Effects of the 2011 Texas Drought on Soil Moisture Capacity in the

Somerville WatershedChris Ingenloff

22 November 2011

Introduction Background Problem Definition Watershed Statistics Methodology Required Work

Agenda

Brazos River Basin Lake Somerville

Watershed

Introduction

Texas 2011 Drought◦ High temperatures◦ Low precipitation◦ Record low reservoir

levels High demand for

sustained soil moisture

Similar conditions expected for the next 1-2 years

Background5%

5% 1%

11%

12%

2%

21%

15%

7%

16%

5%

Somerville Basin Land Cover

Open Water

Developed

Barren Land

Deciduous Forest

Evergreen Forest

Mixed Forest

Shrub/ Scrub

Grassland/ Herbaceous

Pasture/ Hay

Cultivated Crops

Wetlands

Soil Recovery and “Memory”◦ Porosity◦ Field Capacity◦ Wilting Point◦ Residual Moisture

Content

The Problem

Watershed Statistics

0.001

0.01

0.1

1

10

100

1000

10000

100000

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0

Flow (cfs)

Percent Occurrence

Flow Probability in the Somerville Basin

Middle Yegua Creek

East Yegua Creek

Davidson Creek

Yegua Creek at Someville

-40

-20

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9 10 11 12

Temperature(F)

Month

Temperature Statistics in the Somerville Watershed

Mean

Average High/Low

Standard Devation

Average 2010 High

Average 2011 High

2012 Projection

0

2

4

6

8

10

12

1 2 3 4 5 6 7 8 9 10 11 12

Precipitation(in)

Month

Precipitation Statistics in the Somerville Watershed

Mean

Standard Deviation

2010

2011

2012 Projection

Spatial Moisture Content Prediction

Soil Recovery Coefficient

Quantitative Impact of Critical Moisture Content

Water Balance1) dSoil Moisture = Precipitation – Runoff – Evapotranspiration

Methodology

Soil Hydraulic Properties

(raster)

Statistical Precipitation

Model

Runoff/Flow Correlation

(raster)

Statistical Temperature

Model

Statistical ET Analysis

Evapotranspiration Statistical Analysis◦ MODIS Toolbox

LDAS Soil Data to Raster Evaluate

Required Work

Questions?