Abstract: This paper deals wich an infiltrated-ridged paddy soil ecosystem which is constructed by ridging and con-tinuous furrow infiItratiOn irrigation, Comparing with level infiItrated paddy soil ecosystem, this ecosys-tem has coexisted gas-liquid,gas-solid and liquid-solid interfaces,enlarges soil surface by 38%and increases cuItivated layer by 5-10cm. InfiItrated-ridged paddy soil can absorb more solar radiation, its thermal conductivity is obviously increased, thermal capacity decreased,diurnal variatiOn of temperature enlarged,temperature-increasing effect more significant.and heat exchange within soil and between soil and near-landsurface is more frequent.Because of these,soil microbial activity is intensified,which re-sults in an accelerated turnover of soil organic matter and nutrient metabOlism. Higher yield of rice has been obtained f

Key words: fire behavior, mixed fuel, spread speed, residual time,  , fire-intensity, flame length: weighting method.