Estimation of ecological water demands based on ecological water table limitations in the lower reaches of the Liaohe River Plain, China An ArcGIS-based analysis of groundwater spatial structure and groundwater vulnerability in the lower reaches of the Liaohe River Plain Evaluation of the landscape patterns vulnerability and analysis of spatial correlation patterns in the lower reaches of Liaohe River Plain Ecological health assessment of groundwater in the lower Liaohe River Plain using an ArcView-WOE technique Groundwater ecological sensitivity assessment in the lower Liaohe River Plain based on GIS technique