A constrained median statistical routing method and the Pecos River case

This paper develops a mathematical model of constrained nonlinear form for river routing. The data recorded at the gauges are usually estimates of the actual flow. Thus the model automatically makes best-fit adjustments for this data so as to preserve physical and hydrological conditions on the river basin. This best fit is accomplished by minimizing a heavily penalized sum of absolute deviations between the recorded and the adjusted data. The model simultaneously estimates new losses, reservoir storage, spill, and flood inflows. The new estimates conform to physical and hydrological conditions, such as mass balance. The model is applied to the case of the Pecos River and compared to previous studies performed on the river. The results show that a substantial amount of water is owed to Texas. On the average the water owed to Texas per year is 282,000 acre-feet, abovethe amount proposed by New Mexico by 60,000 acre-feet.