以深圳石岩水库流域为研究对象,基于遥感土地覆被和水质实时监测数据,采用比较和数理统计方法探讨了城市化影响下水源地土地利用空间分异的地表水环境效应.结果表明,监测时段流域支流水质均为劣V类,对水库供水安全产生较大威胁;建设用地产生的径流污染程度较高:在农业为主的流域,随降雨量增大,径流污染表现出冲刷增浓效应,而在城建流域则表现出稀释效应;COD和NH3-N在不同雨情之间的差异主要出现在城建区,而总氮(TN)和总磷(TP)在不同雨情之间的差异则主要出现在农业区.由于人口聚集、都市农业开发和城建用地扩张等城市化特征给自然流域的径流水质带来严重的影响.
Taking Shiyan reservoir watershed in Shenzhen City as a case, the effects of urbanization and land use on surface water quality using statistical methods were studied. Classification of remotely sensed image and field investigation were carded out to obtain the data of land use/cover. Land use pattern of sub-watersheds were characterized with cluster analysis. The runoff samples of every sub-watershed were analyzed from dry seasons to rainy seasons. All runoff water quality was worse than the 5th class according to the national surface water quality criterion; urban area was the main source of various pollutants; the compound pollutants index was increscent in agricultural watershed with the increase of rainfall amount, but the trend was the contrary in urban watershed; and the statistical difference for COD and NH3-N concentration among various rainfall existed mainly in urban watershed, while the difference for TN and TP existed mainly in agricultural watershed. Urban growth, population explosion and industrial and agriculturai land use severely affected the water quality of natural watershed.