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The present study on chemistry, environmetrics and quality index of 116 groundwater samples collected in pre- and post-monsoon periods in the years of 2014 and 2015 from the drought-prone Rajshahi City Corporation area, Bangladesh, is carried out for its drinking suitability from management perspective. According to the Bangladesh Drinking Water Standards (2005), parameters like pH, Ca2+, Mg2+, Cl−, Fe(total) and Mn2+ exceed the desirable limit, but within permissible limit without adverse effect except Mg2+ concentration, which accounts for 45% in pre-monsoon period and makes groundwater unsafe for drinking purposes. The groundwater belongs to alkaline earth elements (Ca2++Mg2+) and exceed alkali elements (Na++K+), and weak acids (HCO3−) exceed the strong acids (SO42−) where Ca2+ and HCO3− are dominant ions, and attribute to temporary hardness of groundwater. The groundwater of the aquifer is of Ca2+–Mg2+–HCO3− type. The source of different ions is associated with partial ion exchanges, weathering of calcareous nodules and clay minerals, flow of groundwater system through aquifer lithology, municipal sewerage, anthropogenic influence, etc. The drinking water quality index also reveals that groundwater mostly falls in ‘good’ category having suitability for drinking purposes round the year. But increasing population and water demand in the area may create threat of quality hazard in near future, and regular groundwater quality monitoring should be carried out periodically for supplying safe drinking water to city dwellers.

The aim of the study is to assess the agricultural drought risk condition in the context of global climate change in the western part of Bangladesh that covers about 45% area of the country for the period of 1960–2011. Drought Index (DI) and Drought Hazard Index (DHI) have been calculated by Markov Chain analysis and that of Drought Vulnerability Index (DVI) from socioeconomic and physical indicators. The DI values show that the northern part in general is more drought-prone, having less crops prospect, whereas the southern part is less drought-prone with high crop potentiality. The probability of extreme drought occurrence increases in recent decades in some parts as a result the drought events become more frequent in the areas. The DHI ranges from 15 to 32, and northern part suffers from more extreme drought hazards than that of southern part. DVI also indicates that northern part is exposed to high to very high drought vulnerability as higher percentage of illiterate people are involved in agricultural practices and high percentage of irrigation to cultivable land, but southern part exposed to moderate to low vulnerability because of low values of vulnerability indicators. Finally, agricultural drought exists at high risk condition in northern part and low in southern parts and 21.63, 26.54 and 29.68% of the area poses very high, high and moderate risk, respectively. So, immediate adaptation measures are needed keeping in mind climate features like rainfall and temperature variability, drought risk and risk ranking to make viable adaptation measures.

Monitoring and detecting trends of climatic variables like rainfall and temperature are essential for agricultural developments in the context of climate change. The present study has detected trends in annual and cropping seasonal rainfall and temperature data for the period of 1961–2011 using Mann–Kendall (MK) test, Spearman’s rho (SR) test and modified Mann–Kendall test that has been applied to the significant lag-1 serial correlated time series data, and slope has been estimated using Sen’s Slope estimator for twelve meteorological stations located in the western part of Bangladesh covering about 41 % of the country. Almost 71 % trends explored by MK test in annual rainfall are statistically insignificant, and SR test also complies it. The spatial distribution of rainfall trend shows insignificant positive trends in major part of the area. Significant positive trends both by MK test and by SR test at 95 % confidence levels are observed at rates of 8.56, 11.15 and 13.66 mm/year at Dinajpur, Rangpur and Khepupara stations, respectively, and the Kharif season rainfall of these stations also shows significant increasing trends except Dinajpur. On the other hand, significant decreasing trends in annual rainfall are found at Bhola (−11.67 mm/year) and Rajshahi (−5.951 mm/year) stations and decreasing trends in rainfall dominated the Pre-Kharif season over the area. But, 83.33 % of the stations show rising trends in annual mean temperature with significant positive trends (as observed by both MK test and SR test) at Rangpur, Bogra, Faridpur, Jessore and Bhola stations where the rate of changes vary from 0.013 °C/year at Faridpur to 0.08 °C/year at Bhola. Most of the trends in Rabi and Pre-Kharif seasons of mean temperatures are not statistically significant. However, all stations except Barisal show significant rising trends in temperature in Kharif season. To cope with this changing pattern of rainfall and temperature, effective adaptation strategies should be taken to keep up the agricultural production that is related to livelihood of the most people and to ensure the country’s food security.