Analysis Of Hydrological Characteristics And Change Trend In Westen Region Of Songhua River Basin

With the comprehensive development of the economic society, increasing population and the acceleration of urbanization, most of the basins of China are facing the problems of water resources shortage and water environment deterioration, and Songliao basin is of no exception. Especially, the western region of Songhua River basin is located in the semi-arid continental monsoon climate zone and is the important commodity grain base of Northeast China, but its annual precipitation is less than 500mm. Because of the quantity of water resources, and the distribution is not meet to the remand of the crop growth, the crop production is seriously affected and the local food security is restricted. In recent years, the rapid development and utilization of the region has caused the seriously eco-environmental problems, includes grassland degradation, wetlands shrinkage, desertification, salinization, etc. To relieve the drought and the water shortage in western region of Songhua River basin, the water resources should be used fully and rationally, and then these water cycle regulation key technologies, such as the artificial rainfall, the construction of underground reservoirs, inter-basin water transfer, etc, should be used to strength the water resources regulation ability. And before this, the hydrological characteristics and water cycle change trend in the region should be analyzed, and the relationship between water resources and the food production safety should be ensured, and the influence of climate change and human activities on the regional water cycle should be evaluated scientifically, which could be the basis of the other work.Taking the Taoer River basin as a typical region in the western region of Songhua River basin, the paper begins the correlation studies. Firstly, starting with the study on hydrological characteristics change trend of the Taoer River basin, the paper analyzes the long series basin hydrological and meteorological data by using the hydrological series change analysis method. The results show that the precipitation has an decreasing trend since 1993, the evaporation has an increasing trend since 1992, the runoff has an decreasing trend since 1998 and the groundwater level also has an decreasing trend year by year. Because of the influence of natural factors and human activities, the ecological environment has been damaged seriously, such as the gradually expanding of land desertification and salinizatio, grassland degradation and decreased vegetation coverage.Secondly, the paper studies the influence of climate change and human activities on water cycle, and illustrates the interaction between climate, human activities and land-water from the aspects of the basic principle of the water cycle, the basin climate change and basin human activities. On this basis, the water cycle process is divided into the trunk cycle and artificial collateral cycle. Through the quantitative indicators of absolute strength and relative strength, the paper analyzes the basin water cycle strength and the correlation of water cycle and its influence factors. By using the multiple regression method, the paper quantitatively evaluates the influence of human activities and climate change on the water cycle.Finally, the paper studies the relationship between the water resources and food production security, analyzes the space-time distribution of the basin available water resources and calculates the threshold of basin food production security based on the crop irrigation water demands, regional population, per capita ration standards and other relevant data. Based on the relationship between the crop production and current and prior year water resources, the simple linear regression equation is built and the influence of water resources quantity and distribution on the crop production is analyzed by using the series data scatter diagram. At the same time, the problems of the crop production are illustrated in the condition of hydrological characteristics changes in the future.In summary, the paper analyzes the water cycle variation law and the existing related problems in the western region of Songhua River basin under the influence of the climate change and human activities. In the future, combined with the basin actual situation, the results would play an important role in the positive influence of human activities on water cycle. Through the construction of water resources allocation, the relations between man and nature could be coordinated, and the optimal allocation of water resources could be achieve. Therefore, the study will be the basis of study of key technology in the water cycle regulation, and it will ensure the high and stable crop yield in the commodity grain base of Northeast China and provide the effective technical support for the sustainable development of the regional social economy.