平原区【plain terrain】指的是地形宽广平坦或略有起伏，地面自然坡度很小的地区。
在河北低平原区对引进的11个紫花苜蓿品种进行了三年的比较试验。
The comparison experiments were conducted with 11 domestic and overseas alfalfa varieties in the Hebei Lowland Plain Area.
溶滤和蒸发作用是内陆干旱盆地平原区松散沉积层地下水咸化的主要原因。
Lixiviation and evaporation are main salinization processes of groundwater stored in loose sediments in inland arid basins.
初步评价结果表明，我国地下水水质形势严峻，劣质水分布面积占平原区面积近60%。
The results show that groundwater is seriously polluted as poor quality water covers nearly 60% of the plain regions.
应用推荐