Study On Soil Water And Soil Reservoir In The Middle Reaches Of Manasi River In

Soil water is one of the key links of water cycle system in nature, the material basis of plant growth and survival, and the core elements to maintain ecosystem health operation. At present, research on different forms of water resources is relatively less from the Angle of water cycle. This paper takes Semi-desert region of XinJiang Manasi River middle reaches as study area, on the basis of relevant research at home and abroad, using method of theoretical analysis combining experiments measurements, to study spatial and temporal variability of soil water and status characteristics of soil reservoir research. The study conclusions have important scientific significance to know the water cycle and water balance of semi-desert areas, and have important guiding significance to alleviate the oasis ecological environment problems, which is caused by the shortage of water resources in Xinjiang. The main conclusions of this study are as follows:(1) Found the natural phenomenon of soil moisture which is positive balance in abundant rainfall year and slightly low temperature year. And found the prominent feature of this area that soil profile moisture content increases gradually from up to down and adhesive water content is high among it.(2) It revealed that in wet year soil water effectiveness is in the moderate and easy availability level in spring, soil water availability is in the difficult and moderate level in summer, soil water effectiveness gets better in autumn, which can restore to the moderate and easy availability level. Less rainfall autumn and high temperature spring and summer, the soil water effectiveness is relatively poor.(3) Gained the new knowledge of coarse silt soil water characteristic curve in Semi-desert region. It’s suitable for predicting the soil water characteristic curve with Brooks-Corey model.(4) Revealed soil moisture’s seasonal dynamic changes and vertical variation characteristics for years of0-100cm soil layer in the region of Manasi River middle reaches, which are as follows:On the time dimension, maximum soil moisture occurred in early spring and minimum occurred in summer, then rise in autumn. From late spring to late summer is depletion period of soil moisture, from late summer to early spring of next year is accumulation period of soil moisture. For the vertical distribution,0-40cm soil layer is active layer of soil moisture,40～100cm soil layer is relatively stable layer of soil moisture.The vertical distribution of soil water conforms well to Compartment model.(5) Research reveals that soil water content of interannual difference is mainly determined by the difference of meteorological elements in the region of Manasi River middle reaches. Significantly positively correlation exists between soil moisture and temperature of40-100cm soil layer. For10-80cm soil layer significantly negative correlation exists between soil moisture and temperature, no significant correlation exists between soil moisture and evaporation.(6) Silty loam is the main soil type in this area.0～10cm soil grain size is coarse, average particle size increases with the depth from10to100cm. Among them, the clay content is high within10-50cm depth soil layer. Soil moisture content and soil particle size is negatively correlated in this area.(7) The abandoned land has faster infiltration speed in the region of Manasi River middle reaches. Horton equation is suitable to describe soil moisture infiltration process in this area.(8) Classification standard of soil reservoir was determined in the region of Manasi River middle reaches and calculated storage capacity of all kinds soil reservoir. Filling water period of soil reservoir begins with early autumn and end to next year’s early spring, from late spring and early summer to late summer and early autumn is the period of soil reservoir water loss. The full level capacity of soil reservoir is poor and storage capacity weak in this area.