The Estimate Of Water Conservation Function Of Forests In Ashihe-drainage Basin

This paper was done for researching the water holding capacity of forests in Ashihe-drainage basin. As the basis of forest hydrology theory, testing the routine forest hydrology indexes of ten types forests in Ashihe-drainage basin has done by the method of the basal research. As using the 3S techniques, dealed with the relief map, river map, remote sensing image TM and other data. And combined the anterior experiment results, the research have been extended to drainage region.The results showed that the water holding capacity of ten forest types in Ashihe-drainage basin is very high. The forest litter can hold as much as four multiples than itself. The average of that (353.70%) is higher than the countrywide average index (309.54%) of holding water rate on literature. The orderliness of forest litter's capability in holding water is the conifer higher than the broad-leaved trees. On the contrast, the water holding capacity of soil's sort order is the broad-leaved trees higher than the conifer trees. All of the main ten forest types, the orderliness of water holding capacity is Fraxinus mandshuric wood>stiff broad-leaved trees wood > Quercus mongolica wood > Picea koraiensis wood > Betula platyphylla wood >shaw wood > Pinus koraiensis wood> Larix gmelinii> Populus ussuriensis wood> Pinus sylvestris var.mongolica wood. This rule is identical to the water holding capacity of soils, and also proved that the principal part of forest hydrology effect is soil. All over the drainage-basin area the water conservation of ten types of forests has been to 4.953 hundreds million tons. In fact, the virtual effect of forest is much significative, and that also can reach 0.595 tons. All of above is a huge embodiment of forest hydrological effect.Through this experiment, the water holding capacity of Ashihe-drainage basin has been calculated and offered a good suggestion for manages water conservation forest. On the other side the use of 3S techniques offered a reference in forest hydrology research.