Study And Analysis Of Land Subsidence In The Yellow River Delta Base On GIS

Phenomenon of land subsidence in the Yellow River Delta is obvious, and to acertain extent, which is hindering delta's rapid development. Researches on delta'sland subsidence have theoretical and practical guidance meanings to many aspects ofthe Yellow River Delta, such as disasters' prevention and reduction, land utilization,regulation of river, etc.Four digital elevation models(DEMs) were generated from topographical mapsof the Yellow River delta, which were surveyed in 1956, 1967, 1980 and 1995 in ascale of 1:50 000 respectively. Knowledge on deltaic land subsidence in the deltafrom 1956 to 1995 was obtained through spatial analyses on these DEMs, andspace-time variation rule of land subsidence was obtained through statistical analysestoo. Three major impact factors on land subsidence, which have specific characters inland subsidenceperiod, extension and intensity, were addressed in this paper.Moreover, these three factors played different roles on land subsidence duringdifferent phase. After that, their impacts on land subsidence in the delta were analysed.Based on that, some methods were proposed to prevent from the disasters induced byland subsidence. Finally, the feasibility of InSAR monitoring land subsidence in theYellow River Delta was analyzed briefly since leveling survey is time-take and hardworking.