Abstract: Temporal variation of groundwater depth in 4 groundwater-level monitoring wells in Ganzhou District of Gansu Province in middle reaches of the Heihe River Basin was analyzed. Based on the similarity of groundwater recharge sources, temporal variation trend of groundwater depth and proximity of the locations of groundwater-lever monitoring wells, Ganzhou District was divided into four subregions. Groundwater level in subregion Ⅰ was in a drawdown with a big fluctuation, but it was in a slight increase after 2001; it was in a continuous drawdown in subregion Ⅱ; it was in a slow drawdown in subregion Ⅲ before implementing the water redistribution project but in a sharp drawdown after implementing the project; it was increased at first and then in a drawdown in subregion Ⅳ.

Key words: groundwater depth, spatiotemporal variation, Ganzhou District, middle reaches of the Heihe River