| There are many mountainous parks and a lot of mountain land in Chongqing. With complex terrain and changeful climate, the space-time distribution of water has high heterogeneity in Chongqing Mountainous Park. The space-time distribution of water in Mountain Park is affected by landscape, natural environment conditions, human activities, and combined action of many factors. Although many research results show that the different landscape structure has a significant effect on the on the space-time distribution of water, the research involving this aspect is few, especially for the southern China areas with abundant rain.In recent years, natural conditions and unreasonable artificial landscape construction and so on lead to the natural landscape structure change, making ecological negative effects such as drought, floods, soil and water loss is more and more worse in many Mountain Park, including city park and country park which has a high forest coverage. With this background, In this paper, taking Nan Shan botanical garden in Chongqing as an example, analyzed the different landscape composition and the variations of surface runoff about its space-time variations.On this basis, to discuss Optimization measures on rational use of water resources, to provide the reference and scientific basis for ecological planning of mountain areas water and soil conservation, water resources reasonable use and management in the park of Chongqing and other mountain district in southern China. The main contents and results are as follows:(1) The composition and layout of the Woodland, roads and construction sites is a key to affect the distribution of surface runoff with time and space in Mountain park. In this study, the forest landscape is the most widely distributed, which covers an area of93.12hm"; Followed by building field, which covers an area of13.74hm, and scattered distribution; Road is the third largest with area of3.57hm; Farmland, water, grassland and wasteland landscape covers an area of less proportion with more scattered. Based on the above, the "source" area in the study covers an area of20.9hm2, while the "collect" area is96.11hm2As a result, the "Source" far less "collect", the former mainly distributed in land that gradient less than30%, which make the runoff and soil erosion risk less about the research area.(2)The composition and the distribution of different Communities and different canopy density about forest landscape are mainly influenced by the differences of terrain in Mountainous Park. In the study area of different forest community types, warm coniferous forest is most widely distributed, which covers an area of38.73hm2and which most distribution in high altitude and Steep slope area; Followed by evergreen mixed forest of Coniferous forest and Broad-leaved forest, which covers an area of19.04hm; In third, Evergreen and deciduous mixed forests covers an area of16.13hm2; The area of broad-leaved forest is9.42hm2, in fourth which mainly distributed in the low altitude and below slope of the land; Shrub and bamboo forest area are less. Different forest communities’distribution shows gradient variability that broad-leaved forest---broad-leaved mixed---warm coniferous forest with the elevation height. In the study of Different canopy density forest, the vast majority of the forest is jungle, which area is80.07hm", and it mainly distributed in the escarpment and low mountain zone; the area of Medium canopy density forest is12.31hm2, which mainly distributed in the gentle slope land; Open forest covers an area of0.74hm.(3) The terrain especially the slope is restricting more to the composition and distribution of the construction site in Mountain Park. In research, the construction site mainly includes the building and rigid pavement. Among them, the construction area is10.99hm2and rigid pavement covers an area of2.75hm2.The number of plaques is maximum in small patches, which mainly distributed in the land of the slope. However, there are27.9%of the buildings and18.2%of the pavement use the prohibited land to develop and construct.(4) The distribution of surface runoff with time and space is the result of the topography, vegetation, hydrology, soil and action of artificial combined interference. Under the same rainfall, terrain is an important factor in natural topography and geography conditions impact factor. Terrain affects the composition and distribution of the whole landscape structure, different forest community types, and different coverage of woodland and artificial landscape, which in turn affects the surface runoff. (5) The construction of artificial landscapes, such as roads, construction sites has had a huge impact on the temporal and spatial variation of the runoff in mountainous park. The effect is in turn:the combined influence of roads and construction sites is more than building sites influence; and the building sites influence is more than road building influence. Road constructions lead to runoff increase23518m3every year in the study; and runoff increase287m per hour in rainstorm period. The patches increase13when Average annual runoff yields more than500m3, while the patches increase3when the runoff yields more than50m3per hour in rainstorm. Build construction lead to runoff increase99260m per year in the study; while increase1253m3per hour in rainstorm period. The patches which runoff yield is more than500m3per year increase50; while increase3when the runoff more than50m3per hour in rainstorm period. In The combined effects of integrated construction of roads and building, it increase120186m3every year in the study; while increase1516m3per hour in rainstorm period. The patches increase59when Year runoff yield is more than500m3, while the patches increase5when the runoff more than50m3per hour in rainstorm period. |
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