Open Access Original Research Article

Meteorological Variables That Affect Visibility Degradation and Their Seasonal Trends in the Niger Delta Region of Nigeria

C. O. Nwokocha, C. U. Okujagu, P. I. Enyinna

Journal of Geography, Environment and Earth Science International, Page 1-10
DOI: 10.9734/jgeesi/2019/v19i330084

The study of visibility in the Niger Delta region is necessary because it reflects the atmospheric changes caused by economic expansion in Nigeria. Cities in the Niger Delta (especially Port Harcourt) are the most polluted cities in the country and therefore visibility degradation has become one of the major environmental challenge in Nigeria. Analysis of a 31 years (1981-2012) monthly mean horizontal visibility data and monthly mean datasets of meteorological parameters such as relative humidity and wind direction obtained from Nigerian Meteorological Agency (NIMET) and the National Centre for Environmental Prediction (NCEP) for Calabar, Uyo, Port Harcourt, Owerri, Warri and Akure was done using statistical techniques. A correlation analysis was done and the annual visibility variability indexes from (NIMET) shows significant correlation with the (NCEP) datasets for R/humidity at r=0.1334 and Wind direction at r=0.1210 respectively at 90% confidence level from t-test. This study concluded that the relationship of the atmospheric visibility and meteorological factors are closely related. The results showed that visibility is more correlated with Relative humidity in places with high hydrocarbon activities leading to excess aerosol loading like Port Harcourt while it is better correlated with wind direction in places with less hydrocarbon activities like Calabar and Akure. The results of this study can assist policy makers and operators in establishing positive strategies to improve the air quality.

Open Access Original Research Article

Effect of Municipal Solid Waste (MSW) Leachate on Groundwater Quality in Port Harcourt, Nigeria

O. Olushola Eseyin, I. Charles Osu

Journal of Geography, Environment and Earth Science International, Page 1-12
DOI: 10.9734/jgeesi/2019/v19i330085

Aims: This study was carried out to assess the effect of Municipal Solid Waste (MSW) leachate on groundwater quality in Port Harcourt, Nigeria. Cross-sectional study was conducted around two dumpsites in Port Harcourt, Nigeria on leachates and borehole water.

Study Design: Cross-sectional study of selected refuse dumpsite was conducted in Port Harcourt, Nigeria to assess the effect of Municipal Solid Waste (MSW) leachate on groundwater quality in Port Harcourt, Nigeria. The physicochemical parameters such as pH, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Electrical Conductivity (EC), Nitrite ion, Phosphate ion, Sulphate ion, Chloride ion and heavy metals (Cd, Pb, Zn, Fe, and Cu) were determined by standard protocol of APHA (2012). The samples were analysed by three quality tools/indices such as the Water Quality Index (WQI), Contamination Factor (CF) and Contamination Degree (CD).

Results and Discussion: The result shows that some parameters in the borehole water did not meet the standards of World Health Organization (WHO) and Nigerian Standards for Drinking Water Quality (NSDWQ), and most leachates and borehole water qualities near the un-engineered dumpsites are of poor quality. There was a decreasing trend in concentrations of hazardous contaminants from the leachate to nearby borehole water and eventually the distant borehole water. This shows that the leachates exert great effect on the concentrations of contaminants in the surrounding borehole waters and distant ones.

Conclusion: It is concluded that there is an increase in risk to the borehole and public health that is reported near the unengineered dumpsites; which can spread to other region on bioaccumulation. The result indicated that the dumpsite leachate is producing many potent contaminants to the environment and to the people nearby.

Open Access Original Research Article

Assessment of Rainfall Thresholds for Rain-Induced Landslide Activity in North Sikkim Road Corridor in Sikkim Himalaya, India

Bappaditya Koley, Anindita Nath, Subhajit Saraswati, Kaushik Bandyopadhyay, Bidhan Chandra Ray

Journal of Geography, Environment and Earth Science International, Page 1-14
DOI: 10.9734/jgeesi/2019/v19i330086

Land sliding is a perennial problem in the Eastern Himalayas. Out of 0.42 million km2 of Indian landmass prone to landslide, 42% fall in the North East Himalaya, specially Darjeeling and Sikkim Himalaya. Most of these landslides are triggered by excessive monsoon rainfall between June and October in almost every year. Various attempts in the global scenario have been made to establish rainfall thresholds in terms of intensity – duration of antecedent rainfall models on global, regional and local scale for triggering of the landslide. This paper describes local aspect of rainfall threshold for landslides based on daily rainfall data in and around north Sikkim road corridor region. Among 210 Landslides occurring from 2010 to 2016 were studied to analyze rainfall thresholds. Out of the 210 landslides, however, only 155 Landslides associated with rainfall data which were analyzed to yield a threshold relationship between rainfall intensity-duration and landslide initiation. The threshold relationship determined fits to lower boundary of the Landslide triggering rainfall events is I = 4.045 D - 0.25 (I=rainfall intensity (mm/h) and D=duration in (h)), revealed that for rainfall event of short time (24 h) duration with a rainfall intensity of 1.82 mm/h, the risk of landslides on this road corridor of the terrain is expected to be high. It is also observed that an intensity of 58 mm and 139 mm for 10-day and 20-day antecedent rainfall are required for the initiation of landslides in the study area. This threshold would help in improvement on traffic guidance and provide safety to the travelling tourists in this road corridor during the monsoon.

Open Access Original Research Article

Heavy Metal Concentration and Physicochemical Parameters in Soil and Plants near Unengineered Dumpsites in Port Harcourt, Nigeria

O. Olushola Eseyin, G. J. Udom, I. Charles Osu

Journal of Geography, Environment and Earth Science International, Page 1-11
DOI: 10.9734/jgeesi/2019/v19i330087

Cross sectional study was conducted around two unengineered dumpsites in Port Harcourt, Nigeria on heavy metal concentrations and physicochemical parameters in soil and plants. Physicochemical parameters studied include pH, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Electrical Conductivity (EC), Nitrite ion, Phosphate ion, Sulphate ion, Chloride ion and heavy metals (Cd, Pb, Zn, Fe, and Cu). The result shows that edible plants were observed to have recorded one variety of metal or the other; and a relatively higher concentration of metals were found in the soil than in plant which indicates possible gradual movement of metals from the soil samples into the plants. Chloride ion concentration was negligible in all edible plants, but traces of other anions were recorded in both plants. Both dumpsites have contamination factor (CF) ranging from low to very highly polluted for different metals. Contamination degree (CD) at the dumpsites showed that both sites have very high degree of contamination. Pollution Load Index (PLI) of 4.64 in S1 (Soil sample from Choba dumpsite) and 4.19 in S2 (Soil sample from Ada-George dumpsite) show that there is progressive deterioration of the two sites. Index of geoaccumulation (Igeo) values obtained show that Zn was the only metal that did not enrich the soil with Zero (0) values (S1 = -0.04, and S2 = -2.00); which indicate that it originated from natural processes or crustal materials alone, and not from anthropogenic sources. Other metal concentrations ranged from unpolluted to moderately polluted and to extremely polluted. Bioaccumulation Factor (BAF) showed that all the dumpsites are excluders and are not effective accumulators of metals and anions from the soil into the plants. Urgent attention has to be given to the dumpsites to prevent further degradation of the soil and possible bioaccumulation of metals in edible plants.

Open Access Original Research Article

Mass Balance of the Himalayan Glaciers and Their Regional Variations

Sanchayita Das, Manab Chakraborty

Journal of Geography, Environment and Earth Science International, Page 1-11
DOI: 10.9734/jgeesi/2019/v19i330088

Aim: Popular methods of glacial mass balance studies are time consuming, laborious and therefore, not repetitive at yearly manner. A compact, user-friendly classification algorithm has been applied to estimate Equilibrium Line Altitude (ELA) and mass balance of mountain or valley glaciers at yearly basis using Synthetic Aperture Radar (SAR) data for a period of 2012 to 2015. Cloud cover over the glacier catchment areas was studied to identify major seasons of precipitation over the study areas. The results were also compared to study the regional characteristics of the glaciers.

Study Area: The proposed module was used to analyze data over three Himalayan glaciers, namely, Durung Drung, Gangorti and Zemu. Chhota Shigri glacier was also studied with these three glaciers to understand the regional variations of the Himalayan glaciers.

Methodology: The classification algorithm was fixed for all glaciers and also independent from season, therefore, required least user intervention. The conditional loop based logics, consist of linear equations, classified glaciated region in different physical zones. Purely backscatter based classification result produced error by mixing zones due to overlapped signatures. Altitude thresholds of accumulation zones were employed to segregate the mixing in next level. The method required calibrated ortho-rectified sigma naught dual-pol SAR imagery as primary input. The glaciated area should be provided as Area of Interest (AOI). A Digital Elevation Model (DEM) file is required for altitude threshold. The output classes are saved in separate files with Boolean values. Optical data were used to estimate cloud coverage over the catchments of the glaciers.

Results: Average mass balance of the selected glaciers is estimated as - 0.44 m w.e.a-1 during the study period. The mass balance of the glaciers are comparatively studied with variation in melting seasons, duration of melting periods, on set and cease of melting for each glacier to understand the regional pattern of mass loss.

Conclusion: Co and cross polarized SAR data are employed to derived debris size; however, cross polarized SAR backscattering has better correlation with debris size. The accuracy of the result derived from the developed method is ± 50 mm. Collection of field data on the surface topography is difficult for Mountain glaciers, especially over Himalaya. Use of satellite data can generate detailed information of glacier surface which will be further help to understand role of debris in glacier mass balance.