Determining Temperature trends in the Granary Areas of Peninsular Malaysia using Mann-Kendall and Sen’s Slope Estimator

The spatiotemporal dynamics of temperature as well as rainfall have received greater attention from the scientific communities This study analysed temperature variability in the three granary areas of Peninsular Malaysia using descriptive statistics parametric least square regression and nonparametric Mann- Kendall and Sen s slope estimator The study identified significant warming trend in the annual mean maximum temperature in two of the study areas i e Subang Jaya and Kota Bharu Also significant warming trend was detected in the annual minimum temperature and significant increasing trend in some of the monthly maximum and minimum temperatures for all the three stations Also the result reveals spatial and temporal variation in both the maximum and minimum temperature at annual monthly and seasonal scales For the annual scale maximum temperature this study identified a warming trend for the two stations with about 0 014oC per year 1 4oC per 100 year

Hydrochemical characteristics and identification of groundwater pollution sources in tropical savanna

Groundwater pollution of the watershed is mainly influenced by the multifaceted interactions of natural and anthropogenic processes. In this study, classic chemical and multivariate statistical methods were utilized to assess the groundwater quality and ascertain the potential contamination sources affecting the groundwater quality of Galma sub-watershed in a tropical savanna. For this purpose, the data set of 18 groundwater quality variables covering 57 different sampling boreholes (BH) was used. The groundwater samples essentially contained the cations in the following order of dominance: Ca2+  > Na+  > Mg2+  > K+. However, the anions had HCO3– > Cl– > SO4–2 > NO3– respectively. The hydrochemical facies classified the groundwater types of the sub-watershed into mixed Ca–Mg–Cl type of water, which means no cations and anions exceeds 50%. The second dominant water type was Ca–Cl. The Mg–HCO3 water type was found in BH 9, and Na–Cl water type in BH 29 of the studied area. The weathering of the basement rocks was responsible for the concentrations of these ions in the groundwater chemistry of the sub-watershed. Hierarchical cluster analysis (HCA) grouped the groundwater samples (boreholes) into five clusters that are statistically significant regarding the similarities of groundwater quality characteristics. The principal component analysis (PCA) extracted two major principal components explained around 65% of the variance and suggested the natural and anthropogenic processes especially the agricultural pollutants including synthetic fertilizers, and leaching of agricultural waste as the main factors affecting the groundwater quality. The integrated method proved to be efficient and robust for groundwater quality evaluation, as it guaranteed the precise assessment of groundwater chemistry in the sub-watershed of the tropical savanna. The findings of this investigation could be useful to the policy makers for developing effective groundwater management plans for the groundwater resources and protection of the sub-watershed

Runoff irregularities, trends, and variations in tropical semi-arid river catchment

Study region: Hadejia River Basin (HRB) in North Eastern Nigeria. Study focus: The hydrological trends and variations of surface runoff in Hadejia river catchment were assessed using data spanning 36 years (1980–2015) for proper planning and management of water resources in the basin. New hydrological insight for the region: The temporal and spatial irregularities in the runoff of Hadeia river catchment has been detected. A significant decrease of river discharge from two out of the three downstream stations had been observed. However, there is an increasing trend of the river discharge from all the three upstream stations, though statistically insignificant. The ANOVA [F (5,210) = 106.226, P < 0.05] and cluster analysis results showed significant spatial variations between the upstream and downstream stations. The increasing trend of the discharge in the upstream stations is attributable to high rainfall mean and increased urbanization in the area. However, the significant decreasing trend of the discharge downstream of the river catchment is associated to many factors, notably; high evaporation rate due to high temperature, low rainfall mean and the relatively high infiltration rate encouraged by the high percentage of sandy soil and the sedimentary geological formation. Consequent to these trends and variations, water supply and irrigation, particularly in the downstream areas are at risk. Thus, integrated basin study using hydrological modelling will be helpful to distinguish the individual impact of the blame factors and to predict the river discharge behavior in response to the impact of those factors

Groundwater Condition and Management in Kano Region, Northwestern Nigeria

This paper provides a broad overview of issues on groundwater condition and management in the Kano region of northwestern Nigeria. The aim is to recommend new management strategies that can ensure sustainable groundwater resource management in the region. To achieve the aim of the study, various studies on groundwater conducted in the region were reviewed and key issues were identified. The review revealed that groundwater availability varied between the Basement Complex and Chad Formation areas of the region, with the latter having more of the resource than the former region as a result of the migration of groundwater from the Basement complex to the Chad Formation region. The review also revealed a steady annual decrease of groundwater level during the period 2010 to 2013 and the groundwater beneath the floodplains dropped from 9000 Million Cubic Meter (MCM) in 1964 to 5000 MCM in 1987 in the Chad Formation area of the region. The review further revealed that there is poor knowledge regarding the impact of historical and projected climate variability and change on groundwater availability in the region. This is as a result of the lack of sustained time series data on groundwater resource. Thus, there has been little or no integrated management between groundwater excess and deficiency on one hand, and groundwater pollution management on the other hand. Rainwater harvesting, among other approaches, is recommended for sustainable groundwater management in the region