Soil Erosion Loss Research Articles

Investigating the effect of seismicity on spatial sediment sources and loads using the fingerprinting approach

Elevated soil erosion and suspended sediment loss are some of the most severe environmental problems in the river catchments of Iran. Seismic activity is known to elevate sediment loss and this study investigated sediment sources and loads in the Talar Drainage Basin in Iran, in the context of earthquake frequency and magnitude. A catalogue of earthquakes in the study region was assembled to estimate the expected high-frequency ground motions (i.e., Peak Ground Acceleration (PGA)). The horizontal ground acceleration was estimated using five global and reginal attenuation relationships. To fingerprint sub-basin spatial sediment sources in the study area, two size fractions (<63 μm and 63–125 μm) and 49 geochemical elements were analysed on 30 sediment samples collected from three potential tributary sub-basin spatial sediment sources and 10 target sediment samples collected at the overall basin outlet. Source contributions were estimated using a Bayesian un-mixing model. The estimated relative contributions of the individual spatial sediment sources for both the <63 μm fraction (51.9% (48.6–55.3), 48 % (44.6–51.3), and 0. 1% (0–0.2)) and 63–125-μm fraction (68.2% (66.4–69.8), 31.7% (30.1–33.6), and 0.1 % (0–0.2)) correlated with recorded seismic events. The correlations between sub-basin specific sediment loads and PGA were r = 0.68 for the <63 μm fraction and r = 0.99 for the 63–125 μm fraction. The results demonstrate that seismic activity and ground acceleration can elevate erosivity and erodibility factors. This study supports environmental planners for targeting management to reduce elevated suspended sediment loads and preserve fluvial habitats.

Crop and livestock productivity, soil health improvement and insect dynamics: Impact of different fodder-based cropping systems in a rainfed region of India

CONTEXTFarmers in rainfed areas of South Asia depend on livestock to augment income, and provide manure for soil and crops. However, the full potential of the livestock is not realized due to the non-availability of quality fodder. The deficit may be attributed to limitation in expansion of cultivable land as well as non-availability of fodder from the protected forest areas. It is possible to enhance the productivity of the livestock by crop-livestock systems. OBJECTIVESThis study was conducted to determine the crop and fodder production potential, nutritive value of the fodder, and reductions in soil nutrients loss and pests of the seven fodder-based inter-cropping systems in a rainfed region in South India. METHODSA medium-term field experiment was conducted from 2015 to 2021 at the Gungal Research Farm of ICAR's Central Research Institute for Dryland Agriculture (17o05’ N, 78o39’E) with seven fodder-based cropping systems involving conventional crops either alone or in combinations with annual or perennial fodder species. The seven systems (treatments) were: sorghum + pigeon pea - hedge lucerne, sorghum + pigeonpea - guinea grass, castor - hedge lucerne, castor - guinea grass, sorghum - fodder - clusterbean - fodder-cowpea - fodder -horsegram, sole sorghum, and sole pigeonpea. Impacts of these systems on crop and livestock productivity, reductions in surface soil erosion and nutrient loss, and soil health and pest dynamics were studied. Livestock based studies were also conducted with the harvested fodders. RESULTS AND CONCLUSIONSWe found that sorghum + pigeonpea-hedge lucerne on average can produce 3865 kg ha−1 of sorghum grain equivalent yield and 37,820 kg ha−1 of sorghum fodder equivalent yield. The sorghum + pigeon pea-guinea grass would benefit the farmers with no animals, by selling the high biomass grass fodder and minimizing the risk of crop failure. These two systems are also better in providing green fodder for at least 8–9 months without any supplementary irrigation. We also observed increase in soil N, OC and soil microbes. There was reduction in runoff (by 51–52%) and sediment loss (by 52%), and reduced pest and disease incidence in these systems. SIGNIFICANCEOur study demonstrated that perennial fodder-based cropping systems are an excellent option to enhance the sustainability and livelihood security of rainfed farmers by reducing the risk of crop failure and supporting the livestock. These systems also open up the scope of integrating tree fodders especially in the bunds and farm borders.

Erosion Risk Level at Cameron Highlands with Regards to Soil Erosion Loss

The agricultural activities and urban developments in Cameron Highlands have made them vulnerable to erosion. This situation has been supported by the fact that many ongoing and new proposed development projects have taken place in the Cameron Highlands. Thus, this study evaluates soil loss risk levels by catchment and sub-districts (mukim) in Cameron Highlands using the USLE model with GIS application. The USLE model covers the six factors namely rainfall erosivity, soil erodibility, slope length and steepness, cover management, and conservation practice. In earlier studies, PLANMalaysia and the Department of Agriculture Malaysia recorded land use and land cover have produced different soil loss risk levels in Cameron Highlands. Land-use data from PLANMalaysia represents town construction and development, while land-use data from the Department of Agriculture represents agricultural impact. Based on the result, the soil loss risk level produced by REDAC USM has predicted that 6.72 per cent in Cameron Highlands possess 'HIGH' risk or higher. On the other hand, soil loss risk levels produced using data from PLANMalaysia and the Department of Agriculture have predicted 10.08 per cent and 5.95 per cent, respectively. This new soil loss risk level could guide farmers and local authorities to control current land-use practices, encouraging soil conservation, and minimising soil loss in Cameron Highlands.

Spatial Assessment of Soil Erosion Risk Using RUSLE Embedded in GIS Environment: A Case Study of Jhelum River Watershed

The watershed area of the Mangla Reservoir spans across the Himalayan region of India and Pakistan, primarily consisting of the Jhelum River basin. The area is rugged with highly elevated, hilly terrain and relatively thin vegetation cover, which significantly increases the river’s sediment output, especially during the monsoon season, leading to a decline in the reservoir’s storage capacity. This work assesses the soil erosion risk in the Jhelum River watershed (Azad Jammu and Kashmir (AJ&amp;K), Pakistan) using the Revised Universal Soil Loss Equation of (RUSLE). The RUSLE components, including the conservation support or erosion control practice factor (P), soil erodibility factor (K), slope length and slope steepness factor (LS), rainfall erosivity factor (R), and crop cover factor (C), were integrated to compute soil erosion. Soil erosion risk and intensity maps were generated by computing the RUSLE parameters, which were then integrated with physical factors such as terrain units, elevation, slope, and land uses/cover to examine how these factors affect the spatial patterns of soil erosion loss. The 2021 rainfall data were utilized to compute the rainfall erosivity factor (R), and the soil erodibility (K) map was created using the world surface soil map prepared by the Food and Agriculture Organization (FAO). The slope length and slope steepness factor (LS) were generated in the highly rough terrain using Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM). The analysis revealed that the primary land use in the watershed was cultivated land, accounting for 27% of the area, and slopes of 30% or higher were present across two-thirds of the watershed. By multiplying the five variables, the study determined that the annual average soil loss was 23.47 t ha−1 yr−1. In areas with dense mixed forest cover, soil erosion rates ranged from 0.23 t ha−1 yr−1 to 25 t ha−1 yr−1. The findings indicated that 55.18% of the research area has a low erosion risk, 18.62% has a medium erosion risk, 13.66% has a high risk, and 11.6% has a very high erosion risk. The study’s findings will provide guidelines to policy/decision makers for better management of the Mangla watershed.

Assessment of Soil Erosion Hazards in Kambiti Subcatchment, Murang’a County, Kenya

Erosion is a global problem that destroys soil and adversely affects ecosystem productivity. Soil erosion generally involves many processes but the major activities involve particles being transported and deposited to another location. With an increasing population, soil erosion, water availability, energy production, and biodiversity loss are some of the most pressing environmental problems around the world. Erosion is a hazard associated with agriculture in tropical and semi-arid areas. Kambiti sub catchment is part of the upper Tana catchment. The upper Tana catchment includes 25% of Kenya gazette forest. A large area of land has been degraded, resulting in a drastic reduction in surface water availability during the dry season and poor-quality water during the wet season caused by high silt levels. The main objective of the study is to assess erosion hazards using RUSLE model in Kambiti sub catchment area, Murang’a County. The specific objectives of the study were to determine the effect of rainfall erosivity and soil erodibility factor in Kambiti Sub catchment area in Murang’a County, to determine effect of slope factor to soil loss in Kambiti Sub-catchment area in Murang’a County, to determine the effect of crop protection and management factor in Kambiti Sub catchment area in Murang’a County to soil loss and to determine the strategies for management of soil and water in Kambiti Sub catchment area in Murang’a County. Data was collected from the catchment and analyzed using arc Geographical Information System to obtain the specific parameters in the revised universal soil loss equation model. Interpolation method was used to determine the mean annual precipitation. The k factor is a function of soil texture. Shape file for geological structure for Kenya was obtained from Kenya Agriculture and livestock Research Organisation and analyzed by use of arc GIS to obtain soil erodibility factor. The slope factor was analyzed using digital elevation model from arc view. Digital elevation model was gotten from STRM download. The C factor was derived from Landsat imagery from sentinel of 30metres by 30 metres. It was further analysed by unsupervised classification from Arc GIS. The sentinel clip of Kambiti sub-catchment was joined with ground trothing observations. The results were useful in estimation of soil loss therefore profiling the areas prone to soil loss. Study findings indicated rain drop impact and runoff were primarily responsible for causing erosion in Kambiti sub catchment. Anthropogenic factors played an important role in amplifying the severity of the damage, such as persistent vegetative degradation and destruction of soil structure due to organic matter depletion and routine shallow tillage. In recent years, erosion control has been hampered by the occurrence of gaps in knowledge regarding the integrated nature of erosion processes, leading to land damage caused by rill and inter-rill erosion going unaddressed. Poor people and those lacking capital to invest in reclaiming land are the main causes of abandoning degraded land. Through strategic awareness campaigns and education, soil erosion will be assessed and the knowledge gap will be closed. Participation of farmers in land use decisions is inevitable as it ensures that people who utilize land resources are recognized as equal partners in identifying problems and designing solutions. It was also recommended that Identification and operationalization of alternative off-farm income.&#x0D;

Effects of forest age on soil erosion and nutrient loss in Dianchi watershed, China.

Soil erosion and nutrient loss are important environmental and ecological problems in the Dianchi watershed in southwestern China. Woodlands-the primary land type in the Dianchi watershed-play an important ecological role in controlling soil and water loss. In this study, we compared soil erosion and loss of total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) in woodlands of different ages, i.e., young forest, medium forest, and near-mature forest, at the Dongda River catchment in south-western Dianchi watershed. Furthermore, changes in stoichiometries in soil were analyzed. The average degree of erosion of each forest age stage was below moderate. Based on the non-arable soil erosion modulus models of 137Cs and 210Pbex, the soil erosion rates decreased gradually with the increasing forest age. The forest age affected soil nutrient distribution and loss. The losses of TOC and TP gradually decreased, while the losses of TN first increased and then decreased with the growth of forest age. TOC, TN, and TP were enriched in the topsoil. Forest age affected soil stoichiometry and soil nutrient supply level. In general, the forest can effectively reduce soil erosion and nutrient loss in the red soil area with the forest age increasing.

Effects of Counter Tillage and Slope Gradient on Nutrient Losses on Sloping Farmland

Counter tillage is a typical cultivation practice on the Loess Plateau, which can influence the soil erosion process by intercepting runoff and increasing infiltration. However, few studies have investigated the mechanisms of nutrient losses associated with counter tillage. This study was conducted to reveal the effects of counter tillage and slope gradient on the soil nutrient loss mechanism on sloping farmland. In this study, the rainfall simulation was conducted with a rainfall intensity of 90 mm·h−1 and with five slope gradients (5.24%, 8.75%, 17.63%, 26.79%, 36.40%). The runoff plots involved the counter tillage (CT) and traditional plow (CK), in order to investigate the characteristics of soil erosion and available phosphorus (AP), ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3−-N) losses. The soil erosion characteristics included the time until runoff generation, RR (runoff rate), and SR (sediment rate); the nutrient loss characteristics included nutrient loss concentrations, nutrient loss and nutrient loss rate in runoff or sediment. The results indicated that the RR and SR with a slope gradient of 5.24~26.79% on CT decreased by 11.77~94.92% and 20.69~99.27%, respectively, compared with that of CK. As the slope gradient increased (36.40%), a break in the ridge occurred and the reduction in the RR and SR was weakened; this was likely to be close to that of the CK. Nutrient losses differed significantly between different slope gradients and tillage practices. Nutrient losses increased with an increasing slope gradient. The nutrient losses of AP, NH4+-N, and NO3−-N in runoff, with the slope gradient of 36.40%, increased 75.75%, 76.34%, 75.63%; meanwhile, in sediment, it increased 32.93, 30.70, 32.18 times, compared with the slope gradient of 5.24% on CT. The CT with the slope gradient of 5.24~26.79% had a good effect in controlling nutrient losses; however, for the slope gradient of 36.40%, the effects of CT in controlling nutrient losses decreased. The nutrient loss rate and RR or SR satisfied a linear positive correlation. The reduction benefits of nutrient losses on CT in runoff and sediment can reach 57.7% to 100% and 45.5% to 100%, respectively. In conclusion, CT is an effective tillage practice to control soil erosion and nutrient losses. This study can provide a reference for soil erosion and nutrient loss control on sloping farmland on the Loess Plateau.

Effects of Crop Rotation and Topography on Soil Erosion and Nutrient Loss under Natural Rainfall Conditions on the Chinese Loess Plateau

Erosive rainfall results in the loss of both soil and nutrients, which indirectly triggers soil deterioration and a reduction in land productivity. However, how rainfall affects runoff, soil erosion, and nutrient loss under different crop rotation patterns and topographic factors remains unclear. This experiment observed nine runoff-erosion plots on the Chinese Loess Plateau (CLP) from 2019 to 2020 to determine the effects of crop type, rotation pattern, and slope gradient and length on runoff, soil erosion, and nutrient loss. Runoff, soil erosion, and nutrient loss were highest for the fallow plots; values for these variables for spring corn and winter wheat plots were not significantly different. Crop rotation generated greater runoff, soil erosion, and nutrient loss compared to non-rotation. Soil erosion and associated nutrient loss increased, but not significantly, with slope for gradients of 0.5°, 1°, and 3°, while runoff and associated nutrient loss did not increase. In addition, soil erosion and associated nutrient loss were significantly greater for slope lengths of 20 m vs. 50 m. A structural equation model showed rainfall characteristics significantly impacted runoff and soil erosion and subsequently affected nutrient loss. This study increases the understanding of runoff, soil erosion, and nutrient loss from cropland with gentle slopes on the CLP.

Effects of the Rainfall Intensity and Slope Gradient on Soil Erosion and Nitrogen Loss on the Sloping Fields of Miyun Reservoir.

Environmental loss is primarily caused by soil, water, and nutrient loss, and runoff is associated with nutrient transport and sediment loss. Most existing studies have focused on one influencing factor, namely slope gradient or rainfall intensity, for slope erosion and nutrient loss, but the joint effects of the two factors have rarely been researched. In this context, the impact of slope gradients (0°, 5°, 10°, and 15°) and rainfall intensities (30, 40, 50, 60, 70, and 80 mm/h) on soil erosion and nutrient loss on the sloping fields of Miyun Reservoir were explored using the indoor artificial rainfall simulation testing system. Based on the results of the study, the variation of runoff coefficient with slope gradient was not noticeable for rainfall intensities <40 mm/h; however, for rainfall intensities >40 mm/h, the increased range of runoff coefficient doubled, and the increase was the fastest under 0° among the four slope gradients. The slope surface runoff depth and runoff rate showed positive correlations with the rainfall intensity (r = 0.875, p < 0.01) and a negative correlation with the slope gradient. In addition, the cumulative sediment yield was positively related to the slope gradient and rainfall intensity (r > 0.464, p < 0.05). Moreover, the slope surface runoff-associated and sediment-associated loss rates of total nitrogen (TN) rose as the rainfall intensity or slope gradient increased, and significant linear positive correlations were found between the runoff-associated TN loss rate (NLr) and the runoff intensity and between the sediment-associated NLr and the erosion intensity. In addition, there were positive linear correlations between slope runoff-associated or sediment-associated TN loss volumes and rainfall intensity, surface runoff, and sediment loss volumes, which were highly remarkable. The slope gradient had a significant positive correlation with the slope surface runoff-associated TN loss at 0.05 (r = 0.452) and a significant positive correlation with the sediment-associated TN loss at the level of 0.01 (r = 0.591). The rainfall intensity exhibited extremely positive correlations with the slope surface runoff-associated and sediment-associated TN loss at 0.01 (r = 0.717 and 0.629) Slope gradients have less effect on nitrogen loss on sloped fields than rainfall intensity, mainly because rainfall intensity affects runoff depth. Based on the findings of this study, Miyun Reservoir may be able to improve nitrogen loss prevention and control.

Predicting Soil Erosion Rate at Transboundary Sub-Watersheds in Ali Al-Gharbi, Southern Iraq, Using RUSLE-Based GIS Model

The empirical soil loss model, RUSLE, was used in conjunction with remotely sensed data and geographic information system technology to delineate the soil erosion and watershed priorities in terms of conservation practices at seven boundary sub-watersheds (labeled as SW-00, SW-01, …, SW-06) between Iraq and Iran in the district of Ali Al-Gharbi, southern Iraq. The six factors of the RUSLE model, i.e., the rainfall erosivity, the soil erodibility, the slope steepness length, the crop management, and management practice, were calculated or estimated using information from different data sources such as remotely sensed data and previous studies. The results revealed that the annual soil erosion loss ranges from 0 to 1890 (tons h−1 y−1) with an average of 0.66 (tons h−1 y−1). Values of soil erosion were classified into five classes: very low, low, moderate, high, and very high. The potential soil loss in the high and very high classes ranges from 14.84 to 1890 (tons h−1 y−1), and these classes occupy only 27 km2 of the study area, indicating that the soil loss is very low in the area being examined. In terms of the spatial distribution of soil loss, the northern and northeastern parts (mountains and hills) of the sub-watersheds where the slope is steeper are more likely to erode than the plain area in the southern and southeastern portions, indicating that slope, in addition to rainfall erosivity, has a dominant effect on the soil erosion rate. The study of soil erosion in the watersheds under consideration reveals that only the northern portions of the SW-00, SW-02, and SW-04 watersheds require high priority conservation plans; however, these portions are primarily located in mountain regions, making the implementation of conservation plans in these areas impractical. Due to low soil loss, other sub-watersheds, particularly SW-01, SW-03, SW-05, and SW-06, are given low priority.

Characteristics of Soil Erosion and Nitrogen Loss in Vegetable Field Under Natural Rainfall

The effects of vegetable planting on soil loss and nutrient loss, runoff, soil erosion, and nitrogen (ammonium nitrogen and nitrate nitrogen) losses under individual rainfalls of fruit- and leaf-vegetable fields between April to October in 2021 were observed using in-situ observation testing. The results showed that: ① the runoff, erosion, and nitrogen loss of the fruit-vegetable pattern (eggplant-chili) were 1.27-2.00 times those under the leaf-vegetable pattern (leaf lettuce-sweet potato leaves), especially under the second season vegetable period. Those losses under the second season vegetable accounted for 50.86%-68.83% of the total losses under different vegetable patterns, which were approximately 1.03-2.04 times those under the first season vegetable. The runoff, erosion, and nutrient loss of vegetable fields under different treatments were both concentrated in June and July, and the nitrogen loss was mainly in the form of nitrate nitrogen with surface runoff. ② The runoff, erosion, and nutrient losses under individual rainfalls of vegetable fields under different treatments fluctuated among the vegetable growing season, and the losses were mainly concentrated in several typical rainfall events. On the whole, the loss and concentration of nitrate and ammonium nitrogen in runoff and erosion sediment of vegetables in the first season were lower than those in the second season. The runoff, erosion, and loss of ammonium nitrogen and nitrate nitrogen of fruit-vegetable were higher than those of leaf-vegetable. ③ Both rainfall amount and maximum 30 min rainfall intensity had significantly positive effects on runoff, soil loss, and nitrogen loss. Runoff, erosion, and nutrient losses under different vegetable patterns were mainly generated by moderate rain, heavy rain, and heavy rainstorms, which accounted for 29.58%-46.68%, 24.54%-36.79%, and 24.01%-39.13% of the total losses, respectively. The results also showed that soil erosion and nutrient losses generated by different rainfall grades were obviously different for the fruit- and leaf-vegetable treatments. The results indicated that the vegetable pattern had significant impacts on soil loss and nutrient loss, and the leaf-vegetable pattern could reduce soil erosion and nutrient loss compared with the fruit-vegetable pattern. Furthermore, for different vegetable patterns and vegetable growing seasons, the effects of rainfall on soil loss and nutrient loss were quite different. The results of this study were helpful in clarifying the soil erosion and nutrient loss characteristics of vegetable fields in South China.

Soil erosion models verification in a small catchment for different time windows with changing cropland boundary

This paper presents very detailed studies of soil erosion within a small arable catchment located in the centre of the East European Plain. Sediment redistribution was estimated based on soil profile truncation, radiocesium methods and erosion modelling. WaTEM/SEDEM and State Hydrological Institute model were used for the evaluation of soil losses during rainfall and snowmelt, respectively. Evaluation of soil erosion and sediment redeposition was carried out taking into account historical changes in the cropland boundaries. Model estimates of soil losses from arable land are in good agreement with evaluations of erosion rates based on the results field method applications, taking into account the uncertainty of the methods. Erosion modelling made it possible to fairly plausibly estimate the decrease in soil erosion losses by approximately by a third as a result of a small (about 5%) reduction in the area of arable land in the studied catchment. The main disadvantage of applied erosion models were associated with the insufficient accuracy of estimates of the sedimentation volume and location deposition zones, mainly outside the arable land. The simulated net erosion for the entire catchment was underestimated by 3.5–4.5 times compared with field methods. This simulation block must be calibrated taking into account the regional coefficients of sediment transport in the bottoms of the dry valley network.

Effect of rice husk mulching on germination percentage, yield and economics of pea (Makhyatmubi) Pisum sativum L.

Mulch can effectively minimize water vapour loss, soil erosion, weed problems and nutrient loss. Modification of soil microclimate by mulching favours seedling emergence and root proliferation. Organic mulches add nutrients to the soil when decomposed by microbes in the soil. A field experiment was conducted during the rabi season of 2018 and the treatments comprised of one control (T1 -no mulch) and six levels of rice husk mulching viz, T2 (10q/ha), T3 (20q/ha), T4 (30q/ha), T5 (40q/ha), T6 (50q/ha)and T7 (60q/ ha) were laid out in RBD with three replications. The application of rice husk mulching 60q/ha (T7 ) had significant effect on the germination percentage of the crop. The highest number of pods, pods per plant and longest pod length were recorded in the treatment of rice husk mulching with 60q/ha (T7 ). The test weight was found to be non-significant. With respect to economics of yield production in pea, higher gross returns, net returns and returns per rupee invested (B:C ratio) was obtained by 60q/ha rice husk mulching as compared to the other treatments. From the present investigation it was observed that pea was found to perform better in rice husk mulching of 60q/ha.

Uticaj različitih vrsta višegodišnjeg malča na banku semena korova u voćnjaku

Mulching is an agrotechnical measure often used in orchards and it means covering the soil with the organic or inorganic material in order to prevent the germination of the weeds. The other positive effects imply: the improvement of the physical and chemical soil characteristics, decrease of soil erosion and water loss, the prevention of the soil crusting, etc. The research of the weed seed bank under the different types of mulch was conducted during the growing season of 2021. in a plum orchard located at Rimski Šančevi. The black and white agrotextile and white mulch film, unlike the other mulches, left the surfaces clean, without the weeds. The analysis of the weed seed bank revealed the seeds of 20 weed species, of which 12 were not found to be present in the orchard during the experimental year. The overall germination rate of the obtained weed seeds is low because in the three-year experiment with mulches, there was no influx of new weed seeds for several years, while the old ones lost their germination. The highest germination percentage was noted for the seeds of the following species: Amaranthus retroflexus, Stellaria media and Solanum nigrum, due to their ability to retain germination for a long period of time. The highest number of the seeds per m2 was found in the inter-row space due to the large influx of the seeds during the growing season. The highest germination rate was observed in case of the seeds found under the sawdust mulch. None of the ungerminated seeds showed the viability, as determined by the Crush test.

Геоинформационная система «Речные бассейны России»

An electronic map of basin geosystems of small rivers has been created for almost the entire mainland of Russia. The form of representation is a vector layer of polygonal objects; spatial detail corresponds to the regional level of generalization (scale 1:1 000 000). The research was performed in three stages: 1) The European Part of Russia (with the exception of the Crimea and the Kaliningrad region); 2) The Arctic watershed area of the Asian Part of Russia; 3) The Pacific watershed area (Far Eastern Federal District). In total, over 388 000 objects (basins) have been allocated with an average area of about 47.8 km2. The method used for constructing the basin map includes: selection of the base DEM and the hydro grid map; selection of geometric parameters of the raster grid to represent the initial data and the results of model calculations; correction of the DEM using the hydro grid map; construction of watershed basin boundaries in automatic mode; assessment of the accuracy of the allocation of river basin boundaries for different types of terrain. A specialized geoinformation system “Basins of small rivers of Russia” has been formed. GIS integrates geoinformation representing natural (geomorphometry of the relief, the hydro-climatic parameters, sediment yield and river flow, soils, landscapes) and anthropogenic (land use types, population, transport network, etc.) characteristics of river basins. As an example of solving geoecological and geographical problems, calculations of the intensity of soil erosion for the Lena River basin using a modified model of soil loss are presented. The average value of soil erosion losses in the Lena River basin, taking into account the types of land cover, is 0.22 t/ha/year. This generally indicates a very low intensity of erosion, most of the basin area belongs to the nonhazardous category of soil loss.

Factors influencing informal trail conditions: Implications for management and research in Urban-Proximate parks and protected areas

With growing urban populations in close proximity to natural environments, recreation resource managers in parks and protected areas (PPAs) are increasingly confronted with challenges such as high levels of visitation and severe resource impacts. Additionally, urban-proximate PPAs, particularly informal trails in these areas, have received little research attention relative to more remote PPAs and formal trails. The formation of informal trail networks in urban-proximate PPAs can lead to extensive resource impacts such as loss of vegetation cover and soil erosion. Use-related, environmental, and managerial factors have been found to influence trail conditions and degradation on formal trails. We use a well-established rapid assessment field protocol and GIS-derived calculations to analyze informal trail conditions, and the factors influencing those conditions in a high alpine urban-proximate PPA. We find informal trail networks are extensive and that informal trails are influenced by use-related, environmental, and managerial factors in a similar fashion as formal trails. Additionally, results from predictor effect plots allow us to derive valuable management implications focused on where to concentrate use and minimize environmental impacts. Our study concludes with implications to further advance research related to informal trails, such as the need for sound sampling designs and the potential of trail research as a basis for further analysis on environmental susceptibility.

Community perceptions of the social impacts of the Metolong Dam and Reservoir in Lesotho

In Lesotho, large dams supply South Africa with water, earning Lesotho royalties, as well as supplying this small nation with water and electricity. This study investigated the perceptions of residents regarding the impacts of one of these dams, namely the Metolong Dam and Reservoir. The methodology was qualitative in nature, using document analysis, field notes and semi-structured interviews. Results show that local villagers felt the overall social, economic and environmental impacts were mixed. Environmentally, the area suffered from noise and air pollution, soil erosion and habitat loss during construction, although there were efforts to preserve rare species. Economically, some locals lost land, livestock or income streams, or became food poor. Others however, were able to adopt fish farming or secure employment. Bit community members felt side-lined in terms of employment, with few placed in managerial or supervisory positions. Culturally, people lost access to their ancestral lands and, as a result, despite the preservation of cultural heritage sites, felt their culture was undermined. The influx of migrant workers – although contributing to the local economy – was blamed for young females in the area becoming HIV positive or disrespecting their parents. Although the project built and rehabilitated schools, few local children benefited due to high school fees. Forced idleness, intergenerational poverty and alcoholism now plague the community, with locals relying heavily on grants, remittances, pensions and beer brewing for survival. The study concludes that while the Metolong Dam brought benefits to South Africa, Lesotho and the local community, benefits at local level were uneven at best.

Reflection of traditional farming operations on the sustainability of the main components of internal and external soils systems in the upstream elevation regions of Mazandaran province, Iran

Soil is a vital resource and non-renewable biodiversity during a human life, and without soil living in the world is impossible. The results of global research between agricultural soils and community health, thinkers have not yet reached promising results. For this purpose, 10 years of important environmental information consist of; the type of soil texture system process and related factors were received from official centers as well as in a survey (field). In this regard, to evaluate, analyze and conclude the process of the research area, the strategic multidisciplinary model (SMM), Excel and SPSS program were used. The 10-year information trend of the region (heights of the upstream), which was the findings of the operational research, showed that the conventional agricultural situation is not associated with the principle of convergence on the unity of environmental practice. In this multidisciplinary study, the percentage of (PU), clay and silt, (SOC), the ratio of (B/C) and (DRW), (AR) have decreased . In contrast to the decrease components, the percentage of sand, and (ND), (TUL), (LLS) has increased . So, with such a very strong research strategy in the target area, we were able to provide technical information to politicians and executives about the conventional methods of erosion of the components involved with the operational environment, for agriculture and sustainable natural resources In the continuation of our efforts, we have been able to change the traditional negative beliefs in the target area of the research, on the components that promote the production of opportunity maker crops (endogenous products) in the upstream elevation regions of Mazandaran province, Iran. • The phenomenon of soil erosion and soil loss in the upstream areas is a global problem. • Structural resources in upstream areas require environmental foresight management. • The age of technology low cognitive is the main cause of natural disaster in the sloping areas. • Erosion, drift, subsidence are the result of the low effectiveness economy of the global systems. • The approach triangle of sustainability among farmers reduces upstream environmental threats.

Soil fire severity is more relevant than fire frequency in explaining soil, carbon and nitrogen losses and vegetation recovery after wildfire in NW Spain

NW Spain is one of the regions of Europe most affected by rural fires and where there is a particularly high risk of increased soil erosion after fire. An increase in fire frequency is expected to enhance soil erosion and the associated carbon and nitrogen losses, impairing vegetation recovery and compromising ecosystem resilience.In this study, the influence of recurrent fires on soil erosion, carbon and nitrogen loss as well as on vegetation recovery was assessed in four shrubland areas dominated by Erica australis L. Pterospartum tridentatum (L.) Willk. And Ulex gallii Planch, burned in October 2017. Two of the areas were burned twice, between 2010 and 2017, and the other two areas were burned once, in 2017. Soil burn severity was moderate to high in all experimental sites. Soil erosion along with vegetation cover and diversity were monitored during the two years after fire, on 24 plots of 80 m2.In the first year after fire, the mean sediment yield was 24.1 Mg ha−1 in the areas burned twice and 17.4 Mg ha−1 in the areas burned once. Fire frequency did not significantly influenced soil loss unlike the carbon and nitrogen concentrations in eroded sediments. Sediment losses as well as carbon and nitrogen losses were significantly associated with soil burn severity.Vegetation recovery was not affected by fire frequency in the shrublands, which were dominated by resprouters. No alteration in species composition was observed, indicating the high degree of resilience of the communities.In summary, recurrent fires occurring within an interval of 10 years seemed to have little effect on sediment yield and vegetation recovery. The significant influence of soil burn severity on sediment yield and vegetation recovery highlighted the importance of considering this factor in fire prevention plans for fire-prone areas.

Grassland Reseeding: Impact on Soil Surface Nutrient Accumulation and Using LiDAR-Based Image Differencing to Infer Implications for Water Quality

Long-term phosphorus (P) accumulation in agricultural soils presents a challenge for water quality improvement. P is commonly elevated in soils managed for intensive livestock production due to repeated overapplication of slurry and fertilisers. High legacy nutrient accumulations result in poor water quality via transport pathways such as surface runoff, subsurface drainage, and soil erosion. To achieve environmental water quality targets, improved management strategies are required for targeting and reducing excess agricultural P sources. Reseeding of old swards is known to improve grassland productivity and enhance overall soil health. However, soil disturbance associated with reseeding could have positive and negative impacts on other soil functions that affect the nutrient balance (including improved microbial activity, but also increasing the potential for sediment and nutrient losses). This study investigates the impact of reseeding and inversion tillage in addressing soil surface nutrient surpluses and identifies potential trade-offs between production, environment (through soil erosion and associated sediment and nutrient losses), and soil health. At a study site in the Blackwater catchment in Northern Ireland, we collected high-resolution (35 m) gridded soil samples pre- and post-reseeding for nutrient analyses and combined this with GIS-based interpolation. We found that decreases in sub-field scale surface nutrient content (0–7.5 cm depth) occurred following tillage and reseeding, but that this was spatially variable. In addition, the magnitude of changes in nutrient content was variable between P and other sampled nutrients. LiDAR-based image differencing indicated variability in the magnitude of soil erosion and sediment loss also at sub-field scale. Information on the identified deposition and erosion zones (from LiDAR analysis) was combined with mass wasting data to determine accumulation rates and losses of nutrients in-field and confirmed some of the identified patterns in soil surface nutrient content changes post-reseeding. We conclude that while inversion tillage and reseeding are essential agricultural practices, environmental trade-offs exist through potential nutrient and sediment losses. LiDAR-based image differencing was found to be a useful tool in helping to quantify these risks. Quantifying sediment and nutrient losses as a result of inversion tillage and reseeding induced soil erosion aids in understanding potential trends in water quality statuses.