Based on the importance of coastal saline-alkali soil remediation in Yellow River Delta, China, the Cl-、Na+ transferring tendency in soil and the saline-alkali soil eco-remediation effects were researched by measuring soil Cl-、Na+ 、soluble salt、soil respire rate and dry biomass weight of reed, etc. periodically. The results shows: the concentration of irrigated soil Cl-、Na+ and soluble salt were decreased 57.7-70%、45.7-47.1% and 53.2-59.7%, respectively, and soil salt decreasing level were little influenced by the hydraulic load, inundation depth varies in some degree, but it was influenced by dry-wet alternative irrigating mode The concentration of soil total nitrogen、organic mass、microbial respire rate, and the reed biomass above ground were increased averagely to 2.17、1.20、1.46 and 1.34 multiple respectively afterirrigation with wastewater, which have complex remediation effects on the coastal saline-alkali wetland, but there are some differences among the different irrigating crafts.

As an important aspect of vulnerability ,economic vulnerability is a research hot issue in vulnerability and Tourism sustainability research field. On the basis of defining vulnerability, the paper combines vulnerability with the tourism economic system. Taking the Yellow River delta efficient ecological economic zone as an example, the paper establishes an assessment model of tourism economic system vulnerability, and evaluates the tourism economic system vulnerability using the entropy method and the comprehensive evaluation method. Using obstacle degree analyze the main obstacle factors of cities in the paper . The evaluation result is that the Yellow River delta efficient ecological economic zone has a vulnerable tourism economic system, which is almost in line with the actual situation.

Soil samples were collected from new-developed wetland soil ecosystem of Tamarix chinesis plantation in Chinese Yellow River Delta in different months of 2003. Soil characteristics, temporal change and spatial distribution of microbial community composition and their relationship with nitrogen turnover and circling were investigated in order to analyze and characterize the role of microbial diversity and functioning in the specific soil ecosystem. The result showed that the total population of microbial community in the studied soil was considerably low, compared with common natural ecosystem. The amount of microorganism followed as the order: bacteria> actinomycetes>fungi. Amount of actinomycetes were higher by far than that of fungi. Microbial population remarkably varied in different months. Microbial population of three species in top horizon was corrected to that in deep horizon. Obvious rhizosphere effect was observed and microbial population was significantly higher in rhizosphere than other soils due to vegetation growth, root exudation, and cumulative dead fine roots. Our results demonstrate that microbial diversity is low, while is dominated by specific community in the wetland ecosystem of Tamarix chinesi.

The Yellow River began ceasing affected by natural factors and the unreasonable human activities. The flow broke in the Yellow River and water and sediment flowing into the sea decreased, which lowered the speed of newly formed wetland extending to the sea. The water environment deteriorated; Its composing structure tended to be unsteady; The biologic diversity decreased and wetland function reduced. To ensure that the Yellow River delta and its ecosystem develops sustainablly, it is significant to reduce times and days of the ceasing, keep certain runoff and sediments in the river to the sea and make its watercourse stable.