中国典型山区农业水土资源匹配格局变化——以太行山区、横断山区、黔桂喀斯特山区为例

为了解中国典型山区农业水土资源分布的匹配程度及其格局变化,研究以区域内单位面积耕地拥有的农业水资源量刻画太行山区、横断山区和黔桂喀斯特山区农业水土资源的时空匹配情况。结果表明：① 三大山区耕地分布的集中程度较高。太行山区的耕地主要分布在河北境内的北段地区和山西境内的南段地区,横断山区的耕地主要分布在南段地区,喀斯特山区的耕地分布呈现“南北多中部少”的格局。② 三大山区农业水资源的分布及变化都主要集中在低海拔地区。太行山区的农业水资源主要分布在山西、河南段,横断山区的农业水资源主要分布在四川境内,喀斯特山区的农业水资源较均匀地分布在广西和贵州境内。③ 太行山区农业水土资源匹配程度较差,横断山区、喀斯特山区农业水土资源匹配程度较好。2000—2015年间,太行山区中部、横断山区东部、喀斯特山区南部地区的农业水土匹配程度有变好趋势,而太行山区南部、横断山区西南部、喀斯特山区北部地区的农业水土匹配程度有变差趋势。研究时段内,太行山区的水田转旱地情况突出,太行山区也是三大山区中农业水土资源匹配程度最差的,应该关注太行山区的用水压力,重视农田水利设施维护和农田灌溉水有效利用。

Spatio-temporal variations of the matching patterns of agricultural land and water resources in typical mountainous areas of China

To understand the matching degree and pattern change of agricultural soil and water resources in three typical mountainous areas of China, the matching coefficient of agricultural soil and water resources was introduced to describe the spatial and temporal matching patterns of land and water resources in the study region by the amount of agricultural water resources on the unit area farmland. The results show that: (1) the concentration degree of farmland distribution in the three areas is high. The farmland in the Taihang Mountains is mainly distributed in the northern part of Hebei province and the southern part of Shanxi province, while it is mainly found in the southern part of the Hengduan Mountains. The farmland in karst mountains shows a distribution pattern of "more in the north and south, while less in the center". The farmland in the Taihang and karst mountainous areas decreased first, then increased and again decreased with the increase of elevation. The farmland in the Hengduan Mountains increased first, then decreased, again increased and decreased with the increase of elevation. (2) The distribution and change of agricultural water resources are mainly concentrated in low altitude areas. The agricultural water resources in the Taihang Mountains are mainly distributed in Shanxi and Henan, those in Hengduan Mountains are mainly distributed in Sichuan, and those in the karst mountains are evenly distributed in Guangxi and Guizhou. From the spatio-temporal variations, during 2000-2015, the agricultural water resources in the Taihang Mountains decreased by 6.22%, mainly in Beijing and Henan; those in the Hengduan Mountains decreased by 8.15%, mainly in Yunnan and Sichuan; the agricultural water resources in karst mountains increased by 5.52%, mainly in Guangxi. (3) The matching degree of agricultural soil and water resources in the Taihang Mountains was low, while that in the Hengduan Mountains and karst mountains was high. From 2000 to 2015, the matching degree of agricultural soil and water resources improved in the central Taihang Mountains, eastern Hengduan Mountains, and southern karst mountains, while that in southern Taihang Mountains, southwestern Hengduan Mountains, and northern karst mountains has worsened. During the study period, the conversion of the paddy field to dry land in the Taihang Mountains is prominent, and the matching degree of agricultural soil and water resources in the Taihang was the worst among the three mountainous areas. We should focus on the water pressure in the region, the maintenance of irrigation facilities and the improvement of the effective utilization coefficient of irrigation water.