红壤区土壤pH值的空间预测方法研究
毕业论文关键词：红壤区；空间预测；土壤 pH；普通克里金；土壤类型
Abstract:It has been a great concern of soil science about how to use soil information to help accurately predict the spatial distribution of soil properties. However, there are some differences in different method of distinct properties. In this article,129 soil samples were collected in Yujiang County of the hilly red soil region ,China, three approaches :Soil Type method, Land Utilization Type method and Ordinary kriging are used to predict the PH value of this region, and 124 samples were validated to compare the prediction accuracy of these three methods. We can learn from the study that the correlation coefficients between measured and predicted of Soil Type method （a=0.3162,r=0.345）were larger than that of Land Utilization Type method and Ordinary kriging. The RMSE of Soil Type method, Land Utilization Type method are 0.258 and 0.260,the former is relatively lower, so it is more accurate. On the other hand, there are some differences in Spatial prediction accuracy of these three method in spatial distribution pattern of soil ph value , the Soil Type method can better describe the trend of spatial distribution and polygon, so it is more accurate than the Land Utilization Type method, while the ordinary kriging method is the lest accurate. The study indicated that the Polygon connection method is relatively effective in the prediction of soil ph value in the southern hilly red soil region.
Keywords: red soil region, Spatial prediction, soil ph value, ordinary kriging, soil type
目录
1. 前言 . 1
1.1. 研究意义 . 1
1.2. 国内外研究进展 . 1
1.3. 不足之处 . 2
2. 材料与方法 . 3
2.1. 研究区概况 3
2.2. 样品采集与处理 . 3
2.3. 图斑连接法 4
2.4. 克里金方法 4
2.5. 精度评价 . 5
3. 结果与讨论 . 6
3.1. 数据描述性统计分析 .. 6
3.2. 克里金方法统计分析 .. 7
3.3. 基于不同方法的空间预测分布 . 8
3.4. 不同方法的空间预测评价 8
4. 结论 .. 10
5. 参考文献 11
1. 前言 1.1. 研究意义 土壤pH对许多土壤化学反应和化学过程有着相当程度的影响，并且控制着微生物和植物所需养分的有效性[1]，是土壤的一项重要属性，也是判断土壤肥力高低的一项重要指标。一般来说，植物的正常生长要求土壤的 pH在一个适宜的范围内，超出这个范围，会对植物的生长产生负面影响。在中国南方热带亚热带红壤区，由于不合理施肥、长期酸雨和工矿企业排污等原因造成了非常严重的土壤酸化问题。土壤酸化使得土壤pH值持续下降，加速土壤养分的流失，使土壤贫瘠化，并且会提高重金属元素的溶解度，损害植物的根系[2]。如今，红壤区的酸化已经成为制约我国南方农作物生长的重要因素之一[3]。在此背景下，选用合适的方法和手段对土壤 pH进行较为精确的预测，对精确施肥，改良土壤，防治土壤重金属污染等有着重要的意义。 在大范围的测土施肥工作中，通常以以点代面的方式获取整个地区土壤的 pH信息，即先采取足够数量的样点，再通过按照某种土壤信息对图斑进行连接；或是通过地统计学进行空间插值的方式对整个地区的土壤 pH进行预测。因此预测的精度高低直接影响到作物的适宜性评价、土壤pH的改良方法以及土壤的配肥等，具有非常重要的研究意义。
下一篇：红壤区土地全氮的空间预测方法研究