Impact of Climate and Land Use Land Cover Changes on Soil Erosion


 
 
 Floods are one of the most common natural disasters worldwide. Apart from rainfall, Land Use Land Cover (LULC) changes too are a main contributory factor for floods. This study attempted to understand the link between floods and LULC changes in Kalu river basin, which is the second largest river basin and an area that experiences recurrent floods in Sri Lanka. We studied peak water levels, number of flood events, changes in land use types and impacts in rapidly urbanizing two districts, Rathnapura (upper basin) and Kalutara (lower basin) during 2001-2020. The satellite images (LANDSAT) were obtained for 2001, 2009, 2015 and 2020 and land use classification was done using ArcGIS and Remote Sensing Tools. Main land use types and their transformations were investigated and ground-truthing was carried out. Accordingly, the main types of land uses identified were Natural Vegetation and forests (NV), Settlements (ST- housing and industrial lands), Cultivated Lands (CL), Water Bodies (WB) and Bare Lands (BL). The results indicated that the most drastic change was found in the natural areas (NV) and they have diminished while the lands with anthropogenic impacts (ST, CL and BL) have increased across years. The NV had occupied the highest land area in 2001 (42.4%) and has reduced by 14.2% by 2020. The ST and CL have increased by 8.6 % and 5.2% respectively. The monthly rainfall of Rathnapura and Kalutara (Source: Department of Meteorology, Sri Lanka) has increased with time, which is a main reason for the increasing peak water levels of these areas (Source: Department of Irrigation, Sri Lanka). However, a significant correlation also exists between the change of the settlement area with the peak river water levels in the lower basin (p=0.03, R2=99%; regression analysis). Rathnapura has experienced 3 major floods (floods above the high water alert level) from 2001-2020, while 16 major floods have occurred in Kalutara. During the major flood in 2017, the number of child deaths in Rathnapura was 14 while in Kalutara it was 24. Accordingly, the LULC changes of the whole basin along with rainfall seem to influence on the severity of floods in Kalutara more, as it is located in the lowest elevation level. When natural lands are transformed to anthropogenic- impacted areas with disturbances to the water cycle, increased impervious surfaces, reduced water storage capacities and loss of natural drainage, the flood risk tends to increase. Proactive approaches including proper land use planning and rainwater storage are urgently needed as the climate change too would trigger more floods. Thus, the flood mitigatory actions, especially, in the lower river basin should be a priority to ensure resilience and sustainability.
 Keywords: Kalu river basin, Land Use Land Cover (LULC) changes, Floods
 
 

Climate and land use land cover (LULC) changes play a vital role in the hydrology of any river basin. This study was aimed to investigate the impact of climate and LULC changes on streamflow in the Kunhar river basin, Pakistan. The Soil and Water Assessment Tool (SWAT), calibrated on a monthly basis, was used as a hydrological model to study the impact of climate and LULC changes on the streamflow. The change in average annual runoff due to LULC was increased but not significant; on the other hand, the flow was decreased by 24 m3/s (20%) as compared to the baseline (122 m3/s), due to climate change. On the seasonal and monthly scale, a difference emerged between high and low flows; high flows were increasing and low flows were decreasing in the wet and dry seasons, respectively, due to LULC changes. However, due to climate change, the seasonal and monthly runoffs were decreased significantly. Problems such as depletion in surface water and environmental flow during the dry season were more prominent due to the changes in the streamflow. These problems can be mitigated by afforestation in the bare lands and grasslands and taking structural measures to conserve the water in the high flow season for later use.

<p>Human activities and climate affect the hydrology of a basin. The effect of Land Use Land Cover (LULC) change and climate change on streamflow are basin specific. In this study, an attempt has been made to evaluate the effects of LULC and climate change on streamflow in the Netravathi basin, Karnataka, India. The SWAT model, which reasonably simulates the streamflow of a basin, is used for this study. The analysis was done from the year 1990 to 2018. The watershed is delineated by using ALOS PALSAR DEM. Rainfall and temperature obtained from IMD are used as the climate variables. LULC maps were prepared using Landsat images of 1990 and 2018 in order to assess the LULC changes in the basin. The results showed that the spatial extent of the LULC classes of built-up (3.82%–6.51%), water bodies (0.76%–0.99%), and agriculture (11.96%–17.89%) increased, whereas that of forest (66.56%–51.7%), fallow (3.82%–6.13%), and barren land (13.07%–16.76%) decreased from 1990 to 2018. The streamflow increased steadily (5.02%) with changes in LULC from 1990 to 2018. The results indicate that LULC changes in urbanisation and agricultural intensification have contributed to the increase in runoff, in the catchment during this period. Thus, hydrological modelling integrating climate change and LULC can be used as an effective tool in estimating streamflow of the basin.</p>

Predicting the future of species assemblages under climate and land use land cover changes in Himalaya: A geospatial modelling approach

Understanding the impacts of Land Use and Land Cover (LULC) changes and their drivers is crucial for sustainable management of natural resources. Thus, this rigorous study aimed to examine the trends, drivers, and consequences of land use land cover changes (LULC) in the Lake Ziway catchment, central rift valley of Ethiopia. The study followed a mixed- methodological systematic and justified approach that included remote sensing and GIS techniques, household surveys, focus group discussions, and in-depth interviews. The rigorous study shows that the conversion of forest land into agricultural and settlement lands is the major detected LULC change over the last 30 years in the catchment. Cultivated land has increased by 40.60% and settlement and plantation lands have increased by 61.54% and 60%, respectively. On the other hand, forest land decreased by 54.85% and grazing land have decreased by 15.85% respectively. Water bodies and wetlands have also decreased by 8.70% and 19.32% area coverage, respectively. Both the direct and indirect driving forces of the LULC changes were identified. The study also indicates that the participation of local communities in watershed management is low. The study further indicates that LULC changes observed in the Lake Ziway Catchment had statistically and practically significant environmental and socio-economic impacts. Over all, the rigorous study showed the changes in land use land cover and its drivers were common in Lake Ziway Catchment. Therefore, appropriate policies and strategies are required to address LULC change impacts and enhance sustainable utilization and management of the Lake Ziway catchment.

Land use land cover (LULC) changes are inherently spatial and dynamic with high spatiotemporal variability resulted from complex human-environmental interactions. Current extents, rates and intensities of LULC changes are driving unprecedented changes in ecosystems functions and environmental processes at local, regional and global scales. The study was conducted to assess LULC changes and its drivers using remote sensing (RS) and geographic information system (GIS) in Gojeb River Catchment, Ethiopia. The satellite images at different reference years (1978, 1987, 2001 and 2015) were obtained from Landsat images. Supervised classification with maximum likelihood algorithm was applied for image processing and change analysis. The LULC classes identified were cropland, forestland, shrubland, swamp, and woodland. The study found that the catchment has undergone significant LULC changes. The major changes were expansion of cropland at the expense of other LULC classes at the rate of 29.56% in 1978, 38.91% in 1987, 46.62% in 2001 and 52.74% in 2015. It has gained about 160,736.08 ha with an annual average increment of 4,344.22 ha. Conversely, forestland has undergone reductions at an annual rate of 9,030.0 ha between 1978 and 1987. The conversions of other classes to cropland are mainly associated with more demand for crop production. On the other hand, the conversion of relevant part of forest land to other classes could be due to vegetation degradation. Hence, the conversion of forestland to other land use classes could be attributed to the highly demand of agricultural land, firewood, charcoal, timbers and housing materials. The major driving forces which should be considered in sustainable watershed management were population growth and government induced settlements. Provision of modern alternative sources of energy, agricultural inputs and promoting non-agricultural sectors are also other considerations for the community sustainable livelihood. It is critical to follow holistic view and management of the catchment for successful integrated watershed management endeavours.

Water availability in river basins is a global concern due to its increasing demand, thus making it essential for a nation's development. Understanding the future effect of climate and land use land cover (LULC) changes on the water cycle is fundamental for consistent access to water resources. This study's objective is to use a physically based semi‐distributed model to explore streamflow seasonal projection of the Rokel‐Seli River basin (RSRB) using separate and combined impacts of climate and LULC changes from 2021 to 2060, under projected scenarios (RCP2.6 and RCP8.5). The LULC results showed agricultural, urban, and bare land expansion at the expense of forest land historically, with a projected increase in bare and urban land. The hydrological model calibration and validation of statistical indicators for R and P factors, NSE, R 2 , and KGE performed very well, despite limited data, in replicating the flows. The mean seasonal streamflow is projected to decrease due to different LULC changes, with urban and bare land expansion. The projected streamflow decrease is noticeable under climate change compared with LULC change. As various aspects are responsible for both changes (farming, deforestation, infrastructural development, mining and hydropower supply), this study will enable land and water management authorities to develop suitable strategies to enhance streamflow sustainability in a changing environment.

Land Use Land Cover (LULC) changes analysis is one of the most useful methodologies to understand how the land was used in the past years, what types of detections are to be expected in the future, as well as the driving forces and processes behind these changes. In Ethiopia, Africa, the rapid variations of LULC observed in the last decades are mainly due to population pressure, resettlement programs, climate change, and other human- and nature-induced driving forces. Anthropogenic activities are the most significant factors adversely changing the natural status of the landscape and resources, which exerts unfavourable and adverse impacts on the environment and livelihood. The main goal of the present work is to review previous studies, discussing the spatiotemporal LULC changes in Ethiopian basins, to find out common points and gaps that exist in the current literature, to be eventually addressed in the future. A total of 25 articles, published from 2011 to 2020, were selected and reviewed, focusing on LULC classification using ArcGIS and ERDAS imagine software by unsupervised and maximum likelihood supervised classification methods. Key informant interview, focal group discussions, and collection of ground truth information using ground positioning systems for data validation were the major approaches applied in most of the studies. All the analysed research showed that, during the last decades, Ethiopian lands changed from natural to agricultural land use, waterbody, commercial farmland, and built-up/settlement. Some parts of forest land, grazing land, swamp/wetland, shrubland, rangeland, and bare/ rock out cropland cover class changed to other LULC class types, mainly as a consequence of the increasing anthropogenic pressure. In summary, these articles confirmed that LULC changes are a direct result of both natural and human influences, with anthropogenic pressure due to globalisation as the main driver. However, most of the studies provided details of LULC for the past decades within a specific spatial location, while they did not address the challenge of forecasting future LULC changes at the watershed scale, therefore reducing the opportunity to develop adequate basin-wide management strategies for the next years.

Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce the changes. The study aims to evaluate and quantify the historical changes in land use and land cover in Mukumbura (Ward 2), Mt Darwin, Zimbabwe, from 2002 to 2022. The objective of the study was to analyse the LULC changes in Ward 2 (Mukumbura), Mt Darwin, Northern Zimbabwe, for a period of 20 years using geospatial techniques. Landsat satellite images were processed using Google Earth Engine (GEE) and the supervised classification with maximum likelihood algorithm was employed to generate LULC maps between 2002 and 2022 with a five (5) year interval, investigating the following variables, forest cover, barren land, water cover and the fields. Findings revealed a substantial reduction in forest cover by 38.8%, water bodies (wetlands, ponds, and rivers) declined by 55.6%, whilst fields (crop/agricultural fields) increased by 93.3% and the barren land cover increased by 26.3% from 2002 to 2022. These findings point to substantial changes in LULC over the observed years. LULC changes have resulted in habitat fragmentation, reduced biodiversity, and the disruption of ecosystem functions. The study concludes that if these deforestation trends, cultivation, and settlement land expansion continue, the ward will have limited indigenous fruit trees. Therefore, the causes for LULC changes must be controlled, sustainable forest resources use practiced, hence the need to domesticate the indigenous fruit trees in arborloo toilets.

Evaluating the joint effects of climate and land use change on runoff and pollutant loading in a rapidly developing watershed

It is critically important to quantify the impact of land use land cover (LULC) changes on hydrology, and to understand the mechanism by which LULC changes affect the hydrological process in a river basin. To accurately simulate the hydrological process for a watershed like the Wei River Basin, where the surface characteristics are highly modified by human activities, we present an alternative approach of time-varying parameters in a hydrological model to reflect the changes in underlying land surfaces. The spatiotemporal impacts of LULC changes on watershed streamflow are quantified, and the mechanism that connects the changes in runoff generation and streamflow with LULC is explored. Results indicate the following: (1) time-varying parameters’ calibration is effective to ensure model validity when dealing with significant changes in underlying land surfaces; (2) LULC changes have significant impacts on the watershed streamflow, especially on the streamflow during the dry season; (3) the expansion of cropland is the major contributor to the reduction of surface water, causing decline in annual and dry seasonal streamflow. However, the shrinkage of woodland is the main driving force that decreases the soil water, thus contributing to a small increase in streamflow during the dry season.

Water yield is a key ecosystem function index, directly impacting the sustainable development of the basin economy and ecosystem. Climate and land use/land cover (LULC) changes are the main driving factors affecting water yield. In the context of global climate change, assessing the impacts of climate and LULC changes on water yield in the alpine regions of the Qinghai–Tibet Plateau (QTP) is essential for formulating rational management and development strategies for water resources. On the basis of the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, we simulated and analyzed the spatiotemporal variations and the impacts of LULC and climate changes on water yield from 2001 to 2019 in the upstream regions of the Shule River Basin (USRB) on the northeastern margin of the QTP. Three scenarios were designed in the InVEST model to clearly analyze the contributions of climate and LULC changes on the variation of water yield. The first scenario integrated climate and LULC change into the model according to the actual conditions. The second scenario was simulation without LULC change, and the third scenario was without climate change. The results showed that (1) the InVEST model had a good performance in estimating water yield (coefficient of determination (R2) = 0.986; root mean square error (RMSE) = 3.012, p < 0.05); (2) the water yield significantly increased in the temporal scale from 2001 to 2019, especially in the high altitude of the marginal regions (accounting for 32.01%), while the northwest regions significantly decreased and accounted for only 8.39% (p < 0.05); (3) the spatial distribution of water yield increased from the middle low-altitude regions to the marginal high-altitude regions; and (4) through the analysis of the three scenarios, the impact of climate change on water yield was 90.56%, while that of LULC change was only 9.44%. This study reveals that climate warming has a positive impact on water yield, which will provide valuable references for the integrated assessment and management of water resources in the Shule River Basin.

This paper discusses results of a Gulf of Mexico Application Pilot project conducted in 2008 to quantify and assess land use land cover (LULC) change from 1974 to 2008. Led by NASA Stennis Space Center, this project involved multiple Gulf of Mexico Alliance (GOMA) partners, including the Mobile Bay National Estuary Program (NEP), the U.S. Army Corps of Engineers, the National Oceanic and Atmospheric Administration's (NOAA's) National Coastal Data Development Center (NCDDC), and the NOAA Coastal Services Center. The Mobile Bay region provides great economic and ecologie benefits to the Nation, including important coastal habitat for a broad diversity of fisheries and wildlife. The Mobile Bay region has experienced considerable LULC change since the latter half of the 20th century. Accompanying this change has been urban expansion and a reduction of rural land uses. Much of this LULC change (largely urbanization) has reportedly occurred since the landfall of Hurricane Frederic in 1979. Regional urbanization threatens the estuary's water quality and aquatic-habitat dependent biota, including commercial fisheries and avian wildlife. Coastal conservation and urban land use planners require additional information on historical LULC change to support coastal habitat restoration and resiliency management efforts. This project quantified and assessed LULC change across the 34-year time frame and at decadal and mid-decadal scales. Nine Landsat images were employed to compute LULC products because of their availability and suitability for the application. The project also used Landsat-based national LULC products, including coastal LULC products from NOAA's Coastal Change & Analysis Program (C-CAP), available at 5-year intervals since 1995. Our study was initiated in part because C-CAP LULC products were not available to assess the region's urbanization prior to 1995 and subsequent to post-Hurricane Katrina in 2006. The study area included the majority of Mobile and Baldwin counties that encompass Mobile Bay. Each date of Landsat data was classified using an end-user defined modified Anderson level 1 classification scheme. LULC classifications were refined using a decision rule approach in conjunction with available C-CAP products. Individual dates of LULC classifications were validated by image interpretation of stratified random locations on raw Landsat color composite imagery in combination with higher resolution remote sensing and in situ reference data. Overall classification accuracies for five separate single-date products ranged from 83% to 89%. The results of the LULC change analysis indicate that during the 34-year study period, urban areas increased from 96,688 to 150,227 acres, representing a 55.37% increase, or 1.63% per annum. Most of the identified urban expansion regarded the conversion of rural forest and agriculture to urban cover types. Final LULC mapping and metadata products were produced for the entire study area as well as for multiple watersheds of concern within the study area. The final project products, including LULC trend information, were incorporated into the Mobile Bay NEP State of the Bay report. Products and metadata were also transferred to NOAA NCDDC to allow free online accessibility and use by GOMA partners and by the public.

Land Use Land Cover (LULC) changes in rapidly developing regions substantially influence natural and socio-environmental systems. This study assesses decadal LULC transformations in the ecologically sensitive Upper Yamuna Basin, Uttarakhand, India, integrating remote sensing (Landsat 8 and Sentinel-2 A), Digital Elevation Model (DEM), and GIS tools. The Cellular Automata-Artificial Neural Network (CA-ANN) model was employed to simulate LULC changes for 2023 and project future scenarios for 2040, achieving an overall accuracy exceeding 87% and kappa coefficients above 0.87. Key physiographic factors, including slope (67.79% gentle to moderate) and drainage patterns, were analyzed to understand hydrological and topographical impacts. Results reveal a significant increase in settlement area from 8.06 km² (0.34%) in 2013 to 38.59 km² (1.63%) in 2023, projected to reach 61.47 km² (2.60%) by 2040, primarily at the expense of forests (declining from 54.20% to 49.82% in 2023, with further decrease to 46.74% in 2040) and agricultural land (from 3.19% to 1.32% in 2023, projected to further decline). Water bodies also decreased significantly from 58.07 km² (2.45%) to 30.64 km² (1.29%). Temperature trends indicate a warming climate with maximum temperatures increasing by 0.0421 °C per decade over 32 years, exacerbating environmental stress. These extensive LULC changes contribute to increased vulnerability to floods, erosion, and natural hazards amid rapid urbanization. The study highlights the urgent need for sustainable land management and policy interventions to preserve ecological integrity and mitigate the impacts of climate change in this Himalayan basin.

In the last few decades, rapid urbanisation has led to Land Use Land Cover (LULC) change, which has had a significant impact on the environment, ecosystem and its key goods and services around the globe. Ecosystem Service (ES) provides a wide range of benefits and advantages to communities and local economies. Land Use and Land Cover (LULC) changes have led to rapid alterations in composition, structure, and ecosystem functions, thereby reducing their capacity to provide essential services. Economic evaluation of ecosystem services is very crucial. Ecosystem Service Values (ESVs) are not given as much consideration in urban planning and policymaking, despite the fact that it is well known in the literature that urban ecosystems significantly contribute to human well-being in cities. Using ArcGIS 10.8.1, the LULC changes were computed for Tangail municipality between 2005 and 2023, based on LULC data computed from the Landsat imagery. The Benefits Transfer Approach (BTM) is used to calculate the changes in ESV associated with LULC changes. The research aims to analyse LULC change and assess its impact on ESV at the municipal level, providing a better understanding of how spatial patterns affect ESV. The results show a continuous reduction in ESV during the study periods. Between 2005 and 2023, due to the increase in built-up area, the area increased by about 46.66%. The ESV in Tangail Municipality has decreased from 3.02 million USD to 1.63 million USD during the same period. This study provides valuable insights that can aid in managing land resources and developing plans to mitigate the decline in ESV, ensuring sustainability and long-term ecosystem conservation at the municipal level.