Groundwater Dynamic And Its Ecological Effects In Yellow River Delta

As an important environmental element, groundwater's ecological effect can not be neglected. Knowledge of groundwater system is a pre-requisite for up-to-date integrated land and water management. The relationship between groundwater level, recharge, discharge and vegetation cover is intricate. The vegetation distribution shows obviously spatial difference and temporal variance under the influence of micro-topography, groundwater depth, and soil salinity. A methodology is presented for assessing the vegetation-groundwater relationship, including groundwater model, spatial analysis with GIS, vegetation map translated from remote sense image and vegetation ordination.After analyzing the vegetation and site survey data, the vegetation type in YRD(Yellow River Delta) can be subdivided into three categories corresponding to groundwater depth and salinity tolerant, : forest, economic plants, salt tolerant plants. After combining the vegetation distribution with the groundwater depth, some primary relationship can be acquired. DCCA method is used to quantify this relationship and the results indicate groundwater depth is the most influential environmental factor.Three ecological sub-zones are delineated on the basis of years of land. In each zone, different vegetation composing features and ecological problems in groundwater recharge, transition, discharge areas are discussed separately, using spatial analysis of GIS . From the point of groundwater, the ecological problems in YRD can be concluded as: lack of fresh water in groundwater recharge areas, soil salinization in groundwater transitional areas, and seawater intrusion in groundwater discharge areas.Groundwater-related management measures are brought forward at the last part of this paper, such as water conveyance along river course, controlling irrigation and alleviating salinization, wetland restoration. The potential situation after implementing the measures is simulated by groundwater model. Changes in groundwater level, flow direction, recharge and discharge amount have been...