Study On Spatial And Temporal Distribution Characteristics Of Soil Water On Water Source Area In Yuanyang Terrace

Soil water is the key to climate contact with vegetation water dynamic.It is the main water source for plant growth. Conversion of soil moisture affects t-he infiltration of soil water, evapotranspiration of arboreal land and runoff of waterhed and process of redistribution after infiltration. The Ha-ni terrace has a uniquefour elements isomorphism system, which is "forest, village, terrace, river". As theHani terrace successfully applied for the history of the world cultural heritage, howto maintain a good ecological system and make its sustained utilization of waterresources are problems to be solved. In this paper, we studied spatial and temporaldistribution characteristics of soil moisture of different land use types in Yuanyangterrace of Quanfu village. The conclusions are as follows:(1)Temporal variation of soil moisture of different land use types had obviousdifference. Seasonal variation of soil water on surface was similar with rainfall changes. Temporal variation of soil moisture on surface layer was more intense thandeep layer. Variation of soil moisture on different soil layers was large. With the i-ncreasing of soil depth, the soil moisture content showed increasing trend, its varia-tion coefficient was gradually decreasing. Variation coefficient of soil moisture duri-ng wet season was larger than dry season. Variation coefficient of soil moisture indifferent slope presented: lower slope> upper slope> middle slope. Soil moistureon different soil depths and different slopes in two seasons had significant different,the significant probability Sig=0.000<0.05, suggested that soil depth and slopeposition influenced the distribution of soil moisture.(2) Soil water storage capacity of different soil layers was significantly differe-nt. The variation of soil water storage capacity on surface layer was more intensethan deep layer. The order of soil water storage capacity on surface layer showed:arboreal land <shrub land <grass land, which on deep layer showed: arboreal lan-d> shrub land> grass land. Soil storage capacity of arboreal land, shrub land andgrass land was basically increasing along with the increasing of soil depth. Seasonal changes of soil water storage capacity were obvious. Soil water storage capacityof0~100cm layer showed: arboreal land (227.05mm)> shrub land (163.14mm)> grass land (143.11mm). Variation coefficient of soil water storage capacity showed:arboreal land (12.77%)> grass land (11.16%)> shrub land (10.78%). With the pa-ssage of time, soil water storage capacity showed the trend of increasing and thendecreasing.(3) The gray correlation degree between rainfall and soil moisture on0~100cmsoil layer of different land use types was low, that was changes between soil mois-ture and rainfall was not consistent. The horizontal comparison showed that respon-se of soil moisture to rainfall degree were grass land> arboreal land> shrub land.The gray correlation degree of soil moisture on each month was different. The graycorrelation degree of arboreal land on June to July was the largest, while it was t-he largest on August to October in grass land. The sum of gray correlation degreeby June to October showed grassland> arboreal land> shrub land. The gray corr-elation degree of soil moisture on different layers was different. Soil moisture onsurface layer was closer to the middle layer than the deeper relevance. The orderof grey correlation degree of soil moisture between surface layer and middle layerwas grass land> shrub land> arboreal land. The order of grey correlation degreeof soil moisture between surface layer and deep layer was shrub land> grass land> arboreal land. These indicated that the effect of different soil moisture and landuse types existed significant differences. Soil moisture of each soil layers changeddifferently. Soil moisture change trends of surface layer (0~20cm) and middle layer(20~60cm) was similar. The similarity showed grass land> shrub land> arborealland. Water-cut trend between surface layer and deep layer was weaker than betwe-en surface layer and middle layer，and it was the same between middle layer anddeep layer. Arboreal land significantly affected soil moisture changes in vertical. S-hrub land had a great influence on seasonal variation of soil moisture.