The thrust of this paper is to examine the impact of drought risk on vegetation health in North Central Nigeria. The study applied remote sensing, Geographic information system (GIS) and statistical techniques as rese...The thrust of this paper is to examine the impact of drought risk on vegetation health in North Central Nigeria. The study applied remote sensing, Geographic information system (GIS) and statistical techniques as research methodologies. Monthly rainfall data which span through a period of 56 years (1960-2017) were obtained from Nigeria Meteorological Agency (NIMET) for analysis of variation and drought characterization using SPI. Consequently, drought risk maps were produced for three different periods: 2000-2005, 2005-2010 and 2010-2015. The study made use of the near real time data of Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Normalized Difference Vegetation Index (NDVI) of 16 Day L3 Global 250 m resolution from 2000 to 2016 for analysis of vegetation health. The results of the study proved the efficacy of NDVI in highlighting areas that are currently under vegetation stress, reduction and drought. The states with reduced and low vegetation cover corresponded well to those with low rainfall hence, more vulnerable to drought risk. The summary of the NDVI results showed that Niger, plateau and Nasarawa states have low vegetation cover and are more vulnerable to drought risk.展开更多
The current climate change is affecting the environment in diverse ways. Some of the effects are good and some others bad. The good side has not been given its deserved attention in Nigeria, nor has it in most parts o...The current climate change is affecting the environment in diverse ways. Some of the effects are good and some others bad. The good side has not been given its deserved attention in Nigeria, nor has it in most parts of the world. Some areas are becoming warmer and wetter, which could enhance agriculture. This paper therefore examined the rainfall and temperature trends as tools of climate change over Kano State, north-western Nigeria, which is an area well known for agriculture. Rainfall and temperature data covering a period of 43 years (1971-2013) were collected and analyzed using the moving averages, regression and correlation statistics. Results obtained showed gradual but steady increases in both temperature and rainfall. The results indicate that Kano State is warming at an average annual rate of 0.011°C and becoming wetter at a rate of 21.26 mm per annum. An implication of this increased rainfall for farmers in the area is the opportunity to increase crop and animal production. This is because more rainfall can now be harvested. Also, soil moisture, rivers, dams, and ponds are being recharged more, thus making water more available and longer lasting for crops and animals.展开更多
This study examined the indoor thermal comfort characteristics and it implications for the health of the inhabitants in Yenagoa, Bayelsa state, Nigeria. The study used the experimental and survey research designs to g...This study examined the indoor thermal comfort characteristics and it implications for the health of the inhabitants in Yenagoa, Bayelsa state, Nigeria. The study used the experimental and survey research designs to gather primary data of temperature (dry and wet bulb), and perception of the inhabitants regarding thermal conditions in the study area. The effective temperature equation was used to determine the thermal comfort characteristics of the residential buildings in the study area, while the analysis of variance (ANOVA) model was used to determine the spatial variation in thermal comfort characteristics across the different land uses in the study area. The findings of the study include: the thermal comfort characteristics for the study area ranged between 27.3 ET & 29.08 ET at the dry period and at wet period 25.6 ET and 27.10 ET. The ANOVA model was significant at P < 0.05 (F-118.23, sig-0.00), indicating that there is a significant difference in the thermal comfort characteristics in the study area. The Duncan statistics however, revealed that, the GRA is the coolest when it comes to effective temperature. Furthermore, the respondents identified that;the period of discomfort is mostly afternoon (37.3%) and Nights (35.1%). Health problems as a result of poor thermal conditions include skin rashes (59.8%), heat cramps (26.4%), prickly heat (42%) and heat exhaustion (51.3%). As a result of the findings the study strongly advocates, building residential buildings with several openings and locating such openings in recognition of the wind direction.展开更多
This study centers on applying the statistical downscaling technique to the daily minimum and maximum temperatures of Port Harcourt from the period 1985-2014. To select the period of calibration, the wilby and wigley ...This study centers on applying the statistical downscaling technique to the daily minimum and maximum temperatures of Port Harcourt from the period 1985-2014. To select the period of calibration, the wilby and wigley assumption of 2014 was adopted. However, the Bruckner circle assumption was adopted in selecting the normal under review. Secondary data of minimum and maximum temperatures for Port Harcourt were collected from the archive of Nigerian meteorological agency (NIMET). The grid cell of the HadCM3 corresponding to the Port Harcourt meteorological station was selected from the HadCM3 website to generate the largescale predictors. Data for temperature was there after normalized for the period of calibration. To analyze data, ANOVA and Paired t tests were used. Result showed that, the model was significant at p °C from 1960-2080, while for B2 the increase will be 0.18°C for same period. For minimum temperature, the ANOVA also showed a difference of 0.21°C and 0.11°C for A2 and B2 respectively. The paired t test statistics showed that these variations in temperatures for both maximum and minimum at A2 and B2 scenarios are significant at p < 0.05. Reforestation, afforestation, carbon sequestration are strongly advocated.展开更多
文摘The thrust of this paper is to examine the impact of drought risk on vegetation health in North Central Nigeria. The study applied remote sensing, Geographic information system (GIS) and statistical techniques as research methodologies. Monthly rainfall data which span through a period of 56 years (1960-2017) were obtained from Nigeria Meteorological Agency (NIMET) for analysis of variation and drought characterization using SPI. Consequently, drought risk maps were produced for three different periods: 2000-2005, 2005-2010 and 2010-2015. The study made use of the near real time data of Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua Normalized Difference Vegetation Index (NDVI) of 16 Day L3 Global 250 m resolution from 2000 to 2016 for analysis of vegetation health. The results of the study proved the efficacy of NDVI in highlighting areas that are currently under vegetation stress, reduction and drought. The states with reduced and low vegetation cover corresponded well to those with low rainfall hence, more vulnerable to drought risk. The summary of the NDVI results showed that Niger, plateau and Nasarawa states have low vegetation cover and are more vulnerable to drought risk.
文摘The current climate change is affecting the environment in diverse ways. Some of the effects are good and some others bad. The good side has not been given its deserved attention in Nigeria, nor has it in most parts of the world. Some areas are becoming warmer and wetter, which could enhance agriculture. This paper therefore examined the rainfall and temperature trends as tools of climate change over Kano State, north-western Nigeria, which is an area well known for agriculture. Rainfall and temperature data covering a period of 43 years (1971-2013) were collected and analyzed using the moving averages, regression and correlation statistics. Results obtained showed gradual but steady increases in both temperature and rainfall. The results indicate that Kano State is warming at an average annual rate of 0.011°C and becoming wetter at a rate of 21.26 mm per annum. An implication of this increased rainfall for farmers in the area is the opportunity to increase crop and animal production. This is because more rainfall can now be harvested. Also, soil moisture, rivers, dams, and ponds are being recharged more, thus making water more available and longer lasting for crops and animals.
文摘This study examined the indoor thermal comfort characteristics and it implications for the health of the inhabitants in Yenagoa, Bayelsa state, Nigeria. The study used the experimental and survey research designs to gather primary data of temperature (dry and wet bulb), and perception of the inhabitants regarding thermal conditions in the study area. The effective temperature equation was used to determine the thermal comfort characteristics of the residential buildings in the study area, while the analysis of variance (ANOVA) model was used to determine the spatial variation in thermal comfort characteristics across the different land uses in the study area. The findings of the study include: the thermal comfort characteristics for the study area ranged between 27.3 ET & 29.08 ET at the dry period and at wet period 25.6 ET and 27.10 ET. The ANOVA model was significant at P < 0.05 (F-118.23, sig-0.00), indicating that there is a significant difference in the thermal comfort characteristics in the study area. The Duncan statistics however, revealed that, the GRA is the coolest when it comes to effective temperature. Furthermore, the respondents identified that;the period of discomfort is mostly afternoon (37.3%) and Nights (35.1%). Health problems as a result of poor thermal conditions include skin rashes (59.8%), heat cramps (26.4%), prickly heat (42%) and heat exhaustion (51.3%). As a result of the findings the study strongly advocates, building residential buildings with several openings and locating such openings in recognition of the wind direction.
文摘This study centers on applying the statistical downscaling technique to the daily minimum and maximum temperatures of Port Harcourt from the period 1985-2014. To select the period of calibration, the wilby and wigley assumption of 2014 was adopted. However, the Bruckner circle assumption was adopted in selecting the normal under review. Secondary data of minimum and maximum temperatures for Port Harcourt were collected from the archive of Nigerian meteorological agency (NIMET). The grid cell of the HadCM3 corresponding to the Port Harcourt meteorological station was selected from the HadCM3 website to generate the largescale predictors. Data for temperature was there after normalized for the period of calibration. To analyze data, ANOVA and Paired t tests were used. Result showed that, the model was significant at p °C from 1960-2080, while for B2 the increase will be 0.18°C for same period. For minimum temperature, the ANOVA also showed a difference of 0.21°C and 0.11°C for A2 and B2 respectively. The paired t test statistics showed that these variations in temperatures for both maximum and minimum at A2 and B2 scenarios are significant at p < 0.05. Reforestation, afforestation, carbon sequestration are strongly advocated.
