中国农业科学 ›› 2020, Vol. 53 ›› Issue (9): 1830-1844.doi: 10.3864/j.issn.0578-1752.2020.09.011

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

基于MGWRK的土壤有机质制图及驱动因素研究

乔磊1,张吴平2(),黄明镜3,王国芳1,任健1   

  1. 1 山西农业大学资源环境学院,山西太谷 030800;
    2 山西农业大学软件学院,山西太谷 030800;
    3 山西省农业科学院旱地农业研究中心,太原 030031
  • 收稿日期:2019-11-14 接受日期:2020-02-13 出版日期:2020-05-01 发布日期:2020-05-13
  • 通讯作者: 张吴平
  • 作者简介:乔磊,E-mail:qiaolei1995@126.com。
  • 基金资助:
    山西省重点研发计划重点项目(201703D211002-2);山西省科技攻关项目(20130311008-5)

Mapping of Soil Organic Matter and Its Driving Factors Study Based on MGWRK

Lei QIAO1,WuPing ZHANG2(),MingJing HUANG3,GuoFang WANG1,Jian REN1   

  1. 1 College of Resources and Environment, Shanxi Agricultural University, Taigu 030800, Shanxi;
    2 College of Software, Shanxi Agricultural University, Taigu 030800, Shanxi;
    3 Dryland Agriculture Research Center, Shanxi Academy of Agricultural Sciences, Taiyuan 030031
  • Received:2019-11-14 Accepted:2020-02-13 Online:2020-05-01 Published:2020-05-13
  • Contact: WuPing ZHANG

摘要:

【目的】空间预测是一种获得有机质空间局部细节的重要方法,其准确性对于农田合理管理有着重要意义。本研究通过对比不同的土壤有机质空间制图方法以获得更优的预测精度,在预测的同时揭示环境协变量的空间非平稳性特征及不同环境协变量关系的空间尺度。【方法】选取晋中盆地的7个乡镇作为研究区,对比普通克里金(OK)、回归克里金(RK)、地理加权回归克里金(GWRK)和多重尺度地理加权回归克里金(MGWRK)4种不同方法对土壤有机质的预测能力和效果,并探究影响因子在空间分布中对有机质的影响效应变化和这种影响效应的空间尺度。MGWRK是一种多重尺度地理加权回归(MGWR)与普通克里金方法相结合的方法。【结果】选取坡向、坡度、年均降水量、年平均温度、海拔、植被年总初级生产力、年蒸散量、地形湿度指数、平面曲率、汇流动力指数、地形指数、地形粗糙指数、年平均NDVI为环境协变量参与建模,在多元线性回归建模中,模型统计学意义显著,这表明模型具备统计学意义。从Radius指数来看,各模型模拟效果由好到差依次为RK、OK、GWRK、MGWRK;从制图效果来看,MGWRK与GWRK制图效果相当,从有机质的空间预测图可以看出,土壤有机质在研究区呈现东西两侧偏低、中部偏高的空间格局,其中汾河以东、昌源河流经区域土壤有机质普遍偏高。坡向、年均降水量、年平均温度、海拔、地形指数、年平均NDVI对研究区东部有机质的影响强于西部,而坡度、植被年总初级生产力、年蒸散量、平面曲率、汇流动力指数、地形粗糙指数则表现出截然相反的空间非平稳性特征,地形湿度指数对有机质的影响则体现为北部强南部弱。【结论】MGWRK方法的空间预测精度分别达到了RK方法的69%、OK方法的71.74%、GWRK方法的71.17%。MGWRK在空间非平稳性特征的解释能力和空间可视化表现良好,为有机质的预测和空间非平稳性特征的描述提供方法借鉴。

关键词: 土壤有机质, 土壤制图, 多重尺度地理加权回归克里金, 地理加权回归克里金, 回归克里金, 空间非平稳性特征

Abstract:

【Objective】Spatial prediction is an important approach to obtain location-specific values of soil organic matter (SOM), which is an important figure of soil fertility and farmland management properly. This study was performed to compare different digital soil spatial mapping methods of SOM to get better prediction accuracy and to reveal the spatial non-stationarity characteristics of environmental covariates and the spatial scale of different environmental covariates at the same time. 【Method】In this study, the digital soil spatial mapping method was used, which was a combination of Multiscale Geographically Weighted Regression Model with simple Kriging of the residuals (MGWGK) for mapping SOM in seven towns from Jinzhong Basin. The performance of MGWRK with those of Ordinary Kriging (OK), Regression Kriging (RK), and Geographically Weighted Regression Kriging (GWRK) were compared to explore the relationship between influence factors and SOM on the influence degree and space scale. 【Result】Based on the stepwise regression method, 13 indexes were selected as environmental covariables in the modeling, including aspect, slope, height, annual average precipitation, annual average temperature, gross primary productivity (GPP), evapotranspiration (ET), topographic wetness index (TWI), plan curvature, stream power index (SPI), terrain position index (TPI), terrain ruggedness index (TRI), and the annual NDVI. In the multiple linear regression (MLR), the formula had statistical significance. In the Radius index, the performance of each model was in order from good to bad: RK, OK, GWRK, MGWRK. In the mapping performance, MGWRK was close to GWRK, and both of which were better than OK method and RK method. The SOM in the study area, showed a spatial pattern of higher in middle than east and west side, among which the SOM was high in the east of the Fenhe river and the Changyuan river. The influence of aspect, annual average precipitation, annual average temperature, height, TPI and the annual NDVI on SOM in the eastern of the study area was stronger than that in the western. Whiles slope, GPP, ET, plan curvature, SPI and TRI showed opposite influence in spatial. The influence of TWI on SOM was stronger in the northern than the southern. 【Conclusion】The spatial prediction accuracy of MGWRK was 69% of RK, 71.74% of OK, and 71.17% of GWRK. MGWRK performed well in the spatial non-stationary features and the spatial visualization, which provided a reference for prediction of SOM and description spatial non-stationarity characteristics.

Key words: soil organic matter (SOM), soil mapping, multiscale geographically weighted regression kriging (MGWRK), geographically weighted regression kriging (GWRK), regression kriging (RK), non-stationarity