Land Use and Land Cover Changes and Its Impact on Soil Erosion in Stung Sangkae Catchment of Cambodia

Spatial-temporal dynamic impact of changes in rainfall erosivity and vegetation coverage on soil erosion in the Eastern Mediterranean

In Syria, soil erosion (SoEr) by water is one of the major challenges for sustainability. Thus, the main goals of this research were to evaluate the spatial changes of SoEr between 2000 and 2018 in the whole coastal basin (CB) of Syria and to provide a soil water erosion risk map for the study area. For this purpose, monthly rainfall data, the SoilGrids dataset, satellite image derived NDVI layers, and Digital Elevation Model (DEM) were collected. Through the integration of these layers into the Revised Universal Soil Loss Equation (RUSLE), under a Geographic Information System (GIS), soil loss was assessed. Also, the contribution of land cover changes and R factor on SoEr were evaluated. The outcomes of this assessment illustrated that the R factor ranged from 800 to 2600 MJ mm ha-1 h-1 yr-1, while the soil erodibility factor (K factor) ranged from 0.048 to 0.035 ton ha MJ-1 mm-1. The C factor (vegetation coverage) values ranged between 0.07 and 1 with a spatial average value of 0.44 for the 2000-2009 period and 0.39 for the 2010-2018 interval. The output of RUSLE revealed that average annual SoEr was of 21.35 ton ha-1 y-1 (± 38) for 2000-2009 and 22.47 ton ha-1 y-1(± 41.8) for 2010-2018. Interestingly, the increased SoEr caused by the R factor was dominant (34.65%), followed by changes in both C factor and R factor (13.34%). However, decrease of SoEr rates is due to the increase of the C factor accounting for 36.82% of the CB. The outcome of this research can provide constructive spatial insights for rehabilitation plans for the post-war phase of Syria.

Partnership 4.0: smallholder farmer partnership solutions

The current pseudo-partnership pattern causes the farmers' income to be low from the results of their farming activities, so a partnership pattern is needed that is able to create a mutual partnership. The research which was conducted in Cikarawang Village, Bogor Regency, West Java Province - Indonesia aims; (1) recognize the existing condition of farmers and the use of agricultural land; (2) knowing the distribution of agricultural commodities; (3) identify existing partnership patterns; and (4) provide solutions for partnership patterns that benefit farmers. By using mixed-methods combined with the Drone Participatory Mapping (DPM) approach to produce Data Desa Presisi (DDP), this study succeeded in identifying three statuses of farmers, namely: cultivators, owners and cultivators of their own land, and owners who work on their own land at the same time working on other people's land, with an average access to land management of 3,437.32 m². The small access of each farmer in land management is further exacerbated by the variety of agricultural commodities that are cultivated by farmers. There are at least 19 types of agricultural commodities that are cultivated, but do not meet the economic scale that is able to improve the welfare of farmers. This condition opens up opportunities for the partnership pattern between farmers and middlemen to continue to survive which is actually detrimental to farmers. Partnership 4.0 innovation is present to replace the old partnership pattern by focusing on the basis of technology and information that is fully accessible to farmers to jointly control agricultural activities (upstream-downstream). Partnership 4.0 places farmers and offtakers on an equal footing, so that smallholders can benefit and help achieve the welfare of smallholders.

Analyzing the Benefit-Cost Ratio of Sediment Resources by Remote Sensing Data in the Ping River Basin, Thailand

Sediment is one of the important natural resources on the Earth. Information on sediment resources is key to making decisions regarding soil resources management and mitigation during sediment hazard events. Thus, this research analyzed and mapped the benefit-cost ratio (BCR) of sediment in the Ping River using a Geographic Information System (GIS). Furthermore, the benefit of sediment was analyzed using a new application of the Revised Universal Soil Loss Equation (RUSLE) with a spatial resolution of 1 km2. The results reveal that the potential of annual soil loss and sediment deposition in the Ping River Basin (PRB) were approximately 825 and 530 m3/km2·y, respectively. In addition, the results indicated that there was a higher BCR in the upstream area of the PRB where there was greater sediment deposition. The average benefit of sediment in the PRB is USD 4280/km2·y. It is expected that the BCR of the sediment resources map analyzed in this research will help policy-makers for decision-making on the benefits of sediment resources in Thailand.

The effect of different land use planning scenarios on the amount of total soil losses in the Mikail Stream Micro-Basin

Erosion is seen as a major productivity problem in the world. Unplanned agricultural practices caused by human activities initiate the soil erosion process. Especially in sloping areas, agricultural activities without soil conservation measures accelerate this process. This study prepared land use planning (LUP) scenarios to reduce soil losses in the Mikail Stream Micro-Basin, which has an erosion problem and a rough topography. ILSEN land evaluation method, which is formed by interpreting FAO land evaluation principles according to Turkish conditions, was used in the creation of the scenarios. Soil conservation (terracing and contour agriculture) land-use types (LUT) that can help in erosion reduction were included in the ILSEN method and 8 different LUP scenarios were created. Soil protected (terracing and contour farming) LUTs that can help reduce erosion were included in the ILSEN method and 8 different LAP scenarios were created. The RUSLE Method integrated with the Geographic Information System (GIS) was used to calculate the estimated amount of soil loss caused by the scenarios created. For land evaluation and erosion studies, serial-based soil map of the area and Google Earth images were used. Scenario 7 created has reduced soil loss by 79% compared to the present land use (Scenario 8) of the basin. While the soil loss caused by the present land-use of the basin was 335.95 tons ha^-1 year^-1 on average, the amount of soil loss caused by the 7th scenario was calculated as 69.05 tons ha^-1 year^-1 on average. The results showed that the ILSEN land evaluation method can be a model to be used in the creation of erosion-reducing LUP scenarios in areas with erosion problems.

Assessment of Land Use and Land Cover Changes on Soil Erosion Using Remote Sensing, GIS and RUSLE Model: A Case Study of Battambang Province, Cambodia

Soil erosion causes land degradation which negatively impacts not only natural resources but also livelihoods of people due to low agricultural productivity. Cambodia is prone to soil erosion due to poor agricultural practices. In this research we use Battambang province as a case study to quantify impact of land use and land cover change (LULC) on soil erosion. This study assessed the impact from LULC changes to soil erosion. LULC change maps were analyzed based on Landsat satellite imagery of 1998, 2008, and 2018, computed in QGIS 6.2.9, while the soil erosion loss was estimated by the integration of remote sensing, GIS tools, and Revised Universal Soil Loss Equation (RUSLE) model. The results showed that the area of agricultural land of Battambang province significantly increased from 44.50% in 1998 to 61.11% in 2008 and 68.40% in 2018. The forest cover significantly decreased from 29.82% in 1998 to 6.18% in 2018. Various soil erosion factors were estimated using LULC and slope. Based on that, the mean soil loss was 2.92 t/ha.yr in 1998, 4.20 t/ha.yr in 2008, and 4.98 t/ha.yr in 2018. Whereas the total annual soil loss was 3.49 million tons in 1998, 5.03 million tons in 2008, and 5.93 million tons in 2018. The annual soil loss at the agricultural land dramatically increased from 190,9347.9 tons (54%) in 1998 to 3,543,659 tons (70.43%) in 2008 and to 4,267,439 tons (71.91%) in 2018 due to agricultural land expansion and agricultural practices. These losses were directly correlated with LULC, especially agricultural land expansion and forest cover decline. Our results highlight the need to develop appropriate land use and crop management practices to decrease land degradation and soil erosion. These data are useful to bring about public awareness of land degradation and alert local citizens, researchers, policy makers, and actors towards land rehabilitation to bring the area of land back to a state which is safe for increasing biodiversity and agricultural productivity. Measures to reduce or prevent soil erosion and the use of conservation agriculture practices, along with water and soil conservation, management, agroforestry practices, vegetation cover restoration, the creation of slope terraces, and the use of direct sowing mulch-based cropping systems should be considered.

Numerical Modeling of Failure Mechanisms in Articulated Concrete Block Mattress as a Sustainable Coastal Protection Structure

Shoreline protection remains a global priority. Typically, coastal areas are protected by armoring them with hard, non-native, and non-sustainable materials such as limestone. To increase the execution speed and environmental friendliness and reduce the weight of individual concrete blocks and reinforcements, concrete blocks can be designed and implemented as Articulated Concrete Block Mattress (ACB Mat). These structures act as an integral part and can be used as a revetment on the breakwater body or shoreline protection. Physical models are one of the key tools for estimating and investigating the phenomena in coastal structures. However, it does have limitations and obstacles; consequently, in this study, numerical modeling of waves on these structures has been utilized to simulate wave propagation on the breakwater, via Flow-3D software with VOF. Among the factors affecting the instability of ACB Mat are breaking waves as well as the shaking of the revetment and the displacement of the armor due to the uplift force resulting from the failure. The most important purpose of the present study is to investigate the ability of numerical Flow-3D model to simulate hydrodynamic parameters in coastal revetment. The run-up values of the waves on the concrete block armoring will multiply with increasing break parameter (0.5<ξm−1,0<3.3) due to the existence of plunging waves until it (Ru2%Hm0=1.6) reaches maximum. Hence, by increasing the breaker parameter and changing breaking waves (ξm−1,0>3.3) type to collapsing waves/surging waves, the trend of relative wave run-up changes on concrete block revetment increases gradually. By increasing the breaker index (surf similarity parameter) in the case of plunging waves (0.5<ξm−1,0<3.3), the low values on the relative wave run-down are greatly reduced. Additionally, in the transition region, the change of breaking waves from plunging waves to collapsing/surging (3.3<ξm−1,0<5.0), the relative run-down process occurs with less intensity.