Thank you for submitting your item for appraisal. This appears to be a watercolour by Chen ban ding ( 1876-1970) or a follower.
The two chop marks 陈年大利 (round) and 半丁老人 (square) have been similarly published. I haven´t come across the chop mark lower left.
The estimate is based on similar watercolours offered or sold.
"Asking prices" in the trade and results of chinese auction houses may be higher.