【作者】 李婷；

【导师】 张世熔；

【作者基本信息】 四川农业大学 ， 土壤学， 2005， 硕士

【摘要】 本文应用3S技术、景观格局指数法和马尔柯夫转移矩阵法探讨川北丘陵区闻溪河小流域从1982年到2004年景观格局演变与土壤养分时空变异间的关系,以及系统模拟与预测了其景观格局动态变化趋势。研究结果分述如下: 从1982年到2004年,闻溪河流域景观格局的多样性和破碎度变大,优势度变小。在各类景观演变的时间序列中,旱地、水田、园地和居民点的分离度明显地呈减小趋势;而林地的分离度则呈增大趋势;水域的景观分离度变化幅度不大。各种景观形态分维数的平均值排序为林地>水域>居民点>旱地>水田>园地。从景观格局的演变过程来看,旱地、水田、园地和居民点的分维数呈增大趋势,林地的分维数呈减小趋势。运用马尔科夫转移矩阵模拟2010年和2020年该区景观格局的变化趋势为林地的比例减少,旱地、水田、园地、水域和居民点用地均增加,但以旱地、园地和居民点增加最多。 1982年和2004年两个时段的土壤有机质对比分析表明,近22年来流域东北部、西南部土壤有机质含量普遍增高,中部维持不变,局部地区土壤有机质含量下降。从总体上看,占流域面积69.7%的土壤表层有机质含量增加,而30.3%的土壤有机质含量减少。 1982年土壤全氮含量在从东到西和从南到北方向上都呈线性增加趋势,由东南方向西北部逐渐降低;2004年土壤全氮含量呈抛物线,中部较其他部分略高。22年来土壤全氮含量减少的区域占全流域面积的95.99%,增加的区域占4.01%。土壤碱解氮含量减少的区域占流域总面积的78.60%,增加的区域占21.40%。 2004年土壤全磷样点的平均含量较1982年有所减小,而土壤速效磷样点的平均含量呈增加趋势。22年来土壤全磷含量减少区域占全流域面积的95.25%,增加的区域仅占全区面积的4.75%,其中增加的区域仅位于土地堂的北部边缘部分;土壤速效磷含量减少区域仅占全区面积的20.37%,增加区域占流域面积的79.63%,其中减少的区域仅在冒火山西北部、上里沟北部呈带状分布。 2004年与1982相比,土壤全钾样点的平均含量减小,而速效钾样点的平均含量增加。22年来土壤全钾含量减少的区域和增加的区域分别占该流域面积的81.82%和18.18%;土壤速效钾含量减少的区域和增加的区域分别占全流域面积的38.22%和更多还原

【Abstract】 The temporal-spatial variability characteristics of landscape and soil nutrient were studied by using GIS and remote sensing technical, index of landscape and transition matrix by Markov in the Wenxihe valley in the northern Sichuan Slopes. In addition, the spatial situation and dynamic variety trend was simulated. The results showed that:From 1982a to 2004a, the diversity and fragmentation of landscape in the study area became big, the dominance of landscape diminished. In evolvement, the fragmentation of dryland、 paddyland、 orchard and rural decreased, but which of forestland increased and of water did not change obviously. The order of the average value of various landscape fractal dimensions was forestland> water> rural> dryland 、> paddyland>orchard. From the process of the landscape pattern evolvement, the trend of the fractal dimension of dryland, paddyland, orchard and rural was increased slowly, but the forestland was decreased. By the method of transition matrix by Markov, the trend of landscape pattern change characteristics during 2010 and 2020 was analyzed, the results show that, the proportion of the forestland was diminished; and the dryland, paddyland, orchard, water and rural were all increased during the last 22 years.This paper analyzed the content of soil organic matter (SOM) in 1982 and 2004, the results showed that, the content of SOM in northeast and southwest of study area was increased, in the middle did not change, and in local part was declined. As a whole, the content of SOM in 69.7% of total area was increased; the others were decreased during the last 22 years.In 1982 the soil total nitrogen (STN) content had the linear trend from east to west and from north to south. In additionally, it was gradually lowered from northwest to southeast. The description of the STN was parabola in 2004; the central parts of study area were slightly higher than other parts. The content of STN and SAN all were decreased, the decreased area percentages were 95.99% and 78.60%, respectively; the increased were 4.01% and 21.40%, respectively.Compared to 1982, the content of soil total phosphorus (STP) was decreased, but soil available phosphorus (SAP) was increased in 2004. During the latest 22 years, the increased area of STP and SAPwas 4.75% and 75.63%, the decreased was 95.25% and 20.37%, respectively. Among them, the increased area of STP was existed in the north region of Tuditang; the decreased area of SAP was existed in the northwest of Maohuoshan and in the north of Shangligou.Compared to the 1982, the content of soil total potassium (STK) was declined, but the content of soil available potassium (SAK) was increased. As a while, the percentage of increased and decreased area to the total area of STK was 81.82% and 18.18%, respectively; of SAK was 38.22% and 61.78%, respectively.Compared to 1982, the content of SOM, SAP and SAK was increased in forestland, and the content of STN, SAN, STP and STK was decreased. In dryland, the content of SOM, STN, SAN, STP and STK was declined, and the content of SAP and SAK was increased. In paddyland, the content of SOM, SAP and SAK was increased obviously, but the content of STN, SAN, STP and STK decreased.The change of the landscape would bring on the change of soil nutrient content. When the type of the landscape was transformed form forestland to dryland, the content of STP and STK was decreased; the content of SOM, STN, SAN, SAP and SAK was increased. When it was changed to paddyland, the content of SAN, STP and STK was decreased; the content of SOM, STN, SAP and SAK was increased.Along with the increase of landscape variety and fragmentation and the decrease of domination, the storages of SOM, SAP and SAK in the study area were increased; the storages of SAK, STN, SAN, STP and STK were decreased. Compared to 1982, the isolation diversities of forestland and paddyland were increased, and the fractal dimension of them were decreased; the isolation diversity of dryland decreased 19.00%, and the fractal dimension increased. The storages of soil nutrient were decreased in forestland except SAP. In dryland, the storages of soil nutrient were increased except STN and STP. In paddyland, the storages of STN, STP and STK were decreased, and others were increased.更多还原