中文摘要：

【目的】耕地资源的变化特征是土地利用与土地覆被变化研究的重要内容,也是关系到耕地安全与粮食安全的重大问题。新疆作为中国农业用地较多和后备耕地资源较大的省区,在中国耕地资源保护和持续利用中具有突出地位。渭库绿洲是新疆最典型的荒漠绿洲区,是阿克苏地区最大的灌溉区及新疆重要的产棉区之一,深入了解该绿洲耕地分布及其变化过程,对指导该绿洲农业发展,保障生态安全至关重要。【方法】本研究以遥感资料为数据源,选取动态度、区位指数和板块密度等地理计量模型揭示渭库绿洲近21 a来耕地的时空变化特征,分析其变化的主要原因。【结果】（1）近21a年渭库绿洲耕地发生了显著的时空变化。耕地面积从1994年的2 488km2增加到2015年的3 931 km^2,研究期间增加了1 443 km^2,耕地面积的比例从17%上升到26%,年均变化量68.71km^2,年均变化率2.7%;耕地扩展中心逐渐由绿洲中上游转移到下游,并延伸到绿洲外围,主要表现以耕地为主的农业用地和建设用地为主的非农业用地增加,以及盐渍地和水域大面积减少;（2）从区位指数来看,各县的区位指数存在一定的差异,其中新和县的耕地区位指数均排在第一位,耕地聚集程度远高于全区平均和其他地区,沙雅县的耕地区位指数位于第二,聚集程度也高于全区平均值,库车县的耕地区位指数最小。【结论】经过近21 a的耕地扩展,耕地景观由已杂乱破碎斑块逐渐连接成片,耕地景观的优势进一步增加。降水和径流的增加为渭库绿洲耕地扩展提供了相对有利的气候条件,水利建设与人口增长是影响该绿洲耕地面积变化的主要原因。本研究提出的分析方法能快速、客观反映区域耕地格局的动态变化过程和差异特征,为耕地时空变化研究提供了一种新思路。

英文摘要：

【Objective】Spatial and temporal characteristics of cropland are a main part of the LUCC research and it is becoming more important for food security, land protection and environmental change. Xin Jiang plays a significant role for the protection and sustainable development of the land resource which is ranked the richest province in China, with the agricultural land. The Ugan-Kuqa river delta oasis is considered the most important ＂food and cotton resource area＂ which is the largest irrigated region in the Aksu district in Xin Jiang. The main objective of this study is to analyze the causes of spatial and temporal change of the cropland in the research area, from 1994 to 2015 over 21 years period. 【Method】 The cropland data were obtained from the Landsat images after processing based on the remote sensing platform. The changing rate, location index and plate density were selected for the analysis of the spatial and temporal changing dynamics of the cropland in recent 21 years for the research area. 【Result】（1）The results showed that significant changes in the distribution and extent of cropland were occurred that it covered a surface area of 2 488 km2（17% of the total area） in 1994, 3 931 km^2（26%） in 2015 with an annual increasing rate of 2.7%（68.71 km^2·a^-1）.The increased cropland mostly distributed in the margins of oasis and expanded to desert regions from the middle and upper reaches of the oasis. It could be attributed to agricultural activities and urban construction for increasing cropland and residential land, while the saline land and water land largely decreased;（2） Location index presented that there was a significant regional variation in 21 years period. The rank of location index was in the following order： XinheShayaKuqa, location index of the Xinhe and Shaya＇ counties was larger than mean value of the total area, becoming more concentration in distribution.【Conclusion】Cultivated landscape is becoming continuous from messy pieces over a 21-year period.