The invention discloses a parallel method for large-area
drainage basin extraction of massive DEM data. The parallel method comprises the following steps of: step 1, optimally partitioning
granularity evaluation; step 2, carrying out swale filling and calculating in accordance with
data partitioning and fusion strategies; step 3, carrying out
water flow direction parallel calculation in accordance with the
data partitioning and fusion strategies on the basis of swale filling results; step 4, carrying out confluence accumulation parallel calculation in accordance with the
data partitioning and fusion strategies on the basis of
water flow direction data; step 5, setting confluence thresholds and carrying out
river network water
system parallel calculation in accordance with the data partitioning and fusion strategies on the basis of
water flow direction data and confluence accumulation data; and step 6, carrying out sub-
drainage basin partitioning parallel calculation in accordance with the data partitioning and fusion strategies on the basis of the
river network water
system and water flow direction data so as to accomplish the
drainage basin extraction. With the adoption of the method, the
granularity in data partitioning and an I / O (Input / Output) mechanism are sufficiently considered, and the self data characteristics on the serial
algorithm parallel analysis can be considered as well.