基于水资源分区和地貌特征的新疆耕地资源变化分析

以新疆1995、 2000、 2005及2008年4个时期的土地利用数据为基础,结合水资源分区、 SRTM-DEM和数字地貌等数据,分析了基于水资源分区和地貌特征的新疆耕地资源的变化特征,结果表明:①总体上,不同时段各水资源分区耕地空间分布稍有变化,但总体格局保持不变。不同时段各水资源分区的耕地面积有增有减,但增加量远超过减少量,耕地总体呈现出持续增长的趋势,从1995年到2008年,共增加126.39×10⁴ hm²。②对比4个时期26个水资源分区的耕地数值、 变化和升降形式差异,可将耕地变化形式归纳为上升、 先降后升、 先升后降和升降波动四大类。③新疆耕地空间变化存在分区差异。1995至2008年期间,耕地增加值最大者为叶尔羌河流域,为17.36×10⁴ hm²;而额敏河流域耕地面积缩减量最大,减少3.15×10⁴ hm²。④新疆耕地资源主要分布在2 000 m以下的低海拔和中海拔区域,其中以500~2 000 m区域分布最广;耕地资源主要分布于地势相对低缓的平原和丘陵区,以开发流水地貌类型的山前平原地带为主。新疆耕地变化具有很强的空间差异性,与水资源量及利用状况的空间分异密切相关。

Analysis of Cultivated Land Based on Water Resources Regionalization and Geomorphologic Characteristics in Xinjiang,China

Based on the method and technology of geographic information system (GIS) and statistical analysis, this paper quantitatively analyzes the spatial and temporal distribution and change characteristics of the cultivated land resources from 1995 to 2008 in Xinjiang. The dataset used includes land use data, water resources regionalization, and SRTM-DEM with a horizontal resolution of 90 m.
This paper firstly calculates the quantities and variation of cultivated land area in different periods in order to reflect the distribution and change characteristics of the cultivated land within 26 water resources regions possessed cultivated land area. The results show that: 1) The spatial distribution of cultivated land of every region in different periods slightly changed, and the whole pattern of cultivated land remained unchanged; the area of cultivated land of every region is increased or reduced, but the total area of all regions represents the trend of continuous growth from 1995 to 2008, the increased value is 126.39×10⁴ hm². And the increased rate of cultivated land in three periods is different, especially it is the highest from 2000 to 2005. 2) Through comparing the quantities, variation, rising and falling numerical differences of cultivated land of 26 water resources regions in different stages, variation mode of cultivated land can be grouped into four categories, namely the rising class, firstly falling-then rising class, firstly rising-then falling, rising-falling fluctuation class. 3)There are regional differences in the cultivated land change among water resources regions in Xinjiang. The Yarkand River Basin possesses the highest increased area of cultivated land from 1995 to 2008, the value is 17.36×10⁴ hm². And the area reduction of Emin River Basin is higher than other regions; the area of cultivated land reduced 3.15×10⁴ hm². 4) The cultivated land resources are distributed in low and middle elevation regions below the 2000 m, among which the most widely distributed is in 500-2000 m regions. The biggest change is observed in regions whose elevation is below 1500 m. The cultivated land area is increased both in plain terrain and hilly region, the new additional cultivated land is mainly distributed in plain landform. The piedmont plain area of fluvial landform types is mainly cultivated land resources from landform genetic types in Xinjiang.
There are observably spatial differences of the cultivated land in Xinjiang. The reclamation and desolation of the land become the main and marked characteristics in Xinjiang. Consequently, it is necessary to effectively control the reclamation speed of cultivated land in Xinjiang. To ensure that food safety, the decision maker in Xinjiang should consider how to stand out the local distinguishing feature and realize the sustainable development of oasis agricultural economy. The farmland distribution on the basis of local watershed water resources and geomorphologic characteristic should be reasonably planned.