China
Africa
Explore chapters and articles related to this topic
Soil
Published in Stanley E. Manahan, Environmental Chemistry, 2022
With food as the most basic need that humans have, the sustainability of means to produce food is a top priority. The most basic part of food sustainability is the preservation of soil and its ability to support plant life, especially in the protection of soil from erosion. The preservation of soil from erosion is commonly termed soil conservation. There are many solutions to the soil erosion problem. Some are old, well-known agricultural practices, such as terracing, contour planting (Figure 15.9), and periodically planting fields with cover crops such as clover. For some crops, conservation tillage (no-till agriculture) greatly reduces erosion. This practice consists of planting a crop among the residue of the previous year's crop, without plowing. Weeds are killed in the newly planted crop row by application of a herbicide before planting. The surface residue of plant material left on top of the soil prevents erosion.
Soil Erosion and Its Control
Published in Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose, Watershed Management and Applications of AI, 2021
Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose
Detachment and removal of soil particle from land surface is the basic cause of soil erosion. It is a natural physical phenomenon which has helped to shape the present form of the earth's surface. Advent of modern civilization has increased the pressure on land, leading to its overexploitation and, subsequently, its degradation. This trigged a very fast pace of soil erosion from land surface because of action of two fluids, water and wind. Soil erosion triggered due to overexploitation of land surface is called accelerated erosion and that caused due to natural phenomena is termed geologic erosion. Geologic erosion of soil is caused mainly by effect of rainfall, atmospheric temperature runoff, wind velocity, topography, and gravitational force. It is a continuous, slow, but constructive process resulting in wearing a way of mountains, building up of coastal plains and flood plains, and development of some of the most fertile valleys of the world such as Indo-Gangetic valley in the Indian subcontinent, Nile Valley in Africa, etc. Accelerated erosion of soil is mainly caused by error in management, such as raising of crops without adopting any soil conservation practices, deforestations, etc. It leads to erosion in excess of threshold value of new soil information, causing severe deterioration of the top surface of the land. Deterioration is sometimes so rapid that it disrupts the equilibrium between relationships of soil-plant environment.
Back to pristine levels? Decreasing suspended sediment transport in German waterways
Published in Wim Uijttewaal, Mário J. Franca, Daniel Valero, Victor Chavarrias, Clàudia Ylla Arbós, Ralph Schielen, Alessandra Crosato, River Flow 2020, 2020
T.O. Hoffmann, Y. Baulig, S. Vollmer, J. Blöthe
Since hillslope soil erosion is the dominant source of suspended sediment in the large river systems in Central Europe (Frings et al., 2019; Hoffmann, 2015; Naden, 2010), the strong decline of SSC is either induced by i) strong reductions of the erosion rates in the contributing catchments (e.g the decline of the sediment source), or ii) strong increases of sediment retention (e.g. decline of the transport efficiency) between the eroding sites and the monitoring stations. First, reductions in soil erosion rates are either caused by decreasing rain erosivity, land use changes (i.e. decrease of arable land and reforestation), or soil conservation on agricultural land. The latter mainly includes contour ploughing, non-tillage, cover crops and crop rotation. Second, increases of sediment retention can be located either directly at the border of fields, at which erosion takes place, at the transition from hillslopes to creeks and headwater streams, e.g. through vegetation strips along channels, or through the construction of reservoirs at headwaters (either for water resources or hydropower generation) and dams (mainly for hydropower and to improve navigation) at larger river channels (e.g. waterways). While retention at field borders and along headwater channels is intentionally planned to reduce sediment and nutrient supply to rivers in agricultural landscapes, sediment retention in reservoirs and upstream of dams is mainly an unintended process.
Identification of erosion-prone areas using different multi-criteria decision-making techniques and GIS
Published in Geomatics, Natural Hazards and Risk, 2018
Alireza Arabameri, Biswajeet Pradhan, Hamid Reza Pourghasemi, Khalil Rezaei
On the basis of the morphometric parameters, the ARAS model exhibited the best accuracy in the prioritisation of sub-watersheds among the four MCDM models. The study area was categorised into three priority classes according to the ARAS model. Among the 42 sub-watersheds, 2 fit the very high susceptibility class, 39 are in the high susceptibility class, and 1 falls in the moderate susceptibility class. On the basis of the LC/LU-based watershed prioritisation for erosion susceptibility of the Neka Roud sub-watersheds, the COPRAS model exhibited the highest correlation among the four MCDM methods according to the SCCT and KTCCT indices. The results of this model indicate that the total study area falls in low and moderate susceptibility classes. The prioritisation result based on the combined model of morphometric and LU/LC analysis indicates that WSs 14, 20, 28 and 33 are highly susceptible to erosion and require instant measures for decreasing soil erosion in prone areas. Recognising areas that are susceptible to soil erosion is necessary to develop and implement the best management measures for soil conservation in the mountainous study area. Significant soil conservation measures that can help decrease soil erosion in the study area include strip farming, rotation of crops, change in land use patterns, afforestation and reforestation, plantation of soil-protecting crops, construction of check dams, flood control measures and control of animal grazing.
A comparative study of soil erosion models based on GIS and remote sensing
Published in ISH Journal of Hydraulic Engineering, 2022
The main aim of soil conservation is to protect the soil from erosion and to maintain the productive capacity of the soil. The biological methods helpful in checking the soil erosion are agronomic practices, agrostological methods and dry farming practices. The agronomic and natural measures have been recommended in all regions of watersheds, while mechanical estimates just in very high and high priority sub-watersheds of Upper Lake Bhopal Catchment.