Using Remote Sensing to Understand Water Use in the Milk River Basin
The U.S. and Canada share water from the Milk River that is used to support agricultural irrigation, drinking water, recreation, and wildlife habitat. To help managers make more informed decisions about how to divide the water between the countries, U.S. Geological Survey (USGS) scientists used satellite images and a computer model. This model provides monthly and annual estimates of actual evapotranspiration across the river basin. Evapotranspiration estimates help scientists understand the amount of water that leaves the basin through evaporation, human consumption, and plant use. Understanding the amount of water available in the basin can help managers make more precise decisions about water allocation.
The Milk River flows 729 miles from its headwaters near Browning, Montana through southern Alberta, Canada and back into eastern Montana until it meets the Missouri River near Fort Peck. The river is an important resource for both countries, providing drinking water, irrigation water, recreational opportunities, and wildlife habitat. The amount of water flowing in the river is increased by the St. Mary Canal, which diverts water from the St. Mary River to the Milk River.
Canada and the U.S. have had a long-standing agreement to share the river's water based on the 1909 Boundary Waters Treaty and subsequent 1921 Order. To determine the amount of water that can be withdrawn by each country, scientists currently use “natural-flow calculations” – calculations that determine what the flow of the river would be without human influence.
Understanding water use in the Milk River Basin
To improve the accuracy of water apportionment calculations between the U.S. and Canada, USGS scientists modified a remote sensing model called the Operational Simplified Surface Energy Balance model (SSEBop). This model uses satellite and climate data to estimate monthly and annual evapotranspiration rates within the Milk River Basin from 1985 to the present. These data help scientists understand the amount of water that leaves the basin through evaporation, human consumption, and plant use. Additionally, this project is comparing historical trends in consumptive water use generated by the model to estimates from different methods. The resulting data could be integrated into, or used alongside, natural flow calculations to help inform decisions about water apportionment in the basin. More precise water allocation information could help ensure that the municipal, agricultural, and ecological needs of the basin are met, and the flow of the river is maintained according to the 1909 Treaty.
Improving water management through modeling
Ultimately, this USGS project represents a step towards a more nuanced and accurate understanding of water dynamics within the international Milk River Basin. By combining consumptive water-use data from advanced modeling and on-the-ground measurements, the research can supplement natural-flow calculations. This can provide a more comprehensive foundation for water apportionment decisions. As the project progresses through its final phase, the insights gained will help to inform current management practices and offer a framework for addressing future challenges.
The U.S. and Canada share water from the Milk River that is used to support agricultural irrigation, drinking water, recreation, and wildlife habitat. To help managers make more informed decisions about how to divide the water between the countries, U.S. Geological Survey (USGS) scientists used satellite images and a computer model. This model provides monthly and annual estimates of actual evapotranspiration across the river basin. Evapotranspiration estimates help scientists understand the amount of water that leaves the basin through evaporation, human consumption, and plant use. Understanding the amount of water available in the basin can help managers make more precise decisions about water allocation.
The Milk River flows 729 miles from its headwaters near Browning, Montana through southern Alberta, Canada and back into eastern Montana until it meets the Missouri River near Fort Peck. The river is an important resource for both countries, providing drinking water, irrigation water, recreational opportunities, and wildlife habitat. The amount of water flowing in the river is increased by the St. Mary Canal, which diverts water from the St. Mary River to the Milk River.
Canada and the U.S. have had a long-standing agreement to share the river's water based on the 1909 Boundary Waters Treaty and subsequent 1921 Order. To determine the amount of water that can be withdrawn by each country, scientists currently use “natural-flow calculations” – calculations that determine what the flow of the river would be without human influence.
Understanding water use in the Milk River Basin
To improve the accuracy of water apportionment calculations between the U.S. and Canada, USGS scientists modified a remote sensing model called the Operational Simplified Surface Energy Balance model (SSEBop). This model uses satellite and climate data to estimate monthly and annual evapotranspiration rates within the Milk River Basin from 1985 to the present. These data help scientists understand the amount of water that leaves the basin through evaporation, human consumption, and plant use. Additionally, this project is comparing historical trends in consumptive water use generated by the model to estimates from different methods. The resulting data could be integrated into, or used alongside, natural flow calculations to help inform decisions about water apportionment in the basin. More precise water allocation information could help ensure that the municipal, agricultural, and ecological needs of the basin are met, and the flow of the river is maintained according to the 1909 Treaty.
Improving water management through modeling
Ultimately, this USGS project represents a step towards a more nuanced and accurate understanding of water dynamics within the international Milk River Basin. By combining consumptive water-use data from advanced modeling and on-the-ground measurements, the research can supplement natural-flow calculations. This can provide a more comprehensive foundation for water apportionment decisions. As the project progresses through its final phase, the insights gained will help to inform current management practices and offer a framework for addressing future challenges.