The Analysis Of Channel Evolution In Xin River Tail And Shoaly Land Evolution Of Estuary Based On Remote Sensing Technology

Xin River is one of the five major tributaries flow into Poyang Lake, the tail ofwhich is a important region for Poyang Lake flood, environmental protection and theestuary comprehensive management plan. So it is very important to study the evolutionprocess of river channel in the tail of the Xin River. In the Past，People studied the riverway mainly by field survey and land form map contrast before. Because of the limits ofhuman’s field view and complexity of field survey route, the analyzed results ofevolvement of the river channel concluded by above mentioned methods were differentfrom its actual evolvement more or less.Remote sensing technique has a good characteristic of fast, large-scale andmulti-temporal, suitable for research on evolution of river that span long period and largescale. in dry season, the boundaries of river is more clear and the hydrological featuresare more consistent, so we use the MSS, TM, ETM images in dry time as source data.This paper use remote sensing technology do the research on the two biggest branches ofthe tail of the Xin River and the Lake Entrance region as followings:(1)River information extraction. Based on Spectral Relations method, water indexmethod, vegetation index method, bank threshold value method and conditions operation,we analyzed every waters extraction method, we found that, bank threshold valuemethod and conditions operation method could extract waters in MSS images best;pectro-photometric method could extract waters in TM\ETM images best. And proposedthat band threshold method is more suitable for water extraction.(2)The analyses of channel evolution of the Xin River the trail. From the research ofhistorical data, we found that the trail of Xin River changes a lot from1928to1950; thispaper use ERDAS and ArcGIS analyses8remote sensing images from1972to2010, found that the river channel information didn’t change much, but the river trend tonortheast.(3)The analysis of shoaly land of Xin River estuary. Through the superpositionbetween1973and2010the year estuary single band image, the research of the estuarydeposition dynamic area, analyzes the conclusion: the deposition occurs mainly in theleft or right side of the the main channel into the lake area, and to extend in poyang lake,gradually have to the main channel concentration trend.(4)The analysis of influence factors of river channel and beach evolution.according to the topography and landforms downstream xinjiang river boundaryconditions the average annual sediment production and social project construction,information material, analysis of the evolution of the river beach by natural factors andhuman factors of the comprehensive effect, natural factors make river siltation, beachamplification,broaden the siltation, the artificial factors make river flush, heart beach toshrink, beach Deposit.