基于主成分回归的河南省地下水硝酸盐脆弱性评价

Assessment of groundwater vulnerability to nitrate in He'nan Province of China based on principal component regression

根据水文与地貌特征将河南省分为山区和平原区,选取富水程度、降水入渗、单位面积施肥量、蔬菜种植面积比例和土壤质地作为共性指标,坡度和地下水埋深作为个性指标,利用主成分回归分析确定指标权重,在ArcGIS 9.2的支持下对河南省地下水硝酸盐脆弱性进行评价.结果表明,河南省地下水硝酸盐脆弱性程度以中低水平为主,中等脆弱性以下地区占总面积的68.4%,高脆弱性地区占19.8%,极高脆弱性地区占11.8%.影响河南省平原地区地下水脆弱性的主要因素依次为土壤质地、施肥水平和降水入渗,而影响山区地下水脆弱性的主要因素依次为施肥水平、土壤质地和坡度.研究结果为合理施肥和农业环境管理提供了理论依据.

According to the hydrological and morphological characteristics, He＇ nan Province was divided into mountainous region and plain region. The level of rich water, infiltration modulus of precipitation, fertilization level per unit area, proportions of vegetable planting area, and soil tex- ture were selected as the common indices, and the slope and groundwater depth were selected as specific indices to assess the groundwater vulnerability to nitrate. Principal component regression analysis was adopted to determine the index weights, and the spatial distribution of groundwater vul- nerability to nitrate in He＇ nan Province was assessed with ArcGIS 9.2. In the Province, the groundwater vulnerability to nitrate was mainly at low and medium level, and the region with this vulnerability level accounted for 68.4% of the total. The high vulnerability region accounted for 19.8%, and the extremely high vulnerability region occupied 11.8%. The main factors affecting the groundwater vulnerability to nitrate in plain region were soil texture, fertilization level, and infil- tration modulus of precipitation, while those in mountainous region were fertilization level, soil tex- ture, and slope. This study provided a theoretical basis for reasonable fertilization and agricultural environment management.