The Investigation Into Some Issues On1/50000Streat Sediment Survey

The current method of1/50000stream sediment survey which is follow the methodof1/200000stream sediment survey,leading to some problems that need to improve.Thethesis has presented a new drainage method-river basin method.Design is based on theactual situation of hydrologic and isn’t controlled by grid. River basin method is betterthan the current grid method on reducing missing control place and reducing thesampling difficulty. The measured date of1/50000stream sediment survey is discrete,it’s not appropriate for express by isoline map,the thesis also develop a new method toshow measuring result-stain map. Stain map draw control river basin of each samplingpoint in the picture of the actual sampling point,according to element concentration,wecan apply a different color to control river basin, in order to indicate the distributioncondition of element concentration. Compareed with the current method of expressingisoline map,the anomalous area on the stain map can show more directly,due to it canreact sampling point, also directly indicate the location of the mineralized rocks; Stainmap isn’t proceed with the interpolation and can use the measure figure to drawmap,then missing control place will truthfully show empty space,this method can statemore objectively. the thesis is state briefly the mantle from the hills area around twosides of the river.Soil layer of mantle area are possibly come from alluvial sediments ofthe river,so it doesn’t take soil sample to replace stream sediment;It is much better toconduct the samples by use the method of screen the sediment in hilly region,we need towash containing humic of the mud of the samples;It’s unnecessary to conduct gridprocessing;It is unnecessary through geological structure to definite abnormal lowerlimit.