VEHA
Guidance
Guidance
Virtual Environmental and Humanitarian Adviser Tool – (VEHA Tool) is a tool
to easily integrate environmental considerations in humanitarian response. Field Implementation guidances are useful for the design and execution of humanitarian activities in the field.
Sudden or progressive change in the environment adversely affects the lives or living conditions of people who may have been displaced from their origin. When environmental degradation occurs or sudden onset hazards impact vulnerable areas, people may be forced to move and relocate to areas that then require new infrastructure. The new infrastructure should be built to be resilient and strong enough to endure the impact of future natural hazards.
Excluded people hold the least power to influence decision-making. They should be consulted regarding potential environmental impacts and their personal needs and dependencies on the local environment.
Air pollution
Soil pollution
Water pollution
Desertification
Loss of biodiversity and ecosystems
Natural Resource Depletion
Soil erosion
Reduction in surface water infiltration and groundwater depletion due to excess or unnecessary soil compaction
Reduction in soil quality, nutrients, and ultimately soil loss
Loss of flora and fauna and impacts on human health
Excessive soil compaction impedes the ability of the soil to hold water. This can increase surface runoff, leading to soil erosion, an increase in the risk of flooding, and soil and water losses, while also reducing the recharge capacity of aquifers.
Soil compaction also restricts the flow of air within soils, which together with water loss, damages the structure, quality, and nutrients within the soil and ultimately leads to soil loss. Reduced quality soil and loss of soil ultimately lead to loss of flora and fauna and impacts on human health.
Plan to avoid or minimise soil compaction
Plan to reduce soil erosion and surface water run-off
Plan soil compaction activities only where essential. Consider alternatives such as raft foundations, short piles, ground bearing beams
Soil aeration to reduce the impacts of over compaction
Map flora and fauna and plan remedial measures if required.
Plan construction activities to minimise soil compaction – this can include assessing ground conditions, avoiding the use of heavy machinery, placing large boards of plywood, branches, or steel sheets to spread loads. Plan construction activities to reduce the risk of soil erosion. This may include gentle landscaping to reduce the speed of surface water run-off, or the construction of groundwater infiltration drains/bunds/pits.
Plan soil compaction activities only where it is essential such as under new roads or structures. Consider alternatives such as the use of raft foundations, short piles, use of ground load-bearing beams (which transfer loads to fixed points such as pad foundations).
Light tilling or mechanical aeration may help reduce the impacts of over-compaction. Map flora and fauna and monitor impacts of over compaction on them and plan remedial measures if the loss is observed.
Urban soil characteristics, especially soil physical properties, are subject to dramatic changes due to compaction by intensive human activities, which may cause frequent flood events during the rainy seasons.
The aim of this study was to explore the water infiltration characteristics of urban soils with different degrees of compaction and to determine the effects of infiltration on environmental problems in urban areas. Materials and methods Ten typical land-use patterns with various vegetation and age were selected in Nanjing City, China to determine the infiltration rates by the dual-ring method. Three replicated sites were done in the same combined mode. At the same time, other soil physical and chemical properties that may affect infiltration rate were also determined. In addition, urban surface runoff coefficients were estimated according to final infiltrations and rain intensities in the different degrees of soil compaction.
The quality of floodwater from a strong rainstorm in the main road in Nanjing was analyzed. Results and discussion The final infiltration rates of urban soils were highly variable (from very slow to very fast).
Low soil infiltration rates are related to many factors; however, urban soil compaction is the leading one. Infiltration rates decreased with an increase in the bulk density and with a reduction in the air-filled porosity. Thus, large amounts of macropores increase the infiltration rate and reduce surface runoff. Runoff coefficients of compacted soils with low infiltration rates were high, especially for extremely compacted soil. As a result, the prevalence of flooding is high in compacted soils, and the quality of surface runoff water is reduced during flooding events.
The concentrations of NO 3?-N, total nitrogen, molybdate-reactive phosphorus, total phosphorus, and suspended material in urban surface runoff were significantly higher than those observed in forested or agricultural watersheds. Conclusions In urban areas, low infiltration rates caused by soil compaction have negative effects on the eco-environment of the city and result in increased instantaneous flooding and poor surface water quality. Thus, to improve the eco-environment of urban areas, the amount of greenbelt soil must be increased and soil compaction must be reduced.
Percentage of decrease in area of soil compaction activities
Use of alternative non-compacting foundations
Prevention of environmental damage
Mitigation of environmental damage
Time for assessing ground conditions, and planning construction methods to reduce or avoid ground compaction