Soil Moisture Budget Analysis of Texas Using Basic Climatic Data While Assuming a Possible Warming Trend Across the State.

摘要

The soil moisture regime across Texas was estimated using mean monthly precipitation and temperature data from the ten climatic divisions within the state while assuming an increase in temperature. A model was developed to calculate the monthly soil moisture regime across Texas based on 48 years of record and compare it with a predicted soil moisture regime based on a possible warming trend. Statistical analysis of the data revealed a linear relationship between mean monthly precipitation (MMP) and mean monthly temperature (MMT) existed across the state. The relationship worked best in relatively dry regions of the state between Oct and May and in all regions of the state during the hot and relatively drier summer months. Slope of the regression line of MMP on MMT was found to vary across the state and through the annual cycle. Generally, slopes indicate a decrease in precipitation statewide if temperatures are assumed to increase. A soil moisture profile was predicated using regression equations for the calculation of precipitation and PET as temperatures increased in the model. Only equations which were statistically significant (p-value < 0.05) were used to estimate precipitation as temperature increased 1 F between 1 F and 4 F. The mean monthly precipitation for the 48-year sample was used for months where the relationship was not significant. Growing seasons, or periods of time in which soil moisture is normally available for plant growth, in many regions of the state were shortened by months as temperatures increased within the model.