地面灌溉是目前我国和大多数国家的主要灌溉方式。以畦灌为例,将选定的灌水定额在纵横方向均匀地灌到田间,并尽量避免畦外泄水和深层渗漏。是畦灌的基本要求。要达到这一要求,就必须选择适宜的畦长(L),入畦单宽流量(q),和停水时间。而这些要素又与土壤渗透性能,畦田纵坡(i),畦面糙率 Surface irrigation is currently the main irrigation method in our country and in most countries. For example, pour irrigation, the selected irrigation quota in the vertical and horizontal directions evenly into the field, and try to avoid the water leakage and deep leakage. Is the basic requirements of irrigation. In order to meet this requirement, it is necessary to select the appropriate length (L), inlet width and flow rate (q), and stop time. And these elements and soil permeability, 畦 Tian longitudinal slope (i), 畦 surface roughness