On Coupling Of The Spatial Pattern Of Rural Land Use And Landform Morphological Factors In Inverted Low Mountain Areas

Landform morphology, as the key factor of environment, determines the regional distribution of light, heat, water and the remotion and accumulation of material. Not only does landform morphology create the original spatial pattern of regional land use by elevation, slope, aspect and the composing material on the ground, but also controls the process and speed of the dynamic evolvement of regional land use's spatial pattern and spatial correlations of land use types. Moreover, landform morphology has a retroaction on the changes of land use types and their spatial pattern by working on natural factors such as climate, water system, soil and vegetation etc. Therefore, to analyze the coupling of the spatial pattern of land use and landform morphology from multi-scale and multi-perspective is not only beneficial to identify the respond status of land use types in different landform morphology regions and in different landform morphological factors conditions, but also great of optimizing and collocating of regional human-land system and realizing sustainable development of land resources. However, in previous researches, more attentions on the patch size and its changes of the spatial and temporal pattern of land use/cover in landform morphological factors conditions, including elevation, slope and aspect, in many times at specific area were paid by the method of landscape pattern index or traditional statistic index The coupling of spatial pattern of rural land use and landform morphology is still poorly understood especially based on large-scale datum and multi-perspective. So, taking the typical inverted low mountain Areas of Bashan, Shilian, and Sujia villages in Bashan town of Zhongxian, Chongqing as the study area, the paper, from the perspective of regional geography, has studied spatial distribution pattern and gradient variation of rural residential areas, rural road and land use patches in landform morphological factors conditions, such as elevation, slope, aspect, hypsography, surface cutting depth, surface roughness, SOA and SOS by FRAGSTATS3.3 and ArcGIS9.3, and analyzed the correlation of spatial pattern of rural land use and landform morphological factors by SPSS. Main results and conclusions of the paper are summarized as follows: (1) Rural residential areas are built adapting to landform morphology. Consequently, there are different distribution patterns of rural residential areas in different landform morphology. Results suggested that the distribution shape of rural residential areas appeared banded or round form in regions of simple landform morphology, in contrast, it presented scatter plot freely. To some extent, the distribution of rural residential areas showed "road economy", which is to say that the more perfect road systems were, the more intensive distribution of rural residential areas were. Moreover, the distributive probability of rural residential areas with the form of linear or ribbon was greater in the region of main roads. Results from logistic regression model further suggested the most significant impact landform morphological factors on rural residential areas were elevation, slope and hypsography. Judging from the spatial density of rural residential areas, the percentage of rural residential areas was decreased wholly with the increase of elevation and its difference was great in different gradient of elevation. For example, it was only 0.21 per hectare below 460m, and 2.92 per hectare above 540m. Meanwhile, with the increase of slope, the percentage of rural residential areas was gradually decreased and its change range was gentle. Additionally, with the increase of hypsography, the percentage of rural residential areas decreased gradually, and then, reduced to 0 per hectare sharply. From the spatial concentration, the nearest neighbor point index R of rural residential areas exceeded 0.5 mostly in each landform morphological factors conditions, which showed the distribution types of rural residential areas belonged to random or well-proportioned distribution. What's more, with the increase of elevation, the adjacent distance of rural residential areas was shorten gradually and the neighboring degree was also improved As a result, the spatial distribution trend of rural residential areas became more and more concentrative. Meanwhile, as slope and hypsography increasing, the adjacent distance of rural residential areas was increased wholly and conjunctive degree was reduced. Its spatial distribution appeared random trend. In short, besides landform morphology, the influence factors on the distribution of rural residential areas also included the development of regional social economy and traffic conditions.(2) Rural road is consisted of a hierarchy structure, according to a certain spatial structure and different functions. It can expand any space of full regions due to its horizontal or vertical pierce capability and more connective flexibility. What's more, rural road network has strong combined effects. Generally, the percentages of mechanized road and production road were relatively more in the region which is closer to rural highway or the trunk road outside. In the study area, there were great significantly discrepancies of micro-topography among northwest, northeast, southeast regions, whose spatial structure rates of rural road at all levels were also very different:production road, mechanized farming road, high road were 6:3:1,10:4:1,4:1:0, respectively. Furthermore, the percentages of mechanized road and production road in the region of northwest, where the high road goes through, were more than those in northeast and southeast regions, and the combined effects of road network were also more prominent. Additionally, spatial structure of rural road has a strong selectivity of micro-topography and the gradient variation of rural road in different landform morphological factors conditions shows a significant effect. Results from MLP further suggested there were greater impacts of SOS, surface cutting depth, relief and Surface roughness on rural road's distribution, followed by slope, while elevation as well as aspect was least.(3) The spatial density, spatial shape and combinative features of different land use patches types had various degrees response to different landform morphological factors because of kinds of land using divisions such as the direction, pattern and intensity of land use in micro-geomorphology space units. Consequently, spatial patterns of the different land use patches types were represented by various degree of gradient variation. Seeing from the spatial density of the different land use patches types, it was easy to show that landform morphology had strong binding to the spatial distribution of paddy field, dry field and pond, but it had low binding to the spatial distribution of bare land and woodland. Meanwhile, the mutative characteristics of combinative complexity of different land use patches types, equilibrium degree of spatial distribution of patches, and order degree of land use system of were various in different landform morphological factors conditions. From the perspective of spatial shape and combinative features, for one thing, it was dry field, paddy field, woodland, bare land and pond that had the biggest fragmentation, the most concentration, more regular shape but less variability in the extreme landform morphological factors conditions on the class scale. For the other thing, the landscape indices like the largest patches, the shape of land pattern, SHDI, SHEI, and the fragmentation of landscape had complicated spatial variant characters in different degree of landform morphological factors, including elevation, hypsography, surface cutting depth, SOA, and SOS on the landscape scale. In addition, with the increase of slope and surface roughness, the diversity and uniformity of landscape increased and the connection of the largest patches decreased, but the difference of shape of landscape was small. In terms of aspect, the heterogeneity and fragmentation of the whole land use landscape were the least and the dominance of the largest patches was outstanding on the flat. While on other aspect, both the percentages of each land use patches types and landscape shape were comparable. The diversity and uniformity of landscape also kept the same level nearly. Besides, the effects of different landform morphological factors on the different land use patches types were various. Results from logistic regression model further suggested:elevation, slope and aspect were the significant impact factors to the spatial distribution of paddy field; surface cutting depth, slope, elevation and SOS were the significant impact factors to the spatial distribution of dry field and bare land; surface cutting depth, slope and aspect were the significant impact factors to the spatial distribution of woodland; elevation, slope and surface cutting depth were the significant impact factors to the spatial distribution of pond.With the perspective of regional geography, the coupling of point pattern, line pattern, polygon pattern of rural land use and landform morphology in inverted low mountain areas was analyzed in this paper. Results from the study is not only beneficial to identify the respond status of different spatial distribution model of land use in different landform morphological factors conditions, but also useful to recognize the driving force of landform morphological factors on different land use pattern objectively. In terms of research methods, the paper made a combination of spatial analysis, overlay analysis, geostatistical analysis and landscape indices analysis by FRAGSTATS3.3 and ArcGIS9.3, along with the logistic regression model and MLP neural network model by SPSS Consequently, the coupling of point pattern, line pattern, polygon pattern of rural land use and landform morphology was diversely discussed. Therefore, it has broken through the "bottleneck" limit of the impact of elevation, slope and aspect on spatial quantity structure of land use. The spatial pattern of land use is a complex synthesis as the consequence of interactions of nature environment evolution and human activity. So, besides landform morphology, the influence factor on the spatial distribution of land use, we must also take full account of climate, soil type, geological, hydrological and other natural factors, and population resources, traffic conditions and other socio-economic factors to study the spatial pattern characteristics of land use in different landform morphology regions qualitatively and quantitatively.