Utilizing recent climate data in eastern texas to calculate trends in measures of aridity and estimate changes in watering demand for landscape preservation

Abstract

Eastern Texas houses a transition zone from semiarid conditions in the far west to some of the wettest areas of the continental United States not influenced by mountainous terrain. The region, vulnerable to drought and flooding rains, is projected to experience higher water demand with its growing population. In the coming decades, municipal consumption, including water for landscape preservation, will supplant irrigation as the largest usage category. The amount of supplemental water required to maintain plantings is dependent on evapotranspirative demand and precipitation patterns. Reference evapotranspiration can be calculated using four daily climate parameters in the FAO-56 Penman–Monteith equation. This was combined with soil moisture capacity and daily accumulated precipitation to determine historical evapotranspiration rates at 14 observation stations across the eastern region of Texas from 1973 through 2017 and allowed for the creation of a recursive algorithm that introduced supplemental water for vegetation preservation as conditions crossed thresholds of dryness. Time series data analysis showed an increasing degree of aridity, as higher temperatures have decreased relative humidity and dry periods have become more prolonged and severe under stable average annual precipitation totals. Without additional increases in rainfall, the region is expected to continue its drying trend, leading to moisture-stressed plant life and higher water demands to maintain landscapes in a well-watered state.