Introduction
Background
Traditional drought categorization approached from various perspectives including meteorological, hydrological, agricultural, and socio-economical. However, over the past few decades, new types of drought including snow drought has emerged. Snow plays an important role in global water resource supply, climate and biogeochemical processes. Snowmelt as freshewater supply can feed over 1 billion people around the world. People rely on snow for various activities such as consumption, agricultural use, industrial use and socioeconomical use. For mid-to-high latutude countries, snow precipitation usually contributes a large portion to surface water resources. Under current climate change pattern, drought event has shown an increasing pattern both for its frequency, duration and intensity. This increasing trend in climate pattern can accelerate various climate-related processes such as water cycle, atmospheric circulation pattern, oceanic circulation pattern and so on. With global warming, snow is experiencing a drastic change in various ways, including less snow accumulation or early snowmelt event, which will be an issue for future water supply, especially for snow-dominated regions. These factors can be further used to categorize snow drought: warm snow drought, indicating an early snowmelt despite near-normal precipitation level, and dry snow drought, representing the lack of snow accumulation. Hence, the study of the future snow situation and how it may impact water supply is imperative.
Traditional drought categorization approached from various perspectives including meteorological, hydrological, agricultural, and socio-economical. However, over the past few decades, new types of drought including snow drought has emerged. Snow plays an important role in global water resource supply, climate and biogeochemical processes. Snowmelt as freshewater supply can feed over 1 billion people around the world. People rely on snow for various activities such as consumption, agricultural use, industrial use and socioeconomical use. For mid-to-high latutude countries, snow precipitation usually contributes a large portion to surface water resources. Under current climate change pattern, drought event has shown an increasing pattern both for its frequency, duration and intensity. This increasing trend in climate pattern can accelerate various climate-related processes such as water cycle, atmospheric circulation pattern, oceanic circulation pattern and so on. With global warming, snow is experiencing a drastic change in various ways, including less snow accumulation or early snowmelt event, which will be an issue for future water supply, especially for snow-dominated regions. These factors can be further used to categorize snow drought: warm snow drought, indicating an early snowmelt despite near-normal precipitation level, and dry snow drought, representing the lack of snow accumulation. Hence, the study of the future snow situation and how it may impact water supply is imperative.
Research objectives
This study aims to understand the following questions:
1. Assess the different processes affecting variation of snow drought under different hydroclimatic and ecological regions including mountains, foothills and plains
2. Apply the findings to future water resource management situation, for example, how to properly store an early snowmelt runoff for later use? How to properly extract water from alternative water source when snow precipitation is insufficient?
3. From water resource management perspective, there are a few factors that needs to be determined:
(1) How do we quantatively define under what condition can we define that there is a drought event?
(2) How do we properly establish drought monitoring system and drought warning system?
(3) How to effectively use and reserve water from both macro and micro perspective?
(4) How do we deal with transparency issues for policy making and decision making from authorities?
(5) How do we protect water resource from other perspectives such as soil conservation?
This study aims to understand the following questions:
1. Assess the different processes affecting variation of snow drought under different hydroclimatic and ecological regions including mountains, foothills and plains
2. Apply the findings to future water resource management situation, for example, how to properly store an early snowmelt runoff for later use? How to properly extract water from alternative water source when snow precipitation is insufficient?
3. From water resource management perspective, there are a few factors that needs to be determined:
(1) How do we quantatively define under what condition can we define that there is a drought event?
(2) How do we properly establish drought monitoring system and drought warning system?
(3) How to effectively use and reserve water from both macro and micro perspective?
(4) How do we deal with transparency issues for policy making and decision making from authorities?
(5) How do we protect water resource from other perspectives such as soil conservation?
Expected results
As we know, climate change and global warming are clear trend in near future. Global average temperature has increased by about 1.5 ℃ over the past century, and this change is irreversible. There are a few possible climate trend in near future: keeps increasing, stays relatively stable and decrease. Existing studies almost all indicate that the future global warming will continue to increase, and hence leading to earlier snowmelt. However, snow drought is multivariate driven and temperature is not the sole cause. Due to future climate change, we might experience less precipitation, more severe solar radiation or potentially higher evapotranspiration. Also, there is a higher chance in the future when extreme events such as extremely high or low temperature/precipitation might occur, and these events would lead to either very small amount of water storage or very large amount of surface water (this would cause more frequent spring flood event), so planning to build more water resource reservation project is necessary from both macro and micro perspecrive beforehand seems to be important. Traditional methods such as building dams (large and small), canals, wells or springs, or modern methods such as artificial wetlands can be considered. Also, land cover and land use is experiencing change as well, which could impact surface water / groundwater storage. As a result, future city planning and industrial/agricultural/municipal water use plans should be established beforehand as well. More over, land cover and land use change might impact soil condition as well, hence policies regarding soil conservation should also be considered in this case.
As we know, climate change and global warming are clear trend in near future. Global average temperature has increased by about 1.5 ℃ over the past century, and this change is irreversible. There are a few possible climate trend in near future: keeps increasing, stays relatively stable and decrease. Existing studies almost all indicate that the future global warming will continue to increase, and hence leading to earlier snowmelt. However, snow drought is multivariate driven and temperature is not the sole cause. Due to future climate change, we might experience less precipitation, more severe solar radiation or potentially higher evapotranspiration. Also, there is a higher chance in the future when extreme events such as extremely high or low temperature/precipitation might occur, and these events would lead to either very small amount of water storage or very large amount of surface water (this would cause more frequent spring flood event), so planning to build more water resource reservation project is necessary from both macro and micro perspecrive beforehand seems to be important. Traditional methods such as building dams (large and small), canals, wells or springs, or modern methods such as artificial wetlands can be considered. Also, land cover and land use is experiencing change as well, which could impact surface water / groundwater storage. As a result, future city planning and industrial/agricultural/municipal water use plans should be established beforehand as well. More over, land cover and land use change might impact soil condition as well, hence policies regarding soil conservation should also be considered in this case.