The natural landscape of Saudi Arabia is quite dry and has few natural freshwater resources. Currently, the main freshwater source is desalinated seawater, a product that is expensive because it uses electricity generated from fossil fuels. In addition, a large portion of Saudi Arabia’s population has moved from rural to urban areas, which has changed the landscape’s inherent hydrology, causing large urban floods to plague the city once a year. Guizani (2016) believed that rain water harvesting could be a green solution to both of these issues. Continue reading →
Water is one of the most important environmental resources in the Florida Everglades since the area’s landscape primarily consists of freshwater wetlands. In recent years, economic and agricultural development have reshaped and redirected headwaters to flow into the Atlantic Ocean and Gulf of Mexico instead of the Everglades. This lack of water has left the area at risk of salt water intrusion and drought in addition to threatening its native wildlife populations. Catano et al. (2015) decided to create a model that predicts how climate change will affect the area’s different hydrologic factors and impact wildlife populations. Continue reading →
The majority of the world uses upstream water as its main resource for freshwater. Yet, pollution issues that result primarily from economic development continuously threaten these freshwater sources. Industrialized countries have the financial capital to engineer and build infrastructure such as dams and water treatment facilities to alleviate these issues. Developing countries do not have the means to build the same traditional infrastructure and therefore can struggle with proper water management. Green et al. (2015) realized the need for an integrated water management approach that accounted for different levels of social and economic development and decided to develop the freshwater provisioning index (FPIh). This index measures the amount of upstream freshwater resources available to the human populations living downstream while also taking into account global water source threats. Continue reading →
The already scarce water resources of the semi-arid western United States will become increasingly precarious with the progression of warming and drying climate change. When compounded with growing demand for water, this issue mandates a balanced management practice incorporating sustainable water budgets and land use. Forest restoration efforts are currently slated for an area of some 600,000 acres of National Forest in north-central Arizona, comprising nearly 1% of the state’s footprint. These treatments, anticipated to last the duration of the coming decade, will consist of selective thinning and burning of high-density conifer forest to mitigate wildfire potential and increase the health of regional forested watersheds. The impact of tree removal on surface water has been the subject of previous study but is rarely quantified in regards to groundwater resources. Especially in such a dry region, the future of water availability lies in the relationship between rainfall and recharge of deep aquifers, reservoirs that are permanently diminished through over-pumping. Continue reading →
Roig et al. (2014) assess various sites along the Ebro river basin and collect information on each site’s ecotoxicological status. The data are then used to complement traditional means of evaluating surface water quality. The researchers compare the effectiveness and viability of different ecotoxicicty tests, otherwise known as bioassays, performed with freshwater sediments, and evaluated the relationship between ecological status, pollutant concentrations and pore water and sediment ecotoxicity to make recommendations to the European Water Framework Directive (WFD). Their findings showed a high correspondence of the ecotoxicological measurements to prior measurements of ecological status, especially when ecosystem disruption due to numerous stressors was observed. Continue reading →
The Netherlands has been harvesting the benefits of major European rivers (Rhine, Meuse), of accessibility to the sea and high precipitation at the cost of a constant struggle for safety and survival from the elements themselves. These conditions have bestowed great responsibility to the government to plan and prepare for disasters of drought and flood. Following the 1976 drought, the idea of an integrated water management tool was conceived for use in research and policy making. De Lange et al. (2014) review the outcomes of this integrated water system analysis, as accounted for in the most recent updated of the Netherlands Hydrological Instrument (NHI). According to the outcomes of the research, surface water is managed based on surpluses or shortage, its salt content, and its temperature in an attempt to maximize efficiency for agriculture and consumer uses, preservation of natural resources, and other uses. Continue reading →
Deforestation can have substantial impacts on the vast biodiversity within tropical rainforests. In Hainan, China, importance is placed on trying to protect the habitat and biodiversity in the natural forests, specifically in the Changhua watershed. The Changhua watershed is an important area for China because it has been identified as the “center of endemism for plants and birds”, so conserving this area is particularly important for maintaining biodiversity. In the last few years, biodiversity has been threatened by new rubber and pulp plantations causing forest fragmentation and larger patch distances. In this study, Zhai et al. (2014) looked at the implications of deforestation on biodiversity, especially of endemic species and the ecosystems surrounding using land cover data. Continue reading →
The production of food and economic prosperity are highly dependent on a sufficient water supply. Both the demand and supply for water are affected by climate change-induced adjustments of precipitation patterns, temperature, other climate variables, and shifts in population. Much uncertainty remains among climate change models regarding how precipitation levels and patterns, as well as temperature, will change (Meehl et al. 2007). Also, precipitation changes affect other hydrological variables, such as surface or subsurface runoff and river discharge, and, therefore, effective hydrological and climate change modeling takes these variables into account. Schewe et al. (2013) use multiple global hydrological models (GHMs) and greenhouse-gas concentration scenarios to examine how climate change impacts global water resources. They determined that climate change is likely to intensify regional and global water scarcity. They project that a 2°C increase in global temperature will result in approximately 15% more of the global population experiencing a severe decrease in water resources. They also project this 2°C rise in temperature to increase the number of people living under absolute water scarcity by at least 40%, while some models predict a 100% increase. Along with climate change, they expect future population growth to Continue reading →
Another shot of the high Sierra above South Lake near Bishop, California, taken between rain events at the end of July, 2014. The snowy patches on the north-facing slopes are all that is left of the once much larger glaciers. Otherwise there’s no mountain snow left and precious little runoff at a time of year the runoff would normally have peaked a month ago and still be going strong. There’s a large fire in progress in Yosemite in the direction we’re looking, but so far the smoke is blowing the other way.
Up until this point, there has been no unifying effort to create a global map of groundwater tables. However, a global, comprehensive map of the location and depth of water tables throughout the world can help with finding global patterns of groundwater movement. Fan et al. compiled all existing government records of groundwater tables from over a million well sites around the globe. Where government records were not available, they used data from published literature. The compiled map was not complete though; the water tables in many places around the globe remain unrecorded. In order to look more closely and completely at global, regional, and local trends in groundwater distribution and depth the researchers also used a pre-existing groundwater table model. They found that groundwater tends to be shallowest in the most humid climates, in wetland regions, in arid valleys and along the edges of continents, especially in areas with long, flat, plains of wetlands leading up to the coast. Additionally, the model looked for the influence of three forces—climate, terrain, and sea level—on the water table depth (WTD). While sea level has the strongest influence on WTD globally, regionally climate and topographic gradient are most important, and locally they found that terrain can override climate boundaries and lead to climatic anomalies like oases. —Alison Marks
Fan, Y., Li, H., Miguez-Macho, G. Global Patterns of Groundwater Table Depth. Science 339, 940–943.