Snow, Snowfall, Snowmelt Ionic Characteristics And Snowmelt Process Under Straw Mulch

Based on the Northeast snow, snowfall, snowmelt runoff pH, conductivity, NO3-, Cl-, NO2-, H2PO4-, Ca2+, NH4+, Mg2+, Na+, K+ concentration measurement, combined with snowfall and snow the amount of change, explore new snow, snowfall, snow chemical characteristics variation in the process. And by laying on the surface of Ridge Farm straw covering, a clear influence variation rate of snowmelt and snowmelt area, provide a theoretical basis for the freeze-thaw erosion prediction and prevention of water and soil nutrient loss. Specific results are as follows:(1)The average pH value range is 5.10-6.33 snowmelt weakly acidic; floating range of the average conductivity is 33-63 μS·cm-1;the size of the anion concentration sort of NO3-> Cl->NO2->H2PO4-;size of the cation concentration in order of Ca2+>NH4+>Mg2+>Na+> K+;variation of the content of each ion concentration is inversely proportional relationship between the amount of snow in the area.(2)The average pH value for the snow process range is 5.77-6.46;floating range of the average conductivity is 42-71 μS·cm-1;the thickness of snow and there was no significant correlation between pH, conductivity and thickness of snow was negative significant correlation; the size of the anion concentration sort of NO3->Cl->NO2->H2PO4-;size of the cation concentration in order of Ca2+>NH4+>Mg2+>Na+>K+;anion concentration is a product of the area inversely related to the amount of snow, and the cation is mainly affected by the external environment and the amount of snow.(3)The average pH value for the variation in time after snowmelt process is divided into two forms, one is the average range is 5.86-6.39 February, one is the change in the average range is 5.71-6.35 March; average conductivity float interval is 46-79 μS·cm-1; the size of the order of the anion concentration NO3->Cl->NO2->H2PO4-; size of the cation concentration in order of Ca2+>NH4+>Mg2+>Na+>K+; ion concentrations levels were detected in each of the first day of the largest concentration of content, the average concentration of each test account the total ion concentration of 59% to 71%, and after the ion concentration decreased significantly and were below 30% and in descending order. Each ion concentration in three phases realizable also different, NO2-, H2PO4-,Ca2+,Mg2+,K+ showed snowmelt stage>snow stage>snowfall stage; Cl-, Na+ showed snow stage>snowfall stage> snowmelt stage; NO3-showed snow stage>snowmelt stage>snowfall stage; NH4+ showed snowfall stage>snow stage>snowmelt stage, indicating the ability to save different snow each ion.(4) impact of the amount of coverage for different amounts of straw on snowmelt rate, the results show that:S1.5 first occurred in the early melting snow, SL snowmelt peak maximum rate, the first snow finally are S2.5 intermediation; melting process S1.5, high coverage processing, S2.5 and S3.5 snow accumulation area showed a slowly increasing trend, and is always higher than the low cover processing So, S0.5, S1.0, SL sudden emergence in the mid snowmelt increase, followed by cumulative area covered over low processing; temperature and snow accumulation area of high correlation, each treatment showed S2.5>S3.5>S1.5>SL>S0>S1.0>S0.5; anti-radiation and the rate of snowmelt high correlation with high coverage performance of the correlation of each treatment in the early snowmelt high, and the low coverage of the correlation process is relatively high in the late snowmelt. That the amount of straw covered under this experimental conditions suitable for the 2.5 kg·m-2.