Spatiotemporal hydro-chemical and isotopic dataset of the tropical Nyando river basin in Kenya.

This article presents hydro-chemical and isotopic (δN-, δO‒NO , δB data of water samples and potential nitrate sources from the Nyando river basin, a tributary of the Lake Victoria in Kenya. The data collection involved field sampling of water samples in 23 sampling stations spatially distributed in the basin during nine seasons from July/2016 to May/2018. The hydro-chemical data was generated from the Laboratory analysis of the water samples using the ion chromatogram. Samples for nitrate isotope (δN-, δO‒NO ) analysis were prepared via the bacterial denitrification method and analysed using Isotope Ratio Mass Spectrometer. The data, which is categorised in different land use zones and seasons, is important for understanding the spatiotemporal variation in nitrate and solute concentrations and the role of land use on the river water quality. In addition, the δN-, δO‒NO and δB values are key for elucidating nitrate pollution sources and potential biogeochemical processes for the management and control of nutrient pollution and eutrophication of the Lake Victoria. Furthermore, the dataset can be of great use in water quality models for understanding non-point pollution dynamics in tropical basins. This article is related to [1].