固原市低影响开发措施下土壤水分时空变化

Changes of Soil Moisture and Its Influencing Factors Under Low Impact Development Measures in Guyuan City

[目的]分析宁夏回族自治区固原市低影响开发措施下土壤水分时空变化规律,为该市海绵城市低影响开发(LID)建设及水资源有效利用的相关标准和规范制定提供科学参考。[方法]选取草地、过水草沟和下沉式绿地三种低影响开发措施,研究不同深度土壤储水量的时空变化和稳定性特征,分析不同低影响开发措施下土壤水分在干湿季、不同降雨、冻融条件下的变化情况。[结果]①草地、过水草沟和下沉式绿地的土壤储水量全年分别为101.96,27.22和97.33 mm,雨季和旱季分别为107.37,29.46,101.03和67.6,20.66,69.34 mm;各LID措施下土壤储水量变异系数在26.01%~76.37%之间,均属于中等变异;②暴雨条件草地、过水草沟和下沉式绿地的补给量分别为63.68,14.84和66.49 mm;小雨条件草地、过水草沟和下沉式绿地土壤补给量分别为3.94,1.71和1.26 mm;③冻融期内草地、过水草沟和下沉绿地的冻融量分别为111.16,75.73和46.9 mm,各措施下土壤低温和冻融主要集中于0-10 cm层;④研究区在全年、雨季、旱季、暴雨补给和冻融潜力分别为1 691.31,1 766.46,1 216.31,1 121.8和699.67 m^3。[结论] LID措施下土壤水分补给潜力较大;同时需要考虑不同LID措施的结构、填料、植被覆盖等方法的改进,以提高LID措施的储存能力。

[Objective]The spatial and temporal variation of soil water under the low impact development measures in Guyuan City of Ningxia Hui Autonomous Region was analyzed,in order to provide scientific reference for the low impact development and construction of sponge city and the construction of the relevant standards and norms for the effective utilization of water resources.[Methods]Three low impact development measures,namely,grassland,aquatic grass ditch and sunken green land were selected,to study the spatial-temporal changes and stability characteristics of soil water storage at different depths.And the changes of soil moisture under different measures of low impact development measures in dry and wet seasons,different rainfall and freeze-thaw conditions were analyzed.[Results]①The soil water storage capacity of grassland,aquatic grass ditch and sunken green land was 101.96,27.22 and 97.33 mm respectively all through the year,was 107.37,29.46 and 101.03 mm respectively in rainy seasons,and was 67.6,20.66 and 69.34 mm respectively in dry seasons.The variation coefficient of soil water storage under various low impact development measures was between 26.01%and 76.37%,all of which belonged to moderate variation.②Under rainstorm conditions,the replenishment amount of grassland,aquatic grass ditch and sunken green land was 63.68,14.84 and 66.49 mm,respectively.Under light rain conditions,the soil replenishment of grassland,aqueduct grass ditch and sunken green land was 3.94,1.71 and 1.26 mm,respectively.③During the freeze-thaw period,the freezing-thawing capacity of grassland,aquatic grass ditch and sunken green land was 111.16,75.73 and 46.9 mm,respectively.Low temperature and freeze-thaw were mainly concentrated in 0-10 cm soil layer.④The annual,rainy,dry,heavy rain and freeze-thaw replenishment of the study area were 1691.31,1766.46,1216.31,1121.8 and 699.67 m 3,respectively.[Conclusion]The potential of soil water recharge under the low-impact development measures is great.And the improvement of structure,filler and vegetation cover of different low impact development measures should be considered to improve the water storage of LID measures.