中文摘要：

唐代“河曲”地域呈现着农业经济与牧业经济并存、各有发展的局面。两种人类社会经济活动对自然环境的作用与影响，显示出明显的差异。农业经济基本上分布在“河曲”的边缘地带及黄河沿岸土壤基础、水源条件、地形条件较为优越的地方，使得人类农业经济行为和自然环境间的作用与反作用大体处在相对均衡的态势；畜牧业经济占据着“河曲”的大部分区域，其中定居型畜牧经济活动对局部草原环境施加了缓慢而深刻的影响，导致早期“毛乌素沙漠”的出现。两种人类社会经济行为对环境影响力度的差异相当明显，其原因就在于下列几个方面：封建政府民族政策因素、农牧人口数量差异、农牧人口地域分布差异、自然环境质量差异、利用土地资源方式及程度差异等。

英文摘要：

The ＂Hequ＂ region in the Tang Dynasty boasted of the co-existence and co-growth of agricultural economy and husbandry economy. These two human economic activities differred obviously in their roles in and impacts on natural environment. What accounted for the different roles in and impacts on natural environment were such factors as the ethnic policy of feudal government, imbalance of population between agriculture and husbandry, difference in dirtribution of agricultural population from that of husbandry population, difference in quality of natural environment and difference in means and level of using land resourses.