Abstract: Water resource is necessary for life and production. The contradiction between needs and supplication becomes more seriously with the population increasing and industry developing.Reasonable exploit and using of water resource is the important issue at present. And precise calculation of drainage system and catchments distribution is the basis of the exploit and using. There had been the first investigation of water resource of Liaoning Province in 1984. But due to the time variation and the limitation of the investigation techniques, lot of investigation data of the drainage system and catchments distribution do not precisely fit the situation at present. In this paper, the TM digital images of Landsat were used to interpretation of drainage system and catchments distribution in Liaoning Province, by means of the ER mapper software. Data of multiple scales waves and seasons were used in the interpretation. The techniques of histogram equalization, filtering, linear transform were also employed. Interpretation marks of drainage system and catchments distribution are constructed according to the analysis of the relationship between bands. Principal component was used to interpretation of coastline. Length of rivers and the area of catchments were calculated and compared with the first investigation data. The reasons of the variation were analyzed.

Key words: Paddy soil, Cd contamination, Soil microbial biomass, Soil enzymatic activity, Rice physiological indices