西藏“一江两河”流域耕地适宜性评价及布局合理性分析

Suitability evaluation and layout rationality analysis of on cultivated land in the Yarlung Zangbo River,Nyangqu River and Lhasa River Region,Xizang

针对高效精准掌握耕地适宜性对于农业政策制定、农业规范管理等的现实意义,该文以西藏“一江两河”流域为研究区域,选取地形、气候、区位、土壤和土地利用条件5个方面的12个评价因子,采用加权指数和法、限制因素法和层次分析法相结合的方法对流域耕地适宜性进行评价。在此基础上,通过2021年耕地现状的布局合理性分析,提出相应的耕地优化建议。结果表明:1)受地理位置、海拔等因素的限制,“一江两河”流域总体耕地适宜性程度一般,其中高度适宜区面积为10737.57 km^(2),占流域总面积的4.18%;中度适宜区占3.54%;勉强适宜区占8.16%;不适宜区占比最高,为84.12%。2)“一江两河”流域耕地高度适宜区主要集中在雅鲁藏布江、拉萨河及年楚河中下游两侧区域,从行政区划看,具体分布在日喀则、林芝市、拉萨市、山南市。3)2021年流域现状耕地以高度适宜和中度适宜为主,中度适宜及以上标准的耕地总面积为2694.06 km^(2),占耕地总面积的87.27%。总体来看,研究区现状耕地的适宜性较高,耕地布局较为合理。

In view of the practical significance to master the cultivated land suitability efficiently and accurately for agricultural policy formulation and agricultural standardized management,twelve evaluation factors included in the five aspects of terrain,climate,location,soil and land use conditions were selected to evaluate the cultivated land suitability by using the weighted exponential sum method,restriction factor method and analytic hierarchy process in this paper,which were based on the actual situation of Yarlung Zangbo River,Nyangqu River and Lhasa River Region,Xizang.On this basis,through analyzing the layout rationality of cultivated land in 2021,the corresponding suggestions for optimizing cultivated land were put forward.The results showed that:1)Limited by geographical location,elevation and other factors,the overall suitability of cultivated land in the research area was general,there were 10737.57 km^(2) highly suitable cultivated land,accounted for 4.18% of total cultivated land.The moderately suitable area accounted for 3.54%,the marginally suitable area accounted for 8.16%,the proportion of unsuitable cultivated land was the highest,accounted for 84.12%.2)The highly suitable cultivated land were mainly located in middle and lower reaches of Yarlung Zangbo River,Nyangqu River and Lhasa River.From the perspective of administrative division,specifically distributed in Shigatse,Nyingchi City,Lhasa City and Shannan City.3)The cultivated land of 2021 was mainly highly suitable and moderately suitable,there were 2694.06 km^(2) cultivated land of moderately suitable and above standards,accounted for 82.27%of total cultivated land.On the whole,the suitability of current cultivated land in the study area was higher,the layout of cultivated land was reasonable.