干旱区绿洲土地利用与覆被变化过程

应用遥感和GIS技术及数理统计学方法，以新疆三工河流域冲洪积扇－冲积平原型绿洲为研究区，利用1978年、1987年和1998年的遥感数据，深入研究了70年代中后期以来干旱区绿洲LUCC的过程和趋势。结果表明：（1）遥感和GIS在绿洲土地利用与覆被变化数据获取和空间分析方面是一种非常强大而有效的技术手段；（2）通过建立绿洲LUCC的幅度、速度、区域差异和变化趋势数学模型，可以较好的研究绿洲土地LUCC的过程和趋势，如变化的双向性、单向性、正向性和反向性，变化的纱势或落势等，在三工河流域绿洲应用取得良好效果；（3）自70年代中后期以来三工河流域绿洲LUCC趋势，并存在显著的时空差异；前期绿洲LUCC处于单向转换过程的非平衡状态，并呈现一定的地段分异，其中绿洲上部处于淮平衡状态，而绿洲中部和下部处于非平衡状态。后期绿洲LUCC呈现双向转换为主的发展态势，使绿洲LUCC处于淮平衡状态；绿洲上部和中部处于非平衡状态，绿洲下部处于平衡状态，均表现出不同的变化过程和趋势。

Process of Land Use/ Land Cover Change in the Oasis of Arid Region

Using remote sensing imagery data of 1978, 1987 and 1998, and tak in g the typical oasis in alluvial-diluvial fan/alluvial-plain type in Sango ng River basin as the study area, the process and trend of oasis LU CC are analyzed by applying the methods of remote sensing (RS), geograp hic information system (GIS) and statistics. The main results of oasis LUCC in Sangong River basin are as follows. (1) RS and GIS are powerful techniques and m ethods in capturing oasis LUCC data and analyzing its spatial change. ( 2) Establishing mathematical models in the range, speed, regional diffe rences and trend index of LUCC, especially the model of LUCC trend and s tate, the process and trend of oasis LUCC can be deeply studied, including bi-direction process, single-direction process, positive and negative proces s, rising and falling trend, etc. These models are applied to oasis of Sangong River basin and satisfactory effects have been obtained. (3) The LUCC in oasis has had a slow tendency since 1978 and obviously shows tempor al and spatial differences. In the period of 1978-1987, the index of oasis LUCC trend and state was 0.58, which indicates that oasis LUCC presented non-equilibrium state with the transitional process in single direction and evident regional differences: the state of LUCC was qua si-balanced in the upper part of oasis, but non-balanced in the middle a nd lower parts of oasis. In the period of 1987-1998, the index of oasis LUCC trend and state was 0.3, which indicates that the state of oasis LUCC was quasi-balanced with the transitional process in bi-direction and showed the different regional changes compared with the period during 1987-1 998: the state of LUCC was non-balanced in the upper and middle parts of oasis, but balanced in the lower part of oasis. (4) No matter how qua ntitative change or spatial change, the speed of LUCC in the middle pa rt of oasis is the biggest among its parts and more than that of LUCC of ent ire oasis; the next is the lower part and the smallest is the upper part, whose speeds are all less than that of LUCC of entire oasis.