorological data. This study provides an important reference for high-precision prediction of ET0 under different input combinations of meteorological factors.

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Water quality in two catchment areas: a case study of Crocodile (West) and Berg Catchment areas

Water Practice & Technology ◽

10.2166/wpt.2014.059 ◽

2014 ◽

Vol 9 (4) ◽

pp. 526-533

Author(s):

S. A. Akinseye ◽

J. T. Harmse

Keyword(s):

Water Quality ◽

Catchment Area ◽

Pearson Correlation ◽

Quality Parameters ◽

Water Quality Parameters ◽

Western Cape ◽

Catchment Areas ◽

Domestic Use ◽

Physical And Chemical ◽

Chemical Water

This study focuses on the different physical and chemical water quality parameters of two catchment areas centring on the extent of water pollution in the two basins. Data containing physical and chemical water quality parameters for the Crocodile (West) Catchment area (Gauteng) and the Berg Catchment area (Western Cape) at reconnaissance level of detail were collected from the Department of Water Affairs (DWA) over a period of 5 years, 2007–2011. The relevant data were screened and sorted using the SPSS Software Version 2.0. The data were subjected to ANOVA statistics to search for significant variations in the water quality parameters of concern across the study period in each of the catchment area. The physical and chemical analyses were carried out to determine whether the water quality falls within the total water quality range as prescribed by DWA and WHO for domestic use. Pearson correlation analyses were used to determine the relationship between physical and chemical water quality parameters and the rainfall data over the study period.

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Seasonal survival and migratory connectivity of the Eurasian Oystercatcher revealed by citizen science

The Auk ◽

10.1093/auk/uky001 ◽

2019 ◽

Vol 136 (1) ◽

Cited By ~ 1

Author(s):

Andrew M Allen ◽

Bruno J Ens ◽

Martijn Van de Pol ◽

Henk Van der Jeugd ◽

Magali Frauendorf ◽

...

Keyword(s):

Citizen Science ◽

Avian Species ◽

Future Research ◽

Migratory Connectivity ◽

Space And Time ◽

Demographic Rates ◽

Breeding Populations ◽

Spatio Temporal ◽

Using Data ◽

Model Structures

Abstract Migratory connectivity describes linkages between breeding and non-breeding areas. An ongoing challenge is tracking avian species between breeding and non-breeding areas and hence estimating migratory connectivity and seasonal survival. Collaborative color-ringing projects between researchers and citizen scientists provide opportunities for tracking the annual movements of avian species. Our study describes seasonal survival and migratory connectivity using data from more than 4,600 individuals with over 51,000 observations, predominantly collected by citizen scientists. Our study focuses on the Eurasian Oystercatcher (Haematopus ostralegus), a species that has experienced a substantial and ongoing decline in recent decades. Multiple threats have been described, and given that these threats vary in space and time, there is an urgent need to estimate demographic rates at the appropriate spatio-temporal scale. We performed a seasonal multi-state (5 geographical areas within The Netherlands) live- and dead-recoveries analysis under varying model structures to account for biological and data complexity. Coastal breeding populations were largely sedentary, while inland breeding populations were migratory and the direction of migration varied among areas, which has not been described previously. Our results indicated that survival was lower during winter than summer and that survival was lower in inland areas compared with coastal areas. A concerning result was that seasonal survival of individuals over-wintering in the Wadden Sea, an internationally important site for over-wintering shorebirds, appeared to decline during the study period. We discuss the outcomes of our study, and how citizen science was integral for conducting this study. Our findings identify how the demographic rates of the oystercatcher vary in space and time, knowledge that is vital for generating hypotheses and prioritizing future research into the causes of decline.

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MOOCs Readiness

The International Review of Research in Open and Distributed Learning ◽

10.19173/irrodl.v20i3.3913 ◽

2019 ◽

Vol 20 (3) ◽

Cited By ~ 1

Author(s):

Thirumeni T Subramaniam ◽

Nur Amalina Diyana Suhaimi ◽

Latifah Abdol Latif ◽

Zorah Abu Kassim ◽

Mansor Fadzil

Keyword(s):

Adult Students ◽

Self Efficacy ◽

Structural Equation ◽

Online Courses ◽

Pearson Correlation ◽

Massive Open Online ◽

Online Questionnaire ◽

Social Competencies ◽

Communication Competencies ◽

Important Input

This study seeks to investigate the readiness levels of adult students studying in Malaysian higher education institutions. The online questionnaire used in this study consists of 18 demographic variables and 43 items based on six constructs: technical competencies, communication competencies, social competencies, self-efficacy, self-directedness, and readiness. With a sample of 413 respondents, the constructs were evaluated using measures based on students’ self-identification with each item. Descriptive statistics depict competency, demographic profile of students, and level of readiness. The statistical analyses used for this study were Pearson correlation, multivariate analysis of variance, and structural equation modelling. All six constructs were reliable with Cronbach’s alpha (α) above 0.7. Findings indicate that self-efficacy was significant for massive open online course readiness, and additional factors that could influence this readiness are explored. The findings from this study provide important input towards designing effective massive open online courses.

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