Impact Of Land Use Research Articles

Identification of Soil Quality Factors and Indicators in Mediterranean Agro-Ecosystems

Soil quality offers a holistic approach for understanding the relationships between soil’s biological, chemical, and physical properties, which is crucial for sustainable land use and the management of non-renewable soil resources. This study evaluates the impact of land use on a set of 23 soil quality indicators (SQIs) across 5 land uses of the Mediterranean agro-ecosystems: forest, olive groves, wheat fields, a corn/wheat crop rotation system, and pasture. Seasonal soil sampling was carried out over two consecutive years in three conventionally managed fields representing each land use type. For each sampling, physicals SQIs (soil moisture, porosity-Vp-, bulck density-BD-, water holding capacity-WHC-, clay, silt, sand), chemical SQIs (organic carbon-Corg-, total Nitrogen-TN-, C/N, PH, electrical conductivity-EC-, ammonium-NH4-N-, nitrate-NO3-N- and available nitrogen-Nmin-), and biological SQIs (soil microbial biomass C-Cmic- and N-Nmic-, Cmic/Nmic, Cmic/Corg, Nmic/TN, active carbon—Cact-, Cact/Corg) were evaluated. Through multivariate analysis, five key soil quality factors—organic matter, microbial biomass, nutrients, C/N ratio, and compaction—were identified as indicators of soil quality changes due to land use, explaining 82.9% of the total variability in the data. Discriminant analysis identified organic matter and the C/N factors as particularly sensitive indicators of soil quality changes, reflecting the quantity and quality of soil organic matter, incorporating 87.8% of the SQIs information resulting from the 23 indicators. ΤΝ, accounting for 84% of the information on the organic matter factor, emerges as a key indicator for predicting significant changes in soil quality due to land use or management practices. The TN and C/N proposed indicators offer a simplified yet effective means of assessing soil resource sustainability in the Mediterranean agroecosystems, providing practical tools for monitoring and managing soil quality.

Evaluating and predicting the impact of land use and land cover change on land surface temperature in Lac Duong district, Lam Dong province, Vietnam

Land use and land cover (LULC) change is a key factor influencing land surface temperature (LST) dynamics. This change reflects partly global warming and climate change at local and regional scales. This study aimed to evaluate the effect of LULC on LST change in Lac Duong mountainous district, Lam Dong province in the past 10 years (2013 - 2023), and predict the LST change in 2030. The study used satellite image data from Landsat 8 and 9 OLI to build LULC and LST maps and used the CA-ANN model to predict the LST map. The results showed that the forest land had the LST below 25°C, with the below 20°C LST area correlated negatively with the forest land area, while 20 - 25°C LST correlated positively, especially at the temperature of 22 - 25°C (R2 = 0.97). The 22 - 25°C and 30 - 35°C temperature levels (R2 = 0.76 and R2 = 0.86) correlated sharply with the crop land area. The LST levels between 30 - 40°C reflected the built-up land and bare land with the highest correlation of R2 = 0.68 and 0.88, respectively. The LST level 20 - 22°C represented the water body area (R2 = 0.87). The LULC changes had an impact on the LST change in the past 10 years in Lac Duong district. While the forest land area decreased slightly by 0.5%, the cool LST area fell considerably by 10.5% compared to 10 years ago. An almost doubling of the cropland area also led to a doubling in the 25 - 35°C LST areas. In addition, the 35 - 40°C LST level started to happen in several regions. The LST change was predicted to keep increasing in 2030. The temperature was predicted to increase by 2 - 3°C with a maximum temperature of 42°C.

Impact of agricultural land-use on functional feeding groups of Afrotropical Ephemeroptera, Plecoptera and Trichoptera in the Kat River, Eastern Cape, South Africa

Despite Africa experiencing a substantial rise in inadequately managed agricultural practices, studies examining the effects of these activities on the functional organisation of macroinvertebrates in tropical streams are underdeveloped. The responses of Ephemeroptera, Plecoptera and Trichoptera (EPTs) functional feeding groups (FFGs) to agricultural pollution were investigated in the Kat River, Eastern Cape, South Africa, to identify potential FFG indicators. Physicochemical parameters and macroinvertebrates were sampled from eight sites delineated into four land-use impact categories (highly impacted, HIC; impacted category, IC; moderately impacted, MIC; and least impacted, LIC) based on the percentage of agricultural land cover. The Permutational multivariate analyses of variance (PERMANOVA) results revealed land use (F = 4.2, 3.62; p < 0.05) and season (F = 2.89, p < 0.03) influenced FFGs in the river, with shredder abundances decreasing with increasing agricultural stress. Conversely, collectors, predators and scrapers were tolerant of agricultural disturbance. Nutrient variables (NO3-N, NO2-N and NH4-N), canopy and depth were the critical variables that affected FFG structure in the river. Our findings provided more understanding and insights into the functional structure of EPT in relation to agricultural pollution and can contribute to developing trait-based biomonitoring tools in Africa.

Use of the SWAT Model to Simulate the Hydrological Response to LULC in a Binational Basin between Ecuador and Peru

Land use change has played a crucial role in altering the hydrological behavior, making detailed assessments essential to ensure sustainable water resource management and the conservation of natural ecosystems. This study focuses on simulating the impact of different Land Use and Land Cover (LULC) scenarios for the years 1985, 1995, 2005, and 2015 on the water balance in the Puyango-Tumbes River basin, which spans across Ecuador and Peru, during the period 1981-2015. The results indicated an 18.3% increase in the grassland areas and a significant 38.2% reduction in the savanna zones, contributing to an annual 2.1% increase in the Evapotranspiration (PET) rates. These land use changes led to a 29.2% decrease in the Percolation (PERC), a 20.7% decrease in the Surface Runoff (SURQ), a 33% reduction in the Groundwater Flow (GW_Q), and a 26.6% decrease in the Annual Water Yield (WYLD), as well as a slight reduction of 0.9% in the Lateral flow (LAT_Q). These findings highlight the importance of considering land use changes to ascertain the sustainable management of natural resources, particularly in a transboundary basin.

Assessing the impact of land use and land cover changes on soil properties and carbon sequestration in the upper Himalayan Region of Gilgit, Pakistan

Assessing the impact of land use and land cover changes on soil properties and carbon sequestration in the upper Himalayan Region of Gilgit, Pakistan

Identification and apportionment of groundwater pollution sources in the Guanzhong region based on PMF model

Identifying pollution sources and measuring their impact is essential for protecting groundwater. Groundwater pollution sources in the Guanzhong region were identified using the positive matrix decomposition (PMF) model, and their contributions were quantified. The spatial distribution of socio-economic factors (population, GDP, fertilizer use, farmland, and livestock) was analyzed. Redundancy and correlation analyses were used to assess the impact of land use on groundwater quality. The results showed that the primary groundwater physicochemical constituents exceeding the standard limits were, in descending order, NO3 −, Na+, TDS, F−, SO4 2−, and Cl−, and the most polluted areas were found in the eastern and southern parts of the study area. Land use and socio-economic factors can have diverse impacts on groundwater quality. Five main sources responsible for groundwater quality deterioration in the Guanzhong were comprehensively identified, i.e., agricultural nonpoint sources, domestic pollution from urban and rural development, natural release of fluorine from stratigraphic minerals as well as coal mine storage and combustion, industrial discharges, and water-rock reactions. Natural release from minerals and industrial discharges are the major causes of groundwater degradation in the study area, which is followed by water-rock reactions, agriculture, and domestic pollution.

Urban dynamics and Gen-Z mobility: The influence of land use diversity and density on daily trip patterns in Indonesia

This study aims to assess the impact of land use—specifically land diversity and density—on the trip patterns of Gen-Z in developing cities like Indonesia, where public transport infrastructure is limited. Using travel history data from GMaps Timeline, the movements of 1,057 individuals were analyzed over 150 days on a 24-hour continuous basis, with 65.56% representing Gen-Z and the remainder older generations as a comparison group. Of the 579,360 trips observed, the findings indicate that density and land use diversity significantly influence the number of daily trips and daily mileage per trip. The study also identifies differences in mobility patterns between Gen-Z and older generations and highlights the role of gender in shaping trip patterns in urban areas. The practical implications of the findings emphasize the importance of urban planning strategies that integrate high-density, mixed-use areas to reduce reliance on private vehicles and promote sustainable transportation options. Enhancing the diversity of land use and developing pedestrian-friendly environments enables cities to address the mobility preferences of Gen-Z, which tend to favor sustainable transport modes. Furthermore, this research underscores the critical role of appropriate infrastructure development in fostering sustainable mobility for younger generations. Without such infrastructure and supportive urban planning, the potential to optimize sustainable transport preferences among Gen-Z remains limited. This highlights the urgency for policymakers to prioritize investments in public transport systems and land use policies that promote accessible, efficient, and sustainable urban mobility.

The impact of land use on the acoustic behaviour of cicadas in the Chocó lowland tropical forest of Ecuador

The impact of land use on the acoustic behaviour of cicadas in the Chocó lowland tropical forest of Ecuador

Impact of climate and land use on the temporal variability of sand fly density in Sri Lanka: A 2-year longitudinal study.

Leishmaniasis has emerged as an escalating public health problem in Sri Lanka, with reported cases increasing nearly three folds over past decade, from 1,367 in 2014 to 3714 cases in 2023. Phlebotominae sand flies are the vectors of leishmaniasis. Their density is known to be influenced by context-specific climatic and land use patterns. Thus, we aimed to investigate how these factors drive sand fly density across Sri Lanka. We analysed monthly collections of sand flies (n = 38,594) and weather data from ten sentinel sites representing three main geo-climatic zones across Sri Lanka, over 24 months. Site-specific land use data was also recorded. The influence of climate and land use patterns on sand fly density across the sentinel sites were estimated using distributed lag non-linear models and machine learning. We found that climate played a major role on sand fly density compared to land use structure. Increase in rainfall and relative humidity at real time, and ambient temperature and soil temperature with a 2-month lag were associated with a statistically significant increase in sand fly density. The maximum relative risk (RR) observed was 3.76 (95% CI: 1.58-8.96) for rainfall at 120 mm/month, 2.14 (95% CI: 1.04-4.38) for relative humidity at 82% (both at real time). The maximum RR was 2.81 (95% CI: 1.09-7.35) for ambient temperature at 34.5°C, and 11.6 (95% CI, 4.38-30.76) for soil temperature (both at a 2-month lag). The real-time increase in ambient temperature, sunshine hours, and evaporation rate, however, reduced sand fly density homogeneously in all study settings. The high density of chena and coconut plantations, together with low density of dense forests, homesteads, and low human footprint values, positively influenced sand fly density. The findings improve our understanding of the dynamic influence of environment on sand fly densities and spread of leishmaniasis. This knowledge lays a foundation for forecasting of sand fly densities and designing targeted interventions for mitigating the growing burden of leishmaniasis among the most vulnerable populations, particularly in an era of changing climate.

Desertification sensitivity and its impacts on land use change in the Tarim Basin, Northwest China

Desertification poses a major challenge in the northwestern arid areas of China. Land use activities are increasingly endangered by desertification, including direct impact (e.g., farmland abandonment) and indirect impact (e.g., farmland area control). However, previous studies have primarily focused on the impact of land use on desertification processes, while there has been limited research on the direct and indirect impacts of desertification on land use. Based on the Mediterranean Desertification and Land Use (MEDALUS) and Future Land Use Simulation (FLUS) models, we identify the spatiotemporal distribution of desertification sensitivity and analyze the direct and indirect impacts of desertification on land use in the Tarim Basin from 2000 to 2020. The results showed that the desertification sensitivity areas were primarily concentrated in the critical areas (proportion > 50 %), followed by the fragile and potential areas. In terms of the direct impact, the areas of abandoned farmland due to desertification were 68.25 km2 and 1444.25 km2 during the periods of 2000–2010 and 2010–2020, respectively. Additionally, 3893.25 km2 of farmland was at risk of abandonment. After being abandoned, the farmland was primarily converted into grassland. In terms of the indirect impact, the differences between predicted (simulations without farmland area control) and observed farmland area, serving as an indicator of farmland area control to reduce desertification risks, were 1065.75 km2 in 2010 and 4614.00 km2 in 2020. Our paper provides new insights into the direct and indirect impacts of desertification on land use, providing references for formulating desertification control policies and regional land use planning.

Assessing the Interaction Impacts of Multi-Scenario Land Use and Landscape Pattern on Water Ecosystem Services in the Greater Bay Area by Multi-Model Coupling

Water ecosystem services (WESs) are intrinsically associated with the livelihood of urban residents and are frequently disrupted by human activities. Land use and landscape patterns are key driving factors of alterations in WESs. However, existing research primarily quantifies single-factor influences and often overlooks the interactions between these factors. This study addresses this gap by employing a multi-model coupling approach, integrating the Patch-generating Land Use Simulation (PLUS), Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, and Geographical Detector (GD) models alongside various indicators to analyse the evolution of land use, landscape patterns and WESs in the Greater Bay Area from 2000 to 2020, and to simulate spatio-temporal change patterns in different scenarios from 2030 to 2050. Additionally, this study examines the multi-factorial interactions between land use, landscape patterns, and WESs. The results indicate that (1) urbanisation steadily increased, leading to intensified landscape fragmentation, and water yield (WY) and total phosphorus (TP) consistently increased, while total nitrogen (TN) in water gradually decreased; (2) urban areas exerted the most significant impact on WY in the Greater Bay Area while Patch density (PD) had a stronger influence on WY, and Shannon’s diversity index (SHDI) had the most pronounced effect on TN and TP; (3) the interaction between any two land-use types or landscape indices exerted a greater impact on WESs compared with the impact of individual factors alone. The interaction between urban areas and cropland substantially influenced WY (q¯ = 0.634) and most strongly affected TN and TP in water (q¯ = 0.74 and 0.73, respectively). SHDI and PD had the most significant impact on WY in the economic development scenario (q¯ = 0.19) and exhibited the greatest influence on the TN and TP levels in the ecological priority scenario (q¯ = 0.12 and 0.15, respectively). Our findings can provide theoretical and technical support for the integrated scientific planning of regional water ecosystems and the development of comprehensive land use policies in the future.

A national scale floodplain model revealing channel gradient as a key determinant of beaver dam occurrence and inundation potential can anticipate land-use based opportunities and conflicts for river restoration

The Eurasian beaver (Castor fiber) has expanded its range considerably due to reintroduction and conservation efforts and the species is now found in more than 30 countries across Europe. This expansion brings with it opportunities for nature restoration, the provision of river ecosystem services and the return of naturally functioning floodplains. It also has the potential for conflict with existing human land-use through dam induced floodplain inundation and wetland development. To maximise restoration benefits and minimise conflict, modelling approaches are needed that can predict the likelihood of dam building and include scenarios for subsequent floodplain inundation. This study describes the first national-scale comprehensive study on the drivers of beaver dam occurrence and beaver floodplain inundation potential. This revealed that channel gradient was the overriding driver of both dam occurrence and potential land-use impact. Although widely considered to be a key constraint, channel width exhibited considerably lower explanatory power. The delineation of areas reflecting overall opportunities and conflict reveals that the reintroduction of Castor fiber into Switzerland implies a net benefit from a landscape restoration perspective, though outcomes scaled closely with catchment position. Given the rapidly expanding population range and popularity of continuing beaver reintroductions, this approach could help maximise landscape restoration goals whilst minimising undesirable land-use conflicts that may harm conservation efforts.

Wind erosion escalation in western Slovakia driven by climate and land use and land cover shifts

Wind erosion is a major cause of soil degradation and air pollution and is influenced by climate and land use factors. Understanding the mechanisms behind wind erosion dynamics is crucial for mitigating its harmful effects. This study employs an integrated approach, combining the Analytic Hierarchy Process (AHP) methodology and local knowledge, to comprehensively assess wind erosion in the western region of Slovakia from 2001 to 2021. Using GIS-based AHP, the study assessed the spatial distribution of areas at high risk of wind erosion based on six parameters: wind speed, surface dryness, land use, land cover, soil texture, and field slope. A multicollinearity test was conducted to examine the collinearity of the chosen factors, and it was seen that none of the factors were compromised by multicollinearity. The results showed a significant increase in the risk of wind erosion in the study area over the past 20 years, with very high erosion risk in 2007, 2014, and 2021 increasing by 37 %, 86 %, and 128 %, respectively, compared to 2001. Statistical analyses confirm the significant impact of surface dryness, wind speed, land use, and land cover on wind erosion, emphasizing the need for targeted strategies to mitigate erosion risk. The regression analysis underscores the negative relationship between land use and wind erosion, emphasizing the pivotal role of land management in erosion prevention. These findings contribute valuable insights to the discourse on sustainable land use practices and erosion mitigation, particularly in the context of evolving climate dynamics.

Land-Use Impacts on Soil Erosion: Geochemical Insights from an Urban Drinking Catchment, South-Central Chile

We investigate the influence of land use and land cover (LU/LC) changes on soil erosion and chemical weathering processes within the Nonguén watershed in the Coastal Cordillera of south-central Chile. The watershed is divided into three sub-basins, each characterized by distinct LU/LC patterns: native forest and exotic plantations. A comprehensive geochemical analysis, including trace elements and lithium (Li) isotopes, was conducted on river water and suspended sediment samples collected from streams within these sub-basins to assess how land management practices, particularly plantation activities, influence the geochemical composition of river systems. Our results show that sub-basins dominated by exotic plantations exhibit significantly higher concentrations of major and trace elements in suspended sediments compared to sub-basins dominated by native forests. The elevated trace element concentrations are primarily attributed to increased physical erosion due to forestry activities such as clear-cutting and soil disturbance, which enhance sediment mobilization. Notably, concentrations of elements such as Fe, Al, and As in plantation-dominated sub-basins are raised to ten times higher than in native-dominated sub-basins. In contrast, sub-basins with native forest cover exhibit lower levels of sediment transport and trace element mobilization, suggesting that native vegetation exerts a stabilizing effect that mitigates soil erosion. Despite the substantial differences in sediment transport and element concentrations, Li isotopic data (δ7Li) show minimal fractionation across the different LU/LC types. This indicates that land use changes impact the chemical weathering processes less compared to physical erosion. The isotopic signatures suggest that physical erosion, rather than chemical weathering, is the dominant process influencing trace element distribution in plantation-dominated areas. The study provides critical insights into how forestry practices, specifically the expansion of exotic plantations, accelerate soil degradation and affect the geochemical composition of river systems. The increased sediment loads, and trace element concentrations observed in plantation-dominated sub-basins, raise concerns about the long-term sustainability of forest management practices, particularly regarding their impacts on water quality in urban catchment areas. These results are of significant relevance for environmental management and policy, as they underscore the need for more investigation and sustainable land use strategies to minimize soil erosion and preserve water resources in regions undergoing rapid LU/LC changes.

Impact of Land Use and Land Cover Changes on Soil Physico-Chemical Properties in Southern Tigray, Northern Ethiopia

Soil quality declines due to the conversion of natural vegetation into farmland and grazing areas. The response of soil properties to land use and land cover changes (LULC) exhibits both spatial and temporal variations. This study aimed to assess the effects of LULC changes on the physico-chemical properties of soil in the Wojic watershed. Soil samples were collected from natural forests, bushland, shrubland, and cultivated lands across three landforms of the watershed (upper, middle, and lower) to evaluate the physical and chemical properties of the soil associated with different LULC types. The LULC categories were compared using mean values and critical thresholds for selected physicochemical soil properties. Soil analysis was conducted using R software, employing one-way analysis of variance (ANOVA). A normality test was performed before the post hoc analysis, and Tukey’s honest significance difference (HSD) test was utilized for mean separation among the LULC types. Additionally, a normalized difference vegetation index (NDVI) was calculated for the years 1997 and 2017. A simple linear regression model was developed to estimate soil physico-chemical properties over the past 20 years, using laboratory soil parameters and the NDVI for 2017. The pH values showed a slight decrease in cultivated land (from 5.7 to 5.4), bushland (from 7 to 6.6), and shrubland (from 6.5 to 6.2) over the study period. The analysis indicated a declining trend in physico-chemical properties, attributed to changes in vegetation cover and management practices. Consequently, the government needs to enforce policies and regulations that promote effective land resource management and utilization, with particular emphasis on the proper management and conservation of forests, bushlands, and shrublands, as well as measures to prevent increased land resettlement.

Understanding the relationship between land use/land cover changes and air quality: A GIS-based fuzzy inference system approach.

Air pollution is a global issue that demands urgent attention due to its detrimental effects on human health and the environment. Land Use and Land Cover (LULC) change is an essential factor that significantly impacts ambient air quality through alterations in emission sources, vegetation cover, natural processes, and urban design. This study investigates the spatio-temporal variation of key air pollutants resulting from urban LULC changes in the Delhi region. Findings reveal a notable increase in pollutant concentrations, particularly particulate matter, in 2019 (PM10: 318.65 ± 45.80 µg/m3) and 2023 (PM10: 383.70 ± 61.49 µg/m3), compared to 2008 (PM10: 246.76 ± 30.66). LULC change analysis demonstrates a rise in built-up areas 24.59%(2008 to 2019), 33.62% (2008 to 2023) and a decline in vegetation cover 27.49% (2008 to 2019),32.37% (2008 to 2023). Correlation analysis indicates a positive correlation between PM10 and urban indices (+ 0.63) and a negative correlation between PM10 and vegetation indices (- 0.61), highlighting the impact of LULC on air quality deterioration. Subsequently, a fuzzy inference system model integrates LULC information to develop an air quality index (AQI). Incorporating LULC changes in AQI assessment offers a realistic approach to address the complexity arising from combined air pollutant effects, surpassing conventional AQI calculation methods. The findings underscore the significance of understanding the impact of Land Use and Land Cover (LULC) change on ambient air quality in formulating effective air quality management programs and policies. Integrating this knowledge into policymaking is crucial for the successful abatement of air pollution in urbanized areas.

Quantifying past forest cover and biomass changes in the Ecuadorian Amazon.

Here, we developed and applied models to quantitatively reconstruct forest cover and biomass changes at three lakes in northwestern Amazonia over the past > 1500 yr. We used remotely sensed data and a modern dataset of 50 Amazonian lakes to develop generalized linear models that predict aboveground biomass, using phytolith morphotypes and forest cover as predictor variables. Also, we applied a published beta regression model to predict forest cover within 200 m of each lake, using Poaceae phytoliths. Charcoal and maize phytoliths were analysed to identify past land use. Results showed forest cover and biomass changes at our study sites ranged between 48-84% and 142-438 Mg ha-1, respectively. Human occupation was discontinuous, with major changes in forest cover and biomass coinciding with periods of land use. Forest cover and biomass decreased notably after fire (at all sites) or cultivation events (Lakes Zancudococha, Kumpaka). The timing and ecological impact of past land use were spatially and temporally variable. Our results suggest past human impact was small-scaled and heterogenous in northwestern Amazonia, with a significant impact of fire on forest cover and biomass changes.

Dam Siltation in the Mediterranean Region Under Climate Change: A Case Study of Ahmed El Hansali Dam, Morocco

Dams are vital for irrigation, power generation, and domestic water needs, but siltation poses a significant challenge, especially in areas prone to water erosion, potentially shortening a dam’s lifespan. The Ahmed El Hansali Dam in Morocco faces heightened siltation due to its upstream region being susceptible to erosion-prone rocks and high runoff. This study estimates the siltation at the dam from its construction up to 2014 using bathymetric data and the Brown model, which is a widely-used empirical model that calculates reservoir trap efficiency. Additionally, the study evaluates the impact of Land Use and Land Cover (LULC) changes and projected future rainfall until around 2076 based on siltation rates. The results indicate that changes in LULC, particularly temporal variations in precipitation, have a significant impact on the siltation of the Ahmed El Hansali dam. Notably, rainfall is strongly correlated with the siltation rate, with an R2 of 0.92. The efficiency of sediment trapping (TE) is 97.64%, meaning that 97.64% of the sediment in the catchment area is trapped or deposited at the bottom of the dam. The estimated annual specific sediment yield is about 32,345.79 tons/km2/yr, and the sediment accumulation rate is approximately 4.75 Mm3/yr. The dam’s half-life is estimated to be around 2076, but future precipitation projections may extend this timeframe due to the strong correlation between siltation and precipitation. Additionally, soil erosion driven by land management practices plays a crucial role in future siltation dynamics. Hence, this study offers a comprehensive assessment of the siltation dynamics at the Ahmed El Hansali dam, providing essential information on the long-term effects of erosion, land use changes, and climate projections. These findings may assist decision makers in managing dam reservoir sedimentation more effectively, ensuring the durability of the dam and extending the reservoir life.

Extreme events and ichthyofauna: case report of a neotropical river

The increasing frequency and intensity of extreme weather events and their impact on aquatic ecosystems and fish species is concerning. This manuscript reports and analyzes two events, a drought in 2019 and a flood in 2024, providing valuable insights into the consequences of these events. The rescue of 269 individuals of 19 fish species during the 2019 drought highlights the significant impact of the extreme conditions on the ichthyofauna. Rising temperatures, isolation, and habitat fragmentation must have posed severe challenges for the fish species during this period. On the other hand, the observation of 53 dead individuals of 5 species during the 2024 flood indicates the detrimental effects of this event on the fish population. The association of mortality and dispersal of several species with the existing dam further underscores the complexity of the challenges faced by fish during extreme flood events. The correlation between rainfall, river regime, and the impact of land use and occupation provides an important context for understanding the dynamics of these extreme events. The low rainfall during the 2019 drought and the gradual increase in rainfall between 2022 and 2024 leading to the flood demonstrate the significant role of precipitation patterns in shaping the outcomes for fish species. Additionally, the analysis of land use and occupation, particularly the substantial increase in urbanization in the drainage basin over the last 30 years, highlights the human-induced factors contributing to the stress on aquatic ecosystems. Both extreme floods and droughts have significant implications for fish species. Extreme floods can alter riverbeds, cause direct mortality, and disrupt isolated populations, while extreme droughts can lead to fish kills, and habitat fragmentation, and exacerbate environmental stressors. This analysis emphasizes the urgent need for comprehensive measures to mitigate the impact of extreme weather events on aquatic ecosystems and fish species. Addressing factors such as land use and occupation, water management, and climate change adaptation strategies is crucial for promoting the resilience of fish populations in the face of ongoing environmental challenges. Keywords: drought, Ipanema National Forest, rainfall.

The Assessment of Peak Discharge Increment Due to Land Use Change in the Serang Welahan Drainage 1 (SWD 1) River, Central Java Province, Semarang

SWD1 River is located in one of those flood-prone areas in Central Java that generates flood hazards causing high risk to the surrounding rice fields and communities. However, a comprehensive study of flood hazards in SWD1 River has never been conducted. Nowadays, previous comprehensive flood studies in Indonesia only available for several very developed areas, such as the Jakarta Flood [1] – [5], Bandung Flood and Solo Flood , or new iconic area for mangrove conservation such as Langsa City . Most previous studies conclude that flood hazards in Indonesia are commonly generated by rain runoff, tides, and dam break flows, or a combination of these generators . Existing conditions show that SWD 1 is unable to accommodate runoff from the Wulan River, causing flooding. Based on rainfall data from BMKG, the maximum rainfall per month for a year reaches 323 mm. This study is an effort to analyze the impact of land use change.The research method used analysis of the influence of changes in CN (Curve Number) due to changes in land use on flood discharge as shown through changes in the Soil Conservation Service (SCS-CN) hydrograph on discharge and runoff volume. The selection of the SCS-CN method is due to its widespread adoption in various regions, its extensive use in numerous analytical studies, and its suitability for the characteristics of the watershed under review.The analysis results show that there has been a change in flood discharge from 2019 and 2022 with values of 366.920 and 371.154 m3/second. The discharge values did not change significantly because the CN values were as follows, 83.25 and 83.36. Through analysis, it can be seen that an increase in discharge of 1.14% from 2011 to 2022.The several alternatives are needed to reduce flooding, such as watershed conservation upstream, minimizing land use changes and building flood mitigation infrastructure downstream.