Graduation Year

2014

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Geography, Environment and Planning

Major Professor

Kamal Alsharif

Keywords

Agriculture, Ecosystem Services, Everglades, Everglades Agricultural Area, Sugarcane, Water

Abstract

A large part of the environmental restoration required by the Comprehensive Everglades Restoration Plan calls for more water-storage on lands south of Lake Okeechobee in order to restore the natural water flows of the Everglades watershed. The Everglades Agricultural Area (EAA) can be used for increased water storage in order to relieve coastal estuaries of excess water in the rainy season. This water storage can deliver additional ecosystem services of soil retention and reduced CO2 emissions that could compensate farmers for the cost of water storage by increasing long term farm profitability. The goals of this study were 1) to quantify the environmental and economic trade-offs of different water storage scenarios using water-tolerant sugarcane cultivars, and 2) to quantify the amount of water storage possible in the EAA under different water storage scenarios. A mathematical model was developed to calculate soil depth, soil subsidence, depth to the water table, sugarcane production, farm return, water storage and carbon loss for three different sugarcane cultivars with different water-tolerances. A GIS tool is also developed to estimate the amount of water storage possible in the EAA. The study found that even though water-tolerant sugarcane cultivars experience higher yields and net returns than non-water-tolerant cultivars the water storage costs with these water tolerant cultivars was greater. Raising water tables on farm lands did have the environmental benefits of reduced soil subsidence, extended farm life and increased years of water storage. However total CO2 emissions rise from 14 to 136%. Results of the GIS analysis revealed that water storage capacity for a DWT of 61 cm is 1,404,562 ac-ft, 1,417,400 ac-ft for DWT 45 cm and 1,474,692 ac-ft for DWT 20 cm. The GIS analysis was also able to identify flow ways that could possibly carry water south from Lake Okeechobee and ultimately to the WCAs south of the EAA. These results show that raising water tables in the EAA to deliver the ecosystem service of expanded water storage is overall more costly, but yearly costs are very low. Therefore water storage on farmlands is an affordable interim method of water storage.

Share

COinS