Study On Hydrological Process Of The Hanjiang Basin Based On GIS

With the changing global climate and the impact of human activities, many scholars and research institutions placed the studies of ecological hydrological processes on the focus of attention. Eco-hydrology studies the ecology-hydrological interactions and feedback mechanisms, and is important for regional ecological construction and protection of water resources.Study region of this paper is Middle and lower reaches of Hanjiang River Basin. In the support of RS and GIS, this paper analysis the hydrological characteristics of the Hanjiang River, reveals the effects of weather, topography, vegetation and other factors on hydrological processes, and attempt to simulate and predict the hydrological processes of Hanjiang River, so as to provide scientific basis for Ecological and environmental protection and the management of water resources in this basin. The main content is divided into eco-hydrological process analysis, ecological response of hydrological processes and measures for sustainable development based on eco-hydrological process. The main findings are as follows:By the analysis within humidity, rainfall, temperature and other indicators, this paper considered that weather conditions is an important factor in the runoff area. In one year, temperature and water level, flow rate was significantly positively correlated. In the inter-annual, precipitation and runoff are closely related, and the total annual precipitation and runoff showed a significant positive correlation. For downstream areas, the greater the humidity is, the higher the water level is. Through the analysis of vegetation index for many years, vegetation central of this basin alternately move in both directions of southeast and northwest, and resents a slow-moving process to southeast overall. Vegetation cover in southeast relatively become better, or vegetation cover in northwest relatively be worse. The vegetation cover in the watershed presence periodic fluctuations in3to4years. In one year, vegetation central of this basin alternately move in both directions of southeast and northwest with the changing of the seasons, vegetation cover index peaked in spring and summer for a year. Vegetation cover has significant influence on hydrological processes in this basin. Regional differences of terrain in the study area were obvious. For areas of the maximum slope, traffic is higher than other regions and this is more obvious when rainfall is very concentrated. In a short period of time, terrain contributes more on the changing of flow rate than rainfall. Flow was slowly increased and water level was gradually decreased in this basin. And this paper also use exponential smoothing model to simulate the watershed hydrological process. When smoothness index is0.9, the fitting degree of the predicted and observed values is the best. The model can simulate and make short-term forecasts of hydrological conditions in future based on existing data.