安徽省长江以北地区土壤水分动态模拟初探

A Dynamic Simulation on Soil Moisture in North of Yangtze River in Anhui Province

利用安徽省长江以北地区11个农业气象站1980-2000年实测0-20 cm土壤水分资料,基于土壤水分平衡模型,分季节建立了不同降水条件下的土壤水分模拟模型。当模拟时段内总降水量P≤某临界值P0时,模型以模拟时段初的土壤相对湿度(θ0′)、时段内降水量(P)、>0℃活动积温(∑T>0)、日照时数(∑R)等为自变量;而当P>P0时模型以θ0′、Ln(P)、∑T>0、∑R等为自变量。经对2005年安徽省长江以北地区平均土壤水分模拟值与实测值比较,以及2006年3月28日安徽省长江以北地区各地土壤相对湿度瞬时模拟值与实测值比较,二者达极显著相关关系,说明模型模拟效果较好,但也存在一定的系统偏差,模拟值普遍偏小。该结果对安徽省长江以北地区土壤墒情模拟具有应用价值。

Based on the measured soil moisture data of the top 20cm soil layer of eleven agro-meteorological stations in the North of the Yangtze River in Anhui Province from 1980 to 2000, the simulation models on the soil moisture for different seasons under different precipitation conditions were established. The critical precipitation （P0） in the time-interval for forecasting was defined, and four independent variables were cited such as initial soil relative moisture （ θ＇0 ）, total precipitation （ P）, accumulated temperature （ ∑ T 〉0 ） and hours of sunshine （ ∑ R） in the timeinterval for forecasting. As P 〉 P0, P was modified to Ln （ P）. The simulated values of the relative soil moisture were validated by comparing with the observed values for both 2005 and 2006. It showed a highly coherence. Models could be used to forecast soil moisture in the field in North of the Yangtze River in Anhui Province.