Characteristics of Variation of Water Conservation in Southern Hilly and Mountainous Region of China

The ecosystem function of water conservation and its variation characteristics are analyzed in the southern hilly and mountainous region in this paper by using rainfall storage and transfer matrix based on an ecosystem type data for 2000, 2005 and 2010. Our results show that the total amount of water conservation presents an increasing trend by 1.61× 108m3during 2000-2010, in which the forest ecosystem is the main contributor, accounting for 69.2%, 69.5% and 69.9% in 2000, 2005 and 2010, respectively. The amount of water conservation differs significantly among ecosystem types, and a decreasing order is presented as follows: forestland farmland shrub grassland wetland. Whilst the capacity of water conservation is significantly different among ecosystem types with the following decreasing order: wetland forestland grassland shrub farmland. The ecosystem function of water conservation is mainly concentrated in the high(97.2%), moderate(97.0%) and low(96.9%) grades. Different grades of water conservation can shift from one to another, and in general the transfer of water conservation from the low grade to the moderate and high grades dominates in the whole study region.