The Research On Effects Of Water-saving Irrigation On Soil Environment And Groundwater Level In Guanzhong Region

In order to obtain the effect of water-saving irrigation on the soil and water environment of typical crops in Guanzhong and its mechanism, aims to provide a scientific basis for the sustainable development of water-saving agriculture in arid and semi-arid areas of Guanzhong, and finally realize the harmonious development of water-saving irrigation and ecological environment construction. In this paper, the influence of water-saving measures on soil environment and groundwater, like the canal lining, the transformation of the ridged fields was researched in typical irrigated area, like Jinhui, Tao Qv po, the first period of Donglei and the second period of Donglei irrigated area, in Guanzhong region and draw the following conclusions:(1)The soil organic matter content along the channel were all restricted by the materials of channel lining, lining improvement and the channel maintenance in typical irrigated areas in Guanzhong region. And the trend of the soil organic matter content, the better density of the lining material, the higher perfection, the better maintenance of the channel, was the relatively low, on the contrary, the higher. Where,in Jinhui irrigated area, the soil organic matter content on both sides of the channel was between18.96?162.92 mg/kg, the mean value of 86.07 mg/kg, the coefficient variation of 0.367; In Tao Qv po irrigated area, the value was between 5.21 ?17.57g/kg, the mean value of 10.01 g/kg, the coefficient variation of 0.396; In first period of Donglei irrigated area, the value was between 3.25?21.24g/kg, the mean value of 8.5g/kg, the coefficient variation of 0.336; In second of Donglei irrigated area,the value was between4.82?20.67g/kg, the mean value of 9.53g/kg, the coefficient variation of 0.32. And the content of soil organic matter were all belonged to moderate variation degree and spatial correlation. And compared with the distribution of soil organic matter and the distribution of different particles in the four irrigation areas, it can be seen that the spatial distribution trend of clay content and grain content was almost consistent with the distribution of organic matter, which shows the correlation between the two.(2) Based on the Hydrus-2D model, combined with the change of depth by groundwater in Jinghui irrigated area in recent years, the leakage of the channel under the three different materials lining channels in the Jinghui irrigation area on the 30th day, the 60th day, the 120th day and the 180th day was predicted. The results show that, due to the more anti-seepage material, the less depth of leakage in channel, the supply of groundwater by the leakage was gradually reduced, or even completely interrupted in Jinghui irrigated area.(3) By collecting the data of the border irrigation of the previous scholars and combining with the WinSRFR model, the influence of the transformation of the ridged fields on the soil environment was simulated. It is found that when the length of the borders was from 60m to 160m, the width increased from 4m to 9m, the single width flow was become smaller, so that the time required for the water-flow advance was longer and the process of the water-flow regression becomes shorter. At the same location, with the increase of border width, the infiltration in soil was reduced and then increased. When the width of the border was range from 4m to 9m, the length of the border range from 60m to 160m,which did not affect the process of the water-flow advance. When the width of M was 4m, the rate of the single wide larger,the rate of the water-flow regression was slow and the time of water-flow regression increases obviously. When the width of M was 6m or 9m, the flow of single width was small and the leakage would be produced at the end of border, preceded by elsewhere. Meanwhile, at the same location, with the increase of border length, the infiltration in soil was higher and was impact obviously by the border length.