Drought

The Wind River Indian Reservation (WRIR) in west-central Wyoming is home to the Eastern Shoshone and Northern Arapaho tribes, who reside near and depend on water from the streams that feed into Wind River. In recent years, however, the region has experienced frequent severe droughts, which have affected tribal livelihoods and cultural activities. Scientists with the North Central Climate Adaptation Science Center (NCCASC) at Colorado State University, the National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln, and several other university and agency partners in the region worked in close partnership with tribal water managers to assess how drought affects the reservation, which included the integration of social, ecological, and hydro-climatological sciences with local knowledge. The study revealed a long history with drought in the region, as well as issues that limit the tribe’s ability to manage their water resources. In addition, changing hydroclimate conditions were identified that can result in changing drought characteristics, which increases the need for adaptive management strategies. The findings are helping to inform the creation of a climate monitoring system and drought management plan, which have been supported with additional technical and financial support from the High Plains Regional Climate Center (HPRCC) and NOAA’s National Integrated Drought Information System (NIDIS). The drought plan will integrate climate science with hydrologic, social and ecological vulnerabilities and risks, and identify response capacities and strategies to support the Tribal Water Code and related resources management. Ultimately, the plan will help the tribes ensure that agricultural and other societal needs are met during times of drought. As part of the project, tribal water managers and the public were also engaged in educational activities related to water resources and drought preparedness through joint activities with Wyoming Experimental Program to Stimulate Competitive Research (EPSCoR) to build the tribe’s ability to response to future drought.

This project supported the activities of the Climate Foundational Science Area (FSA) at the North Central Climate Science Adaptation Center (NC CASC). These activities included foundational research into drought processes relevant to the different climatic zones and ecosystems in the NC CASC region. We examined role of the atmospheric thirst for water from the land surface (aka, Evaporative Demand), how that may change during the 21st century and affect drought related risks in the future. We developed and did outreach with a drought index called the Evaporative Demand Drought Index (EDDI), that solely looks at the Evaporative Demand parameter, for its drought early warning potential, its ability to capture flash droughts and indicate persistence of severe drought conditions. Our research also examined how mountain snowpack is changing in the Intermountain West region of our domain, what processes are driving that change. For this, we focused on Wyoming’s Wind River Mountain Range because of its relevance to water resources for the Wind River Indian Reservation. Our findings show that as the region is experiencing warming, the snowline is shifting up and proportionally more rain is falling as precipitation than snow during the cold season leading to lower snowpack thickness and earlier melt. Climate FSA through this project was extensively involved in supported several NC CASC projects and stakeholders in providing assistance with climate science understanding, and use and provision of climate data. We have developed a strong stakeholder network in the region, and, in several cases, maintained a sustained engagement to promote literacy and integration of relevant climate science and data into understanding ecological impacts and develop strategies to foster resiliency in different social-ecological systems.

The purpose of this study was to understand how the U.S. Department of Interior’s federal land and resource managers and their stakeholders (i.e., NPS, BLM, FWS, BOR, BIA and tribes, among others) are experiencing and dealing with drought in their landscapes. The database is part of the Drought Risk and Adaptation in the Interior project. We conducted in-depth interviews (n=41) with DOI and tribal land managers in three case sites across the north central United States (northwest Colorado, southwest South Dakota, and Wind River Reservation), the goal of which was to develop a better understanding of drought vulnerabilities, risks, and responses in high-risk, multi-jurisdictional landscapes across the Missouri River Basin. DRAI posed the following research questions: 1. How do different resource managers from the Department of Interior (DOI), other federal agencies, and tribal communities perceive and characterize drought risk for the lands they manage? 2. How are their respective grassland/rangeland, fish and wildlife, and forest management decisions affected by those drought risk perceptions? 3. What indicators (e.g., climate science, local knowledge) are used to document and understand drought conditions and progression? 4. What are the impacts of drought to key management targets and livelihoods? 5. What are their differential capacities (and barriers) for responding to and preparing for drought risks? Data was analyzed using a grounded-theory approach, where risk perceptions, responses, and capacities to respond are derived from the stakeholders themselves. The database includes 41 in-depth interview transcripts with DOI (USFWS, BLM, NPS, BIA) land/resource managers, state and district water administrators, and tribal land and resource managers from 3 case sites. A range of expertise was represented in these interviews and included water resource managers/engineers, ecologists, wildlife biologists, fire coordinators, rangeland management specialists, among others. Each transcript has been coded, analyzed, and compared across cases and management situations in the context of the 5 overarching questions, as well as in the context of the inter-related climate drivers, ecological impacts, and adaptation/responses in the context of drought and climate change. The database includes 300+ social, climate, and ecological codes that describe the social-ecological context of drought and drought management in each respective case. See cross-listed publications and reports for major findings.

Preparing for and responding to drought requires integrating scientific information into complex decision making processes. In recognition of this challenge, regional drought early warning systems (DEWS) and related drought-information tools have been developed under the National Integrated Drought Information System (NIDIS). Despite the existence of many tools and information sources, however, the factors that influence if a tool(s) is (are) used, which tools are used, and how much benefit those tools provide remain poorly understood. Using the Upper Colorado River DEWS as a case study, this study investigated how water, land, and fire managers select from among many available tools. The Upper Colorado River Basin (UCRB) was one of the first pilot areas, beginning in 2009, for implementation of a regional drought early warning system (DEWS) under the NIDIS program, which now supports eight regional DEWS. (In 2016, the UCRB DEWS was expanded and reconfigured into the Intermountain West DEWS). The selection of the UCRB for a pilot DEWS reflects the regional importance of drought monitoring for managing water supply for agriculture and other uses, and the need for effective decision support related to drought. New drought-information tools were developed specifically for the UCRB DEWS, and a number of others have been created since 2009, adding to the pre-existing toolkit for drought decision making. The various tools that are now available in the Upper Colorado River Basin region can be expected to be more or less suitable for different decision makers’ needs. As a result, the broad decision context of this case study (managing drought) was fixed, but the information needs of users varied. This provided the opportunity to examine the varied choices decision makers make about which of the available tools to use or not use. The research identified four broad categories of tool use that map to particular decision contexts. Water supply managers, land managers with rangeland management responsibilities, land managers focused on ecological health, and fire managers each use a suite of indicators and tools that match their particular decision context and timeframe at which they make decisions. Important differences also emerged in how respondents find out about tools, with water managers reporting strong inter-agency connections while land managers tend to rely on information from others within their agencies. Fire managers also play a key role in keeping others in the land management agencies informed about drought.

Drought is a complex environmental hazard that impacts both ecological and social systems. Accounting for the role of human attitudes, institutions, and societal values in drought planning is important to help identify how various drought durations and severity may differentially affect social resilience to adequately respond to and manage drought impacts. While there have been successful past efforts to understand how individuals, communities, institutions, and agencies plan for and respond to drought, these studies have relied on extensive multi-year case studies in specific locations. In contrast, this project seeks to determine how social science insights and methods can best contribute to ecological drought preparedness and resilience in situations where extensive field study is not feasible.  Specifically, the project team will investigate what a rapid social assessment method might look like in the context of ecological drought, how it may be applied, and what benefits it may contribute to drought preparedness and resilience. This method would allow researchers to expeditiously identify and analyze relevant characteristics of the social system that have bearing on the problem of ecological drought and allow water and resource managers, community leaders, and others involved with drought preparedness and response to quickly identify, assess, and measure important social factors that influence the effects of drought to ecosystems. This project will include analyzing currently available rapid assessment methods from other topical areas (including ecological, rural, hazards, etc.) to inform the method to be developed by providing relevant design criteria. A prototype version of the method will be developed and pilot tested with the identified audience to determine effectiveness and strengths and weaknesses.  Finally, the method will be refined and made available more widely to Department of Interior resource managers.

Landscape Evaporative Response Index (LERI) is remotely-sensed high-resolution information of the evaporative response from the land in near real time. LERI assesses anomalies in actual evapotranspiration (ETa), as percentiles, across the Contiguous US and northern Mexico at a 1-km spatial resolution. LERI is based on the ETa data produced by the U. S. Geological Survey using the operational Simplified Surface Energy Balance (SSEBop) model. SSEBop combines evapotranspiration fraction generated from remotely sensed MODIS thermal imagery, acquired every 8 days, with climatological atmospheric evaporative demand. To quantify LERI, a rank-based, non-parametric method is used to estimate percentiles of the SSEBop ETa, over a period of ETa accumulation, compared to the available period of record (January 2000 to present). LERI percentiles are also binned into four drought categories (LD0 - LD3) analogous to the US Drought Monitor (USDM) categories (i.e. D0-D3) and using the same percentile breaks that USDM considers for soil moisture. By its numerical design, LERI essentially represents the evaporative response of the landscape driven primarily by the anomalous state of soil moisture to meet the climatological atmospheric demand through a combination of evaporation (from soil and leaf surfaces) and transpiration (root-stomata-air) processes. Real-time and high-resolution assessment of this soil moisture state is extremely salient to understanding and forecasting ecological responses. LERI serves as an experimental drought-monitoring and early warning guidance tool and has the potential to inform research into understanding characteristics of Ecological Drought. Preliminary work finds LERI to closely track modeled moisture conditions in the upper soil layers (~10 cm). LERI can complement other drought-monitoring indices and modeled soil moisture products. Work is ongoing to assess LERI’s ability to capture signals of drought early warning, and its unique ability to assess land-surface moisture state. LERI maps, and spatial and historical time series data could be accessed at https://www.esrl.noaa.gov/psd/leri/.    

This project facilitated the engagement of the North Central Climate Adaptation Science Center’s (NC CASC) Climate Foundational Science Area (FSA) to identify and address the physical climate science challenges that are important for ecologists and natural resource managers in the NC CASC region, as well as meet their needs for climate information to assess impacts to their desired system and develop strategies for effective climate adaptation. A drought index called the Landscape Evaporative Response Index (LERI) was developed to provide a near real-time assessment of soil moisture conditions across the Contiguous United States (CONUS) based on satellite observations. This projects also supported development of climate scenarios for different stakeholder-driven projects. New utilities were added to another drought index, the Evaporative Demand Drought Index (EDDI), that our team has previously developed. The project team also put together a book chapter that examinesthe relevance of the concept of evaporative demand and extremes in evaporative demand during the 21st century for drought assessment and monitoring.