Study On Division Of Soil Salinization Degree In Hongyashan Irrigation District

Hongyashan Irrigation District of Minqin County in Gansu Province is located in the east of Hexi Corridor.The climate is dry,the precipitation is scarce and the evaporation is large.Under the background of this bad ecological environment,the unreasonable development and utilization of local water resources led to the soil salinization disaster in this region.The central government and the State Council attach great importance to the ecological environment problem of Hongyashan Irrigation District.Therefore,it is of great practical significance to study soil salinization in Hongyashan irrigated area.This study takes soil salinization in the Hongyashan Irrigation District of Minqin County,Gansu Province as the research object to soil apparent electrical conductivity test,field investigation and sampling and laboratory test analysis.Furthermore,the relationship equation of soil salinity based on soil apparent electrical conductivity and soil moisture content is established.Then the spatial distribution map of soil salinity was drawn by ArcGIS to analyze the spatial distribution characteristics of soil salinity in the Hongyashan Irrigation District.Finally according to the degree of soil salinization classification basis,The classification standard of salinization degree in Hongyashan Irrigation District was established,and the soil salinization degree zoning map was obtained,and its spatial distribution characteristics were analyzed.The main conclusions are as follows:(1)Soil apparent electrical conductivity is closely related to soil moisture content,soil salt content,Ca²⁺,Mg²⁺,SO₄^2-and HCO₃^-.It was found that the correlation between soil apparent electrical conductivity and soil salinity can be divided into three stages:<2%?2%?2-10%and>10%,When the soil moisture content was less than 2%,the soil apparent electrical conductivity could not accurately reflect the change of soil salinity.Therefore,the soil moisture content<2%is not considered.Soil salinity equations based on soil apparent electrical conductivity and soil moisture content at soil moisture content of 2-10%and>10%were established respectively,the final result is satisfactory.(2)According to the relational equation,To obtain soil salinization information in the study area,and the spatial distribution map of soil salinity was drawn and its distribution characteristics were analyzed.The results showed that the distribution of soil salinity in Hongyashan Irrigation District was banded or speckled,The spatial hierarchy is distinct,and the overall trend is higher in the north and lower in the south,higher in the east and lower in the west.(3)Based on the classification basis and classification standard of soil salinization degree of relevant documents were analyzed.The salinization degree standard of Hongyashan Irrigation District was established,and the subdivision map of soil salinization degree in Hongyashan Irrigation District was obtained,and its spatial distribution characteristics are divided.The results show that the division from the geographical location the degree of soil salinization increased from south to north and from west to east.From the position of the irrigated area,soil salinization degree for Huqu>Quanshan>Baqu;From the town location,the salinization degree of Shoucheng,Xiqu and Donghu is the highest;The salinization degree of Shuangzike,Quanshan and Suwu is higher;The salinization degree of Xuebai and Dongba is the lowest.