Abstract: An exceptionally serious flood was occurred in Nanjing County located in the upper andmiddle reaches of the West Stream of the Jiaolong River On Sept.22,1981.The half ofthe county town was flooded and the loss was heavy.Our investigation revealed that theheavy rain brought by typhoon “8116”was the primary cause of the flood.The disruption ofecological balance caused by human activities aggravated this disaster.For example,theincrease of mud in the river water led to the change of sections of riverbed,which reducedthe ability of flood discharge by the river.According to the above analysis,the strategy ofharnessing the river was discussed.

Key words: dryland, plastic film mulching and rain harvesting modes, chlorophyll fluorescence parameter, yield, water use efficiency.