Severity, extent of disaster damage on Soil, Water and Irrigation Infrastructure. Soil erosion, water availability, accessibility and quality. Siltation, damage to canal network, tube wells, open wells, dug wells, channels, ponds etc.

Flooding can erode topsoil from prime growing areas, resulting in irreversible habitat damage. Storms, cyclones  and tornadoes can destroy forests and damage irrigation systems, silos, barns as well as other structures involved in agriculture production.

Drought is a major cause of water shortage and soil erosion and has devastating impacts, especially in countries with reduced capacity to absorb the shocks. For instance, in the Marshall Islands, the El Niño-driven drought in 2015 and 2016 led to the depletion of the already scarce water resources in storage facilities, combined with increased salinity of groundwater to unsafe levels. In arid and semi-arid areas, prolonged or frequent episodes of drought can lead to the irreversible stage of desertification unless prevention measures are adopted.

Floods are frequently associated with water contamination and accelerated processes of soil degradation. When water recedes after flooding, some of the pollutants in the water are left in the soil. Silt and contaminated water degrade soils, particularly in cultivated areas. For instance, the floods that affected Sri Lanka in 2016 caused soil erosion and accumulation of silt in low agricultural lands, as well as water contamination in dug wells, causing widespread negative impacts on agricultural production that were estimated at about USD 2.6 million in damage (Government of Sri Lanka, 2016).

What is the role of soil health in natural disaster mitigation?

 “We can’t make it rain, nor can we prevent a hurricane,” says Moebius-Clune. “But land managers can manage their land to increase the soil’s ability to take in, or infiltrate and drain, rainwater.” Increasing the amount of rainwater that infiltrates into the ground across the landscape ultimately decreases soil erosion and the potential for flooding by giving rain that could become flood water a place to go. “Soils that hold more water are also beneficial to crops in periods of drought,” adds Moebius-Clune. “That is another significant benefit of soil health management practices.”

By building healthier soils, land managers across the nation can increase human safety and protect critical infrastructure for all Americans when disaster events occur. Natural disasters impact us all. Improving the health of our nation’s soils is one step we can take to prepare for and ultimately mitigate those impacts.

What does managing for soil health look like?

Soil health is the capacity of the soil to function as a vital living ecosystem to support plants, animals and humans. Whether managing an urban backyard or 1,000 acres of cropland, Moebius-Clune notes that key soil health management principles remain largely unchanged. “Healthy soils are generally undisturbed with abundant and diverse life, no compaction and relatively high levels of organic matter and stable aggregates.”

NRCS recommends four major principles for building healthy soils: minimize soil disturbance, maximize soil cover, maximize biodiversity and maximize the presence of living roots.

Farmers are encouraged to adopt conservation practices like no-till, crop rotations and cover crops to achieve these goals, but farmers aren’t the only ones able to make a difference. Soil health management principles can apply in nearly all human managed landscapes when properly adapted, even in small backyards.

Natural disasters, including floods, hurricanes, tornadoes, earthquakes, and tsunamis, can disrupt and contaminate water supplies. Flooding and other disasters can damage drinking water wells and lead to well contamination from livestock waste, human sewage, chemicals, and other impurities.

An in situ post tsunami study was conducted to assess the effect of water management and rainfalls in soil properties and water quality at a low-lying coastal area of central Chile affected by Mw 8.8 Earthquake Tsunami during 2010. Soil samples were taken at two depths (0 to 20 and 20 to 40 cm) during 2010 and late 2012. Water quality in a local shallow well was also monitored in 2010 and 2012. High soil salinity was recorded 2 months later than tsunami occurs, closely associated to water-soluble chloride and cations (Cl⁻ > > Na⁺ > > Ca²⁺ > Mg²⁺ > K⁺), ionic toxicities, and vegetal inhibition by less available water to plants. An initial reduction in soil pH due to ionic strength and coarse-textured class of soil was observed and the sodium adsorption ratio (SAR) in soil varied between 5.7 and 11.2 (mmol L⁻¹) showing to be saline. Although SARw values are very high (>18 (mmol L⁻¹)), it does not exist risks of reduction on soil infiltration rates according to ECw (>5 dS m⁻¹) obtained. After 2 years, soil salinity was drastically reduced in the affected areas due to high soil permeability and natural attenuation (rainfalls and leaching effects), with sulfate and bicarbonate concentrations showing excessive values. Further, irrigation water quality returned to pre-tsunami situation, with only levels of sodium slightly exceeding desirable range from health point of view. Finally, it is suggested a proper design of irrigation systems before implementing other management practices.

Earthquakes impact on food security and agriculture-based livelihoods through:

• damage to irrigation systems

Flood Impacts

Flooded soils create significant challenges for agricultural lands. The floods have many direct impacts, the most prominent being:

• Deposition of sand and debris on productive lands;

• Erosion of agricultural soils; and

• Flooded soil syndrome—loss of beneficial fungi which mobilize soil-based plant nutrients. As a result of these effects after floods, farmers are challenged by yield losses and devastation of arable land. Subsequently, producers need to plan for the slow recovery of their arable soils.

Post-Flooding Soil Management

Deposition of sediment and other debris on otherwise productive land requires post-flooding management to:

• Remove sediment and debris barriers to crop production; • Repair the physical damage to the soil;

• Stimulate soil microbial activity; and

• Limit indirect impacts like soil crusting. Experts in the science and management of soils have identified methods to revitalize soil health so farmers can repair their soils and return land to a productive state. Agricultural consultants and university extension staff provide information about these methods and assistance in implementing the steps to recovery. However, not all fields can be reclaimed and losses are often significant

Recovery Plans

Producers face a number of legal, economic, and physical challenges when developing their recovery plan.

Removing barriers to crop production

 To adequately address debris and sedimentation in fields, farmers must first determine if the material and objects can be tilled into the soil, or if physical removal is required. Physical removal is costly because of the volume of the material and the distance of transport. Regulations prevent sediments from being placed into the river

Repairing the physical damage to soil

Erosion occurs when soil is carried away with the flood water. Gullies and gaps in the field will form as a result of the loss of soil. Some erosion can be corrected with tillage. However, more often, the gullies are filled with sediment and then topsoil from another area in the field. If the cost of repair is too high, the farmer may be forced to abandon the field. Land easement programs offered by the USDA Natural Resources Conservation Service may offer options to reclaim some of the lost capital.

Stimulating soil microbial and fungal activity

Arbuscular mycorrhizae (AM) are symbiotic fungi that grow on and in plant roots. The fungi penetrate roots without harming them. As a result, the fungi receive food—carbohydrates— from the plant and the plant will receive nutrients—primarily phosphorus—from the fungi. Since no plants grow in these fields during prolonged flood events, the fungi are lost from the system. In order to re-establish the population of fungi, producers can plant cover crops. A “cover crop” provides good ground cover to protect the soil from erosion and can range from legumes (beans) to small grains. Cover crops add organic matter to soil while also stimulating microbial and fungal activity.

“Overall soil health, including soil texture, structure, water holding capacity, and nutrient availability, must be restored to allow for agricultural productivity after flooding.”

Hurricane-driven redistribution of organic matter in soils provides the nutrients needed for forest ecological communities to bounce back from severe storm impacts, the researchers found.

After a tornado has destroyed homes in an area, there is an immediate danger from hazardous household cleaning products, automotive products, insecticides and herbicides and workshop supplies like paint and paint strippers. These hazardous materials and chemicals become exposed during the destruction of urban areas and they can contaminate the water and the soil, making it a toxic environment.

One of the most dangerous man-made materials that becomes a hazard after a tornado is asbestos. Tornado destruction of homes and garden sheds built from asbestos results in large amounts of asbestos being deposited on the ground and in the atmosphere. This is a highly toxic material to humans, and it can also be a hazard to nature creating toxic levels of asbestos in the soil, threatening native animals and poisoning their habitat and water supply. Tornadoes can spread asbestos over great distances, breaking it into small pieces that are difficult to locate for cleanup purposes.

Strong Winds/Squall: Cyclones are known to cause severe damage to infrastructure through high speed winds. ... Rain is a serious problem for the people which become shelter less due to cyclone. Heavy rainfall from a cyclone is usually spread over wide area and cause large scale soilerosion and weakening of embankments.

India is highly vulnerable to natural hazards especially earthquakes, floods, drought, cyclones and landslides. Studies indicate that natural disaster losses equate to up to 2% of India Gross Domestic Product (GDP) and up to 12% of Central government revenue.

The cyclones that occur between Tropics of Cancer and Capricorn are known as Tropical Cyclones. Tropical cyclones are weather systems in which winds equal or exceed gale force (minimum of 34 knot, i.e., 62 kmph). Indian sub-continent is the worst affected region of the world, having a coast line of 7516 kms. (5400 kms along the mainland, 132 kms in Lakshadweep and 1900 kms in Andaman and Nicobar Islands) is exposed to nearly 10% of the world Tropical Cyclones. There are 13 coastal states/UTs encompassing 84 coastal districts which are affected by cyclones. Four States (Andhra Pradesh, Odisha, Tamil Nadu and West Bengal) and one UT (Pondicherry) on the East Coast and One State (Gujarat) on the West Coast are more vulnerable to cyclone disasters.

Recurring cyclones account for large number of deaths, loss of livelihood opportunities, loss of public and private property and severe damage to infrastructure, thus seriously reversing the developmental gains at regular intervals.

Impact of fire on soil 

Nutrient levels and soil organic matter both increase after fire. A significant increase in soil pH, carbon and nutrients was also recorded immediately after a prescribed grass fire.

Crude oil spill affects plants negatively by creating conditions which makes essential nutrients like nitrogen , Oxygen etc needs for plant growth unavailable to them from the spilled affected soil. 

Farms and Grasslands

As spilled oil on land prevents water absorption by the soil, spills on agricultural locations or grasslands have the effect of choking off plant life.

Chernobyl disaster in the Ukraine was and remains the world's worst nuclear power plant disaster. Large amounts of radioactive contamination were spread across Europe due to the Chernobyl disaster, and cesium and strontium contaminated many agricultural products, livestock and soil.

The 2011 Fukushima Daiichi nuclear disaster, the world's worst nuclear accident since 1986, displaced 50,000 households after radiation leaked into the air, soil and sea. Radiation checks led to bans of some shipments of vegetables and fish.

Though difficult to predict accurately, it is expected that thermal effects from a nuclear explosion would be the cause of significant casualties. Initial radiation. ... When a nuclear detonation occurs close to the ground surface, soil mixes with the highly radioactive fission products from the weapon.

Study of the environmental impact of war focuses on the modernization of warfare and its increasing effects on the environment. Scorched earth methods have been used for much of recorded history. However, methods of modern warfare cause far greater devastation on the environment. The progression of warfare from chemical weapons to nuclear weapons has increasingly created stress on ecosystems and the environment. Specific examples of the environmental impact of war include: World War I, World War II, the Vietnam War, the Rwandan Civil War, the Kosovo War and the Gulf War.

Land degradation has long lasting effects on communities, such as soil erosion and contamination, making them increasingly vulnerable to further land degradation, as well as to socio-economic and political powers.

Military campaigns require large quantities of explosive weapons, a fraction of which will not detonate properly and leave unexploded weapons. This creates a serious physical and chemical hazard for the civilian populations living in areas which were once war zones, due to the possibility of detonation after the conflict, as well as the leaching of chemicals into the soil and groundwater.

Agent Orange

Agent Orange was one of the herbicides and defoliants used by the British military during the Malayan Emergency and the U.S. military in its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War. An estimated 21,136,000 gal. (80 000 m³) of Agent Orange were sprayed across South Vietnam,[14] exposing 4.8 million Vietnamese people to Agent Orange, and resulting in 400,000 deaths and disabilities, and 500,000 children born with birth defects.[15] Many Commonwealth personnel who handled and/or used Agent Orange during and decades after the 1948-1960 Malayan conflict suffered from serious exposure of dioxin. Agent Orange also caused major soil erosion to areas in Malaya. An estimated 10,000 civilians and possibly insurgents in Malaya also suffered heavily from defoliant effects, though many historians likely agreed it was more than 10,000 given that Agent Orange was used on a large scale in the Malayan conflict and unlike the U.S., the British government manipulated the numbers and kept its secret very tight in fear of negative world public opinion.

Strontium 90

The United States government studied the post-war effects of a radioactive isotope found in nuclear fallout called Strontium 90. The Atomic Energy Commission discovered that “Sr-90, which is chemically similar to calcium, can accumulate in bones and possibly lead to cancer”.  Sr-90 found its way into humans through the ecological food chain as fallout in the soil, was picked up by plants, further concentrated in herbivorous animals, and eventually consumed by human

Land and resource use

Military land use needs (such as for bases, training, storage etc) often displace people from their lands and homes. Military activity uses solvents, fuels and other toxic chemicals which can leach toxins into the environment that remain there for decades and even centuries. Furthermore, heavy military vehicles can cause damage to soil and infrastructure. Military-caused noise pollution can also diminish the quality of life for nearby communities as well as their ability to rear or hunt animals to support themselves.

 Advocates raise concerns of environmental racism and/or environmental injustice as it is largely marginalized communities that are displaced and/or affected

 

Impact on water

          Effects of a Tsunami on the Marine Ecosystem

Impact of Tsunami Disaster on the Water Environment

Tsunami waves poisoned the fresh water supplies and the soil by salt water infiltration and deposition of a salt layer over arable land. It has been reported that in the Maldives, 16 to 17 coral reef atolls that were overcome by sea waves are totally without fresh water and could be rendered inhabitable for decades. Uncountable wells that served communities were invaded by sea, sand and earth; and aquifers were invaded through porous rock. Salted-over soil becomes sterile, and it is difficult and costly to restore for agriculture. It also causes the death of plants and important soil micro-organisms.

The flood waters of the Tsunami contaminated water supply systems and in many cases destroyed. Millions of people lack safe water and are at risk of potentially deadly water borne diseases like cholera, diarrhea, malaria and typhoid. With over 150,000 people dead from the Tsunami, waterborne epidemics or out breaks is a major concern (WHO, 2004). After the 2004 Indian Ocean tsunami, contaminated water supplies and infrastructure destruction threatened the lives of many survivors of the disaster. The tsunami impacted water quality by flooding septic tanks and causing their contents to contaminate ground and surface water. Seawater also penetrated into groundwater tables, making the water unfit for human consumption. The tsunami also destroyed rural water supply systems across the region.

The impact of the Asian Tsunami related to water environment can be described in three time frames: immediate, medium-term and long-term. Immediate impacts include physical destruction of water and wastewater treatment plants, supply pipes and sewers. Some plants not physically destroyed can be severely affected by power failures and worker unavailability. Immediate impacts include cross contamination of water supplies, salt and silt in supply sources makes water unusable for consumption and possible contaminations from biological (human and animal corpses, dead vegetation etc) sources.

Aquifer contamination by salt water is one of the severe long term impacts and also the most difficult to treat. Other long term impacts may include pollution from chemical and oil spills. The United Nations Environment Program (UNEP) estimated that the recent Indian Ocean tsunami extensively damaged Indonesia's coastal environment, causing $675 million in losses to natural habitats and important ecosystem functions.

Drinking water is cited as a health priority in most emergencies. Much of the drinking water response to the Indian Ocean tsunami focused on providing a sufficient quantity of water, with perhaps less focus on quality. Following a disaster, there is enormous pressure on political leaders and public health officials to take disease control interventions mainly spread through contaminated water. The tsunami raised unique challenges for those involved in these efforts.

In most respects the profile of a tsunami resembles that of a flood caused by a hurricane or cyclone. Therefore, disaster response guides consider Tsunamis as floods although the hydrological and engineering issues associated with saline water infiltration are vastly different.

After a Tsunami, subsurface pressure wave precedes the surface wave and causes an upward movement of the freshwater lens. Water levels in wells rise. Previously fresh parts of the aquifer turn brackish. When the area is completely flooded and saline water infiltrates through the unsaturated zone especially in areas with permeable soils. Salt water fills wells and enters the aquifer. Other pollutants present on the surface are spread with the water and will also contaminate the groundwater.

When the floodwater recedes and saline water remains in pools and puddles, increasing the duration of the infiltration. The saline water mixes with the fresh groundwater and intrudes the freshwater areas.

How do Earthquakes Affect Groundwater Levels? ... These step changes can be large enough to make a well flow at land surface, or to cause a well to go dry near an earthquake. Typically, however, the water-level changes are several feet or less

Land slide affect the character and quality of rivers and streams and groundwater flow. Large amounts of earth and organic materials enter streams as sediment as a result of this landslide and erosion activity, thus reducing the potability of the water and quality of habitat for fish and wildlife.

Volcanic impact on sea level and the global watercycle

Large volcanic eruption inject aerosols into the stratosphere. These aerosols reflect sunlight causing a global dimming, thus lowering temperatures at the earth surface. The cooling of the ocean 'skin' causes less evaporation.

Severe floods can cause problems with the drinking water supply. In areas affected by flooding, there is a risk that contaminated flood water can enter drinking water treatment plants and / or water pipes. There may also be interruptions in the water supply.

The water in your watershed quenches thirst, grows food, washes clothes, and powers industry. However, too much water can cause raging floods and flush pollutants and soil into rivers and streams.

Continue to disinfect any water used for drinking or food preparation, or use bottled water until sampling has shown the water to be safe and free of contamination. You should consider retesting your well several weeks after flooding since groundwater contamination after a flood may impact the well.

Benefits of a Flood

There are benefits of flooding despite its immediate ill effects. For farmers and those in the agricultural sector, it helps them in the long run by providing nutrients to the soil that were lacking. This makes the soil more fertile and increases agricultural production.

This tends to occur after much longer periods of sustained high rainfall. Higher rainfall means more water will infiltrate into the ground and cause the water table to rise above normal levels. Groundwater tends to flow from areas where the ground level is high, to areas where the ground level is low.

Runoff is magnified due to the loss of vegetation and the development of hydrophobic soils during intense wildfires. ... After a fire, increased runoff provides the pathway for the transport of chemical-laden sediment to surface water, which may have substantial waterquality impacts.

Post-fire erosion and flooding can carry soil and ash (and anything in its path) tostreams and lakes. ... In some cases, upland erosion can kill fish or drastically alter habitat. Increased concentrations of dissolved organic carbon are a concern in drinking water sources.

Traffic accidents sometimes lead to the spread of hazardous compounds to the environment. Accidental spills of hazardous compounds on roads in the vicinity of vulnerable objects such as water supplies pose a serious threat to water quality and have to be assessed. This study compared three different assessment methods, electrical resistivity measurements, analytical flow calculations, and 1D and 2D dynamic flow modeling, to describe rapid transport processes in the road shoulder and roadside verge after a major spill. The infiltration and flow paths of water-borne substances were described during simulated discharge of pollutants on different road types.

Full-scale tracer tests using sodium chloride were carried out at nine different road locations in Sweden. Analysis of grain size distribution and infiltrometer tests were carried out at the road shoulder and verges. The pathways and travel times were traced using resistivity measurements and 3D inverse modeling. The resistivity measurements were compared to analytical flow calculations and 1D and 2D dynamic modeling. All measurement sites were highly heterogeneous, which caused preferential flow. Vertical flow velocities of 1.4–8.6 × 10⁻⁴ m/s were measured. The results of the analytical calculations and flow modeling were of the same order of magnitude. The measurements showed that almost all infiltration goes directly into the road embankment, hence the composition and structure of the built-up road must be considered. The non-destructive resistivity measurements and 3D modeling provided useful information for clarifying the infiltration and flow pattern of water-borne compounds from road runoff.

Oceans are polluted by oil on a daily basis from oil spills, routine shipping, run-offs and dumping. ... Oil spills cause a very localised problem but can be catastrophic to local marine wildlife such as fish, birds and sea otters. Oil cannot dissolve in waterand forms a thick sludge in the water.

Water and industrial accidents

Major industrial accidents may cause far-reaching transboundary effects and may lead to accidental water pollution. The Signatories to the Convention on the Transboundary Effects of Industrial Accidents and the Parties to the Convention on the protection and Use of Transboundary Watercourses and International lakes decided to cooperate on issues related to the prevention of accidental pollution of transboundary waters.

The Environmental Protection Agency recommends reverse osmosis water treatment to remove radioactive isotopes that emit beta-particle radiation. But iodine-131, a beta emitter, is typically present in water as a dissolved gas, and reverse osmosis is known to be ineffective at capturing gases.

Human Impacts

Wars, both between and within nations, have great consequences for water resources and humans who rely on them. Beyond limiting access to water and damaging water resource ecosystems, the economic devastation and social deterioration that war causes further compounds a society's water management problems 

Irrigation infra structure

The impact of a landslide can be extensive, including loss of life, destruction of infrastructure, damage to land and loss of natural resources.

Deep landslides, triggered by major earthquakes or volcanic activity can destroy thousands of square kilometres of land and kill thousands of people.

Flood also damages the agriculture infrastructure like irrigation facilities, agriculture supporting structures

More severe droughts in the United States will bring great challenges to irrigation water supply. ... Based on the results, the model-projected irrigation infrastructure has played a greater role in changes in irrigationthan drought in most areas under the current climate except some southwestern counties.

Impacts to Irrigation Water

Surface water that has deteriorated due to runoff from a fire is usually dark in color. ... In most cases, however, high concentrations of ash and sediment will be more of a physical problem with irrigation infrastructure and systems than a chemical hazard to crops.

Gases released like SO_2,  CO₂, NO_x may lead to acid-rain formation which ultimately damages the environment including soil and water. This has been experienced by a developed country like Canada whose lakes, pools and puddles have received the acid rains formed due to heavy industrial activity of U.S A. which lies to the southern side of Canada. This transcontinental migration of pollutants.