【作者】 刘京；

【导师】 常庆瑞；

【作者基本信息】 西北农林科技大学 ， 土壤学， 2010， 博士

【摘要】 耕地资源数量减少、质量下降与人口数量迅速增长引发的生态环境和人类发展的矛盾已经引起人们广泛关注。应用现代化手段提高土壤资源管理水平已成为了一个亟待解决的问题。本论文以陕西土壤、陕西省第二次土壤普查数据集以及农业部测土配方施肥资料为数据基础,以SOTER数据库技术为技术依托,建立了包含土壤、地形地貌与社会经济统计等资料的综合性陕西省土壤信息系统。以系统为依托,对陕西省土壤类型的空间分布及景观格局、土壤养分的空间分布规律、土壤肥力质量评价、土壤有机碳密度的空间分布及储量估算以及县域土壤养分时空变异进行了研究。获得研究结果如下:第一,陕西省土壤信息信息系统的设计。采用C#语言与ARC Engine开发方法,经过分析、设计、编码和测试的软件开发过程,获得具有属性数据管理、空间数据管理和模型应用功能的SOTER数据库管理系统。以COMGIS技术为基础,通过需求分析、概念结构设计、逻辑结构设计和物理设计的GIS开发过程开发出陕西省土壤信息系统,实现土壤空间数据的管理与分析等功能,以满足实际应用的需要。系统具备了专业模型的应用功能,可以根据需要从空间数据库和属性数据库中提取相关数据应用,提高土壤资源的定量化、标准化和模式化管理水平,为土壤资源管理决策支持系统和精准农业的研究奠定良好的基础。第二,陕西省土壤类型的空间格局分析:(1)分析了陕西省土壤类型的空间水平分布及不同高程带土壤类型的垂直分布特征。结果表明:从南向北依次为黄棕壤、黄褐土、褐土、黑垆土、栗钙土和灰钙土带。土壤垂直分布规律,主要表现在秦岭和大巴山、黄龙山等山地。(2)用景观生态学的方法,从面积特征、形态特征和类型特征三方面分析了陕西省土壤类型的景观分布格局。陕西省面积最大的土壤是黄绵土,风沙土、水稻土、潮土、新积土、沼泽土、盐土、红土、山地草甸土、亚高山草甸土、栗钙土、石质土图斑的平均面积均较小,说明其在陕西省境内分布比较分散,大部分属于区域性土壤。从土壤类型的分布密度来看,盐土、石灰岩土、山地草甸土、红土、新积土、亚高山草甸土、栗钙土、棕壤、潮土等分布数量较少,且图斑破碎。(3)运用分形理论和GIS技术,计算出了陕西省土壤土属图斑的分维数,获得了陕西省土壤土属的分维数分布图。陕西省土壤分维数有着比较明显的分布特征:黄土丘陵沟壑区以及陕西南部山区的沟道中各土壤类型的分维数最大;陕北黄土高原大部分塬面上分布的土壤次之;再次是咸阳地区、渭南地区、商洛地区以及汉中的部分地区的土壤;陕西南部的安康地区、渭河沿岸以及榆林的长城沿线的土壤分维数最小。(4)对陕西省土壤类型图斑镶嵌结构稳定性进行排序,得出各土属的稳定性程度。草甸沼泽土斑块镶嵌结构稳定性指数最高,石?质土斑块镶嵌结构稳定性指数最低,为定量地描述陕西省土壤信息及数字陕西土壤提供参考。第三,陕西省土壤养分的空间分布规律研究。利用1︰25万地形图,建立了陕西省数字高程模型(DEM),分析了陕西省地形地貌特征及其分布规律。将DEM及其延伸图-坡度图与土壤养分图叠置,分析陕西省土壤养分的空间分布规律,结果如下:(1)随海拔高度的增加,气温逐渐下降,湿度相应增大,自然植被的丰度、盖度及多样性也随之变化,引起了土壤养分的垂直分布的变化。随海拔上升土壤有机质含量呈上升趋势,各种土壤养分积累增强。(2)坡度影响土壤水分的再分配,亦是土壤温度变化的主要影响因子,干燥时,土壤温度变化较快,湿润时,土壤温度变化较慢,因而导致土壤中的生物过程和物理化学过程差异比较大,影响了土壤中的各养分的积累。(3)随着海拔高度的变化,土壤pH值也有明显的变化规律。随着海拔升高,土壤由弱碱性逐渐转向酸性。随着坡度的增大,土壤pH值逐渐降低。(4)土壤中有效态微量元素含量随着气候、地形、成土母质、成土作用等的不同,含量和分布有较大差异。表现为土壤有效锌、有效锰、有效铁含量呈现由北向南递增的分布规律,而土壤有效硼则有北高南低的趋势。第四,陕西省土壤肥力质量评价。(1)利用GIS空间分析方法,通过对各评价因素图叠加,形成土壤肥力评价单元,采用层次分析法确定各因素的权重,实现了肥力评价与自动制图。(2)评价结果将陕西省土壤肥力分为6个等级,定量反映了陕西省各个区域及各类型土壤的肥力水平,探讨了各土壤肥力水平的主要制约因素,分析了陕西土壤肥力水平的分布特征和空间格局。第五、陕西省土壤有机碳密度及储量估算。根据陕西省第二次土壤普查结果和1: 50万的土壤图初步估算了全省土壤有机碳密度和储量,以及土壤有机碳密度空间分布特征,得出以下的结果:(1)陕西省土壤有机碳储量约为1.41×1012 kg,陕西省土壤占全国面积2.2%,土壤有机碳储量占全国储量的1.58%,平均有机碳密度为6.87 kg/m2,低于全国平均水平。(2)陕西省地形起伏大,在高山地区随着海拔的升高,气候、植被发生明显的差异,且南北跨度大,从北到南跨3个气候带,植被、水热条件在水平方向上差别较大,使土壤有机碳密度也随之差异显著。在全省的22个土壤类型中,有13个土壤有机碳密度低于全国平均水平,占全省土壤总面积的77.42%,其中石质土的土壤有机碳密度最小,为0.09 kg/m2。第六、县域土壤养分空间变异研究。以陕西渭北旱塬区合阳县为研究区域,运用地统计学的基本理论与GIS的空间分析技术,研究了23年来合阳县土壤养分含量的时空变化规律。结果表明:(1)合阳县表层土壤有机质、碱解氮和速效磷含量均有不同程度的提高,土壤速效钾含量有升有降,基本保持了含量较丰富的状况,但土壤养分水平的总体仍然较低。(2)运用地统计学基本理论,利用Kriging理论?模型进行空间插值,获得土壤养分空间分布图及合阳县23年来各土壤养分级别变化图,并分析了土壤养分的时空变化规律。更多还原

【Abstract】 The conflict issues between ecological environment and human activities has been widely concerned in the world, for example, the reduction in cultivated land resources, decline of soil quality and the rapid growth of population. With the development of soil science, computer technology and its interdisciplinary, the applied field of soil science has been extended a large. Forth more, soil information system has become a hot topic in academic research in recent years. Studies from different aspects have shown that application of soil information system not only improves the effective in soil monitoring, mapping and modeling level, but also strengthens the soil science research and application.In China, the common soil resources data in the management is isolated and dispersed relatively lower level and poor exchange channels in dada usage at the same time. Whilst, with the development of soil survey, a great deal of information is accumulated and how to improve information management level of soil resources has becoming a pressing problem. In this thesis, "Shaanxi soil", "Second soil survey data set of Shaanxi Province", "Shaanxi Native Soil" and the soil testing and fertilizer program data from Ministry of Agriculture are referenced, based on the SOTER database technology, comprehensive soil information system of Shaanxi Province is designed and developed. Simultaneously,Soil types with its spatial distribution pattern, spatial distribution of soil nutrients, soil quality, soil organic carbon density with its spatial distribution, the temporal variability of soil nutrients of Shaanxi province are been analyzed and evaluated. Following with main conclusions:Firstly, Soil Information System of Shaanxi Province is designed and developed. Using C# programming language and the ARC Engine development approach, with the help of the idea of project management, Soil Information System of Shaanxi Province is designed and developed based on the COMGIS technology. The system has the function of design, editing, storage, statistics and analysis and others, it is more practicable for soil information management and precision agriculture research for the future.Secondly, Shaanxi Province soil types with its spatial pattern are comprehensively analyzed. Include: (1) soil type spatial distribution and formation characteristics; (2) landscape distribution patterns of soil types about the area characteristics, morphological features and its major soil feature; (3) the soil fractal dimension distribution based on the fractal theory and GIS technology; (4) the sort of soil structural stability for quantitative description of different soil types.Thirdly, the spatial distribution of soil nutrients was explored. Based on 1:250 000 topographic maps, a digital elevation model of Shaanxi Province (DEM) is established. According to the landform features, with a overlay and integration with slope map and soil nutrients map, spatial distribution characteristics about altitudes gradient, slope gradients and soil organic matter, soil total nitrogen, total potassium, soil pH, 4 kinds of soil trace elements are been thoroughly deducted.Fourthly, the quality of soil fertility is evaluated. With the methods of GIS spatial analysis and the superposition of various evaluation factors, the formation of soil fertility evaluation unit is deducted. While AHP method is adopted to achieve fertility evaluation by determining the weight of each factor.Fifthly, the content of soil organic carbon density is estimated. According to the second soil survey outputs and the 1: 500 000 soil map, soil organic carbon density and storage, as well as spatial distribution of Shaanxi province are preliminaryly estimated.Sixthly, Heyang County in Shaanxi Weibei Plateau is taken as special case, spatial variation of soil nutrients are analyzed. Using GIS geostatistics spatial analysis techniques, the soil nutrient content in the past 23 years of Heyang County is analyzed.更多还原