Abstract: Spatial heterogeneity is an essential property of precipitation and water resources. Based on the results of the second integrated assessment to water resources in China, the Lorenz curve is used to calculate Gini coefficients and Lorenz asymmetric coefficients, which represent the degree and source of spatial heterogeneity respectively. Results indicate that different types of water resources in China show considerable or strong spatial heterogeneity. And the heterogeneity across different water resources divisions increases from east and south coasts to northwest, depending on the area, average precipitation, and other natural conditions. For each division, the heterogeneity in precipitation is the smallest, followed by groundwater resource, total water resources, and surface water resource; and water resources heterogeneity is featured with asymmetry dominated by those sub-divisions with less amount of water resources, or relative symmetry.

Key words: water resources, spatial heterogeneity, Lorenz curve, Gini coefficient, Lorenz asymmetric coefficient