Indication of the Two Linear Correlation Methods Between Vegetation Index and Climatic Factors: An Example in the Three River-Headwater Region of China During 2000–2016

The within-growing-season correlations (WGSC) and the inter-growing-season correlations (IGSC) are widely used linear correlation analysis methods between vegetation index and climatic factors (such as temperature, precipitation, and so on). The WGSC method usually calculates the linear correlation coefficient between vegetation index and climatic factors of each month in all the growing seasons, for instance, whether vegetation index or temperature had data of 204 months (12 months × 17 years) during 2000–2016 to get the WGSC. The IGSC calculates the linear correlation coefficient between the vegetation index and climatic factors in the same month of each growing season among all the years, for example, only 17 couples’ data of vegetation index and temperature during 2000–2016 were used to get the linear correlation of IGSC. What is the difference between the results of the two methods and why do the results show that difference? Which is the more suitable method for the analysis of the relationship between the vegetation index and climatic conditions? To clarify the difference of the two methods and to explore more about the relationship between the vegetation index and climatic factors, we collected the data of 2000–2016 moderate resolution imaging spectroradiometer (MODIS) 13A1 normalized difference vegetation index (NDVI) and the meteorological data-temperature and precipitation, then calculated WGSC and IGSC between NDVI and the climatic factor in three river-headwater regions of China. The results showed that: (1) As for WGSC, the more of the years included, the higher the correlation coefficient between NDVI and the temperature/precipitation. The correlation coefficient of WGSC is dependent on how many years’ the data were included, and it was increased with the more year’s data included, while the correlation coefficients of IGSC are relatively independent on the amount of the data; (2) the WGSC showed a pseudo linear correlation between NDVI and climatic conditions caused by the accumulation of data amount, while the IGSC can more accurately indicate the impact of climatic factors on vegetation since it did not rely on the data amount.

Download Full-text

Assessing the impact of seasonal precipitation and temperature on vegetation in a grass-dominated rangeland

The Rangeland Journal ◽

10.1071/rj13098 ◽

2014 ◽

Vol 36 (2) ◽

pp. 185 ◽

Cited By ~ 11

Author(s):

Fang Chen ◽

Keith T. Weber

Keyword(s):

Vegetation Index ◽

Climatic Factors ◽

Growing Season ◽

Vegetation Growth ◽

Factors Affecting ◽

Growing Seasons ◽

Normalised Difference Vegetation Index ◽

Moderate Resolution Imaging Spectroradiometer ◽

The Impact ◽

Precipitation And Temperature

Changes in vegetation are affected by many climatic factors and have been successfully monitored through satellite remote sensing over the past 20 years. In this study, the Normalised Difference Vegetation Index (NDVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Terra satellite, was selected as an indicator of change in vegetation. Monthly MODIS composite NDVI at a 1-km resolution was acquired throughout the 2004–09 growing seasons (i.e. April–September). Data describing daily precipitation and temperature, primary factors affecting vegetation growth in the semiarid rangelands of Idaho, were derived from the Surface Observation Gridding System and local weather station datasets. Inter-annual and seasonal fluctuations of precipitation and temperature were analysed and temporal relationships between monthly NDVI, precipitation and temperature were examined. Results indicated NDVI values observed in June and July were strongly correlated with accumulated precipitation (R2 >0.75), while NDVI values observed early in the growing season (May) as well as late in the growing season (August and September) were only moderately related with accumulated precipitation (R2 ≥0.45). The role of ambient temperature was also apparent, especially early in the growing season. Specifically, early growing-season temperatures appeared to significantly affect plant phenology and, consequently, correlations between NDVI and accumulated precipitation. It is concluded that precipitation during the growing season is a better predictor of NDVI than temperature but is interrelated with influences of temperature in parts of the growing season.

Download Full-text

The Relationship between NDVI and Climate Factors at Different Monthly Time Scales: A Case Study of Grasslands in Inner Mongolia, China (1982–2015)

Sustainability ◽

10.3390/su11247243 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7243 ◽

Cited By ~ 8

Author(s):

Zhifang Pei ◽

Shibo Fang ◽

Wunian Yang ◽

Lei Wang ◽

Mingyan Wu ◽

...

Keyword(s):

Time Scales ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Meteorological Data ◽

Pearson Correlation ◽

Growing Season ◽

Multiple Time Scales ◽

Multiple Time ◽

Climate Factors ◽

The Relationship

There are currently only two methods (the within-growing season method and the inter-growing season method) used to analyse the normalized difference vegetation index (NDVI)–climate relationship at the monthly time scale. What are the differences between the two methods, and why do they exist? Which method is more suitable for the analysis of the relationship between them? In this study, after obtaining NDVI values (GIMMS NDVI3g) near meteorological stations and meteorological data of Inner Mongolian grasslands from 1982 to 2015, we analysed temporal changes in NDVI and climate factors, and explored the difference in Pearson correlation coefficients (R) between them via the above two analysis methods and analysed the change in R between them at multiple time scales. The research results indicated that: (1) NDVI was affected by temperature and precipitation in the area, showing periodic changes, (2) NDVI had a high value of R with climate factors in the within-growing season, while the significant correlation between them was different in different months in the inter-growing season, (3) with the increase in time series, the value of R between NDVI and climate factors showed a trend of increase in the within-growing season, while the value of R between NDVI and precipitation decreased, but then tended toward stability in the inter-growing season, and (4) when exploring the NDVI–climate relationship, we should first analyse the types of climate in the region to avoid the impacts of rain and heat occurring during the same period, and the inter-growing season method is more suitable for the analysis of the relationship between them.

Download Full-text

Climatic conditions for crop production in Nordic countries

Agricultural and Food Science ◽

10.23986/afsci.72854 ◽

1998 ◽

Vol 7 (2) ◽

pp. 149-160 ◽

Cited By ~ 12

Author(s):

Arne Oddvar Skjelvåg

Keyword(s):

Crop Production ◽

Climatic Factors ◽

Growth Index ◽

Growing Season ◽

Climatic Conditions ◽

Nordic Countries ◽

Plant Production ◽

Yield Level ◽

The Difference ◽

Moisture Conditions

Climate is today a more determinant factor for yield level than it was in the past, when soil fertility was more important. The regional variation in radiation during the growing season in Nordic countries is less than that in temperature conditions. A combined plant growth-related index of these climatic factors accumulated during the growing season decreased from an annual value of 106 at 56°N (Ødum, East Jutland) to about 90, 60 and 44 at 60°N, 67°N and 70°N, respectively. The difference between coastal areas in Norway and the Finnish interior was either negligible or about 10% in disfavour of the coast at 67°N. When the moisture conditions of an imaginary pasture crop on a sandy soil were taken into account, the combined accumulated growth index of radiation, temperature and soil moisture was 71 at Ødum. On the Norwegian coast, the values were 72, 49 and 37, whilst in Finland, up to northeastern Norway, they were 56, 43 and 35 at 60°N, 67°N and 70°N, respectively. Plant production potential may be directly related to the accumulated growth index.

Download Full-text

COVID-19 and The Impact of Climatic Parameters: A Case Study of Bangladesh

10.21203/rs.3.rs-630089/v1 ◽

2021 ◽

Author(s):

Rehana Parvin

Keyword(s):

Wind Speed ◽

Correlation Coefficient ◽

Climatic Factors ◽

Climatic Variables ◽

Series Data ◽

Climatic Parameters ◽

Pm 2.5 ◽

Lagged Effects ◽

The Impact ◽

The Relationship

Abstract This study examines the relationship between climatic factors and the prevalence of COVID-19 in Bangladesh. Pearson correlation coefficient, Spearman correlation coefficient, and Kendall's correlation coefficient have all been put to use to assess the intensity and direction of the relationship between climatic factors and COVID-19. The lagged effects of climatic parameters on COVID-19 daily-confirmed cases from Bangladesh are being looked into using the Auto Regressive Distributed Lag (ARDL) model. As a result, two non-climatic variables, such as population density and the human development index, are taken into account as control variables. As climatic variables, average temperature (°C), average humidity (percent), average PM 2.5, and average wind speed (km/h) were well chosen. The time series data used in this analysis was from May 1, 2020 to April 14, 2021. The findings of correlation analysis indicate that there is an important, significant, and positive relationship between COVID-19 widespread and temperature (°C), humidity (percent), and wind speed (km/h), whereas there is a negative, weak, and significant relationship between PM 2.5 and COVID-19 widespread. In addition, the ARDL findings suggested that temperature (°C), PM 2.5, and wind speed (km/h) have major lagged effects on COVID-19 in Bangladesh, while humidity (percent) has negligible lagged effects. For policymakers and investors alike, the consequences of this study are important in Bangladesh.

Download Full-text

The modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China

Respiratory Research ◽

10.1186/s12931-021-01744-6 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Rui Zhang ◽

Yujie Meng ◽

Hejia Song ◽

Ran Niu ◽

Yu Wang ◽

...

Keyword(s):

Air Pollution ◽

High Temperature ◽

Air Pollutants ◽

Meteorological Data ◽

Effect Of Temperature ◽

Distributed Lag ◽

Modification Effect ◽

Incidence Risk ◽

The Impact ◽

The Relationship

Abstract Background Although exposure to air pollution has been linked to many health issues, few studies have quantified the modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China. Methods The data of daily incidence of influenza and the relevant meteorological data and air pollution data in Ningbo from 2014 to 2017 were retrieved. Low, medium and high temperature layers were stratified by the daily mean temperature with 25th and 75th percentiles. The potential modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo was investigated through analyzing the effects of air pollutants stratified by temperature stratum using distributed lag non-linear model (DLNM). Stratified analysis by sex and age were also conducted. Results Overall, a 10 μg/m3 increment of O3, PM2.5, PM10 and NO2 could increase the incidence risk of influenza with the cumulative relative risk of 1.028 (95% CI 1.007, 1.050), 1.061 (95% CI 1.004, 1.122), 1.043 (95% CI 1.003, 1.085), and 1.118 (95% CI 1.028, 1.216), respectively. Male and aged 7–17 years were more sensitive to air pollutants. Through the temperature stratification analysis, we found that temperature could modify the impacts of air pollution on daily incidence of influenza with high temperature exacerbating the impact of air pollutants. At high temperature layer, male and the groups aged 0–6 years and 18–64 years were more sensitive to air pollution. Conclusion Temperature modified the relationship between air pollution and daily incidence of influenza and high temperature would exacerbate the effects of air pollutants in Ningbo.

Download Full-text

Impact of climatic conditions on the parameters of failure flow of military vehicles

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/09544070211020228 ◽

2021 ◽

pp. 095440702110202

Author(s):

Nikolaj Dobrzinskij ◽

Algimantas Fedaravicius ◽

Kestutis Pilkauskas ◽

Egidijus Slizys

Keyword(s):

Climatic Factors ◽

Armed Forces ◽

Climatic Conditions ◽

Operating Conditions ◽

Technical Equipment ◽

Factors Affecting ◽

Military Vehicles ◽

Equipment Reliability ◽

Number Of Factors ◽

The Impact

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.

Download Full-text

The role of L/W in the solar radiation for Saharian cities

E3S Web of Conferences ◽

10.1051/e3sconf/20199105006 ◽

2019 ◽

Vol 91 ◽

pp. 05006

Author(s):

Rami Qaoud ◽

Alkama Djamal

Keyword(s):

Solar Radiation ◽

Solar Energy ◽

Energy Levels ◽

Direct Solar Radiation ◽

Test Field ◽

Natural Lighting ◽

The Difference ◽

The Impact ◽

The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

Download Full-text

Abstract 279: The Impact of Heart Failure on Depression and Quality of Life is Greater in Men than Women

Circulation Cardiovascular Quality and Outcomes ◽

10.1161/circoutcomes.5.suppl_1.a279 ◽

2012 ◽

Vol 5 (suppl_1) ◽

Author(s):

Rory Hachamovitch ◽

Brian Griffin ◽

Alan Klein ◽

Benjamin Nutter ◽

Irene Katzan ◽

...

Keyword(s):

Quality Of Life ◽

Heart Failure ◽

Demographic Data ◽

Cardiovascular Assessment ◽

Related Quality ◽

Health Related ◽

The Difference ◽

The Impact ◽

The Relationship

Background. Patients (pts) diagnosed with congestive heart failure (HF) have been reported to have more frequent depression and worsened health related quality of life (HRQOL). Although depression is more common in women than men in this condition, the impact of HF on depression and HRQOL in men versus women is unclear. We sought to examine the relationship between pt sex, HF diagnosis, and pt-perceived depression and HRQOL. Methods. Depression (PHQ-9) and HRQOL (EQ5D) data were collected using tablet computers from pts presenting for routine outpatient cardiovascular assessment at our institution between November, 2010 and December, 2011. Demographic, clinical, and historical data was collected as per routine. We examined the association of pt sex and clinical diagnosis of HF with instrument results after adjusting for potential confounding information using mutliple linear regression. Results. Of 3046 pts (age 61±15), 39% were female and 8.7% were diagnosed with HF. Overall, PHQ-9 was greater, and minor or major depression (PHQ-9≥10) was more frequent, in women than men (4.6±4.6 vs. 3.3±4.4; 14.0% vs. 8.9%, both p<0.05) and in HF pts than pts without HF (5.9±5.6 vs. 3.6±4.3, 22.0% versus 9.6%; both p<0.05). Similarly, HRQOL was worse in women than men (EQ-5D 0.80±0.18 vs. 0.87±0.16; p<0.01) and in HF pts than no HF (EQ-5D 0.76±0.18 vs. 0.85±0.17; p<0.01). However, the difference in PHQ-9 between pts with versus without HF was greater in men (6.23±6.06 vs. 3.02±4.06, p<0.01) than women (5.43±4.85 vs. 4.55±4.58, p=0.09). After adjusting for cardiovascular diagnoses, comorbidities, clinical and demographic data, multivariable modeling of PHQ-9 revealed a significant interaction between pt sex and HF diagnosis (p=0.001; see Figure) such that women had greater PHQ-9 scores compared to men without HF, but in the setting of HF, mens' PHQ-9 scores were greater. Modeling of EQ-5D also revealed that after risk-adjustment an interaction between HF diagnosis and sex was present with a similar pattern of findings. Conclusion. Although depression is more frequent and severe in women compared to men, and in pts with versus without HF, HF appears to impact depression severity more in men compared to women.

Download Full-text

Family Climate Patterns and Its Relationship with Self-Concept among Students at the University of Islamic Sciences in light of the Variables of Gender and Age

International Journal of Education ◽

10.5296/ije.v9i1.10980 ◽

2017 ◽

Vol 9 (1) ◽

pp. 145

Author(s):

Fatima Mohammad Rashed Al Talahin ◽

Hana Khaled Al –Raqqad ◽

Eman Saeed Al- Bourini ◽

Bilal Adel Al-Kateeb

Keyword(s):

Pearson Correlation ◽

Statistical Significance ◽

Self Concept ◽

Family Climate ◽

Gender And Age ◽

Climate Patterns ◽

The Difference ◽

The University ◽

The Impact ◽

The Relationship

The aim of this study is to clarify the relationship between self-concept and patterns of family climate among students at the University of Islamic Sciences, and also aimed to investigate the effect of gender and age on this relationship.The sample of the study consisted of a group of students were selected randomly, totaling (139) students; (58) male and (81) female students.Two questionnaires were distributed on 139 students. The first questionnaire was on the impact of patterns of family climate on self-concept and the second one about self-concept. Then the researcher analyzed the results of each item in the questionnaire using appropriated statistical methods, calculated the correlation between self-concept and patterns of family climate using the Pearson correlation coefficient, and G-test to find the difference between correlation coefficients.The results showed a positive statistical significance relationship between family climate patterns on one hand and between self-concept in all its dimensions on the other hand.

Download Full-text

Malaria and the climate in Karachi: An eight year review

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.36.icon-suppl.1712 ◽

2019 ◽

Vol 36 (ICON-Suppl) ◽

Author(s):

Fivzia Herekar ◽

Sundus Iftikhar ◽

Ahsana Nazish ◽

Sabeen Rehman

Keyword(s):

Chart Review ◽

Climatic Factors ◽

Meteorological Data ◽

Climatic Variability ◽

Climate Variables ◽

Creative Commons ◽

Medical Chart Review ◽

Special Supplement ◽

The Relationship ◽

Open Access Article

Background and Objective: Malaria is an arthropod-borne infectious disease transmitted by the mosquito Anopheles and claims millions of lives globally every year. Reasons for failure to eradicate this disease are multifactorial. The seasonality of the malaria is principally determined by climatic factors conducive for breeding of the vector. We aimed to study the relationship between climatic variability and the seasonality of malaria over an eight-year duration. Methods: This was a retrospective medical chart review of 8,844 confirmed cases of malaria which presented to The Indus Hospital, Karachi from January 2008 to November 2015. Cases were plotted against meteorological data for Karachi to elicit monthly variation. Results: A secular incline and seasonality in malaria cases over the duration of 8 years was seen. More cases were reported in the summer, rainy season compared with the other three seasons in each year. There was significant association with specific climate variables such as temperature, moisture, and humidity. Conclusion: There is a marked seasonal variation of malaria in Karachi, influenced by various environmental factors. Identification of the ‘the concentrated period’ of malaria can be helpful for policymakers to deploy malaria control interventions. doi: https://doi.org/10.12669/pjms.36.ICON-Suppl.1712 How to cite this:Herekar F, Iftikhar S, Nazish A, Rehman S. Malaria and the climate in Karachi: An eight year review. Pak J Med Sci. Special Supplement ICON 2020. 2020;36(1):S33-S37. doi: https://doi.org/10.12669/pjms.36.ICON-Suppl.1712 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download Full-text