简介:TobuildarapidandaccuratemethodforgreenhousevegetablelandinformationextractionusinganindexmodelderivedfromTMdigitaldataofQingzhouCity,ShandongProvince,basedonasystematicanalysisofthespectralcharacteristicsofdifferentlandusetypesinthestudyarea,asubsetoftheimagewasfirstmadetoeliminatethemountainousregionnotassociatedwithvegetabledistribution,andthenwaterbodypixelsweremasked.WiththistheV1indexmodelforgreenhousevegetablelandextractionwasdeveloped.TheindexmodelindicatedgreenhousevegetablelandforQingzhouinApril2002wasconcentratedinthesoutheastandaroundruralresidentialareas.Fielddatausedforanaccuracyevaluationshowedthatgreenhousehectaresdeterminedwithremotesensingwere95.9%accurate,andaccuracyforthespatialdistributionofgreenhousevegetablelandcrosscheckedwitharandomsamplewas96.3%.Therefore,thisapproachprovidedaneffectivemethodforgreenhousevegetablelandinformationextractionandhaspotentialsignificanceformanagementofgreenhousevegetableproductioninthestudyarea,aswellasNorthChina.
简介:土壤水分入渗特性与不同层次土壤水分密切相关,影响农田弃耕后的植被演替过程。为深入理解鄂尔多斯高原弃耕农田土壤水分入渗随植被演替的变化规律,以鄂尔多斯高原软梁、硬梁不同年限的弃耕农田为对象,采用双环入渗仪测定土壤水分入渗参数,利用Kostiakov-Lewis模型模拟软梁和硬梁弃耕农田(共计12个弃耕类别)的水分入渗过程,分析它们的水分入渗规律。结果表明:1)软梁土壤初渗速率随弃耕年限增加呈不显著的降低趋势;稳渗速率和累积入渗高度随弃耕年限增加呈现先降低后增加的趋势,且在弃耕10年时显著降低;2)硬梁土壤初渗速率、稳渗速率和累积入渗高度随弃耕年限增加均呈先增加后降低的趋势,且在弃耕10~15年之间明显升高。随弃耕年限增加,软梁土壤水分入渗浅层化,硬梁土壤水分入渗能力有所提高。研究结果可为鄂尔多斯高原弃耕农田植被恢复提供科学依据。