基于开垦年龄的新疆盐渍化耕地时空特征分析

以新疆2013年绿洲灌区盐渍化土壤数据为基础,结合2000、2005、2010年和2013年4期土地利用数据,定量分析了基于开垦年龄(地龄)和流域分区的2013年新疆盐渍化耕地时空分布特征。结果表明:(1)2013年新疆盐渍化耕地面积为323.45×10~4hm~2,占耕地总面积的37.46%;(2)地龄大于13 a、8~13 a、3~8 a和1~3 a盐渍化耕地分别占同龄耕地的30.26%、45.98%、63.48%和69.05%,表明地龄越小,盐渍化耕地比重越大;(3)随着地龄的减小,耕地盐渍化程度逐渐加重,即轻度盐渍化耕地比重不断下降,中度和重度盐渍化比重不断上升;(4)2000年以来新增耕地来源中,开垦草地的比重不断下降,而未利用土地的开垦比重不断上升,开垦条件渐差;(5)新疆盐渍化耕地分布具有明显的地域性,全疆有9个流域分区耕地中盐渍化比重大于50%,其中7个流域分区的盐渍化耕地面积占新疆盐渍化耕地总面积的66.41%;依据地龄将不同流域分区盐渍化耕地面积的变化归纳为上升型、降低型、先升后降型和先降后升型4种类型。

Spatiotemporal Variation of Salinized Cultivated Land with Different Cultivation Years in Xinjiang

In this paper,the spatiotemporal distribution of salinized cultivated land with different cultivation years in different drainage basins in Xinjiang in 2013 was quantitatively analyzed.The datasets used in the study included the land use data in four years and the data of saline soil in an irrigated area in 2013.The results are as follows:①The area of salinized cultivated land in 2013 was 323.45 × 104 hm2,and the proportion of area of the salinized arable land was 37.46％ of the total area in the irrigated areas in Xinjiang;② The proportions of salinized cultivated land with 13,8-13,3-8 and 1-3 cuhivation years were 30.26％,45.98％,63.48％ and 69.05％ respectively;③ The salinization level of salinized cultivated land became more serious with the decrease of cultivation years,that means the proportion of slighdy salinized cultivated land was continuously decreased,but the proportions of moderately and seriously salinized cultivated land were gradually increased;④ Since 2000,the proportion of grassland in the new cultivated land was decreased,but that of unused land was increased,and the reclamation conditions became worse;⑤ The distribution of salinized cultivated land in Xinjiang was regional,the proportion of salinized cultivated land was higher than 50％ in 9 drainage basins,which accounted for 66.41％ of the total salinized land area in Xinjiang.The variation of salinized cultivated land in the study area could be divided into 4 types.