Land Conversion Research Articles

Spatiotemporal Assessment of Land Use System in Kathmandu Valley of Nepal Using Geospatial Techniques

The Kathmandu Valley is one of the growing urbanization trend spreading capital city of Nepal. This metropolitan valley is experiencing a significant transformation of its landscapes in the last few decades resulting in large land use and land cover change. A systematic study of the urbanization trend and LULC has been felt need on this valley. Considering the importance of LULC change this study is carried out using Arc GIS to assess land use system and change dynamics in the study area based on Landsat imagery of the years from 2000 to 2019 at yearly interval. From the study of LULC of Kathmandu valley over the period selected a remarkable change scenario was observed in Agricultural land, Forest area, Vegetation land, Built up and River Bed area. Built up area is found significantly increased by 16% during the period in Kathmandu Valley. Forest area is found increased by 3%, whereas because of concrete structures built in the city caused decrease in water body in the valley by 3% up to the year 2008 and found increased later years with the increase in forest area. The effects in rivers system are observed significantly. River bed area is found decreased over this time period by 9%.This study showed the fast expansion of urbanization area and rapid conversions of agricultural land in Kathmandu Valley (study area).

Transforming Agricultural Land into Residential Areas: A Socio-Economic Study in Tamiang Subdistrict, Mandailing Natal Regency

The conversion of agricultural land into residential areas has become increasingly prevalent due to rapid population growth and the rising demand for housing development. This process presents various challenges, particularly for communities that rely on agriculture as their primary source of livelihood. This study aims to examine the socio-economic impacts of agricultural land conversion into residential areas in Tamiang Village, Kotanopan Subdistrict, Mandailing Natal Regency, North Sumatra Province. Using a qualitative method with data collected through observation, interviews, and literature review, the study found that land conversion in Tamiang Village has reduced the amount of agricultural land, altered land ownership patterns, and shifted livelihoods from agriculture to non-agricultural sectors. Factors such as population growth, economic motivations, inheritance considerations, and the strategic location of the land are the main drivers of this conversion. The findings of this study provide insights into the socio-economic dynamics in rural areas and offer considerations for formulating policies that balance residential development with agricultural sustainability.

Green and Low Carbon Development Performance in Farmland Use Regulation: A Case Study of Liyang City, China

Farmland use regulation strictly regulates the conversion of agricultural land for other agricultural purposes and the construction of agricultural facilities, thereby optimizing the land use pattern in rural areas. However, different measures and intensities of farmland use regulation can affect the overall performance of green and low-carbon development in rural areas. This study utilizes system dynamics modeling and simulation to conduct a case study based on current land use data from 10 towns in Liyang City, China. The empirical results indicate the following: (1) Based on comprehensive measurements of green and low carbon development performance, Liyang City exhibits a pattern of higher indices in the south and lower indices in the north. Towns such as Tianmu Lake, Daibu, and Shezhu show relatively high average comprehensive indices of 0.31, 0.30, and 0.28, significantly higher than other towns. (2) Simulation of farmland use regulation’s impact on green and low carbon development performance reveals that Scenario One, involving additional construction land occupying farmland, achieves a comprehensive index of only 0.23, significantly lower than the other scenarios. (3) Based on calculations and field surveys, Liyang City’s villages are categorized into four types, with the largest number being industry-integrated villages (94 villages). Accordingly, policies for farmland use regulation are designed for different village types. Therefore, future farmland use regulation should be tailored with differentiated institutional designs according to the development needs of different villages. This study’s findings provide insights into green and low-carbon development in rural areas.

Roughness Ecosystem-based Approach to Estimate the Exposure Area of Tsunami on a Coastal City: A Case Study in Bengkulu City, Indonesia

Bengkulu City, as the main activity center in Bengkulu Province, is experiencing significant population growth. However, geographically, the city is vulnerable to tsunami disasters. High population growth outside the line with coastal area management also increases the risk of tsunami disasters in Bengkulu City due to green land conversion into built-up land. This condition is exacerbated by coastal abrasion that threatens the coastline, brings residential settlements closer to the shoreline, and conflicts over spatial utilization of the coastal green belt. Therefore, implementing tsunami mitigation measures, mainly through coastal ecosystem-based strategies, is crucial. This study compares the spatial modeling of tsunami inundation in Bengkulu City with three roughness scenarios of coastal vegetation: coastal forest and mangrove. These scenarios include a scenario without coastal vegetation, a scenario based on existing conditions, and a scenario with optimized coastal vegetation. Spatial modeling was conducted using cost distance analysis modeling to calculate the effectiveness of coastal vegetation in reducing tsunamis. The results showed that coastal forests and mangroves in existing conditions could effectively reduce tsunamis by 3.84% compared to land cover without coastal forests and mangroves. The coastal vegetation optimization scenario has effectively reduced the exposure area by 5.00% compared to that without vegetation. The coastal vegetation optimization scenario also has an effectiveness of 1.20% compared to the existing condition. The findings underscore the critical role of coastal vegetation as a natural barrier against tsunamis and emphasize the potential advantages of optimizing land cover to improve coastal protection.

The impact of land-use change on the ecological environment quality from the perspective of production-living-ecological space: A case study of the northern slope of Tianshan Mountains

Elucidating the relationships between production-living-ecological space (PLES) and ecological environments can help identify new strategies to promote sustainable development. The northern slope of the Tianshan Mountains represents a typical complex ecosystem characterized by mountain-oasis-desert interactions in arid regions with prominent human-land conflicts and intricate ecological environments. Here, we analyzed the spatiotemporal variations in land use in the study area from the perspective of PLES. Based on moderate resolution imaging spectroradiometer (MODIS) data, an improved remote sensing ecological index (IRSEI) suitable for arid areas was established to evaluate the eco-environment quality (EEQ) by introducing salinity and cleanliness indexes. A stepwise regression model was then used to identify and quantify the impact of the PLES transfer modes on EEQ. The results showed that: (1) The oasis area was dominated by agricultural production land, whereas the desert and alpine areas were dominated by other and pasture ecological lands, respectively. The oasis area primarily involved the conversion of pasture ecological land to agricultural production land, whereas the desert and alpine areas showed mutual transformation of ecological space. (2) The size relationship of the EEQ in each sub-region was alpine region (0.555) > oasis region (0.509) > desert region (0.424). The EEQ in the study area showed an overall upward trend but decreased in the alpine region. (3) Changes in the PLES and IRSEI primarily occurred in the oasis region. Among the 21 PLES transfer modes that affect EEQ, an increase in agricultural production land was the primary mode that enhanced IRSEI, whereas an increase in impervious surfaces significantly decreased IRSEI. The degree of influence was as follows: industrial and mining production (−0.594) > urban living (−0.462) > rural living land (−0.316). In addition, EEQ is also affected by the combined effects of climate, topography, and other factors. By proposing IRSEI, we highlight the impact of land-use transfer mode on ecological environment quality from the perspective of PLES, which can provide a reference for ecological environment evaluation in arid areas and is of great significance for land-use planning and ecological environment protection.

Potential of Arbuscular Mycorrhizal Fungi to Overcome Drought Stress and Low Nutrient Availability in Dryland Farming

There is an increasing rate of land conversion in Indonesia that can threaten food self-sufficiency. Therefore farmers and the government must expand agriculture by developing agriculture on potential available lands such as drylands. However, drylands in Indonesia have low productivity due to low water and nutrient availability. This article aims to determine the potential use of arbuscular mycorrhizal fungi to overcome drought stress and low nutrient availability in drylands. The method used in writing this article is a desk literature study conducted by collecting data from various sources, such as scientific journals, seminar proceedings, and online reports available in related government office in West Nusatenggara Province. The data obtained were then analyzed qualitatively by identifying, reviewing, and synthesizing information to produce a complete and comprehensive explanation. The results of the literature study showed that arbuscular mycorrhizal fungi have the potential to overcome drought stress and low nutrient availability in drylands. The use of arbuscular mycorrhizal fungi can be a sustainable solution to increase agricultural productivity in drylands.

Potential of Black Rice Mutants (M4) Through Genetic Parameters to Develop Superior Drought-Resistant Varieties

Rice plays an important role in meeting carbohydrate requirement and calorie needs to ensure food security. However, in recent years, rice productivity has decreased due to land conversion and climate change such as El Niño. The productivity of drought-resistant rice can be increased through breeding. Genetic diversity and heritability are important genetic parameters in the plant breeding process. Information about genetic diversity and heritability helps determine genetic progress through selection. This research aims to examine the potential genetic diversity and heritability of several mutant lines (M4) of black rice (G10) in order to develop superior rice varieties that are adaptive to dry land. In this research, we used experimental methods using a Randomized Block Design (RBD), calculating the value of the Genetic Diversity Coefficient (GDC) and heritability between quantitative characters. The results of narrow genetic research were found in the characteristics of the number of productive tillers and weight of 100 grains, while high heritability was found in the characters of plant height, moderate heritability was found in the total number of tillers, panicle length, number of empty grains per panicle, and weight of 100 grains. Overall, this research succeeded in identifying mutant lines (M4) of black rice (G10) which have the potential to be developed into superior varieties, especially for cultivation in dry land.

Potential of Arbuscular Mycorrhizal Fungi to Overcome Drought Stress and Low Nutrient Availability in Dryland Farming

There is an increasing rate of land conversion in Indonesia that can threaten food self-sufficiency. Therefore farmers and the government must expand agriculture by developing agriculture on potential available lands such as drylands. However, drylands in Indonesia have low productivity due to low water and nutrient availability. This article aims to determine the potential use of arbuscular mycorrhizal fungi to overcome drought stress and low nutrient availability in drylands. The method used in writing this article is a desk literature study conducted by collecting data from various sources, such as scientific journals, seminar proceedings, and online reports available in related government office in West Nusatenggara Province. The data obtained were then analyzed qualitatively by identifying, reviewing, and synthesizing information to produce a complete and comprehensive explanation. The results of the literature study showed that arbuscular mycorrhizal fungi have the potential to overcome drought stress and low nutrient availability in drylands. The use of arbuscular mycorrhizal fungi can be a sustainable solution to increase agricultural productivity in drylands.

Reformulation of Policies to Prevent Land Conversion of Rice Fields In Achieving Indonesia's National Food Security

Background Increased population growth and imbalance between the need for rice are driving the conversion of numerous rice fields into non-agricultural zones and posing a significant threat to national food security. Therefore, this research is carried out to effectively address Indonesian government’s policy in preventing conversion of rice fields due to the lack of harmonization between cross-sectoral policies. Method A juridical-normative research method is used to analyze policy problems through legal theory and reality. The method is studying regulations against social phenomenon in food security sourced from the unconformity between the policies and the reality. It started by elaborating a way of thought, synthesizing conclusions, stating errors, and advising the re-formulation of policies to change the appropriation of land that in turn will affect national food security. Results The results show that there is proposed concept for reformulating rice field policies to integrate policies across sectors, ensure coherence in policy planning, and enhance the efficiency policies. The addition and harmonization of the components will strengthen the protection of the rice fields while preventing inconsistency and overlapping of authority from different sectors. The realization of this re-formulation will in time manifest national food security. Conclusions Indonesian government stipulates various policies to prevent the conversion of rice fields and to manifest national food security. However, of inconsistency and overlapping authority persist in its practice. Further close examination and reviews show the need reformation of policy for a transfer of land appropriation.

Land Surface Temperature Anomalies as Indicators of Urban Land Cover Change—A Study of Two Indian Cities

Rapid urbanisation over the years has led to the loss of natural land cover, thereby affecting Land Surface Temperature (LST) distribution in urban areas. This study aims to analyse LST anomalies (calculated as the deviation from the normal) over selected Indian cities and check if critical land cover changes can be identified. LST from Landsat Thermal Infrared (TIR) images acquired in March, April and May from 1988 to 2020 were used to estimate LST anomalies. Positive LST anomalies were observed mainly over barren and impervious areas; however, some areas showed a negative anomaly where the barren lands were converted to vegetated areas. The study has demonstrated that while some developed areas exhibit a positive anomaly indicative of significant changes or development, there are instances where the conversion of barren land to developed (i.e. built up) areas has resulted in a negative anomaly. Developed areas that are closer to the water creek or mangroves were associated with lower anomaly values indicating the cooling effect of the water body and vegetation. Conversely, the core urban areas generally exhibited higher LST values with positive anomalies indicating a warming effect. These findings can be used by city planners to identify hotspot areas and develop more effective strategies and policies to address the challenges of urban heat. They also highlight the regions that require infrastructural resources and policy changes to reduce the temperature.

Mapping opportunities and barriers for coexistence between people and pumas in the Argentine Dry Chaco

AbstractAimThe persistence of large carnivore populations depends on their survival outside protected areas, where they often impact local livelihoods through livestock depredation. Understanding the impacts of human behaviour on large carnivores in shared landscapes is thus important but is often overlooked in habitat assessments or conservation planning. We employed an integrated approach that considers human behaviour and landscape structure metrics to assess the potential for human‐puma (Puma concolor) coexistence in the Chaco region, a global deforestation and defaunation hotspot.LocationArgentine Dry Chaco (~490,000 km2).MethodsWe identified suitable puma habitat patches and movement areas using occupancy modelling and combined it with a spatial human‐puma conflict risk model based on interview data to identify ‘safe’ and ‘unsafe’ habitat patches. We then used resistance surfaces to identify ‘safe’ and ‘unsafe’ movement areas, as well as ‘severed’ movement areas where anthropogenic land conversion inhibits movement.ResultsSafe puma habitat patches (i.e., suitable and safe) covered 29% of the region, whereas attractive sinks (i.e., suitable but risky) represented 12%. Movement areas corresponded to 60% of the region, while conflict risk and high landscape resistance undermined connectivity: unsafe and severed movement areas covered 10% and 11% of the region, respectively. Nearly 98% of safe habitat and movement areas occurred outside protected areas.Main ConclusionsWe provide an integrated conceptual framework and spatial explicit template for a three‐pronged conservation strategy to (1) protect safe habitat and movement areas, (2) mitigate livestock depredation in attractive sinks and unsafe movement areas and (3) restore landscape in severed and matrix areas to improve ecological connectivity. This would allow pumas to maintain viable populations while reducing negative impacts on local people. More generally, we show how integrating habitat and conflict risk models can reveal opportunities and challenges for human‐carnivore coexistence beyond protected areas.

Sub-national scale mapping of individual olive trees integrating Earth observation and deep learning

The olive tree holds great cultural, environmental, and economic significance in the Mediterranean region. In particular, Morocco has been making dedicated investments over $10 billion since 2008 to fuel the transition from cereal to olive production. Understanding the spatial extent of this large-scale land conversion is critical for a variety of socioeconomic purposes. In response to this demand, we conducted a study to map individual olive trees in northern Morocco using satellite imagery and deep learning techniques at a sub-national scale. This study utilized cloud-free, very-high-resolution DigitalGlobe imagery collected between 2018 and 2022 to identify each individual olive tree in six northern Morocco provinces. We compared various deep learning models, including both transformer-based and CNN-based models, to generate patch-level spatial constraints and pixel-level tree identification. We found that transformer-based models outperformed CNN-based models in both tasks. Additionally, spatially constraining the pixel-level results improved olive tree mapping accuracy to varying degrees, depending on the initial performance of the model. The evaluation of the olive map generated from this study shows high accuracy in both surveyed and unsampled regions. This research represents the first-of-its-kind individual olive tree mapping at the sub-national scale that can help monitor the large-scale land conversions such as about 110,000 ha of olive plantings in the six Moroccan provinces studies here. Meanwhile it demonstrates a cost-effective and efficient prototype approach that can be adapted to identify similar tree crop expansion occurring in other parts of the world.

Land use transformation by urban informal settlements and ecosystem impact

The rapid expansion of informal settlements poses significant challenges to urban ecosystems and their services, a pressing issue that this study addresses by examining its impacts in Addis Ababa. This study delves into the impact of informal settlements on ecosystem services in Addis Ababa, comparing them with formal settlements. Utilizing geographic information systems (GIS) and remote sensing, it employed Landsat imagery, aerial photography, and base maps to track spatiotemporal changes and analyze trends. Through a GIS overlay approach, informal settlements and associated land use changes were identified, while the benefit transfer method assessed ecosystem service values. The findings revealed a significant increase in informal settlements on the city’s outskirts, expanding from 77 ha in 2009 (2% of the total area) to 765.6 ha in 2023 (21% of the total area). Nearly half (48.5%) of these informal settlements were established on previously natural land covers through encroachment. The research highlighted the ongoing conversion of agricultural land, forests, and urban green spaces into informal settlements, particularly on the city’s outskirts, leading to significant encroachment on these areas. This transformation caused an annual loss of $1,665,033.7 in ecosystem services from 2009 to 2023. Significant impacts were identified on food production, climate regulation, and habitat ecosystem services. Overall, the annual loss in ecosystem services due to land use changes amounted to $1,933,320.08. Informal settlements accounted for 86.1% of this total loss, highlighting the urgent need for targeted interventions to mitigate their disproportionate effects on ecosystem services. The study underscores the urgency of addressing the impact of informal settlements on ecosystem services through effective urban planning, sustainable land management practices, prevention of encroachment on natural land covers, and promotion of sustainable ecosystem management and utilization.

Significant Demographic Factors Fuelling Housing Deficit in Ado-Ekiti, Nigeria

This article assesses the significant demographic factors fuelling housing deficit in Ado-Ekiti, Nigeria. Using a mixed method approach as survey design coupled with a combination of purposive and stratified sampling technique, 1254 households were selected for administration of questionnaires during data collection process. Questionnaires, interviews were the major instruments of data collection from seven residential development corridors (RDCs) in Ado-Ekiti. Ministries, Agencies and Departments (MDAs) supported secondary data. Findings revealed that high population growth, rapid urbanisation and migration increased housing deficit in the study area. Hence, this study observed an increase in live births (162, 901) than deaths (45, 046) in Ado-Ekiti. Also, findings revealed an increase in building concentration (57.7%) from 2000-date. Similarly, this study observed an increase in challenges such as urban sprawl and infrastructure deficiency (L-INFRA) encountered as a result of rapid urbanisation. The study noted an increase in quantitative housing deficit (223,086) in 2023. Thus, a quantitative housing deficit of 334,554 housing units would arise in 2034.Furthermore, sharing of dwellings with other households (SHAD), a resultant effect of high migration trends constituted 43.4 percent across the RDCs in Ado-Ekiti. Also, improved infrastructural facilities (33.8%) was the modal reason for staying (RESTAY) in the study area. Using Paired T-test, this study further validated that a perfect positive relationship (1.000) exists between population growth and housing deficit in Ado-Ekiti. Therefore, this study recommends adoption of effective Family Planning Methods (FPMs), regional distribution of infrastructural facilities and conversion of under-utilised lands for an efficient housing delivery in Ado-Ekiti.

Assessing the Impact of Land Conversion on Carbon Stocks and GHG Emissions

Assessing the Impact of Land Conversion on Carbon Stocks and GHG Emissions

Land conversion and lack of protection significantly reduce suitable wolf habitat amount and functional connectivity in the Adirondack-to-Laurentians (A2L) transboundary wildlife linkage

Land conversion and lack of protection significantly reduce suitable wolf habitat amount and functional connectivity in the Adirondack-to-Laurentians (A2L) transboundary wildlife linkage

Long-term sustainability of the water-agriculture-energy nexus in Brazil's MATOPIBA region: A case study using system dynamics.

The global demand for agricultural commodities has driven extensive land conversion to agriculture in Brazil, especially in the MATOPIBA region. This area encompasses the Rio Grande Basin, a major tributary of the São Francisco Basin that is known for expanding intensive irrigated agriculture and hydropower generation. However, recent data reveal declining precipitation and aquifer recharge, potentially exacerbating ongoing water and land conflicts. This study investigates the long-term sustainability of agricultural expansion amid the worsening water scarcity using a system dynamics model. Findings suggest that rising costs and decreasing profits due to irrigation water shortages may hinder the expansion of irrigated land. By 2040, the irrigation demand may remain partly unmet, while downstream flow and baseflow could decrease. Additionally, agricultural expansion will significantly raise energy demand, posing a developmental challenge. We suggest that ensuring the sustainability of the Rio Grande Basin depends on improved water management and exploring alternative energy sources to address existing constraints.

Identification of landscape features structuring movement connectivity for Namibian elephants

ContextHuman modification of landscapes poses a significant threat to wildlife, particularly in Africa where population growth and land conversion are expected to increase. Habitat loss and fragmentation have led to declines in wildlife populations, highlighting the need to identify and preserve critical habitats, including core use areas and connectivity between them. Most recently, the identification of habitat corridors has become a key objective.ObjectivesOur study objectives are to (1) empirically quantify connectivity across the Kunene—Etosha landscape in Northwestern Namibia using GPS tracking data on wild African elephants, and (2) assess the landscape features (i.e., geologic, biotic, and human-made) influencing connectivity and corridor types (e.g., fast movement corridors versus slow multi-use movement corridors).MethodsWe used GPS telemetry data from 66 elephants collared in Northwestern Namibia to empirically quantify connectivity using a graph theoretic approach and assess landscape features influencing connectivity. Based on the ‘movescape’ approach, we identify different types of corridors and examined how landscape features differed across these corridors using multiple regression models on locations classified into different types of use categories by machine learning algorithms.ResultsOur results revealed strong variation in connectivity across the landscape, with paths of high connectivity near water sources between the study areas. We found that factors related to water sources and human presence primarily influenced connectivity. Water holes serve as hubs across the ecosystem for both male and female elephants with lower use areas peripheral to areas with water. Connectivity between Kunene and Etosha National Park was relatively rare among the collared elephants, but we highlight the key areas used to move between the two regions.ConclusionWater was the key feature structuring space use, and human presence influenced connectivity between water points, highlighting the importance of landscape planning in relation to limited water sources and human activities. Our results suggest that focusing management efforts on areas where water is limited for both elephants and humans will be important to reduce conflict and maintain ecosystem connectivity.

Bird Diversity on an Under-Constructed Educational Campus: A Case Study of Nalanda University, Rajgir, India

Bird species have been critically impacted by increasing anthropogenic activities such as infrastructural construction. Academic institutions with dedicated semi-natural landscapes may provide shelter to high bird diversity. However, assessing the bird diversity of an under-construction campus becomes critical for future comparison. This study was conducted at Nalanda University Campus, India, for five months, as the campus was at the fag-end of the construction phase with diverse land use changes. 91 bird species were found on campus primarily dominated by insectivores and omnivores. Occurrence, and migratory status of the species revealed that 47% were resident, primarily occupying aquatic habitats. Despite presence of Least Concern IUCN status bird species in the campus, substantial number of them had a declining abundance index at the national level. Sites with high land conversion showed a low number of bird species. The overall dominance and evenness highlighted a good bird diversity, contrary to altered sites where both these attributes were high. Data for the documented bird species on citizen science platforms highlighted limited information on species interactions. This study attempted to bring attention to the unchecked impact of construction activities on bird diversity and regular monitoring in the widely discussed emerging semi-natural shelters, i.e., academic campuses.

Analysis of the Spatiotemporal Changes in Cropland Occupation and Supplementation Area in the Pearl River Delta and Their Impacts on Carbon Storage

In recent years, the “dual carbon” issue has become a major focus of the international community. Changes in land use driven by anthropogenic activities have a profound impact on ecosystem structure and carbon cycling. This study quantitatively assesses the spatiotemporal changes in cropland occupation and supplementation in the Pearl River Delta from 2000 to 2020 using the InVEST model, analyzing the spatial clustering of carbon storage changes caused by variations in cropland area. The PLUS model was employed to simulate land-use patterns and the spatial distribution of carbon storage in four future development scenarios. The results indicate the following: (1) From 2000 to 2020, the net change rate of cropland area in the Pearl River Delta was −0.81%, with a decrease of 16.49 km2 in cropland area, primarily converted to built-up land and forest land. (2) Carbon storage in the Pearl River Delta exhibited a pattern of lower values in the center and higher values in the periphery. The terrestrial ecosystem carbon storage in the Pearl River Delta was 534.62 × 106 t in 2000, 518.60 × 106 t in 2010, and 512.57 × 106 t in 2020, showing an overall decreasing trend. The conversion of cropland and forest land was the main reason for the decline in total regional carbon storage. (3) The area of carbon sequestration lost due to cropland occupation was significantly greater than the area of carbon loss compensated by new cropland, indicating an imbalance in the quality of cropland occupation and supplementation as a crucial factor contributing to regional carbon loss. (4) Under the ecological priority scenario, the expansion of built-up land and the reduction in ecological land such as cropland and forest land were effectively controlled, resulting in the minimal loss of carbon storage. The soil organic carbon pool of cropland is the most active carbon pool in terrestrial ecosystems and has a significant impact on carbon storage. Clarifying the relationship between “cropland protection measures–land use changes–ecosystem carbon storage” will improve cropland protection policies, provide references for regional carbon sequestration enhancement, and support sustainable socio-economic development.