El Salvador - Groundwater research project lower basin of the rio Grande de San Miguel - Vol 2, app. 1, Geographic and hydrologic features, geology and exploratory drilling.

abastecimiento de agua alluvial soils approvisionnement en eau basalt cartografia cartographie cartography classification des sols cours d'eau cursos de agua drainage drenaje elemento primario del suelo farmland fertilidad del suelo flow rate fluid flow flujo gasto geographical distribution groundwater table hidrologia hydrologie hydrology infiltration irrigated land land use measurement mesure muestreo nappe souterraine primavera printemps regadio rivers rock sampling soil soil classification soil fertility soil parent materials soil texture soil types sol spring suelo terre agricole textura del suelo texture du sol tipos de suelos type de sol utilisation des terres volcanic soils water supply