I have a CSV file with water level measurments in a well, taken once a year for 40 years. Is there a way to show this data as a graph (x axis being the date and y axis the water level) in QGIS?
Why do you need to produce the graph using QGIS? I would suggest using R (free software) or excel.
go to file / change dir... and navigate to the folder with your csv
data = read.csv("yourdata.csv") x <- data$date y <- data$waterlevel plot(x,y) ?plot
If you need to display the graph in QGIS you can save the image as a TIFF from R and import it into QGIS.