基于土地利用格局的农田环境质量监测取样方法

Land use patterns-based sampling method for monitoring farmland environmental quality

为有效地监测京郊农田环境质量,该文提出了基于土地利用格局的农田环境质量监测的取样方法。方法通过遥感影像分类,获取京郊小麦地、裸露农田、草地、林地、果园及设施农业用地6种土地利用类型的空间分布特征。给定样本总量,每种土地利用类型所配给的样本量取决于该土地利用类型的田块总面积和田块数量。对同一土地利用类型,用随机偏爱取样方法选择样本点,即田块被取样的概率与该田块的面积和高程的综合权值成正比。基于土地利用格局的取样方法的优点是,用有限的样本最大限度地反映土地利用类型的空间分布格局,使样点更具代表性。

A land use patterns-based sampling method was proposed to monitor farmland environmental quality in suburban regions of Beijing.The spatial distribution patterns of six types of land use,i.e.,wheat filed,bare field, grassland,woodland,orchard land and facility agricultural filed were extracted using classification of images of remote sensing.Given a certain number of samples,the number of samples for different land use types depended on total areas and the number of plots of the land use type.Under the same land use type,a random-biased sampling was implemented, and the probability of each plot in the land use type to be included into the samples was proportional to the weighted value of its area and digital elevation.The advantage of land use pattern sampling is that limited sampling points can reflect maximally the spatial patterns of land use types,and that method makes samples more representative.