Open Access Original Research Article

Simulation of Meteorological Drought of Bankura District, West Bengal: Comparative Study between Exponential Smoothing and Machine Learning Procedures

Shrinwantu Raha, Shasanka Kumar Gayen

Journal of Geography, Environment and Earth Science International, Page 1-16
DOI: 10.9734/jgeesi/2019/v22i130135

Simulation of drought is needed for proper planning and management of water resources. This study has been developed using the following five key points: a) primarily from rainfall Standard Precipitation Index (SPI), Percentage to Normal (PN), Decile based drought index (DI), Rainfall Anomaly Index (RAI), China Z Index (CZI), and Z-score are estimated on yearly basis (1901-2017), those indices are added and a new index standardized total drought (Sd) has been established. b) Considering Sd as the input parameter a comparative assessment has been made between 4 individual models (3 models from exponential smoothing, 1 model from machine learning) in simulation and prediction of drought status of next 18 time steps (years) in Bankura District and Winexpo model outperforms the other models as it obtains minimized Standard Error (SE), Random Mean Square Error (RMSE), Mean Absolute Error (MAE), and Mean Absolute Percentage Error (MAPE) and highest Correlation coefficient (R2) value. c) The cumulative drought proneness of the region is also assessed and it is found that the whole district will be drought-prone within the year 2100. This region is historically a drought prone region and agricultural shock is the common issue. In such a circumstance simulation of drought is a good attempt. Though a lot of models already developed in case of simulation of drought but still a perfect, continuous long term prediction is a big issue to solve. This study provides a comparative study between exponential smoothing and machine-learning procedures and also introduces a new combined index standardized total drought.

Open Access Original Research Article

Measuring Hazard Vulnerability by Bank Erosion of the Ganga River in Malda District Using PAR Model

Rubia Biswas, A. K. M. Anwaruzzaman

Journal of Geography, Environment and Earth Science International, Page 1-15
DOI: 10.9734/jgeesi/2019/v22i130136

River banks are characterised by dynamic environments that change in response to a variety of inputs. Bank erosion ordinarily means losses of bank materials and individual particles or aggregates by fluvial, sub-aerial and geo-tectonic processes. It is a common phenomenon of geomorphic hazard associated with flood plains and meandering or braided river system. The problem of bank erosion and shifting of the course of the river Ganga in certain C.D. blocks of Malda District is not purely an environment-related problem but a unique combination of both environment and ‘development’ project. The objective of the present paper is to measure the vulnerability of the villages that are situated adjacent to the Ganga River. Data was obtained from both primary as well as secondary sources. The primary data was collected through observation method and through informal interviews with the affected people. Secondary information was obtained from various research works encountered during the study. The study was framed on the lines of Pressure and Release (PAR) model developed by Wisner, Blaikie, Cannon and Davis (1994 & 2003). The inhabitants of these villages are facing serious problems related to employment, health, education, sanitation, drinking water supply and market due to the river bank erosion. In some areas people suffer from the irony of dual citizenship. No remedial measures are seriously taken by concerned authorities to solve this problem. Thus, it is incumbent on the part of the government and NGOs to devise corrective mechanism to curb the threat to the existence of the affected people as well as to improve their quality of life.

Open Access Original Research Article

Channel Planform Dynamics along Distributary Channels: Case Study of the River Nun a Major Distributary of the River Niger

Tombra S. Akana, O. C. Adeigbe

Journal of Geography, Environment and Earth Science International, Page 1-11
DOI: 10.9734/jgeesi/2019/v22i130137

Channel planform dynamics were analyzed for the River Nun; a major distributary of the River Niger from 1985 to 2015 using GIS and Remote sensing applications. Satellite imagery of the area from 1985, 1995, 2005, and 2015 were analyzed by means of GIS and used to determine the planform characteristics and changes in width, sinuosity, and shoreline migration rates. The channel planform dynamics were determined by comparing sequential changes in the position of the shorelines in these years. Sinuosity adjustments during the study were small and range between 1.74–1.76. The initial sinuosity (1.74 in 1985) increased to 1.75 in 1995 and then increased to 1.76 in 2015. Channel expansion is observed to be the dominant planform process, owing to periodic floods within the study area. The river’s channel width barely expanded from 1985 to 1995 (by 0.1 %). However, there is a constant increase in expansion within the study years that by 2005-2015 expansion had increased to 9%. The bank erosion was prevalent. Mean erosion rates ranged from 0.7 m/year in 20 years (1985-2005) to 2m/year in 30 years (1985-2015). In the 1st 10 years (1985-1995) less than 0.1 m of deposition was observed. The mean erosion rates ranged from 1.3 to 1.6 m/year on the left side and 2.8 to 3.8 m/year on the right side of the channel. Mean accretion rates of 1.2 m/year on the left side and 1.8 m/year on the right side were observed. The channel is observed to move generally towards the east (right).

Open Access Original Research Article

Modeling of Subsurface Integrity Using Dar-Zarrouk Parameters: A Case Study of Ikekogbe UBE Primary School, Ekpoma, Edo State, Nigeria

Bawallah Musa Adesola, Ilugbo Stephen Olubusola, Aigbedion Isaac, Aina Adebayo O., Oyedele Akindele Akintunde

Journal of Geography, Environment and Earth Science International, Page 1-17
DOI: 10.9734/jgeesi/2019/v22i130138

In this present study area, most building failures often start with minor/major cracks which widen over time, and it is often followed by post construction remedial measures which fail after sometime, thereby leading to total collapse and sinking of such buildings. The research was carried out in order to be able to unravel the causes of major cracks along the side of a major class room block at Ikekogbe, UBE Primary School, Ekpoma, Edo State, Nigeria in less than five (5) years after it was constructed. The cracks were visible both at the front and at the back of the building along the same axis and almost at this same distance as it was at the front of the building. The investigation involved Electrical Resistivity method using three techniques; Vertical Electrical Sounding (VES), 2-D Electrical Resistivity Tomography (ERT) and Horizontal Profiling (HP). The traverses were established along E-W directions and Eight (8) VES were carried out using Schlumberger array with current electrode spacing varying from 1 to 40 m, with 2-D ERT using Dipole-Dipole electrode array with inter-station separation of 5 m and an expansion factor that varied from 1 to 5 and HP using Wenner array with an electrode spacing of 5 m interval. The VES interpretation results were used to determine the second order parameters for modeling of subsurface integrity/competence. The 2 D imaging (Dipole-Dipole) gave information on the subsurface characteristic and the Wenner profile was characterised by low resistivity at the region of 30 to 45 m considered as the weak zone. Correlating the results with subsurface integrity model along traverses one and three, there was a high degree of correlation as this region coincides with the very low/low integrity/competence with the foundation of the classroom overlying this layers. The research revealed that the problem of structural failures/crack noticed along the building walls and axis was not as a result of human problem alone but mainly the existence of very low/low integrity/competence layers which contributed greatly to the cracks observed on the classroom block. These results reveal that the three Electrical resistivity techniques used for this study are complimentary to each other.

Open Access Original Research Article

Sedimentological and Geochemical Characterization of Surficial Sediment of a Meander Section of Mbaa River at Nneise–Ugiri Community in Imo State of Nigeria

Raphael Oaikhena Oyanyan, Martin Chijioke Nwachukwu, Modestus Chijioke Ohaegbulem, Nonyelum Stella Iloanya

Journal of Geography, Environment and Earth Science International, Page 1-13
DOI: 10.9734/jgeesi/2019/v22i130139

Sediment deposition has increased at a meander section of Mbaa river resulting in a drastic reduction of water storage. It has necessitated calls for sand-mining or periodic dredging which could have far-reaching impacts on the aquatic ecosystem, depending on the texture and chemical compositions of the sediment. Therefore, surficial sediments samples were analyzed for textural characteristics, mineralogy and chemical compositions. Grain sizes and mineralogical analysis showed that the sediments were moderately sorted, mesokurtic, near symmetrical - slightly positive skewed, subangular – subrounded medium grained-sands, and consist of about 2.5% feldspar, 2.7% rock fragments, 5.4% hematite and 89% quartz. Mean TOC and pH were 0.39 wt% and 6.48 respectively. Atomic Absorption Spectrophotometer (AAS) analysis results showed general low concentrations of metal elements: mean values of alkali/alkali earth metals ranged from 1.33 - 3.72ppm, transition metals ranged from 0.12 - 23.07ppm; while Pb (a poor metal) was not detected. General low concentrations of metals and TOC; and non-detection of Pb suggest lack of mineralization zones and minimal anthropogenic impacts in the upstream areas.  Textural and chemical characteristics and moderate energy of river water flow suggest that human resuspension of the sediment deposit will result in minimal lateral dispersion of sediment in the water column, except during heavy rainfall. Therefore, periodic dredging or sand mining will cause minimal impact on the aquatic ecosystem, especially in the distant downstream areas, whereas within the meander section and nearby areas of the river, it is expected that there will be a significant change in water quality parameters due to the increase in the concentrations of suspended and dissolved compounds.