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This study aims to investigate the dynamic pattern of landscape ecological units (LEUs) and analyse spatial variations of the ecological risk in Parangtritis coastal dune, Yogyakarta, Indonesia. A quantitative method was used in this research as part of landscape ecological analysis using a geographic information system. LEUs were interpreted by small format aerial photographs (SFAPs) and verified through field survey, then were calculated using the formula within grids to produce the ecological risk index (ERI) in the total area. According to the sub-class and class scenario, many LEUs showed changes in their landscape pattern. The ERI in the study area consisted of five levels (very low to very high), each of which was spatially varied. The ecological risk formed clusters coinciding with certain LEUs where fragility chiefly contributed to the sub-class scenario, while disturbance contributed to the class scenario.

Landslides often occur in the study area as a continuation of the erosion process on very thick soil from a series of volcanic ash deposition during the Tertiary and Quaternary periods. Rapid land cover changes from agricultural land into settlement increase runoff significantly causing accelerated soil erosion. Soil conservation approaches using parameters to reduce surface runoff and soil loss are less acceptable in agricultural society. Soil conservation methods aimed at reducing runoff and soil loss are not widely embraced in agricultural communities, efforts in soil conservation must be economically beneficial. Vegetative-based erosion control is the most suitable option for the agricultural communities. However, there needs to be improvements in terms of plant arrangement that is adapted to the spatial arrangement of slopes and is focused on zones along rills and gullies. Selection of tree species planted for erosion control that have the value of increasing economic income is the key to the success of planned soil and water conservation efforts.

The appropriate use of fertilizers and mulches can reduce methane emissions in chili cultivation. This research seeks to assess the impact of various conditions on methane emissions, encompassing chili cultivation under the following scenarios: absence of fertilizers, application of organic fertilizers, use of NPK (nitrogen, phosphorus, and potassium) fertilizers, absence of mulch, utilization of organic mulch, and application of inorganic mulch. Fertilizer application was combined with mulching to assess their impact on methane emissions. The study was conducted at two different sites with similar soil types. NPK levels were also measured to determine their correlation with methane emissions. The findings show that applying NPK fertilizers boosts the levels of soil nutrients, such as nitrogen (N), phosphorus (P), and potassium (K), while organic fertilizers contribute to an increase in soil organic carbon content. The application of organic mulch increases soil NPK levels while reducing methane emissions. In contrast, the use of plastic mulch significantly increases methane emissions, particularly when combined with NPK fertilizers. Soil nitrogen levels show a correlation with methane emissions exceeding 90%, while phosphorus and potassium exhibit moderate relationships with methane emissions (72%). The results of this research are anticipated to offer valuable insights into optimal fertilization and mulching practices for chili cultivation, with the aim of reducing methane emissions. [ABSTRACT FROM AUTHOR]

Mapping mountain ecosystems is needed for local planning. Ecosystem boundaries are influenced by interrelated physical and environmental factors rather than singular physical features. Tropical mountain landscapes exhibit diverse surface patterns, impacting their terrestrial ecological systems. Using river network data and digital terrain models (DTMs), we delineated ecosystem groups based on seven surface parameters: river order, channel sinuosity, elevation, slope, aspect, roughness index, and curvature. A multivariate clustering method identified ecosystem groups with similar attributes, further clarified using geological and land cover maps to account for surface and subsurface material variations and their processes. Our analysis identified five distinct ecosystem units: the young Sumbing volcanic peak, old Sumbing volcanic peak, old Sumbing volcanic slope, transitional volcanic, and old Menoreh volcanic ecosystems. The parameters that have a strong influence in limiting these units are elevation, slope, curvature, and roughness. Despite being part of the same mountain range, these ecosystems exhibit markedly different physical land characteristics. The surface-boundary-based delineation method provides a practical approach to defining mountain ecosystems, aligning spatial planning with land capacity and ecosystem service provisioning. By incorporating insights from river flow patterns and DTMs, this method captures the complexity of land surfaces shaped by past volcanic-tectonic activity and ongoing erosion-deposition processes. The resulting spatial boundaries reflect both current natural capital and dynamic limiting factors, demonstrating its potential for effective and detailed landscape management in complex mountainous regions. [ABSTRACT FROM AUTHOR]

As shalot land decreases annually, it is crucial to take deliberate measures to boost production on current agricultural land. This study aimed to formulate a strategy for optimizing shallot agricultural land in two different landscapes in the tropics. A rapid scan approach was used to identify land characteristics, while linear regression analysis was used to identify land limiting factors on shallot productivity. Literature and DPSIR (Driving Forces, Pressures, States, Impacts, and Responses) were used to develop a land optimization strategy. Typically, the pedogeomorphology analysis showed that both landscapes studied had initial alkaline conditions. Specifically, the fluvial landscape experienced a drastic acidification range (pH 4.55-7.39) due to anthropogenic factors, while the structural landscape maintained its alkaline conditions (pH 6.58-7.74). The regression results showed that the anthropogenic modifications made soil pH and EC limiting factors for productivity (R² = 0.61 for pH; R² = 0.68 for EC). Optimal results were consistently at pH conditions approaching neutral, with EC approaching one dS/m. Finally, land and water management is the best response to land optimization, accompanied by policies favoring local farmers. These findings can be used in policy-making to manage shallot agricultural land in other tropical areas. [ABSTRACT FROM AUTHOR]

A crucial component of water supply in aridic tropical regions is the construction of small reservoirs. Interestingly, various problems arise in the construction and management of small reservoirs, so the role of small reservoirs in providing surface water is considered less than optimal. This study aimed to identify problems that cause the function of small reservoirs to be less than optimal and to provide direction for small reservoir management in dry tropical areas. The investigation was carried out in two primary stages, site analysis to identify issues with small reservoir usability and regional analysis to identify physical characteristics regionally. Determining small reservoir points was carried out using SPOT 6/7 imagery with a resolution of 1.5 m. Land system maps and morphometry were used to analyze the physical characteristics of the small reservoir site. Field surveys and in-depth interviews were conducted to identify the benefits and limiting factors in the construction of small reservoirs. The results revealed small reservoirs are found in locations with low altitudes (0-100 masl) and undulating terrain (8-15%). According to the findings, 95.3% of small reservoirs were still water-filled. However, many problems resulted in the suboptimal utilization of small reservoirs. Specifically, the problems faced were structural damage due to 1) erosion-landslides (74.77%), 2) sedimentation (33.64%), 3) seepage (7.48%), 4) embankment collapse (6.54%), and 5) leakage (2.80%). Most of the community does not utilize the small reservoirs due to the limited infrastructure. Pipes to distribute water are only available at around 46.73%, while water tanks are only 43.93%. Directions for future management are aimed at 1) adding infrastructure, 2) sediment management, and 3) community-based management. [ABSTRACT FROM AUTHOR]

Gully erosion can cause significant soil loss; thus, it must be controlled. This study aimed to develop a landscape design for controlling gully erosion in a volcanic environment with a thin soil layer. The primary data used was Unmanned Aerial Vehicle (UAV) data combined with field surveys and in-depth interviews. A collaborative approach was used to develop the landscape design to minimize the impact of gully erosion. The finding showed that gully erosion had entered adult to old age since the scars (incisions) at the gully bottom existed. According to the community, gullies must be controlled, although they do not affect land productivity. Vegetative control is the most favored method of gully erosion control. Local vegetation with the potential for additional value is chosen to control gully erosion. Strengthening community capacity is the most favorable way to manage gullies. Through good understanding, local communities can control the development of gullies. Further strengthening of regulations related to gully erosion control will have a domino effect on land sustainability. This finding can be extrapolated globally to locations with similar land characteristics. [ABSTRACT FROM AUTHOR]

Regions prone to deep landslides are characterized by thick materials exceeding 10 m and frequent natural disasters. This research aims to analyze the recent occurrence of Pesanggrahan landslide in Central Java, Indonesia, which is a region consisting of both settlements and rice fields. Surface mapping was conducted using aerial photos and direct field observations. Additionally, subsurface conditions to identify the unconsolidated material layers below the landslide surface have been analyzed using the seismic refraction method. The primary velocity (Vp) values are represented in 2D subsurface cross sections. Differences in Vp values corresponded to different geological layers. There were four distinct layers: Top Soil (TS), Clay (CL), Weathered Bedrock (WB), and Tuff Breccia (TB) within the 2D seismic refraction cross-section with Vp values ranging from 150 to 1,800 m/s. The ranges of Vp are: 150-600 m/s for Top Soil (TS), 600-1,200 m/s for Clay (CL), 1,200-1,800 m/s for Weathered Bedrock (WB), and values exceeding 1,800 m/s for Tuff Breccia (TB). The material layer is critical for sustainable land management strategies aimed to control landslides. Furthermore, the potential depth of the sliding plane was managed through effective environmental management practices, including proper disposal of household waste and minimizing the cutting of steep slopes. [ABSTRACT FROM AUTHOR]

Identifying the predisposing factors of soil erosion acceleration is an intriguing worldwide subject, since each site has unique characteristics. Here, the authors aimed to analyze the influence of slope position on soil erosion acceleration in the Tertiary-Quaternary Volcanic Landscape. Soil erosion was measured through a volumetric approach. Soil properties analysis included soil texture, aggregate stability, permeability, bulk density, particle density, porosity, and organic matter. Soil properties were purposively assessed at 18 sampling points. This study showed that the slope position determined soil erosion and characteristics. Typically, the dominant processes were soil aggregate destruction due to raindrops and transportation by runoff on the upper slope. In addition, greater flow volume and higher flow erosivity are the ultimate consequences of flow accumulation from the upper slope. Those processes resulted in the even distribution of 14.6 ton/ha rill erosion at the peak of the rainy season. Surprisingly, the most significant soil erosion process on the middle slope was runoff scouring, which resulted in 4.7 tons per hectare of gully erosion at some concave spots. Furthermore, the dominant mechanism on the lower slope was the debris deposition. Although the soil parameters on the middle slope were good, soil erosion developed because the overland flow reduced soil porosity and permeability. Since gully and rill erosion are the primary causes of soil loss, the slope position directly impacts the volume and direction of overland flow. Finally, controlling the soil erosion rate should be concentrated on rill and gully erosion. Communities and stakeholders can use the findings to implement sustainable land management, particularly in the regions with comparable typologies. [ABSTRACT FROM AUTHOR]

High need for precision agriculture today has been associated with the completeness of the data available. The application of smart technology becomes the main alternative for fulfilling incomplete data and predicting future data. This paper presents the results of a research that aims to monitor and to predict water availability for determining conservation strategy on water availability using time series data from satellite rainfall, spanning from 2007 to 2022. We employed the innovative use of remote sensing technology, global rainfall measurement (GPM) and Climate Hazards Group InfraRed Rainfall with Station data (CHIRPS), to assess and correct satellite-derived rainfall estimates against ground-based observations. Conducted in the Serang watershed of Mount Merbabu’s volcanic landscape, the research employs a quantitative descriptive approach. We used coupled climate models MIROC6 and MRI-ESM2-0 in the CMIP-6 Framework for rainfall projections 2023–2030, then continued with the F.J. Mock model simulations for water availability projection. Our findings reveal a significant impact of climate change on water availability over the decade, with the most extreme conditions observed in 2029 and 2030, where the increasing of water availability reaching 10 m3 /s. The results showed that CHIRPS performed well in describing rainfall data. The novelty of this research highlighting the potential of: firstly, the use of satellite rainfall data for this specific region has not been extensively studied before; secondly, the discovered impacts of climate change to the water availability are particularly noteworthy, and thus contributing to the sustainability of agricultural practices in response to climate change. A limitation of this study is the short investigation period of just one decade, which does not fully capture the long-term impacts of climate change. Future research is recommended to utilize satellite data over extended periods to better represent extreme climate events and derive drought and wetness patterns over durations exceeding one decade. [ABSTRACT FROM AUTHOR]

Background and research aims: Most of volcanic landscapes on Java, Indonesia, are increasingly being used for agriculture. As a consequence, high rate of soil erosion due to agricultural cultivation cannot be avoided. Agricultural reservoir is one of methods to maintain soil loss due to erosion. Most research to date, however, have been based on the function of the reservoirs rather than on the arrangement of the reservoirs which are usually locally specific. Thus, an evaluation of the arrangement for agricultural reservoir becomes a crucial innovation. This study was aimed at examining the effectiveness of agricultural reservoir arrangement along rill erosion in reducing runoff volume as well as erosion rate, and increasing sediment trapped. Methods: The research was conducted using the field survey method at a key sampling area by considering the dominant relief and land cover on the volcanic landscape of the Sumbing Volcano. Data collected includes soil properties (texture, organic matter, porosity, soil pore distribution, permeability, and soil infiltration rate), runoff discharge, runoff volume, and sediment delivery. Research started by determining the points for placing the agricultural reservoirs along the rill erosion and continued with field and laboratory measurements. Results: Our results showed that placing agricultural reservoirs along the rill erosion effectively reduced erosion by 99.97%. Consequently, the erosion rate was only 5.5 × 10−4 ton ha−1. The effectiveness of agricultural reservoirs in reducing runoff volume and sediment delivery was 99.72% and 94.15%, respectively. Conclusion: Agricultural reservoirs that are placed along the rill erosion effectively trap sediment and reduce runoff so that erosion rates decrease. Implications for conservation: Placing agricultural reservoirs along rill erosion can improve the effectiveness of reservoirs in decreasing the erosion rate. This strategy helps reduce runoff and sediment to maintain the productivity of agricultural land. Finding a suitable strategy for the evaluation of erosion and sedimentation processes has important implications for soil and water conservation. [ABSTRACT FROM AUTHOR]

Landslides are widely understood to cause damage to the geological features and the surrounding environment. Our study focuses on the northern region of the Karangsambung-Karangbolong Geopark (KKNG), characterized by diverse lithology and multi-phase tectonics. This study aims to explore (i) landslide susceptibility assessment, (ii) geomorphological characteristics and distribution of landslide susceptibility, and (iii) identification of landslide impacts on geosites. We mapped morphogenesis, morphology, materials, and processes to understand the geomorphological context, identifying three primary landforms: structural, pediments, and fluvial. For landslide susceptibility mapping, we used the XGBoost algorithm with cross-validation and utilized the area under the receiver operating characteristic curve (AUROC) for model validation. The XGBoost model revealed a high susceptibility classification for 10 geosite points. Landslides have negative impacts, such as Olistoliths of coral limestones, Exotic-blocks of chert, and calcareous red claystone that change landforms and damage outcrops. Nevertheless, some landslides have positive impacts on the geosite, such as Exoticblocks of phyllites, and Exotic-blocks of pillow lava and radiolarian chert, because landslides can reveal fresher outcrops and rock structures, and the outcrop area becomes larger. Landslide mapping has successfully identified geosites that are highly vulnerable and have adverse impacts, especially those with certain lithological characteristics. This research on viewing disaster as a harmful process has evolved into a more holistic view of the disaster. This view includes various positive aspects that involve understanding the complex interactions between geology and geomorphology towards the geosite. By understanding the relationship between geomorphologic features (morphology, material, process, morpho-arrangement) and landslide occurrence, effective management strategies can be implemented to develop geological heritage further. [ABSTRACT FROM AUTHOR]

This study aims to comprehensively examine the dynamics of river morphology changes influenced by the occurrence of two distinct lahar floods which occurred in the years 1975 and 2010 respectively In order to achieve the stated objectives, temporal images representing the conditions of the study area several years after the occurrence of the lahar floods were obtained and used to examine river morphology changes. Furthermore, temporal data from remote sensing and UAV were collected and used to analyze morphology changes of river valleys in the study area. The analysis was carried out using three parameters namely river slope, riverbank morphology, and river curvature. River slope was 0.74%, showing a relatively flat gradient, and this condition resulted in a meandering river morphology Morphology of riverbank was observed to have the "U" shape, providing more surface area for river water to drain· Additionally, the sinuosity ratio (SR) during the two lahar flood periods were found to be dynamic. During the 2010 lahar flood period, the SR pre-lahar flood was 1.92, which increased significantly to 2.65 eight months after the event, and decreased drastically to L60 one year later. It is important to comprehend that the main factor responsible for these changes during the period was flood. The obtained results showed that the SR value for the next decade, starting from 2010, experienced consistent fluctuations. These fluctuations provided evidence that river morphology was always experiencing changes even without major triggers. For the analysis of the 1975 lahar flood period, the SR value was obtained from the PBB maps three years before the event, five years post-event, and from an analysis of Google Earth images ten years after the disaster. Similarly, the SR in this period was observed to fluctuate significantl; and the meander became simpler in the tenth year after the occurrence of flood. The results of this study provide evidence that spatial analysis with temporal images is more efficient and economical for studying the dynamics of river morphology. [ABSTRACT FROM AUTHOR]

ENSO is a global climate phenomenon that has been able to affect weather and climate conditions in Indonesia, especially in the southern part of Java Island, which is represented by Yogyakarta province. Subseasonal to seasonal (S2S) is a seasonal period that tries to bridge the gap between a relatively short period and a climate that has a relatively long period. The author has conducted a study that aims to determine the effect of the global ENSO phenomenon on the increase and decrease in rainfall in the southern part of the Java island region during the S2S season. In this study, the data obtained from the Nino 3.4 data and seasonal rainfall data in The southern part of Java, which is represented by Yogyakarta province in the years 2001–2022 were used. The method used is the Monte-Carlo Bootstrap permutation resampling method. The results show that in general the southern part of the Java Island region is affected by El Nino and La Nina phenomena both in the peak period of the rainy season and the peak of the dry season of JFM, JJA, ASO, and OND although the responses from several sample areas have different effects. [ABSTRACT FROM AUTHOR]

A 1:2,500-scale geomorphological map was created to illustrate the landslide characteristics on the southern flank of the Sumbing Volcanic Landscape (SVL), Java Island, Indonesia. High-resolution LiDAR Digital Terrain Model (DTM), Global Navigation Satellite System (GNSS) data, Unmanned Aerial Vehicle (UAV)-based aerial photographs, and field surveys were integrated to enable detailed landform interpretation of post-volcanic mass wasting processes. Landslides were classified by type, activity level, and origin. Additionally, morphometric analysis, including slope and area measurements, was conducted. Through this detailed geomorphological mapping process, it reveals that most recent landslides have developed within relict landslides, which were previously overlooked. It also detects smaller, more hazardous landslides caused by human activities, in addition to those triggered by natural forces. This study represents the first large-scale geomorphological mapping effort integrating high-resolution datasets in Indonesia's dormant volcanic landscapes. It will enhance understanding of landslide characteristics and will support disaster management strategies. [ABSTRACT FROM AUTHOR]

There has been a limited amount of research focused on the design of landslide maps, which are considered as one of the potential means to communicate disaster risks to the public. Hence, this article aims to conduct a systematic review of the process involved in creating landslide maps specifically for the purpose of disaster risk communication with non-expert users. While this topic is still under-studied, it has gained increasing coverage in the peer-reviewed literature over the past five years. The review examines the variations in the process of creating landslide maps, considering aspects such as planning, mapping techniques, presentation, and dissemination. However, there are several areas that require improvement, including diversifying the types of maps, considering the role and involvement of users, developing more user-friendly designs, and reducing reliance on experts during the dissemination process. The findings of this review provide valuable insights into the current limitations in establishing these maps and offer guidance for future research in this field. [ABSTRACT FROM AUTHOR]

Gully erosion has the ability to transport enormous amounts of soil material, which can degrade tropical volcanic landscapes as the highest potential of agricultural land. It is critical to understand gully erosion control activities in order to reduce the initiation and development of gully erosion. The goals of this study were to: 1) classify the different forms of gully control; 2) pinpoint the advantages and disadvantages of the gully control system; and 3) suggest forthcoming changes to gully erosion control systems in tropical volcanic landscapes. Field surveys employing random sampling were used to collect data on gully erosion points and control system. The findings of the study were explained using exploratory descriptive analysis. The research findings demonstrate that gully erosion control was accomplished through biological (vegetative), mechanical and combination methods, which were classified into nine categories. While mechanical methods have benefits in terms of strength in slowing the rate of gully growth, biological systems have advantages in terms of cost and energy. Adopting a continuous live wicker and wicker check dam system might assist in preventing cracks in the gully dimension. This study's findings can potentially reduce gully erosion susceptibility for local communities and are expected to be implemented globally in settings with similar features. Further research could be conducted on multiple tropical volcanoes with comparable issues in order to improve the performance of research results. [ABSTRACT FROM AUTHOR]