Optimal Allocation of Rainfall in the Sichuan Basin, Southwest China

摘要

Traditional water allocation at a regional or basin scale can be too coarse to be used in a local area such as a village. For example, in the hilly area of Sichuan Basin the landform is fragmented and land use pattern consists of small farms. Furthermore, seasonal drought occurs frequently due to spatially and temporally variability in rainfall patterns. These droughts often lead to a reduction in crop yield or no yield at all. Due to the remoteness and scale of the farms, the farm populations are dependent on the annual crop yield. A poor harvest can mean serious hardships to the farmers. In order to mitigate the seasonal drought we first analyzed the drought characteristics from both meteorological and soil aspects. The results showed that both the spring droughts and canicular days (dog-day) droughts had in excess of a 60% chance of occurring. Using a water balance approach, we found that a series of storage ponds and bunds could greatly reduce the impact of these droughts.