关键词: 胞外酶, 赤潮, 富营养化, 碱性磷酸酶

Abstract: In mountain region of upper Heihe River, the characteristic of soil water regime is of unsaturated, and thus, to accurately estimate the values of its topsoil unsaturated hydraulic conductivity (K₁₀) is essential for ecohydrological modeling. Taking the Pailugou catchment in upper Heihe River as a case, its topsoil K₁₀ values were measured, and simulated by the pedotransfer functions (PTFs) integrating with factors-soil mechanical composition, bulk density, and average particle size. The observedK₁₀in forestland, grassland and bare land was 0.21±0.20, 0.20±0.16 and 0.93±0.63 cm·h^-1, and its spatial variability coefficient was 0.95, 0.79 and 0.67, respectively. The simulatedK₁₀ was sensitive to soil mechanical composition and bulk density, resulting in different estimation effect of different PTFs estimation models for different sites. Therefore, the PTFs estimation models should be tested before application. The PTFs estimation models of K₁₀ for Pailugou catchment were fitted, with R²=0.76 and the sample geometric mean error ratio GMER=1.77, indicating that they were practically applicable in the study region.

Key words: Aquatic ectoenzyme, Red tide, Eutrophication, Alkaline phosphatase