High Intensity Rainfall Research Articles

Slope Risk Management System on Toll Road: A case study Semarang-Salatiga Section

Landslide is a geohazard event which can be caused by several factor, such as high rainfall intensity, slope geological feature and the slope geometry itself. Tropical wet climate and typical geomorphology of Indonesia derives landslide event as common disaster during the wet season. Nowadays, the paradigm in road slope management has changed to put the Slope as an Asset, like other infrastructure. In this case study, a slope risk management system was created to assist road slope managers in planning periodic monitoring and maintenance. As the building have the BIM System, the slope can also be digitalized as GeoBIM. Based on case studies, this system can be used to inventory and create an electronic database of road slope assets. Furthermore, the road slope assets are assessed and prioritized based on geological hazards and economic consequences. In the end, each slope asset will have routine maintenance schedules, costs, and a historical data of repairs and damage. Therefore, the slope asset can be handled effectively and efficiently.

Simulation of overland flow in the Domica cave area flood events using the r.sim.water module

The flash floods are very important hydrometeorological situations affecting the Domica cave area. The flash floods depend on several factors such as the amount of precipitation, land cover, phenological phase of the vegetation, or soil infiltration rate. This paper focuses on the simulation of flood events occurring in the winter and summer seasons on the Silická plateau. The main aim of the paper is the evaluation of the effects of model parameterisation and interpretation of spatial aspects of the overland flow during the flood events. GRASS GIS software, specifically its r.sim.water module was used for hydro-logical modelling of the surface runoff. The simulation included a detailed digital eleva-tion model calculated from airborne laser scanning data and land cover derived from a detailed orthoimagery map. The infiltration rate parameter and the Manning’s roughness coefficient were estimated based on land cover classes. The simulation produced water depth maps describing flood events. The results showed that during the winter season in 2016, a smaller rainfall intensity was necessary for flood occurrence and that this phenomenon is primarily caused by frozen soil, through which no water is being infiltrated. The simulation of summer flood event in 2017 shows similar results of runoff accumulation but with higher rainfall intensity and infiltration rate. The flash flood event in 2021 turned out to be differ-ent, with such extreme rainfall intensity that even higher infiltration rate was insufficient in slowing the surface runoff. The results also proved the suitability of the chosen method for small-scale high-resolution hydrological simulations. URL: https://www.gcass.science.upjs.sk/

Keynote lecture. Forecasting the inundation of postfire debris flows

In the semi-arid regions of the western United States, postfire debris flows are typically runoff generated. The U.S. Geological Survey has been studying the mechanisms of postfire debris-flow initiation for multiple decades to generate operational models for forecasting the timing, location, and magnitude of postfire debris flows. Here we discuss challenges and progress for extending operational capabilities to include modeling postfire debris-flow inundation extent. Analysis of volume and impacted area scaling relationships indicated that postfire debris flows do not conform to assumptions of geometric self-similarity. We documented sensitivity of impacted areas to rainfall intensity using a candidate methodology for generating inundation hazard assessments. Our results emphasize the importance of direct measurements of debris-flow volume, inundated area, and high temporal resolution rainfall intensity.

Influence of approach shape of debris flow on impact load subjected to open Sabo dam under an overturning experiment of open Sabo dam

Recently high intensity rainfall disaster induces some structural failure of steel pipe open Sabo dam. To prevent such failure of the dam, a new design concept is necessary at the severe load exceeding the present design load. However, influence of debris flow impact load on steel pipe open Sabo dam is not clear to make a design load. The study experimentally approaches a vertical load distribution shape and its time history based on comparison with a wedge approach shape or a front boulder concentrated shape. The load and moment action of a front boulder concentrated shape debris flow is greater than that of a wedge approach shape. Mechanism making the difference is made clear by observation of vertical detail measurement of impact load.

三峡库区典型茶园土壤水分对不同降雨模式的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 三峡库区典型茶园土壤水分对不同降雨模式的响应 DOI: 10.5846/stxb202201240232 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（42077065）；国家自然科学基金项目（U224022） Response of soil moisture in typical tea gardens to different rainfall regimes in the Three Gorges Reservoir Area Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤水分是坡面产流和生物地球化学过程的关键控制因素。降水事件可以通过引起土壤剖面不同深度的土壤水分响应，从而影响流域中的径流路径、产流机制和土壤侵蚀过程等。基于三峡库区典型分布的茶园为对象，通过长期定点、高频的气象和水分数据观测，研究不同降雨模式下茶园不同土层深度（0-10、10-20、20-30、30-40cm）土壤水分的时空变化特征，分析茶园不同深度土壤在雨季的水分动态变化规律和对不同降雨模式的响应特征。结果表明：（1）研究区内的降雨和土壤水分含量均表现出明显的季节性特征。降雨在7月达到最大值，土壤水分含量则在8月达到峰值。表明降雨是影响土壤水分含量变化的重要因子，土壤水分对降雨有着明显的响应过程。（2）在相同降雨条件下，土壤含水量具有明显的垂直梯度变化。随着土层深度的增加，土壤水分对降雨的响应逐渐呈现出滞后现象。表层土壤（0-20cm）对降雨的响应较为迅速且幅度更加明显，深层土壤（30-40cm）水分含量变化相对稳定，并且对降雨的响应时间更加滞缓。随着土层深度的增加，土壤水分含量的变化幅度逐渐趋于平稳。（3）土壤水分含量对不同的降雨模式表现出显著差异。在较大雨强条件下，土壤水分变化出现了上升期、平台期及退水期。在小雨强短历时的降雨中，降雨对土壤水分的影响主要表现在土壤表层（0-10cm）。在降雨初期，降雨强度越大，土壤水分入渗越快，土壤的响应深度越深。研究三峡库区典型分布的茶园在不同降雨模式下的土壤水分变化特征，为三峡库区坡地的降水资源优化配置和园地面源污染防控提供理论依据，对区域水土流失治理以及面源污染物防控具有重要意义。 Abstract:Soil moisture is a key control factor for slope runoff generation and biogeochemical processes. Rainfall events can affect runoff paths, runoff mechanisms, and soil erosion processes in watersheds by causing soil moisture responses at different depths in the soil profile. Based on the typical tea gardens in the Three Gorges Reservoir Area, through long-term, fixed-point and high-frequency meteorological and moisture data observations, the temporal and spatial variation characteristics of soil moisture in different soil depths (0-10, 10-20, 20-30 and 30-40cm) of tea gardens under different rainfall regimes was studied, and the dynamic variation of soil moisture in the rainy season at different depths of tea gardens and the response characteristics to different rainfall regimes were analyzed. The results showed that:(1) The rainfall and soil moisture content in the study area showed obvious seasonal characteristics. Rainfall peaked in July and soil moisture levels peaked in August. It showed that rainfall was an important factor affecting the change of soil moisture content, and soil moisture had an obvious response process to rainfall. (2) Under the same rainfall conditions, soil water content had obvious vertical gradient changes. With the increase of soil depth, the response of soil moisture to rainfall gradually showed a hysteresis phenomenon. The topsoil (0-20cm) responds to rainfall more rapidly and the amplitude was more obvious, the change of water content in the deep soil (30-40cm) was relatively stable, and the response time to rainfall was more sluggish. With the increase of soil depth, the variation range of soil moisture content gradually became stable. (3) The soil moisture content showed significant differences with different rainfall regimes. Under the condition of high rainfall intensity, soil moisture changes appeared in the rising period, the plateau period and the retreating period. In the rainfall with small rainfall intensity and short duration, the effect of rainfall on soil moisture was mainly manifested in the soil surface layer (0-10cm). The greater the rainfall intensity, the faster the soil moisture infiltration, and the deeper the soil response depth were exhibited in the early stage of rainfall. Studying the characteristics of soil moisture variation characteristics in typical tea gardens in the Three Gorges Reservoir area under different rainfall patterns will provide a theoretical basis for the optimal allocation of precipitation resources and the prevention and controlling of ground source pollution in the gardens, which is of great significance to regional soil erosion control and the prevention and control of non-point source pollution. 参考文献 相似文献 引证文献

Flood simulation to determine flood hazard susceptibility of downstream Singkil watershed in Aceh Province

The damage to the Singkil watershed, one of the largest watersheds in Aceh Province, has become a concern for many parties, primarily due to increased flood events in the downstream area of the watershed. Based on previous studies, the problems which cause flooding are watershed damage due to illegal logging and high rainfall intensity reaching 3000-4500 mm/year, and increased erosion of 0.887 tons/ha/year, which causes a decrease in river capacity due to sedimentation. For this reason, this study aims to do 2D flood hydraulic modeling for five return periods of 2, 5, 10, 25, and 50 years which can be a reference for flood management in Aceh Singkil District. The hydrological analysis of the design flood discharge for several return period was carried out using Nakayasu and SCS-CN method. 1D-2D flood simulation generated using GeoHECRAS software to study flood hazard characteristic at downstream by combining tidal effects. The flood event in September 2012, a 10-year return period flood, became the basis for validating and calibrating the simulation model. Based on flood simulation result, it is known the downstream area of the Singkil watershed, Aceh Singkil districts is an area with a high flood potential and frequently occurs.

Loss Characteristics of Non-point Pollutant from a Mixed Agriculture Watershed

In order to explore the temporal and spatial variability of non-point source pollution in an agriculture watershed, the water quality and quantity characteristics of five flood events at Shuangqiao station in Siheshui watershed (south China) were monitored. Five pollutants, including BOD5, TSS, TP, TN, and NH3-N, were measured and analyzed. The characteristics of pollutant concentrations and load-transport rates were investigated. It is shown that the pollutant concentrations in the flood events are remarkably larger than those in the non-flood events. The temporal sequences of peak values between pollutant parameters and runoff flows are explored. It indicates that the time interval would be short if the high-intensity rainfall occurred in the initial period of a flood event. Most of the peak values of pollutant concentrations preceded the flow peaks. The correlation coefficients between TSS and other pollutant concentrations are analyzed. It is shown that there is a significant correlation between the concentrations of TSS and TP in the flood events.

Advection-Free Convolutional Neural Network for Convective Rainfall Nowcasting

Nowcasts (i.e., short-term forecasts from 5 min to 6 h) of heavy rainfall are important for applications such as flash flood predictions. However, current precipitation nowcasting methods based on the extrapolation of radar echoes have a limited ability to predict the growth and decay of rainfall. While deep learning applications have recently shown improvement compared to extrapolation-based methods, they still struggle to correctly nowcast small-scale high-intensity rainfall. To address this issue, we present a novel model called the Lagrangian convolutional neural network (L-CNN) that separates the growth and decay of rainfall from motion using the advection equation. In the model, differences between consecutive rain rate fields in Lagrangian coordinates are fed into a U-Net-based CNN, known as RainNet, that was trained with the root-mean-squared-error loss function. This results in a better representation of rainfall temporal evolution compared to the RainNet and the extrapolation-based LINDA model that were used as reference models. On Finnish weather radar data, the L-CNN underestimates rainfall less than RainNet, demonstrated by greater POD (29% at 30 min at 1 mm·h <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> threshold) and smaller bias (98% at 15 min). The increased ETS values over LINDA for leadtimes under 15 min, with maximum increases of 7% (5 mm·h <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> threshold) and 10% (10 mm·h <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> ), show that the L-CNN represents the growth and decay of heavy rainfall more accurately than LINDA. This implies that nowcasting of heavy rainfall is improved when growth and decay are predicted using a deep learning model.

Aplikasi Sistem Informasi Geografis Dalam Pemetaan Zonasi Rawan Banjir Kecamatan Monano Kabupaten Gorontalo Utara

Monano Subdistrict is one of the sub-districts located in Gorontalo UtaraRegency, Gorontalo Province, which does not have a flood hazard map. Thisstudy aims to determine the geological conditions and create a flood hazardmap. This study collected field data, such as lithological data, plotting dataon flood coordinates of each village, as well as validation data of the floodhazard level. The spatial analysis used in this research scores on flood-proneparameters, such as slope, rainfall, and land use that are overlayed alongwith lithological data. As a result, four geomorphological units are obtained:volcanic hills, denudational hilss, and fluvial and marine plains. From thegeological aspect, four units of lithology constituents are produced, such asandesite units, agglomerate units, sandstone units, and alluvial deposit units.The data also exposes that: slopes range from 0-45o flat to very steep, landuse is covered by settlements, rice fields, shrubs, and forests, as well asrainfall which refers to a very high intensity of rainfall, which is 2771 mmper year. The data obtained produces a flood hazard map divided into threeclasses: low, medium, and high.

Soil Erosion Estimation Using Geospatial Technology: A Study of Jyadul Khola Basin, Gorkha, Nepal

Estimation of soil erosion from drainage basins is essential while assessing the severity and its impact on agriculture, forests, barren land, waterbodies, and built- up areas. Jyadul Khola basin significantly affects the ecological processes that feed into the Budhigandaki River in the south-eastern side of Gorkha District. This paper has attempted to estimate the mean erosion rate based on the erosion severity classes. Remotely sensed Ziyuan-3 satellite image processed in Earth Resources Data Analysis System (ERDAS) Imagine, Geographical Information System (GIS), and Revised Universal Soil Loss Equation (RUSLE) model were used in this study. The land use land cover (LULC) classification results were validated by using confusion matrix by computing overall accuracy and kappa coefficient which is 95% and 0.94 respectively. The basin had been classified into 6 categories based on erosion severity. The results indicated 92.7% of land (0-5 t ha–1 yr–1) is low severe followed by 2.39% (10-20 t ha–1 yr–1) moderate, 2.07% (5-10 t ha–1 yr–1) high, 2.04% (20-40 t ha–1 yr–1) very high, 0.67% (40-80 t ha–1 yr–1) severe and 0.10% of land (&gt;80 t ha–1 yr–1) which is very severe for soil erosion. The total annual mean soil loss was found to be 13526.60 t yr–1 and soil erosion classes ranges from 0 to 305.34 t ha–1 yr–1 for the entire study area. Kuwapani, Lakuri Bhanjyang, Khadkagaun, Garapani and Kaulebhagar area are the most susceptible to soil erosion. It is observed that barren land, steep slopes, and high intensity of rainfall are major factors for soil erosion hazard. This outcome can serve as a foundation for decision-makers to conserve high risk areas and plan effective measure to lessen impending disasters.

Canola yield and quality under tile drainage in the Canadian Prairies

For areas with seasonally shallow water tables and poorly drained soils, subsurface drainage systems are ideal for removing excess water from the root zone and improving soil workability, trafficability, and timeliness of field operations. With increased interest in tile drainage in southern Manitoba, the objective of this study was to evaluate the impacts of drainage on canola yield and canola oil qualities over three growing seasons (2019-2021) in Winkler, Manitoba. The study was carried out on replicated field plots with three different drainage treatments: controlled drainage (CD), free drainage (FD), and no drainage (ND). Subsurface drain tiles were installed at a depth of 0.9 m. The drains were spaced at 8 m for CD and 15 m for FD. Compared to FD plots (3.02 Mg/ha), the CD plots (3.51 Mg/ha) had significantly higher yields in 2019 with good rainfall. With low rainfall in 2020 and 2021, the impact of drainage, especially CD, diminished, with no significant differences between the treatments. In 2020, the average yields were 3.12, 2.52, and 2.97 Mg/ha for ND, CD, and FD, respectively. Similarly, in 2021, there was no significant difference between CD (1.14 Mg/ha), FD (1.52 Mg/ha), and ND (1.07 Mg/ha). The impact of CD under drought conditions was not significant. This could be related to the narrower drain spacing, which tends to remove water rapidly within the soil profile during short periods of high-intensity rainfall. The canola quality assessments (oil, protein, glucosinolate and fatty acid profile) showed no significant differences between ND, CD, and FD in each of the years. This suggests that environmental variables (mainly temperature and precipitation) may have masked drainage impacts on canola quality.

Kajian Kapasitas Pompa sebagai Alternatif Solusi Pengendalian Aliran Balik di Kampung Glintung (GWS) Kota Malang.

The phenomenon of flooding that occurred in Glintung Village (GWS), especially those that occurred in RT 01, RT 02 and RT 03, is a phenomenon that is rarely found in other areas. Usually, floods occur due to high rainfall intensity, causing excess water which cannot be accommodated by waterways, to overflow into floods. The floods in the GWS indicate a backflow phenomenon which causes water that should flow into the river to turn around and overflow into residents' settlements. To anticipate floods due to backflow which have a bigger impact, one effort that can be done to solve this problem is to install pumps to reduce the volume of flooding in the area. So an analysis is needed to determine the required pump capacity to reduce the flood volume. The results of the analysis show that reducing the volume of flooding can be done by installing 3 pumping stations and 3 pumps with a capacity of 100 m3/hour for RT 03, 3 pumps with a capacity of 50 m3/hour, for RT 02 and 1 pump with a capacity of 50 m3 /hour for RT 01. In addition, it is also necessary to install a backflow valve and repair the existing river retaining wall.

Mapping Potential Soil Water Erosion and Flood Hazard Zones in the Yarlung Tsangpo River Basin, China

The ubiquity of soil water erosion in the Yarlung Tsangpo River Basin leads to a series of natural hazards, including landslides, debris flows and floods. In this study, the Revised Universal Soil Loss Equation model (RUSLE) was used to quantify potential soil water erosion, while the Height Above Nearest Drainage model (HAND) was used to delimit potential flood hazard zones. Remote sensing and geographic information system technologies were employed to spatialize the results, which showed that the annual soil loss from water erosion was less than 1239 t ha−1 y−1. The total soil loss was estimated to be over 108 × 106 tons, of which about 13 × 106 tons (12.04% of the total) occurred from the agricultural land in the downstream valley. Soil erosion mapping was performed using six levels of soil erosion intensity and the effects of precipitation, land use/land cover and topography on soil erosion were revealed. Increases in precipitation and slope gradient significantly increased the soil loss rate, while the maximum rate of soil loss occurred from densely vegetated land, reaching 9.41 t ha−1 y−1, which was inconsistent with erosion preconceptions for this land type. This may be due to a combination of the region’s unique climate of high intensity rainfall and steep slopes. Flood hazard mapping showed that all regional cities were located in a flood hazard zone and that, within the total basin area (~258 × 105 ha), 9.84% (2,537,622 ha) was in a high flood occurrence area, with an additional 1.04% in aa vulnerable to moderate flood hazard area. Approximately 1.54% of the area was in a low flood risk area and 4.15% was in a very low flood risk area. The results of this study provide an initial identification of high-risk soil water erosion and flood hazard locations in the basin and provide a foundation upon which decision-makers can develop water and soil conservation and flood prevention policies.

Evaluation of extreme precipitation over Southeast Asia in the Coupled Model Intercomparison Project Phase 5 regional climate model results andHighResMIPglobal climate models

AbstractModelling rainfall extremes and dry periods over the Southeast Asia (SEA) region is challenging due to the characteristics of the region, which consists of the Maritime Continent and a mountainous region; it also experiences monsoonal conditions, as it is located between the Asian summer monsoon and the Australian summer monsoon. Representing rainfall extremes is important for flood and drought assessments in the region. This paper evaluates extreme rainfall climatic indices from regional climate models from CORDEX Southeast Asia and compares them with the results of high‐resolution global climate models with a comparable spatial resolution from the HighResMIP experiment. Observations indicate a high intensity of rainfall over areas affected by tropical cyclones and long consecutive dry day periods over some areas in Indochina and the southern end of Indonesia. In the model simulations, we find that both coupled and sea surface temperature‐forced HighResMIP model experiments are more similar to the observations than CORDEX model results. However, the models produce a poorer simulation of precipitation intensity‐related indices due to model biases in the rainfall intensity. This bias is higher in CORDEX than in HighResMIP and is evident in both the low‐ and high‐resolution HighResMIP model versions. The comparable performances of HighResSST (atmosphere‐only runs) and Hist‐1950 (coupled ocean–atmosphere runs) demonstrate the accuracy of the ocean model. Comparable performances were also found for the two different resolutions of HighResMIP, suggesting that there is no improvement in the performance of the high‐resolution HighResMIP model compared to the low‐resolution HighResMIP model.

Divergent hydrological responses to intensive production under different rainfall regimes: Evidence from long-term field observations

The progress in intensive production over recent decades have greatly altered land-use patterns, often resulting in simplified landscapes. Intensive production is particularly necessary in mountainous areas where arable land resources are scarce, but it is a pervasive concern that landscape simplification will increase pressure for mountain flood disaster control. In this study, rainfall, runoff and sediment process data from 1995 to 2015 were observed for a typical intensively developed mountainous watershed. Data were used to investigate the effects of intensive production on the hydrological response characteristics discharge, suspended sediment concentration, runoff depth, and sediment load under three different rainfall regimes, namely rainfall regimes I (long duration, light rainfall intensity), II (short duration, high rainfall intensity), and III (long duration, high amount). Orchard area in the watershed increased from 4.43 % to 37.44 % under intensive production from 1995 to 2015. Intensive production led to high-intensity land use as well as homogenization and simplification of the landscape, which inevitably caused changes in hydrological processes in the mountainous watershed. Intensive production resulted in a significant downward trend in runoff coefficients (p = 0.001) and sediment loads (p = 0.006) under the three different rainfall regimes. Average sediment concentration decreased significantly and continuously (2394 to 12.53 kg m−3) during the 20 years of the study, and average runoff fluctuated but decreased from 0.218 m3/s in 2000 to 0.093 m3/s in 2015. According to hysteresis analysis, the proportion of counterclockwise loop events decreased after intensive production but remained the dominant circulation mode (40 %). The proportion of events in eight-figure loops increased from 0.06 % before intensification to 25 %. The increase in complex circulation implied that development of intensive production increased the sources of sediment in the watershed. The study increases understanding of hydrological responses to intensive production in complex mountainous watersheds and provides practical references for sustainable watershed management and optimization of land use allocation.

Influence of hydraulic properties to residual soil

Tropical country such as Malaysia experienced high intensity and long period of rainfall, which is the main factor of slope failure. The increasing of seepage subjected by rainfall not only distress suction distribution, but also affects hydraulic properties of soil lead to the decreasing of soil strength. This also leads to soil slope failure. The main hydraulic properties for soils are Soil-water characteristic curve (SWCC) and hydraulic conductivity, k. The relationship of these parameters is highly influenced by tropical soil, thus contributes to soil instability phenomenon. The main objective of this paper is to study the relationship between soils' hydraulic properties and particle size distribution (PSD). Four types of soils investigated in this research include one sample taken from Universiti Kebangsaan Malaysia (UKM)'s reserved forest, and three samples were commercially obtained. Other than soil basic properties, pressure plate extractor and permeability tests were conducted for SWCC and permeability, respectively. Tests show that different types of soils demonstrate different characteristic of SWCC and hydraulic conductivity. Result also shows that PSD has the influence and affect the result of hydraulic properties of soils. This study is expected to enhance the understanding of complex phenomenon of residual soil instability.

Assessment of potential flash flood hazards. Concerning land use/land cover in Aqaba Governorate, Jordan, using a multi-criteria technique

Aqaba is the principal port and the onlymaritime outletin Jordan. It is located in the northeastern tip of the Red Sea and is characterized by hyper arid climatic conditions. As such, Aqaba frequently experiences high intensity rainfall as flash floods. This paper intends to build a flash flood vulnerability map for Aqaba city and assess its impact on land use/land cover (LULC), that could help decision makers to take it into consideration in the planning process Six spatial layers were considered including: rainfall, elevation, slope, stream order (distance to stream), soil, and LULC. These layers were processed using GIS tools, multi-criteria analysis (MCA); in particular, the analytical hierarchy process (AHP) method was used to identify the optimal weights of each parameter contributing to potential flash floods. The map showed that 1960.5 km2 (24.4 %) 1960.5 km2 (28.4 %) corresponding to high, and very high PFF, respectively. River mouth, canyons, and flat low altitudes areas are vulnerable to high and very high flash floods hazards risk especially in urban and agricultural areas. In addition, they revealed that steep and ridge slopes, upper-stream high altitudes are less susceptible to FF hazards.

Impact of Climate Change on Soil Erosion

Global warming is expected to result in a more vigorous hydrological cycle, including total rainfall and more frequent high-intensity rainfall events, which affect soil erosion and cause a threat to agricultural land sustainability and productivity, particularly in tropical and subtropical regions. This study aims to determine the effects of climate change on soil erosion in Taiwan. This experiment assesses the risk of soil erosion in Taiwan over 2 – 200 years. To determine the predictor of soil erosion risk, the study used USPED. Result showed there was an increase in sediment yield because of soil erosion. Hence, targeting conservation practices to erosion-prone areas, expanding conservation coverage, and adapting agronomic practices may be necessary to prevent excessive soil erosion under climate change scenarios that include intensified precipitation.

Relationship between Knowledge and Preventive Behavior of Leptospirosis in Berbah District Sleman Regency Yogyakarta in 2021

Public Health is the resultant from an balance of individual, agent, and environment problems. Individual knowledge and the ability to adapt to the environment vary greatly. The individual awareness and sensibility towards surroundings will contribute to the public health status. Environmental factor in the raining season with high intensity of rainfall cause some risks such as flood. It can be a disaster and destroy the facilities in the area. This can be a transmission media, a new habitat of insects for certain disease, one of them is Leptospirosis. The condition after flood with low level of clean water facilities can make these bacteria live and reproduce, with warm temperatures, neutral pH of water, humidity and also high rainfall. Leptospirosis cases in Indonesia are sufficiently high which in 2019, there are 845 cases with mortality rate for 16.26%. Some factors may affect the number of the case. This research is aimed to know the factors related to the preventive behavior of leptospirosis. It was held in Public Health Center Berbah Yogyakarta. The method of research is quantitative research with design survey method, quasi experiment. The population is the clients visiting to Public Health Center Berbah, with the average number of clients coming are 200 clients/day. The sample is taken by accidental sampling to the clients with the number of daily visits (50 persons). The result shows, that of five analyzed factors, knowledge is the factor related to the preventive behavior of leptospirosis.

Model Test and Numerical Simulation of Slope Instability Process Induced by Rainfall

Due to rainfall infiltration, slope instability becomes frequent, which is the main reason for landslide disasters. In this study, the stability of slope affected by rainfall was analyzed using an indoor model test and geo-studio simulation method, and the variation law of phreatic line, seepage field, the most dangerous sliding surface, and safety factor with time were studied under rainfall infiltration. Research results showed that under the effect of rainfall, the slope failure presented a typical traction development mode. With the increase of time, the phreatic line of the slope kept rising, the water head keeps increasing, the seepage depth in the slope became deeper, and the slope stability worsened until the slope was damaged. The water head height decreased gradually from the slope left boundary to the right, and the water head width decreased gradually. The soil at the slope back edge was damaged, and the sliding soil accumulated at the slope foot, forming a gentle slope, which increased the shear strength of the slope, making the slope finally reach a stable state. In this process, the overlying soil changed from an unsaturated state to a saturated state, the pore water pressure and soil pressure increased, and then the slope was damaged, both of which decreased. Under high rainfall intensity, the slope was damaged, the soil in the slope was rapidly saturated, and the time required to produce the sliding area was short. When the rainfall intensity was the same, the smaller the slope angle was, the smaller the safety factor was. When the slope angle was the same, the greater the rainfall intensity was, the smaller the safety factor was.