Authors: MAO Zhan-po 1, WANG Shi-yan 1, ZHOU Xiao-ling 2, LIU Chang 1
1. China Institute of Water Resources and Hydropower Research, Beijing 100038, China
2. Research Center for Eco-Environmental Sciences, CAS, Beijing 100085, China
Abstract: The agriculture nonpoint source pollution is the major influencing factor to lake eutrophication in the middle and lower reach of Changjiang River. Understanding of the distribution of soil nutrients at the field and catchment scale is of importance for improving agricultural management to control agriculture non-point source pollution. Based on the spatial analysis function of GIS, spatial heterogeneity of soil nutrients in a multipond-system of the Liuchahe watershed was studied using semivariogram of geostatistics. Theoretical semivariogram models of soil organic matter (OM), total N (TN), nitrate (NO3-N), ammoniacal nitrogen (NH4-N) and total P (TP) were accord with spherical model. The ratio of random variance (nugget) to total variance was low, these values were 28.8% for TP, 73.2% for TN, 44.0% for NH4-N, 77.35% for NO3-N, 23.9% for OM, respectively. The significant differences in ranges of these five soil nutrients were found. The TN had the highest values of variation, the next is TP, while the NH4-N and NO3-N were the lowest. These differences in ranges can be explained by the particular properties of soil nutrients, land use patterns and multipond-system landscape.
Key words: soil nutrients, multipond-system, spatial heterogeneity, geostatistics
Published in: Journal of Hydraulic Engineering, Vol. 42, No. 4, 2011
Article ID: 0559-9350 (2011) 04-0425-06
