河北省土壤温度与干湿状况的时空变化特征

土壤温度和干湿状况是表征土壤特性的重要参数,在土壤系统分类中作为诊断土壤某些亚纲、土类及亚类划分的参考依据。基于河北省142个气象观测站1951—2010年的日值气象数据,利用GIS空间分析技术,对河北省近60年的土壤温度和干湿状况的时空变化规律进行了分析。结果表明:(1)1951—2010年的平均土温和平均干燥度指数呈现上升趋势,且1981—2010年的上升速率均高于1951—1980年。(2)河北省主要有冷性和温性两种土壤温度状况,与1951—1980年相比,1981—2010年的温性土壤向北有所移动,移动的距离和面积大约为14.26 km和5 665 km2。(3)河北省的土壤干湿状况分布具有明显的地域差异,地表干湿状况可分为湿润、半湿润和半干旱三个等级;东部和北部区域气候湿润状况优于西部和南部,也间接表明了土壤的干湿分布状况。该研究结果为土壤系统分类定量化的诊断特性取代传统土壤分类中的地带性概念提供参考。

Spatio-temporal variation of soil temperature and soil moisture regime in Hebei Province

Soil temperature and dry-and-wet state that have an influence on the physical, chemical and biological process of siol formation is an important parameter of characterizing the soil, and serve as the classification basis of some soil subclasses, soil type and subtype.At the same time,water and heat exchange between soil and atmosphere each other and climate influences the thermal and wet-and-dry state directly. Therefore, based on primary meteorological data of 142 meteorological stations during 1951-2010, the temporal and spatial variation of soil moisture and temperature state were analyzed by using the method of GIS technology in recent 60 years in Hebei province. The results show that(1) the annual average soil temperature and average aridity index of 1951-2010 years showed a rising trend, and rising rate of 1981-2010 years are higher than that of 1951-1980 years, which indicates that the arid soil of Hebei is presenting a slowly increasing state. (2)There are mainly two kinds of soil temperature conditions that are cold and warm soil respectively in Hebei province. Compared with 1951-1980 years, the moving distance of warm soil of 1981-2010 years is 14.26km and the area is 5664.67km2. (3)The distribution of soil wet-and-dry state has obvious geographical differences and the dry-wet status can be divided into the humid, semi humid and semi-arid in Hebei province. From the perspective of spatial distribution,the regions of high aridity are mainly distributed in a part of counties including Kangsang basin and Bashang Plateau so on.The regions of low aridity are mainly distributed in the southwest corner of Chegnde,north of Tangshan,most parts of north central in Qinghuangdao and small northern area.This shows that wet-and-dry state of the northern and eastern regions is superior to that of the south and west,which also indirectly indicates the distribution of soil moisture; From the perspective of time variation, compared with from 1951 to 1980, increasing aridity index of Bashang plateau,the east of Hebei and the south of Handan-Qinghe-Renxian-Pingxaing ranges from 0.01-0.85 during 1981-2010 and decreasing aridity index of northeast,northern plateau and eastern plain of south central region ranges from 0.01 to 0.59. This shows that dry-and-wet state of climate changes with time,which will affect status quo of soil moisture. The study provides reference for using diagnostic characteristics of quantification instead of the zonal concept of traditional soil classification.