白桐灌区在河南省南阳境内白河与桐河之间,耕地面积约160万亩,分属南阳、新野、唐河三县。灌溉水源是白河上的鸭河口水库。1958年以来。当地群众修建了一些渠系工程,收到一定的灌溉效益。但由于当初缺乏系统的规划,这些渠道中很大一部分截断和占据了天然河道,打乱了原有排水系统,加之渠首工程属临时性的,引水保证程度极 Bai Tong Irrigation District in Nanyang City, Henan Province, the White River and Tong River between cultivated area of ​​about 160 mu, belonging to Nanyang, Xin Ye, Tanghe three counties. Irrigation source is the Duhekou reservoir on the White River. Since 1958. The local people built some canal systems and received some irrigation benefits. However, due to the lack of systematic planning at the beginning, a large part of these channels cut off and occupied the natural river channels, disrupted the existing drainage systems, and the headworks were temporary. The degree of water diversion