*2.3. Scenario Development*

The primary management practices of irrigated and dryland cotton under the baseline scenario in the DMFB basin are listed in Table 2. A flowchart of the modeled cultivation practices in the Texas Panhandle is shown in Figure 2. As for the classification of hydroclimatic years, if the precipitation of an individual year was 25% lower than the long-term average (1994–2009) annual precipitation of 517 mm, it was identified as a dry year. Likewise, if the precipitation of an individual year was 25% higher than the long-term average, it was treated as a wet year. The remaining years were considered normal years. According to the aforementioned classification of the hydroclimatic regimes, the dry years were 1994, 1998, and 2003. The wet years were 1997, 2004, and 2007. For the scenario development of alternative cultivation practices, ten scenarios were simulated under each hydroclimatic condition in this study, including two alternative irrigation application depths of 12.7 mm (0.5 inch) and 38.1 mm (1.5 inches) per application for irrigated cotton, two alternative planting dates of early planting (a half month ahead) and late planting (a half month delay) for irrigated and dryland cotton, and two alternative maturity cultivars of short-season cotton (5% less accumulation of heat units to maturity) and long-season cotton (5% more) (Table 3). The selected irrigation application depths represent associated irrigation management by local growers across the Texas Panhandle due to diverse well capacities and soil water holding capacities. The alternative planting dates chosen in this study cover the

usual cotton planting window in this region. The short- and long-season cotton cultivars are commonly used locally in response to the changing climate and management needs.

**Table 2.** Management practices for irrigated and dryland cotton production under the baseline scenario in the Double Mountain Fork Brazos basin.

