Understanding the change dynamics of land use and land cover (LULC) has a critical influence on hydrological characteristics of a watershed, economic development, ecological variation, and climate changes, and has been used to resolve the current dilemmas between land, water, energy, and the food sector. It is also essential as the change observed reflects the status of the environment and provides input parameters for sustainable natural resource management and optimization. The Chamo catchment has undergone a large change in LULC which has increased the soil erosion and lake sedimentation. In this paper, long-term variations in LULC were evaluated using MODIS and ESRI Sentinel-2 datasets. As a result, a significant variation in LULC was observed in the study area from 2001 to 2022. Spatial and temporal variations of LULC were observed between the two datasets. Based on MODIS, grassland was the dominant LULC class, whereas for ESRI, rangeland and cropland were the dominant LULC. The result of the study was essential for policy-makers and stakeholders for management of sustainable economic development, lake water management, ecological maintenance, and climatic change adoption pathways. The findings of the study provided evidence that MODIS and ESRI Sentinel-2 are effective datasets used for detecting LULC variations that be applied in different areas.

  • LULC was evaluated in the Lake Chamo catchment using MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets from 2001 to 2022.

  • The estimated result shows long-term variations in LULC during the study period.

  • Variations in land use type were observed between the two data products.

  • The evaluated result was essential for policy-makers, water resource managers, and socioeconomic development of the growing population in the study area.

The land use and land cover (LULC) changes are a dynamic and complex process that can be caused by both anthropogenic and natural factors (Birhanu et al. 2019; Samal & Gedam 2021). The primary drivers of LULC changes have been carried out by human activities (Betru et al. 2019; Dibaba et al. 2020). For the past 1,000 years, human beings have been altering LULC to obtain livelihoods and other necessities. The amount, rate, and severity of LULC change are significantly higher now than they were previously particularly in the developing nations, whose economies are mainly based on agriculture (Hassan et al. 2016). It is well understood that the LULC change can alter regional hydrological conditions, which may further result in a variety of impacts on the water resource system (Li et al. 2007). Human activities including societal development, overgrazing, the inappropriate utilization of forest, agricultural land expansion and increasing population have all contributed to a substantial increase in LULC which leads to simultaneous changes in natural environments, ecosystem services and hydrological change (Zewdie & Csaplovies 2015; Samal & Gedam 2015).

Many factors influence land use and cover changes, including time, scale, politics, economic, social, and cultural factors (Calicioglu et al. 2019). At all spatiotemporal scales, LULC changes have been recognized as significant drivers of environmental changes (Adepoju et al. 2006). Such changes, along with other negative changes (e.g., climate change, biodiversity loss, and water, soil, and air pollution), should be the top priorities for humans (Zabihi et al. 2020). Therefore, updated and precise LULC maps are essential for sound planning, sustainable development, environmental monitoring, worldwide change, the evaluation of forest degradation, and water resource management (Dewan & Yamaguchi 2009). The effective use and management of natural resources depends on the result of land use and land cover changes. Therefore, international researchers have put considerable effort into studying land-use land cover using different approaches, and it is better to evaluate the land-use land cover change of Lake Chomo catchment for sustainable lake water management and maintain the ecosystem of the catchment.

The land cover land use dynamics in Ethiopia have changed with an increasing population, due to its economy largely depending on agriculture and land use. Land cover conditions are considerably changing (Getachew & Melesse 2012; Berihun et al. 2019; Aredo et al. 2021). Specifically, shrub lands, bare lands, forest covers and grasslands (GLs) were converted to settlement and agricultural lands in many parts of the country (Tadele & Förch 2007; Rientjes et al. 2011; Gumindoga et al. 2014; Andualem & Gebremariam 2015; Jemberie et al. 2016). Rising rates of urbanization and agricultural land at the cost of natural vegetation have significant influence on the hydrological responses of a basin. LULC also has a significant influence on the hydrological fluxes due to variations in the physical characteristics of the land surface and soil, such as roughness, architectural resistance, stomatal conductance, albedo, leaf area index (LAI), root depth, and infiltration capacity (Maza et al. 2020; Srivastava et al. 2020). Disturbance of vegetation and the subsequent change to other land-use land cover classes are known to have multiple impacts on land productivity, stream flows, geomorphological processes and the socioeconomic status of the river basin. The effect changes from basin to basin based on the extent and intensity of the natural land cover conditions and characteristics (Samal & Gedam 2021). Changes in LULC availability and distribution have a substantial influence on climate, environmental challenges, and natural ecosystem conditions (Cihlar 2000; Yan et al. 2015). Furthermore, changes in global LULC are a major cause of significant concern for future LULC trends (Prestele et al. 2016; Karki et al. 2018). Additionally, LULC changes are a critical aspect of sustainability and management of natural resources (Degife et al. 2018; Hou et al. 2019; Motlagh et al. 2020). The Lake Chamo catchment is one of the rift valley sub-basin and is found in a semi-arid and drought-prone region in Ethiopia (MoWE 2007). Due to an increasing population, human activities have been increasing rapidly in the catchment, like deforestation, increasing agricultural farm land, which leads to climate change, environmental conservation, environmental pollution and soil erosion, which affect economic development to meet food and housing requirements. Additionally, several studies have been conducted on LULC dynamics in Ethiopia at a basin level (Simane et al. 2013; Teklu & Kassahun 2017; Wondie 2018; Giweta & Worku 2018). But, to the present, no such investigation has been available in existing literature for Lake Chamo Catchment. Therefore, understanding and identifying detailed historical LULC dynamics knowledge over a lengthy series of periods and analyzing their patterns and processes is critical in the lake basin for land development decision-makers and planners.

Geographic information system (GIS) and remote sensing (RS) techniques provide helpful approaches for understanding, analyzing, and monitoring LULC over time in landscapes (Kotaridis & Lazaridou 2018; Armin et al. 2020). Many investigations on LULCs have been conducted using these tools (Hua 2017; Mannan et al. 2019). Zhou used an integrated approach to detect the changing green spaces pattern 3 and identified that the change was caused by fast urbanization and greening programs (Zhou & Wang 2011). Different satellites deliver historical images that can be used to evaluate the effects of human and other elements over time (Goldblatt et al. 2016; Gomez et al. 2016; Haque & Basak 2017). Additionally, Landsat periodic imagery data for a specific area is a reliable data source that can be utilized to forecast LULC trends in that area. GIS and RS techniques are effective for displaying spatial modeling methods (Nouri et al. 2014). Thus, modeling, simulation, and predicting LULC changes using temporal and spatial data are crucial for improving LULC planning and management. Although the complexity of developing models and simulations is great, they are necessary to detect the LULC changes and analyze the causes and consequences of this phenomenon (Yang et al. 2012). Furthermore, various approaches for determining historical and prospective LULC have been established to assist stakeholders in economic improvement, land conservation, and land-use planning. In addition, several models for simulating future scenarios of LULC have been created. These models deliver appropriate approaches for detecting the spatial variability patterns in LULC. Moreover, model validation is required for an accurate assessment of LULC prediction in a particular area by comparing predicted and observed LULC changes (Nath et al. 2020).

In the Lake Chamo catchment, LULC change is a common phenomenon. This continuous change in land cover land use has an impact on the lake ecosystem by altering the magnitude and pattern of hydrological variables, increasing soil erosion, thereby exacerbating the water management problem. To the best of the author's knowledge, detail and quantitative analysis have not yet been conducted in Lake Chamo catchment, which has already faced many changes due to increased farming and deforestation. There appears to be a gap in the available information and national decision-making process and rational planning in water resource monitoring and ecological restoration of Lake Chamo catchment. Generally, this study aims to evaluate the patterns of LULC changes in expanding agricultural area in the Lake Chamo catchment. The main focuses of this study are: (1) to identify the LULC based on satellite images of the years 2001 and 2022 using RS and GIS application, (2) to evaluate the LULC changes in Lake Chamo catchment between 2001 and 2022 in a quantitative manner, (3) to calculate the factors of the LULC change in the study area. This study is expected to contribute to the decision making in enabling a better emergency response and plan toward sustainable land development activity as well as mitigating the challenges of the rapid growth of agricultural land and deforestation. The adopted approaches for long-term variability of LULC and its result will be regarded as a new and honest contribution to the Chamo basin.

Study area

Lake Chamo catchment is located in the southern part of Ethiopia (Figure 1). It is located between the latitudes of 5°3′54″ and 6°03′57″ N and the longitude of 37°15′18″ and 37°40′37″E. The catchment area is 1,867 kilometers square. The third-largest rift valley lake called Lake Chamo was located in this catchment, which is essential for fisheries, agriculture, and tourism. The elevation of the study area ranges from 1,108 to 3,380 meters above mean sea level. The mean precipitation of the study area ranges from 0 to 291.23 mm per month. The average temperature ranges between 12.6 and 34.1 °C.

Methodology

Spatiotemporal detection of LULC change by using Landsat images in the ArcGIS model has become a commonly utilized method in recent years (Adepoju et al. 2006; Biro et al. 2013; Ayele & Tarekegn 2020; Selmy et al. 2023). In this study, MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets were used to estimate the LULC change in Lake Chamo catchment using supervised images classification method in ArcGIS 10.4. This classification method was essential for grouping the LULC sensed from satellite images and widely used algorithms (Brahmabhatt et al. 2000; Jensen 2005; Bayarsaikhan et al. 2009), which classify satellite imaging pixels based on spectral reflectance properties that are similar or identical (Lillesand et al. 2004). Ground truthing points were taken as the representative sample of the identified LULC type for the accuracy evaluation of image calcification by using the confusion matrix of the spatial analysis tool of ArcGIS (Ramachandran & Reddy 2017; Yoshe 2024). The method is the probability function that assumes the training data for each class in each band to determine a normally distributed land class (Basukala et al. 2017). Thematic layers and other area estimations have also been done using ArcGIS 10.4. Microsoft Excel has been used for making calculations of land cover change and graph etc. The generalized workflow for this study is shown on the flow diagram to easily understand the steps used for LULC detection (Figure 2). Then the descriptions of the methodology are given in the following section.
Figure 1

Map of the study area.

Figure 1

Map of the study area.

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Figure 2

Simplified methodology for LULC change detection.

Figure 2

Simplified methodology for LULC change detection.

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Data acquisition

Remotely sensed and spatial data are trustworthy data for detecting and comprehending the dynamic causes of LULC in any terrain (Hansen et al. 2000). RS data acquisition involves collecting information about the Earth's surface without physically being there. This is usually done by using instruments such as satellites, airplanes, drones, or ground-based sensors to capture images, spectra, and other data. The type of instrument used depends on the spatial and spectral resolution required for the specific application. Satellites are used for large-scale mapping, while drones are used for high-resolution imaging of specific areas. Data acquisition can involve active or passive sensing, with active sensors emitting energy and measuring its reflection, while passive sensors measure the energy emitted by the Earth's surface. For this study, remote sensing images of NASA LPDAAC collection of MODIS Land Cover-V6.1 (MODIS MCD12Q1 V6.1) from the Earth explorer site (https://earthexplorer.usgs.gov, accessed on 25 July 2024) at a location of 05O58′ 20″ N latitude and 037O 31′ 49″ from 2001 to 2022 and used for LULC classification. The satellite images that were collected by USGS earth explorers provide many kinds of satellite imagery for free. Cloud-free images are not easy to find using free sources of data, so no more than 10% of cloud cover was applied in the additional criteria tab while searching and about 4–6% of cloud covers were found, which did not affect the result of LULC classification. The datasets were downloaded as HDF files and imported in to ArcGIS 10.4. To minimize errors due to different seasonal variation in vegetation distribution or in LULC change detection, images of the same annual season were used (Kindu et al. 2013; Dibaba et al. 2020).

Preprocessing data

Preprocessing was essential to increase visual interpretation and spectral separability of earth surface characteristics, as well as provide improved inputs for automated image processing algorithms (Maini & Aggarwal 2010). For this study, the downloaded images were pre-processed in ArcGIS 10.4. This approach produces adjusted satellite images that are radio-metrically and geometrically corrected (Lillesand et al. 2015). Radiometric corrections are generally used to normalize multi-temporal satellite images for time-series comparisons. The true band of the image was extracted by using the extraction algorithm of ArcGIS 10.4 spatial analyst tool.

Image classification

For the 2001–2022 image, the classification process is mainly conducted in three steps; training, sample selection, classification and evaluation or accuracy assessment. First, a numerical ‘interpretation key’ that characterizes the spectral characteristics for each feature type of interest is created using representative sample sites of recognized cover types, or training regions. About 300 training samples were created for each class. Then, each pixel in the data collection is statistically compared to each interpretation key category and labeled with the name of the category it ‘most closely resembles.’ The maximum likelihood technique is the most widely used and well-known parametric classification for LULC change classification (Brahmabhatt et al. 2000; Bayarsaikhan et al. 2009). According to the Bayesian equation, estimating the weighted distance or probability d of an unknown measurement vector X belongs to one of the recognized classes, Mc was evaluated based on the following Bayesian equation.
(1)
where c was a specific class; d was weighted distance (likelihood); X was the candidate pixel's measurement vector, Mc is the sample's mean vector, and ac is the likelihood in percent that any candidate pixel belongs to class C (defaults to 1.0, or is entered from a priori knowledge); covc is the covariance matrix for the class c pixels in the sample; |Covc| was its determinant in matrix algebra, covc−1 was its inverse; ln was its natural logarithm function, and T was its transposition function (matrix algebra). In the classification approach, eight major LULC classes were developed, such as savannas (Sav), GLs, evergreen broadleaf forests (EBFs), permanent wetlands (PWLs), croplands (CLs), CLs or vegetation mosaics (VMs), water bodies (WBs), and barren land (BL).

Accuracy assessment

After the LULC classification was carried out, the land use from 2001 to 2022 was prepared. Then, by comparing the sample LULC classes of the classified layer and the reference layer, the classification accuracy of the resulting land use map was assessed. The land use classification map of 2001, 2011, and 2022 was used to evaluate the land cover map overall accuracy (OA), producer's accuracy (PA), user's accuracy (UA) and Kappa coefficient for the study area were evaluated using Equation (2).
(2)
OA is calculated by dividing the total number of correctly classified pixels (i.e., the sum of the major diagonal) by the total number of reference pixels.
(3)
The PA indicates how well test set pixels of the given cover type are classified.
(4)
The UA is a measure of commission error that indicates the probability that a pixel classified into a given category actually represents that category on the ground.
(5)
where Kstat was Kappa statistic, N was total number of samples, Xij was the product of total number of sample and total diagonal values, XRT is the row total, XCT is the column total and r was the number of categories. The statistics or coefficient evaluates the difference between the actual agreement of a classified map and the chance agreement of a random classifier compared with reference data (Minta et al. 2018).

Change detection

Because of their cost-effectiveness and high temporal resolution, RS- and GIS-based change detection methods are widely used. Multi-temporal datasets can be used from different dates to discriminate between each other and detect the changes. In order to find areas of change, the post-classification comparison technique includes classifying images and comparing the relevant classes. The post-classification comparison approach obtained the greatest classification accuracy in a comparative analysis of diverse techniques (Sun et al. 2009). A method of post-classification comparison based on the MLC algorithm was used with Landsat data to validate land-use changes in the Lake Chamo basin. The post-classification comparison was conducted by converting the classified raster images into vector layers. The changes in LULC were calculated for each land cover type and represented in separate images in this investigation for better understanding. The quality of the thematic maps that image categorization produces determines how accurate the results are (Minta et al. 2018; Yesuph & Dagnew 2019). The following equation was used to calculate the degree of change (C) for each LULC from 2001 to 2022.
(6)
where Xi was initial year of LULC area; Xj is final year LULC area, Cij is the change in LULC class (the total gain or loss of LULCC).
The change in class is divided by the covered area in the base year and again multiplied by 100. A straightforward computation was used to calculate the percentage change (C%). Also, it has been conducted in each land-use class (Minta et al. 2018; Yesuph & Dagnew 2019).
(7)

The number of classes in the image is indicated by IJ. Cij indicates how much class IJ has changed. (Pij) is the percentage change in class IJ. Xi is ‘basic image’ (20001). The most current picture is Xj (2022).

Normalized Difference Vegetation Index

The Normalized Difference Vegetation Index (NDVI) has been widely used for RS of vegetation for many years. This index uses radiances or reflectances from a red channel around 0.66 μm and a near-IR channel around 0.86 μm. It is used to quantify vegetation greenness and is useful in understanding vegetation density and assessing changes in plant health. NDVI is calculated as a ratio between the red (R) and near-infrared (NIR) values in traditional fashion:
(8)

The index is easy to interpret: NDVI will be a value between −1 and 1. An area with nothing growing in it will have an NDVI of zero. NDVI will increase in proportion to vegetation growth. An area with dense, healthy vegetation will have an NDVI of one. NDVI values less than 0 suggest a lack of dry land. An ocean will yield an NDVI of −1.

Enhanced Vegetation Index

The Enhanced Vegetation Index (EVI) is useful in areas with dense green vegetation, because it doesn't become as saturated as NDVI. EVI ranges between −1 and 1. The healthy vegetation value is somewhere between 0.2 and 0.8. In recent times, EVI has proved to be an efficient technique in vegetation change detection and derivation of canopy biophysical characteristics of a particular region.
(9)
where G is a gain factor, C1 and C2 are the coefficients of the aerosol resistance term which uses the blue band to correct for aerosol influences in the red band.

NIR, Red, and Blue are atmospherically-corrected and partially atmosphere-corrected (Rayleigh and ozone absorption) surface reflectances.

L is the canopy background adjustment that addresses non-linear, differential NIR and red radiant transfer through a canopy.

The coefficients adopted in the MODIS-EVI algorithm are as follows: L = 1, C1 = 6, C2 = 7.5, and G = 2.5.

EVI is similar to the NDVI and can be used to quantify vegetation greenness. However, the EVI corrects for some atmospheric conditions and canopy background noise and is more sensitive in areas with dense vegetation.

The Normalized Difference Water Index method

The Normalized Difference Water Index (NDWI) is an index for delineating and monitoring water content changes in surface water. To monitor changes related to water content in WBs, NDWI was evaluated using green and NIR wavelengths, defined by McFeeters (1996): The value of NDWI ranges between −1 and +1. It shows that the NDWI value between −1 and 0 shows a bright surface with no vegetation or water content and +1 represents water content. Additionally, the NDWI less than 0.3 indicates no water and a value greater than or equal to 0.3 shows water content.
(10)

In the present study, the LULC was evaluated for the last 22 years, from 2001 to 2022. Based on the spectral characteristics and MODIS MCD12Q1 V6-1, the study area was classified as EBF, Sav, GLs, PWLs, CLs, VMs, BL, and WBs. The details of long-term LULC change for each land cover type have been described in the following. This finding is in line with earlier, similar studies (Elagouz et al. 2019; Kamel 2020; Mohamed et al. 2020; Said et al. 2020; Abd El-Hamid et al. 2022).

Accuracy assessment of the LULC classification

The accuracy of classified images was assessed by evaluating the UA, PA, OA and kappa coefficients for the years 2001, 2010, and 2022. Table 1 shows the summarized LULC classification accuracy for 2001, 2010, and 2022. Based on the estimated results, the OAs of the classified images for the years 2001, 2010, and 2022 were 88.4, 89.1, and 91.4%, respectively. The OA of the classified images exceeded the minimum recommended accuracy of 85%, which shows high accuracy and reliability for LULC dynamics evaluation and consistent with related studies (Anderson et al. 1976). For the years 2001, 2010, and 2010, the kappa statistics of the LULC were 0.86, 0.91, and 0.88, respectively, showing that the agreement between the identified LULC classes and the geographical data is strong. Based on Viera and Garrett (2005), the kappa value higher than 0.8 indicates strong agreement, whereas kappa values ranging between 0.61 and 0.8 demonstrate very good agreement and the result of the kappa value for this study was higher than that of the recommended value. Additionally, the kappa values were described as a considerable agreement to near perfect agreement, which agrees with similar studies (Irwin et al. 2009). The results for OA, producer accuracy (PA), user accuracy (UA) and kappa coefficient were presented in Table 1. The classification images are valid for evaluation using ground truth for land cover dynamics evaluation.

Table 1

Statistical accuracy assessment for LULC evaluation

MODIS MCD12Q1 V6–1 LULC2001
2010
2022
Percentage of accuracy
PAUAPAUAPAUA
EBF 86.8 92.9 98.0 88.2 89.0 92.5 
Sav 88.3 77.6 84.4 79.5 86.5 89.7 
79.5 93.2 88.4 92.2 87.9 95.6 
PWL 83.5 89.5 84.7 83.8 92.1 91.9 
CL 91.6 96.0 94.0 93.5 98.3 97.5 
VM/CL 89.4 93.4 91.2 87.6 88.5 84.3 
76.6 78.3 82.4 81.2 86.8 89.3 
WB 99.2 98.3 98.7 97.6 96.5 95.5 
OA 88.4 89.1 91.4    
Kstat 0.86 0.91 0.88    
MODIS MCD12Q1 V6–1 LULC2001
2010
2022
Percentage of accuracy
PAUAPAUAPAUA
EBF 86.8 92.9 98.0 88.2 89.0 92.5 
Sav 88.3 77.6 84.4 79.5 86.5 89.7 
79.5 93.2 88.4 92.2 87.9 95.6 
PWL 83.5 89.5 84.7 83.8 92.1 91.9 
CL 91.6 96.0 94.0 93.5 98.3 97.5 
VM/CL 89.4 93.4 91.2 87.6 88.5 84.3 
76.6 78.3 82.4 81.2 86.8 89.3 
WB 99.2 98.3 98.7 97.6 96.5 95.5 
OA 88.4 89.1 91.4    
Kstat 0.86 0.91 0.88    

Temporal variation of LULC from 2001 to 2022

EBF change detection

Broadleaf evergreen trees have large leaves, like those of the palm and rubber trees that have large leaves staying green all year long with a canopy greater than 2 m and greater than 60% tree cover. A broadleaf evergreen forest is more commonly referred to as a tropical rain-forest. From the classification of LULC in this study, EBF covers the lowest area compared with other land cover types during the study period. A change in EBF has been shown in Figure 3. According to the result, the EBFs for lake Chamo catchment were 1.83 km2 (0.1%), 1.49 km2 (0.08%), 0.84 km2 (0.04%), 0.98 km2 (0.05%), 0.98 km2 (0.05%), 1.43 km2 (0.08%), 1.18 km2 (0.06%), 0.72 km2 (0.04%), 0.84 km2 (0.04%), 1.0(0.05%), 1.17(0.06%), 2.02 km2 (0.11%), 2.18(0.12%), 3.91 km2 (0.21%), 1.53(0.08%), 1.32 km2 (0.07%), 1.03 km2 (0.06%), 0.72 km2 (0.04%), 2.0 km2 (0.11%), 2.0 km2 (0.11%), 1.56 km2 (0.08%) and 1.45 km2 (0.08%) from 2001 to 2022, respectively (Figure 3(a)). Figure 3(a) shows the yearly areal coverage of EBF during the study period and the dramatic change of EBF that has been observed between 2002 and 2022. The result for gain and loss of LULC shows that the highest increase in EBE was observed between 2011 and 2012, 2013–2014, 2018–2019 with the area of 0.85 km2 (72.81%), 1.73 km2 (79.5%) and 1.28 km2 (178.31%), whereas the highest decline in area was observed between 2002 and 2003, 2007–2008, and 2014–2015 with the area of 0.66 km2 (43.9%), 0.45 km2 (38.6%), and 2.37 km2 (60.73%), respectively (Figure 3(b)). The percentage of change in the year was evaluated using Equation (7).
Figure 3

Change detection in EBFs.

Figure 3

Change detection in EBFs.

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Cropland

According to the result of classification, the total area coverage of CL was 239.30 km2 (12.82%), 250.37 km2 (13.41%), 229.78 km2 (12.31%), 200.94 km2 (10.76%), 222.19 km2 (11.90%), 246.45 (13.2%), 195.99 km2 (10.5%), 231.14 km2 (12.38%), 196.52 km2 (10.53%), 144.40 km2 (7.74%), 188.38 km2 (10.09%), 234.60 km2 (12.57%), 218.41 km2 (11.7%), 218.50 km2 (11.71%), 311.31 km2 (16.69%), 291.90 km2 (15.64%), 325.69 km2 (17.45%), 289.49 km2 (15.51%), 378.82 km2 (20.30%), 378.82 km2 (20.30%), 216.13 km2 (11.59%) and 172.71 km2 (9.25%) from 2001 to 2022, respectively (Figure 4(a)). The gain and loss of CL for the study period was shown in Figure 4(b). A maximum gain was observed between 2014 and 2015 with the value of 92.81 km2, whereas a maximum loss of area was observed between 2020 and 2021 with a value of 162.68 km2.
Figure 4

CL variations.

Changes in Sav

The change in Sav LULC was the third major LULC type in the lake catchment during the study period. A significant change in LULC was observed and the area coverage of Sav was 549.57 km2 (29.45%), 621.80 km2 (33.31%), 572.03 km2 (30.64%), 519.00 km2 (27.80%), 478.70 km2 (25.64%), 465.19 km2 (24.92%), 532.19 km2 (28.51%), 451.37 km2 (24.18%), 397.11 km2 (21.28%), 515.76 km2 (27.63%), 398.69 km2 (21.35%), 360.24 km2 (19.3%), 375.97 km2 (20.14%), 374.17 km2 (20.06%), 319.80 km2 (17.14%), 406.28 km2 (21.77%), 383.45 km2 (20.55%), 436.24 km2 (23.38%), 366.24 km2 (19.62%), 366.24 km2 (19.62%), 432.94 km2 (23.21%), and 413.84 km2 (22.18%) from 2002 to 2022, respectively (Figure 5(a)). The decreasing trend of savanna LULC was observed during the study period. The result for the gain and loss of savanna LULC shows that the highest increase was observed between 2009 and 2010 with an area of 118.65 km2 (29.9%), whereas the highest decline in area loss was observed between 2010 and 2011with the area loss of 117.07 km2 (22.7%), respectively (Figure 5(b)).
Figure 5

Variations in Sav land.

Figure 5

Variations in Sav land.

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3.2.4. Changes in GL

The change in GL cover type is the major and the first largest LULC type in the study area and shows a significant increasing and decreasing trend during the study period (Figure 6(b)). Based on the result of classification, the total area coverage of GLs was 671.24 km2 (35.97%), 643.26 km2 (34.46%), 723.73 km2 (38.77%), 807.26 km2 (43.24%), 826.00 km2 (44.24%), 828.74 km2 (44.4%), 814.47 km2 (43.63%), 865.96 km2 (46.39%), 956.29 km2 (51.24%), 883.77 km2 (47.34%), 965.19 km2 (51.69%), 952.89 km2 (51.06%), 950.02 km2 (50.9%), 945.92 km2 (50.7%), 911.53 km2 (48.87%), 838.42 km2 (44.94%), 831.20 km2 (44.53%), 811.09 km2 (43.47%), 793.74 km2 (42.53%), 793.74 km2 (42.53%), 860.56 km2 (46.13%) and 931.07 km2 (49.89%), respectively, from 2001 to 2022 (Figure 6(a)). The gain and loss of GL for the study period was shown in Figure 6(b). A maximum gain was observed between 2008 and 2009 with a value of 90.32 km2 (10.43%), whereas a maximum loss of area was observed between 2015 and 2016 with a value of 73.11 km2 (8.02%). The positive value shows the gain in area, whereas the negative value shows the loss of area of LULC.
Figure 6

Variations in GLs.

Figure 6

Variations in GLs.

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Changes in PWLs

Figure 7 shows the change in PWL of the study area during the study period. A slight gain and loss in wetland was observed in the study area from 2001 to 2022. The areal coverage of PWL was 37.93 km2 (2.03%), 32.24 km2 (1.73%), 30.61 km2 (1.64%), 28.00 km2 (1.5%), 26.69 km2 (1.43%), 30.18 km2 (1.62%), 30.74 km2 (1.65%), 29.75 km2 (1.59%), 25.81 km2 (1.38%), 28.16 km2 (1.51%), 27.35 km2 (1.46%), 29.30 km2 (1.57%), 30.92 km2 (1.66%), 34.51 km2 (1.85%), 34.74 km2 (1.86%), 39.61 km2 (2.12%), 39.15 km2 (2.1%), 40.41 km2 (2.17%), 38.22 km2 (2.05%), 38.22 km2 (2.05%), 53.94 km2 (2.89%) and 50.23 km2 (2.69%) from 2001 to 2022, respectively (Figure 7(a)). The gain and loss of CL for the study period was shown in Figure 7(b). A maximum gain was observed between 2020 and 2021 with the value of 15.72 km2 (41.13%), whereas a maximum loss of area was observed between 2001 and 2002 with a value of 5.69 km2 (15%) (Figure 7(b)).
Figure 7

Variations in PWLs.

Figure 7

Variations in PWLs.

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Natural Vegetation Mosaics

Natural Vegetation Mosaics (NVMs) is one of the LULC types presented in the Lake Chamo catchment and evaluated for the study area, which demonstrates a rapid decline in NVM area during the study period. The analysis shows that the yearly areal coverage of NVM was 70.42 km2 (3.77%), 25.00 km2 (1.34%), 20.05 km2 (1.07%), 22.61 km2 (1.21%), 25.29 km2 (1.35%), 11.76 km2 (0.63%), 9.72 km2 (0.52%), 5.22 km2 (0.28%), 5.68 km2 (0.3%), 9.48 km2 (0.51%), 1.59 km2 (0.09%), 3.31 km2 (0.18%), 5.78 km2 (0.31%), 5.48 km2 (0.29%), 3.02 km2 (0.16%), 5.85 km2 (0.31%), 2.45 km2 (0.13%), 4.93 km2 (0.26%), 2.82 km2 (0.15%), 2.82 km2 (0.15%), 8.98 km2 (0.48%) and 1.43 km2 (0.08%), respectively, from 2001 to 2022 (Figure 8(a)). The change in area between each year was also evaluated and a very high decline in the area of NVM was observed between 2001 and 2002 with a value of 45.43 km2 (64.51%). An increment in area was observed between some years and the highest incremental area was observed between 2020 and 2021 with a value of 6.17 km2 (218.93%) (Figure 8(b)).
Figure 8

Variations in CLs/VMs.

Figure 8

Variations in CLs/VMs.

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Barren land

BL shows LULC of an area. At least 60% of the area is covered by non-vegetated barren (sand, rock, soil) area with less than 10% vegetation. The annual change in BL was 3.87 km2 (0.21%), 4.29 km2 (0.23%), 4.65 km2 (0.25%), 7.30 km2 (0.39%), 9.65 km2 (0.52%), 8.57 km2 (0.46%), 8.50 km2 (0.46%), 9.19 km2 (0.49%), 11.33 km2 (0.61%), 10.10 km2 (0.54%), 9.88 km2 (0.53%), 9.10 km2 (0.49%), 8.03 km2 (0.43%), 7.60 km2 (0.41%), 6.74 km2 (0.36%), 5.88 km2 (0.32%), 6.58 km2 (0.35%), 6.01 km2 (0.32%), 6.23 km2 (0.33%), 6.23 km2 (0.33%), 4.94k km2 0.26%) and 5.80 km2 (0.31%), respectively, from 2001 to 2022 (Figure 9(a)). A rapid increment of area was observed between 2003–2004, 2004–2005, and 2008–2009 with a value of 2.65 km2 (57.11%), 2.35 km2 (32.2%) and 2.15 km2 (23.4%), respectively. The highest increment was observed between 2003 and 2004 with the value of 2.65 km2 and the highest decline was observed between 2020 and 2021 with the value of −1.29 km2 (Figure 9(b)).
Figure 9

Variations in BLs.

Figure 9

Variations in BLs.

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Change in WBs

The change in WBs for the study area during the study period was 292.01 km2 (15.65%), 288.50 km2 (15.45%), 285.16 km2 (15.37%), 280.86 km2 (15.04%), 277.42 km2 (14.86%), 274.39 km2 (14.70%), 273.96 km2 (14.68%), 273.39 km2 (14.65%), 272.67 km2 (14.61%), 274.08 km2 (14.68%), 274.95 km2 (14.73%), 274.85 km2 (14.73%), 275.13 km2 (14.74%), 275.48 km2 (14.77%), 276.62 km2 (14.83%), 276.57 km2 (14.82%), 276.68 km2 (14.83%), 277.06 km2 (14.85%), 278.31 km2 (14.91%), 278.31 km2 (14.91%), 286.48 km2 (15.36%) and 289.65 km2 (15.52%) from 2001 to 2022, respectively, presented in Figure 10(a). The gain and loss of CL for the study period was shown in Figure 10(b). A maximum gain was observed between 2020 and 2021 with a value of 8.18 km2 (2.94%), whereas a maximum loss of area was observed between 2003 and 2004 with a value of 4.3 km2 (1.2%) (Figure 10(b)).
Figure 10

Variations inWBs.

Figure 10

Variations inWBs.

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Spatial variation of LULC

Figure 11 shows the spatial distribution of the LULC in the Lake Chamo catchment in 2001, 2010 and 2022. It can be seen from the figures that GL is the major LULC type, accounting for 36, 47.34, and 49.89% in the years 2001, 2010, and 2022, respectively. The grass LULC type shows an increasing trend for the selected years and dominates the study area. The savanna LULC accounts for 29.45, 27.63, and 22.18%, respectively, in the years 2001, 2010 and 2022, respectively. The changes in EBF were 0.1, 0.05, and 0.08% for the years 2001, 2010, and 2022, respectively. The changes in PWL were 2.03, 1.51, and 2.69% in the years 2001, 2010, and 2022, respectively. The variations in crop land were 12.82, 7.74, and 9.25% for the years 2001, 2010, and 2022, respectively. The changes in NVM were 3.77, 0.51, and 0.08% for the years 2001, 2010, and 2022, respectively. The variation in bare land was 0.21, 0.54, and 0.31% for the years 2001, 2010, and 2022, respectively. The change in body water was 15.65, 14.68, and 15.52% for the years 2001, 2010, and 2022, respectively. The degree of LULC change can effectively reflect the breadth and depth of development. The evaluated result shows a significant variation in LULC in each land cover type. The variation in LULC in the study area was observed due to anthropogenic and natural factors. The process and trend of land use change over 22 years were evaluated using a three-period LULC dataset and the LULC changed significantly over the 22 years in the study area. In the study area, the LULC type was influenced by a variety of factors operating on one spatial and temporal level and acting not in isolation but in intricate web and time-specific relationships. The increasing population is one of the major factors that affects the variation in LULC in the study area. The change in LULC occurs initially at the level of individual land parcels. Aggregately, the individual land use decisions produce LULC change that leads to higher spatial levels. Internal and external pressure on land managers also influences the land-management unit, and their decisions are influenced by their personal traits and local environmental conditions as well as by the immediate and broader environmental, socioeconomic, institutional, and political settings within which the land unit is embedded. Generally, the human driving forces such as all forms of formal and informal activities were the major cause of LULC variation in the study area and consistent with similar studies (Naidoo 2005; Monteiro et al. 2018). Landforms are also the main factors influencing land use/cover diversity and patterns. The topographic factors such as elevation, aspect and slope change the water and heat supply of vegetation and the physical and chemical conditions of soil, which led to the change in LULC and is consistent with similar studies (Hoylman et al. 2018; Chen et al. 2021). In addition, the change in climate also has a significant influence on the ecosystem distribution and vegetation growth and is common in the study area, which is consistent with similar studies (Monteiro et al. 2018; Guo et al. 2020; Erdös et al. 2022; Acharki et al. 2023). This type of LULC evaluation provides a significant and prime role in planning, management and monitoring programmes of natural resources like water resources and the ecology of the environment, which ensures sustainable development. The pattern of land cover land use has a significant impact on the study area, leading to a continuous increase and decrease in the degree of land use. The LULC change is the result of multiple variables such as social and natural factors.
Figure 11

Spatial LULC change detection from MODIS MCD12Q1 V6.1 in 2001, 2010, and 2022.

Figure 11

Spatial LULC change detection from MODIS MCD12Q1 V6.1 in 2001, 2010, and 2022.

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Comparison of MODIS MCD12Q1 V6.1 LULC and Sentinel-2 LULC classification

For the comparison analysis, the MODIS MCD12Q1 V6.1 LULC and Sentinel-2 LULC classification were carried out using the GEE cloud platform applying random forecast classification algorithm to classify the surface use type information of Lake Chamo catchment from 2017 to 2021. The OA and kappa coefficient of LULC for the GEE-based land use classification was 98.0 and 97.8% which is higher than the threshold of accuracy reported by similar studies (Irwin et al. 2009). 310.18 km2 (16.64%), 227.28 km2 (12.19%), 0.80 km2 (0.04%), 556.95 km2 (29.88%), 32.54 km2 (1.75%), 1.54 km2 (0.08%) and 734.49 km2 (39.41%) in 2017, 310.53 km2 (16.66%), 206.28 km2 (11.07%), 2.83 km2 (0.15%), 695.24 km2 (37.3%), 34.63 km2 (1.86%), 2.33 km2 (0.12%) and 611.94 km2 (32.83%) in 2018, 310.45 km2 (16.66%), 181.78 km2 (9.75%), 2.04 km2 (0.11%), 781.69 km2 (41.94%), 34.08 km2 (1.83%), 2.80 km2 (0.15%) and 550.93 km2 (29.56%) in 2019, 320.34 km2 (17.19%), 371.01 km2 (19.91%), 13.38 km2 (0.72%), 735.74 km2 (39.48%), 43.07 km2 (2.31%), 23.27 km2 (1.25%) and 356.95 km2 (19.15%) in 2020, 333.16 km2 (17.88%), 183.32 km2 (9.84%), 12.72 km2 (0.68%), 765.33 km2 (41.06%), 44.27 km2 (2.38%), 2.04 km2 (0.11%) and 522.92 km2 (28.06%) in 2021 for water, trees, flooded vegetation, crops, built area, bare ground and rangeland/savanna, respectively. The GEE cloud platform could quickly and accurately realize the land use classification in the study area and effectively solve the problems of a large amount of data processing and complex workflow in the process of land use classification in a large area. The pixel oriented RF classification method used in this manuscript realizes LULC classification in the study area. The OA and kappa coefficient of the classification results meet the requirements. This type of classification is based on the software analysis of an image without the user providing sample classes. This involves grouping of pixels with common characteristics. The computer uses techniques to determine which pixels are related and groups them into classes. The Sentinel-2 LULC classification using GEE has higher accuracy related to MCD12Q1 V6.1. Different results were obtained from both datasets in the study area during the study period. The spatial variation of LULC variation from MODIS MCD12Q1 V6.1 LULC and ESRI Sentinel-2 dataset are presented in Figure 12. As presented in the result, there was significant variation in LULC and in this paper, detailed LULC for MODIS MCD12Q1 V6.1 was explained more. The variation in land use and land cover change affects climatic change, soil erosion, water storage and ecological conditions of the catchment. The rangeland land classification under Sentinel-2 includes GL and savanna. In 2017, for the ESRI Sentinel-2 LULC classification, rangeland is the dominant LULC, followed by crop land. From 2018 to 2021, crop land is the dominant LULC in the study area. For MODIS MCD12Q1 V6.1, GL is the dominant LULC followed by Sav, crop land, water body, NVMs, permanent wet land, BL and evergreen broad leaf forest. The area of water body evaluated using Sentinel-2 LULC classification was higher than areal coverage from MODIS MCD12Q1 V6.1. For the Sentinel-2 LULC classification, the area of water body was above 300 km2 for the selected years and the area of MODIS MCD12Q1 V6.1 was below 300 km2. The cause of variation in area between the two datasets was due to variation in spatial resolution. The Sentinel-2 LULC has 10-m spatial resolution, whereas the MODIS LULC Type Product (MCD12Q1) has 500-m spatial resolution. The LULC change affects the environment, economic development, WBs, the ecosystem and climate of the environment, which could be managed well to improve sustainable economic development.
Figure 12

LULC classification of MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets.

Figure 12

LULC classification of MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets.

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Variation of NDVI, NDWI, and EVI

Figure 13 shows the monthly and yearly evaluated value of NDVI, NDWI and EVI for the study area from 2013 to 2023. Based on the estimated result, the monthly value of EVI, NDVI, and NDWI ranged between 0.114 and 0.383, 0.142–0.41, and 0.066–0.29, respectively, whereas the yearly value of EVI, NDVI, and NDWI ranged between 0.129 and 0.278, 0.155–0.326, and 0.09–0.217, respectively, from 2013 to 2023. This investigation has shown that the monthly and yearly values of NDWI were less than 0.3 during the study period and shows a significant variation for the study period. The findings of the current study provided evidence that the value of EVI, NDVI, and NDWI were greater than 1. A higher correlation coefficient was observed between EVI, NDVI, and NDWI with correlation values of 0.98, 0.96 and 0.97. Generally, the estimated value of EVI, NDVI and NDWI demonstrates a decreasing trend for the study area from 2013 to 2023. For both yearly and monthly results, the value of NDVI was higher than NDWI followed by EVI, and NDWI shows the lowest value during the study period. The NDVI and EVI were used to quantify vegetation greenness and NDWI was used to delineate and monitor surface water content, which agrees with similar studies (Li et al. 2010).
Figure 13

Monthly and yearly EVI, NDVI, and NDWI for the study area from 2013 to 2023.

Figure 13

Monthly and yearly EVI, NDVI, and NDWI for the study area from 2013 to 2023.

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The current study was carried out to assess variation in LULC type in Lake Chamo catchment using MODIS and ESRI data in ArcGIS 10.4. The study area was classified as EBF, Sav, GLs, PWLs, CLs, VMs, BL and WBs for MODIS data, whereas for ESRI dataset water, trees, flooded vegetation, crops, built area, bare ground and rangeland/savanna were identified. The OA of the classified images for the years 2001, 2010, and 2022 were 88.4, 89.1, and 91.4%, whereas the kappa statistics of the LULC were 0.86, 0.91, and 0.88, respectively, for MODIS datasets. The OA and kappa coefficient of LULC for the ESRI-based land use classification was 98.0 and 97.8%, which is higher than the threshold of accuracy reported by similar studies (Irwin et al. 2009). Based on Viera and Garrett (2005), the kappa value higher than 0.8 indicates strong agreement, whereas kappa values ranging between 0.61 and 0.8 demonstrate very good agreement and the result of the kappa value for this study was higher than that of the recommended value. Additionally, the kappa values were described as a considerable agreement to near perfect agreement and are consistent with similar studies (Irwin et al. 2009). The result for producer accuracy and user accuracy was presented in Table 1 for each LULC class of MODIS dataset. Concerning the accuracy assessment of the used dataset, a producer accuracy and user accuracy of greater than 76% was obtained in all years for MODIS dataset. The results revealed that GL was the major LULC for MODIS dataset, whereas crop land was the dominant LULC type for ESRI datasets. Built-up areas and crop land show an increasing trend in the ESRI dataset due to increasing populations. For MODIS dataset, fluctuations in LULC type were observed during the study period. The rate of change of WBs for ESRI dataset were 16.64, 16.66, 16.66, 17.19, and 17.88% from 2017 to 2021, respectively, trees were 12.19, 11.07, 9.75, 19.91, and 9.84%, flooded vegetation were 0.04, 0.15, 0.11, 0.72, and 0.68%, built-up area (1.75, 1.86, 1.83, 2.31, and 2.38%), bare ground (0.08, 0.12, 0.15, 1.25, and 0.11%), crops (29.88, 37.3, 39.48, and 41.94) and rangeland/Savanna (39.41, 32.83, 29.56, 19.15, and 28.06%), respectively, from 2017 to 2021. For MODIS dataset the rate of change of EBF was 0.06, 0.04, 0.11, 0.11, and 0.08%, Sav (20.55, 23.38, 19.62, 19.62, and 23.21%), G (44.54, 43.47, 42.53 42.53, and 46.13%), PWL (2.1, 2.17, 2.05, 2.05, and 2.89%), crop lands (17.45, 15.51, 20.30, 20.30, and 11.59%), NVM (0.13, 0.26, 0.15, 0.15, and 0.48%), B (0.35, 0.32, 0.33, 0.33, and 0.26%), WB (14.83, 14.85, 14.91, 14.91, and 15.36%). Furthermore, the most considerable increase and decrease in LULC type was observed during the study period for the study area. This variation in LULC type was due to human interventions, which are mainly based on agricultural development, due to an increasing population and other activities. The study area is inhabited by rural people in which their livelihood depends on agriculture and thus the natural growth is relatively higher than urban areas. Currently, the population of the study area has increased and its effect on the environment and water resources is devastating. Due to population growth, farm land owned by the parents is continuously shared by the number of children and, therefore, land fragmentation continues. On the other hand, its size is desolately declining. This has caused natural resource scarcity and has supported natural resource degradation in the study area. Moreover, population growth results in cultivated land expansion at the expense of natural vegetation and grazing in the study area. This finding is similar to recent studies conducted in other parts of Ethiopia, which demonstrate that population growth is the main cause of the LULC change (Bewket 2003; Asmamaw et al. 2011; Gebru 2016). Due to this, different land uses compete with one another, and can reduce the quality of natural resource bases and land productivity, including water resources. Agricultural growth is still based on areal expansion (Abate 2011) and thus, there was mismanagement of land, including cultivating steep slopes and marginal land, overgrazing and destruction of forest for different purposes. On the other hand, the livelihoods of many people in the study area rely on the sale of firewood, charcoal and other things. In recent years, firewood and charcoal have become the most commercialized energy sources for both the rural and urban communities in the area, which is similar to the finding conducted in the sub-basin of the upper Blue Nile in north Gojjam (Ewunetu et al. 2021). So, the human driving forces such as all forms of formal and informal activities were the major cause of LULC variation in the study area and consistent with similar studies (Naidoo 2005; Monteiro et al. 2018). Generally, the main causes of LULC changes in the study area include population pressure, agriculture and settlement expansions to marginal mountain areas, increasing wood demand for fuel, collection of farm implements and construction wood, charcoal production, livestock grazing and others. Landforms are also the main factors influencing land use/cover diversity and patterns. The topographic factors such as elevation, aspect and slope change the water and heat supply of vegetation and the physical and chemical conditions of soil, which led to the change in LULC and is consistent with similar studies (Hoylman et al. 2018; Chen et al. 2021). Similarly, climate change directly and indirectly affects LULC and the ecosystems by altering the pattern, distribution and practice of land, which was also reported by similar studies (Turner & Gardner 2015; Monteiro et al. 2018; Guo et al. 2020; Erdös et al. 2022; Acharki et al. 2023). LULC changes such as deforestation, cultivated land expansion and urbanization also have a long-term impact on hydrological processes such as stream flows, evapotranspiration (ET), groundwater recharge, surface water availability, leaching and infiltration rate, which affects water resource availability and also agrees with similar studies (Loveland & Mahmood 2014). Additionally, LULC change and its dynamics are directly related to biodiversity and productivity of land and have enormous environmental and societal impacts which affect both local and global systems by altering the interaction of energy, greenhouse gases and water between land and the atmosphere (Sleeter et al. 2017). Hence, sustainable land use planning and management should be put in place for local communities, with particular emphasis on close supervision of bare land restoration, forest and bush land conservation, making grazing lands available through restoration of degraded land and regulating further expansion of areas under cultivation. A people-centered approach to the integration of conservation of the natural resource base (water, soil, trees and local biodiversity) and development to overcome natural resource degradation was a key strategy recommended in this study. This community-based conservation and resource management system uses new beliefs about the suitability of communities to suggest policy recommendations. The implicit assumption behind these recommendations is that communities have incentives to use unsustainable resources when they are not involved in resource management. If communities are involved in conservation, the benefits they receive will create incentives for them to become good stewards of resources. Measures to address water availability in the Lake Chamo catchment include: Setting up the appropriate institutional and legal framework for comprehensive water management; building capacity and raising awareness of water resources and other natural resource management at all levels; creating effective monitoring systems for ground and surface water resource assessment. The natural degradation and soil erosion is common in the study area, which leads to sedimentation of the lake and affects the lake ecosystem and needs awareness for lake water management. Government policies and institutions also must be aware of the rapid land use changes to maintain or enhance natural resource management and sustainable economic development. Additionally, yearly variation of LULC for each land use type was evaluated and change was detected in the year of the study period from 2001 to 2022 and the result revealed that savanna and GL were the dominant LULC in the study area during the study period. The investigation has shown that changing land use and land cover was a pervasive, rapid, and significant trend in the study area during the study period. This study gives valuable information to policy-makers and stakeholders for sustainable economic development, lake water management, ecological maintenance and climatic change adoption pathways in the study area. Based on the estimated result, the monthly values of EVI, NDVI, and NDWI ranged between 0.114 and 0.383, 0.142–0.41, and 0.066–0.29, respectively, whereas the yearly values of EVI, NDVI, and NDWI ranged between 0.129 and 0.278, 0.155–0.326, and 0.09–0.217, respectively, from 2013 to 2023. This investigation has shown that the monthly and yearly values of NDWI were less than 0.3 during the study period and shows a significant variation for the study period. The NDVI and EVI were used to quantify vegetation greenness and NDWI was used to delineate and monitor surface water content, which agrees with similar studies (Li et al. 2010). Changing land use types provides immediate economic benefits for the community but dramatically alters or causes imbalances in ecosystem services, including water availability. For example, the conversion of GL and forest to CL and built-up area is expected to have an impact on the hydrological cycle, increasing soil erosion and runoff. This, in turn, leads to the deterioration of ecological services, which may have an impact on the local community's livelihood. Proper GL, forest, and shrub-bushland management is critical for the long-term viability of water availability and climate change. Appropriate LULC management was essential for the long-term variability of climate change in the study area and ecological restoration of the lake catchment. Understanding and managing LULC changes is also crucial for addressing environmental challenges, promoting efficient utilization of natural resources, sustainability of environmental and ecological systems for the well-being of both present and future generations. Generally, the results of the study revealed a substantial change in land cover use in the study area over the period (2001–2022). The findings recommend that major stakeholders, including environmental protection agencies, forest guides, water resource organizations and municipal assembly authorities, should develop feasible holistic preventive measures that seek to ensure effective and efficient utilization of resources and promote the livelihoods of individuals who depend on these resources for survival.

This study was carried out in the Lake Chamo catchment to evaluate LULC variation based on MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets on spatiotemporal changes. Multi-temporal satellite imagery can provide the essential measurement of spatial and temporal phenomena for areas where it is difficult to evaluate LULC using traditional mapping. Therefore, this study focused on detecting and analyzing LULC changes in the study area over the different periods examined from 2002 to 2022. The estimated result shows that 8 land-use land cover types were observed for MODIS MCD12Q1 V6.1 dataset, while 7 land-use land cover types were obtained for ESRI Sentinel-2 dataset in the study area during the study period. The result shows a significant variation in LULC changes for the study area during the study period. Based on the accuracy assessment, the OAs of the classified images in the years 2001, 2010, and 2022 were 88.4, 89.1, and 91.4%, whereas the kappa statistics of the LULC were 0.86, 0.91, and 0.88, respectively. The spatiotemporal variation of LULC from MODIS MCD12Q1 V6.1 shows that the savanna LULC type accounts for 29.45, 27.63, and 22.18%, respectively, in the years 2001, 2010, and 2022, respectively. The changes in EBF were 0.1, 0.05, and 0.08% for the years 2001, 2010, and 2022, respectively. The changes in PWL were 2.03, 1.51, and 2.69% in the years 2001, 2010, and 2022, respectively. The variation in crop land was 12.82, 7.74, and 9.25% for the years 2001, 2010, and 2022, respectively. The changes in NVM were 3.77, 0.51, and 0.08% for the years 2001, 2010, and 2022, respectively. The variation in bare land was 0.21, 0.54, and 0.31% for the years 2001, 2010, and 2022, respectively. The change in body water was 15.65, 14.68, and 15.52% for the years 2001, 2010, and 2022, respectively. The Sentinel-2 LULC type shows that 310.18 km2 (16.64%), 227.28 km2 (12.19%), 0.80 km2 (0.04%), 556.95 km2 (29.88%), 32.54 km2 (1.75%), 1.54 km2 (0.08%) and 734.49 km2 (39.41%) for the 2017, 310.53 km2 (16.66%), 206.28 km2 (11.07%), 2.83 km2 (0.15%), 695.24 km2 (37.3%), 34.63 km2 (1.86%), 2.33 km2 (0.12%) and 611.94 km2 (32.83%) in the year 2018, 310.45 km2 (16.66%), 181.78 km2 (9.75%), 2.04 km2 (0.11%), 781.69 km2 (41.94%), 34.08 km2 (1.83%), 2.80 km2 (0.15%) and 550.93 km2 (29.56%) in the year 2019, 320.34 km2 (17.19%), 371.01 km2 (19.91%), 13.38 km2 (0.72%), 735.74 km2 (39.48%), 43.07 km2 (2.31%), 23.27 km2 (1.25%) and 356.95 km2 (19.15%) in the year 2020, 333.16 km2 (17.88%), 183.32 km2 (9.84%), 12.72 km2 (0.68%), 765.33 km2 (41.06%), 44.27 km2 (2.38%), 2.04 km2 (0.11%) and 522.92 km2 (28.06%) in the year 2021 for water, trees, flooded vegetation, crops, built area, bare ground and rangeland/savanna, respectively. According to the result, the degree of LULC change can effectively reflect the breadth and depth of development. The monthly values of EVI, NDVI, and NDWI ranged between 0.114 and 0.383, 0.142–0.41, and 0.066–0.29, respectively, whereas the yearly values of EVI, NDVI, and NDWI ranged between 0.129 and 0.278, 0.155–0.326, and 0.09–0.217, respectively, from 2013 to 2023.

The increased population and agricultural activities in the lake basin area have a considerable impact on LULC types. Additionally, natural factors such as change in climate, land forms, and soil type affect the LULC type. This investigation has shown that changing land use and land cover is a pervasive, rapid, and significant trend in Lake Chamo catchment. The findings of the current study provided evidence that MODIS MCD12Q1 V6.1 and ESRI Sentinel-2 datasets are an effective dataset used for detecting LULC variation in the study area and also can be used in different areas. The result of the study demonstrates that the policy-makers and stakeholders of the Lake Chamo catchment need to be conscious of the rapid change of land use which affects the lake water body. Therefore, it concludes that a major land use was identified, and the increasing population is a driving factor to trigger the transformation of the study area during the study period.

Conceptualization, methodology, original draft writing, preparation, and development of model was done by A.K.Y.

The author approved that this article is new and original, and not published in any other journal.

We agree to participate in the journal.

The author agrees to publish the journal.

Data cannot be made publicly available; readers should contact the corresponding author for details.

The author declares no competing interests.

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