Relationship and Its Experimental Verification between Uniformity Coefficient and Distribution Uniformity under Sprinkler Irrigation

To explore the relationships between uniformity coefficient(CU)and distribution uniformity,a detailed theoretical analysis was carried out and the relationships were verified through uniformity coefficient experiments under sprinkler irrigation.According to different methods for partial measuring points,the distribution uniformity coefficients included low quarter distribution uniformity(DUlq),high quarter distribution uniformity(DUhq),low half distribution uniformity(DUlh)and high half distribution uniformity(DUhh).The results showed that DUhqand DUhhwere always bigger than CU.The relationships between DUlqand DUlh with CU were determined by the specific test data.Therefore,it is necessary to choose different coefficient as evaluation criteria of spray irrigation depending on the local circumstances.