经济合理地确定排涝区的调蓄水位

DECIDE ECONOMICALLY AND REASONABLY THE PONDAGE WATER-LEVEL OF THE STORM DRAINAGE AREA

排涝区一般都利用低洼地作为调蓄区；调蓄水位高则排涝保护面积少，效益也低；调蓄水位低则反之，通过效益和费用分析，作效益和费用曲线图，确定调蓄水位临界值，以确定经济合理的调蓄水位．

The storm drainage area takes ordanarily the bottom land as the pondage area. If the pondage water-level is high, the storm drainage protection area would be little, the benefit is low. If the pondage water-level is low, conversely, the benefit is high. Through benefit and cost analysis, we can draw the benefit and cost curve and decide the critical valLle of the pondage water-level in order to decide the economical and reasonable pondage water-level.