Determination of the Most Priority Conservation Areas Based on Population Pressure and Erosion Hazard Levels in Lesti Sub-Watershed, Malang Regency, Indonesia (original) (raw)
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IntechOpen, 2020
In a watershed, the Erosion Hazard Level (EHL) is usually associated with erosion rate and existing soil solum. In Lesti Sub-Watershed, erosion rate increases every year due to erosivity factor, erodibility, the length and slope, as well as crop factor and land conservation action. Analysis of erosion associated with population pressure has not been much discussed in the Lesti Sub-Watershed. This topic needs to be explored given that the erosion rate that affects sedimentation in the Sengguruh Reservoir, as an outlet of the Lesti Sub-Watershed, cannot be separated from the population activity therein. The population activity and the choice of use of land suppress the land so that it affects the carrying capacity of the watershed. Measuring land strength is usually based on the value of existing population pressure and its effect on vulnerability or erosion hazard level. This study seeks to assess the relationship between erosion hazard level and population pressure, as well as to determine the priority conservation areas in the Lesti Sub-watershed. The research approach uses a mixed method. The Soemarwoto formulas (1985) is applied in the method of population pressure analysis, and EHL is obtained spatially from the erosion rate of MUSLE (Williams, 1975) as well as from soil solum. The results shows that from 12 sub-districts in Lesti Sub-watershed there is 1 sub-district which has high population pressure as well as severe EHL. This sub-district is the most priority area for environmental conservation.
Land Degradation & Development, 2007
Soil erosion is one form of land degradation, which is caused by the interacting effects of numerous factors such as biophysical characteristics and socio-economic condition of a particular watershed. Previous erosion studies focused on the use of soil erosion models (e.g. USLE, EUROSEM, SLEMSA etc.), which have been developed under local conditions (e.g. United States, Europe, Africa, etc) and mostly use only biophysical factors as inputs to the models. In this study, a methodology that integrates both biophysical and socio-economic aspects into a framework for soil erosion hazard assessment using principal component analysis (PCA) is described. The analysis is done at the land unit level. With the particular conditions of the study area that is characterized by Inceptisols and Alfisols soil types, nine different land uses with mixed vegetation and forest area dominant in the steep slope, high annual rainfall (>2500 mm), high population with mostly low income and low education, were considered. These were used in formulating a soil erosion hazard index (EHI) equation which relates a number of key factors consisting of biophysical and socio-economic variables, namely soil texture, slope steepness, land cover, soil conservation practices, income and farmers' knowledge. Weighting and scoring of these key factors were used to develop the EHI equation and to calculate an index value of erosion hazard for every land unit. Results indicate that more than 60% of the area has erosion hazard ranging from moderate to very severe, and most of the land units with high erosion hazard were found at the mountain areas. It was also found that erosion hazard was severe in areas with high silt content, followed by high rainfall and steep slope, low crop cover without any soil conservation practices coupled with lack of awareness on soil erosion and low income. The key factors identified and level of erosion hazard obtained can be used to formulate conservation measures in critical areas which are prone to soil erosion. Copyright © 2007 John Wiley & Sons, Ltd.
Conservation direction based on estimation of erosion in Lesti sub-watershed, Malang District
IOP Conference Series: Earth and Environmental Science, 2019
Management of watershedis a part of regional development. Lesti sub-watershed as one of upstream Brantas watersheds faces erosion problems and criticality of land that is not balanced with conservation efforts based on ideal needs according to carrying capacity of the environment. The reduced function of the Sengguruh Reservoir in upper Brantas River has caused a disruption to its role in flood control, water supply for irrigation and generating a large portion of hydroelectric power in East Java Province. This study seeks to provide the latest erosion-based conservation direction with MUSLE methods and spatial analysis of GIS that considers proportional social, economic and environmental aspects. The results of the analysis are used in order to determine the priority sub-districts for handling conservation within Lesti Sub-watershed to reduce erosion problems. Of the 12 sub-district on Lesti Sub-Watershed, some sub-districts identified as having the highest Erosion Hazard Level (TBE) area marked in red on the map are in sub-districtof Wajak, Tirtoyudo, Dampit, Sumbermanjing Wetan, Gedangan and Bantur. Environmental conservation directives are suggested to be focused on these 6 sub-districts through the application of vegetative soil and water conservation, technical civilization and combination involving the community and in accordance with local conditions.
Indonesian Journal of Earth Sciences
Erosion is a form of damage to the soil caused by changes in land function on certain plains without management. The Padang Batung Sub-district area experienced land damage which was characterized by the distribution of critical land area reaching half of the area. The purpose of this study is to analyze the level of erosion hazards that occur in Padang Batung Sub-district. This study used a terrain unit map as the basis for the sample analysis unit. The number of samples in this study was 20 samples using the purposive random sampling method. The data analysis used is in the form of the Universal Soil Loss Equation (USLE) equation which can predict the level of erosion hazard through several parameters in the study area. The results showed that the erosion hazard level in Padang Batung Sub-district was dominated by severe criteria with an affected area of 74 km2 with an average erosion rate of 345.27 tons/ha/yr. One of the dominating factors causing the high erosion in Padang Batun...
Analysis of Erosion Hazard in Upstream Ciliwung Watershed Bogor , West Java , Indonesia
2019
Erosion is the loss of a soil or parts of soil from a place that is transported by water or wind to another place. The growing quantity of human activity makes buildings around upstream Ciliwung watershed Bogor, West Java, Indonesia increase as well. The current condition of natural and environmental resources in the upstream Ciliwung watershed is quite apprehensive where environmental damage is already severe due to inappropriate use and use of land and urgent life needs. Therefore, mapping the spatial distribution of erosion hazards in the relevant research area needs to be done. The method that researcher use to predict erosion is the Universal Soil Loss Equation (USLE) equation. This equation is an erosion estimation model used to calculate the amount of erosion that occurs in the long term in an area. This equation can predict the average erosion rate in a plot of land at various slope steepness with a certain rain pattern for each existing cropping effort and soil management a...
Jurnal Perencanaan Pembangunan: The Indonesian Journal of Development Planning, 2021
The reduced age function of Sengguruh Dam/Reservoir due to erosion in the upper of Brantas Watershed (Lesti Subwatershed area) interferes with its role in flood control, irrigation water supply, and the supply of most of the hydroelectricity in East Java Province, Indonesia. This study aims to estimate erosion, analyze the interrelationship of the causative factors, and provides environmental conservation direction. The research uses mixed methods. The quantitative method of erosion rates is done by calculating the Modify Universal Soil Loss Equation which is supported by GIS tools. The qualitative method is carried out with questionnaires and interviews in the Lesti Subwatershed area. The results showed that the current erosion rate in each ha of land (average) in the Lesti Subwatershed was 153,868 tons /ha/year (exceeding the tolerable erosion rate of 30 tons/ha/year). The rate of erosion in the Lesti Subwatershed has always increased in the last 14 years. Of the 12 Subdistricts i...
Journal of Chinese Soil and Water Conservation, 2019
In forest and land rehabilitation (FLR), the watershed is the major unit of watershed management. Furthermore, the watershed approach is the basis of FLR evaluations, which include evaluations of hydrology, land erosion, and other environmental factors. Currently, sustainable FLR planning is in the development stage. The present research was conducted to identify the erosion hazard level as a result of FLR performed on the Tambun Watershed in Central Sulawesi, Indonesia. Analysis of the erosion hazard level was conducted using the USLE equation. The results of this research revealed that FLR performed in a community forest and nursery, where Paraserianthes falcataria and Palaquium obovatum trees had been planted, had not been able to reduce the rate of soil erosion. Happen increase in soil erosion from 955.63 ton/ha/year (prior to FLR) to 1,097.52 ton/ha/year (after FLR). This was because these two types of plants were broad-leaved. Therefore, selecting the right type of plant is necessary. In particular, needle-leaved plants should be used in FLR activities to minimize soil erosion.