The researchers studied the levels of nitrogen and phosphorus in the Zhalong Wetland by collecting water samples in summer 2003. They used geostatistics and GIS to analyze the spatial variability of these nutrients. The results showed that nitrogen and phosphorus levels varied across the wetland, with water depth playing a key role in this variability. The maps created from the analysis indicated a uniform distribution pattern of these nutrients. Overall, the study found that water depth influences the spatial variability of nitrogen and phosphorus in the Zhalong Wetland.