Land Suitability for Rice Paddy Cultivation in Lop Buri Using GIS Analysis for Sustainable Productivity

Introduction

Climate change has a significant impact on rice paddy production, affecting yield, quality, and food security. For instance, recent empirical assessments indicate that rising temperatures continue to pose a substantial threat to rice production, with global estimates showing yield reductions of 3% to 15% depending on regional conditions and magnitude of warming (Chen et al., 2021; Zhao et al., 2017). According to the International Rice Research Institute (IRRI), change in rainfall can lead to water scarcity or flooding, both of which negatively impact rice paddy production. The higher CO₂ levels can reduce the concentrations of essential nutrients like zinc and iron in rice grains, potentially impacting human health (Huang et al., 2019). As climate change has become a severe issue and poses challenges impacting rice paddy production that require urgent attention and effective adaptation measures to ensure food stability in the form of floods, droughts, and other hazardous weather events, the agricultural sector must deal with its consequences in many ways, making it difficult to grow crops, and leading to crop failure and lowered yields (Peng et al., 2004; Wassmann et al., 2009; Zhao et al., 2017). Thailand has implemented several systems, including emergency food distribution programs, water supply management, and strategic reserves to ensure accessibility to food and water during crisis (Food and Agriculture Organization, 2020; Office of the national Economic and Social Development Council, 2021). This measures aim to maintain basic food security and mitigate the impact of natural disasters, pandemics, and other emergencies on vulnerable populations. Additionally, according to the National Statistical Office’s survey in 2022, the COVID-19 pandemic led Thai households to experience inadequate consumption of nutritious food, highlighting the limitations in food security.

Food security has been addressed in the World Food Summit 1996. Food insecurity can lead to a significant impact on health, especially in young children and the elderly, as well as poverty, displacement, and the potential to fuel social and political unrest (Cook & Frank, 2008; Gundersen & Ziliak, 2015; Weiser et al., 2015). Study indicates that children facing food insecurity are at higher risk for developmental delays and academic difficulties (Shanker et al., 2017). Families often turn to cheaper, calorie-dense foods that lack essential nutrients, contributing to long-term health issues (Parker et al., 2017). The AARP Foundation (2009) highlights that food insecurity among seniors can exacerbate pre-existing health conditions and lead to higher healthcare costs. Individuals living in poverty often lack the financial means to purchase adequate and nutritious food. Conflict, natural disasters, and economic instability can lead to displacement, where people are forced to leave their homes, often resulting in food insecurity (Guragain et al., 2025). Referring to the World Food Program (2021), refugees and internally displaced persons face heightened levels of food insecurity, leading to adverse health outcomes and increased vulnerability. According to the Global Food Security Index (GFSI), in 2022, Thailand ranked 64th in global food security, which assessed and reported on the food security situation in 113 countries worldwide.

The definition of food security is still used until now. Food security comprises four components: availability, accessibility, utilization, and stability. Thailand currently has sufficient food production to serve the needs of country’s population. Referring to the capability to obtain nutritious and quality food resources which reflects on the issue of hunger. In 2023, the global Hunger Index (GHI) reported that level of hunger of Thailand was ranked 53rd out of 116 countries.

The global food crisis has emerged as a multidimensional challenge with implications that extend across households, communities, and international systems. Climate change remains one of its principal drivers, contributing to substantial disruptions in precipitation patterns, soil conditions, and temperature regimes, thereby intensifying production risks, increasing food demand, and heightening economic vulnerability (Guragain & Doneys, 2022) especially in low- and middle-income countries (FAO, 2022).

These disruptions have far-reaching implications, aligning closely with the urgency highlighted in the United Nations’ 2030 Agenda, in which No Poverty, Zero Hunger, and Good Health and Well-being represent the top global development priorities (United Nations, 2015). Sustainable agriculture and food security therefore function not only as development goals but also as essential foundations for human livelihoods and long-run economic stability (FAO, 2021; World Bank, 2020).

For developing countries, eliminating hunger is a significant concern and is key to maintaining national security and stability. The food crisis has had a substantial impact on the agriculture sector, particularly on smallholder farmers who face who face increasing exposure to input price volatility, land and water competition, and resource scarcity—pressures that constrain both production capacity and market participation (FAO, 2022; Von Braun et al., 2023; World Bank, 2020). In addition, as the competition for land and water increases and resources become scarce, the small-scale farmers and livelihoods of the communities who depend on agriculture may be left out of the market in favor of those who are more financially stable.

Interestingly, global demand for rice continues to rise steadily, placing additional production burdens on major rice-exporting countries in Asia (FAO, 2022; IRRI, 2021). However, in many densely populated Asian regions, highly productive paddy areas have been rapidly converted into urban developments, industrial zones, or high-value cash crops, resulting in a net loss of agricultural land (ADB, 2020). Consequently, the potential to expand rice cultivation is increasingly constrained, as most suitable arable land has already reached its cultivation limits across Asia (FAO, 2020).

Agriculture has long served as a cornerstone of Thailand’s socio-economic development, mirroring the structural characteristics of many developing countries. Over the past several decades, approximately 10% of Thailand’s GDP has consistently derived from agricultural activities (World Bank, 2022). In terms of production value and cultivated area, five major crops—rice, maize, sugarcane, cassava, and soybean—collectively account for more than 60% of the national agricultural GDP, underscoring the sector’s continued economic significance. Thailand also maintains deep-rooted cultural and economic ties to rice cultivation: the country ranks fifth globally in total rice cultivation area and remains the world’s second-largest rice exporter, with annual shipments of roughly 8.2 million metric tons (FAO, 2022; IRRI, 2021; USDA, 2023).

Despite Thailand’s ambitions to enhance rice production, the expansion of rice-growing areas is increasingly constrained. Most agriculturally suitable land has already been utilized, and opportunities to develop new rice paddy areas are extremely limited (FAO, 2020). At the same time, rice production systems face heightened instability due to climate variability, soil degradation, and resource scarcity factors that collectively threaten long-term productivity and sustainability. Strengthening scientific understanding of land suitability for rice paddy cultivation is therefore essential for informing sustainable agricultural planning and maintaining Thailand’s competitiveness as a major rice producer.

While Thailand continues to be a major global rice producer, not all regions have equally suitable conditions for sustainable rice cultivation. Among these regions, Lop Buri province stands out due to its historical significance in rice production, yet it faces challenges related to land quality, water availability, and climate variability. Therefore, a detailed assessment of land suitability at provincial levels is essential to identify opportunities for sustainable rice paddy production.

Lop Buri Province exemplifies these broader national dynamics. Although rice cultivation has historically played an important role in the province’s economy and rural livelihoods, the area faces persistent challenges associated with marginal soil quality, irregular water supply, and increasing climate uncertainty (OAE, 2022). As these constraints intensify, identifying suitable land for rice production requires an integrated, spatially explicit approach that accounts for interactions among land use patterns, irrigation access, soil properties, topography, and climate conditions. To address this need, the present study employs a GIS-based land suitability assessment framework incorporating land use, irrigation accessibility, precipitation patterns, soil pH, soil texture, slope, and temperature—drawing on established methodologies for spatial land evaluation (FAO, 1976; Malczewski, 2004).

Although existing studies have examined rice production challenges in Thailand, significant gaps remain in the spatial analysis of land suitability at sub-provincial scales. Many previous assessments focus on national or regional patterns and often rely on limited sets of biophysical indicators, neglecting the combined effects of climate variability, irrigation infrastructure, and socio-economic constraints. Moreover, empirical studies specifically addressing land suitability for rice cultivation in Lop Buri are scarce, resulting in limited evidence for localized land-use planning and agricultural policy design. This gap underscores the need for a high-resolution, multi-criteria evaluation tailored to the environmental and institutional context of Lop Buri Province.

The primary objective of this study is therefore to generate a detailed land suitability map for rice paddy cultivation in Lop Buri Province by integrating diverse biophysical and socio-economic datasets. This evidence-based approach supports strategic land allocation, enhances agricultural decision-making, and provides scientifically grounded guidance for local authorities (Malczewski & Rinner, 2015). Additionally, by engaging local administrators and community stakeholders, the study identifies on-the-ground challenges, knowledge gaps, and institutional constraints affecting rice production. The resulting policy recommendations aim to promote sustainable rice cultivation, strengthen land-use planning, and improve agricultural support mechanisms, ultimately contributing to regional food security while maintaining the ecological integrity of Lop Buri Province.

Methodology

Study Area

The study area, the province of Lop Buri, is situated between latitudes 14°48′2″N and 100°39′5″E (Figure 1). Lop Buri has a tropical savanna climate, located in the central region of Thailand, east of the Chao Phraya River valley, between the Lop Buri River and the Pasak River. This region is known as the “Rice Bowl of Thailand,” which has the largest farm size per household, and holds most of the irrigated land. Lop Buri is neighbored by eight provinces: Phetchabun,Chaiyaphum, Nakhon Ratchasima, Saraburi, Phra Nakhon Si Ayutthaya, Ang Thong, Sing Buri, and Nakhon Sawan. The total amount of land in Lop Buri covers 6,199.8 Square Kilometers and divided into 11 administrative districts: Ban Mi, Chai Badan, Khok Chareon, Khok Samrong, Lam Sonthi, Nong Muang, Phatthana Nikhom, Sa Bot, Tha Luang, and Tha Wung, 122 subdistricts, and 1,126 villages (Ministry of Agricultural and Cooperatives, 2016). The amount of developing land is increasing, but there remains a substantial room for development.

OPEN IN VIEWER

Figure 1.

Study area, Lop Buri, Thailand.

In Lop Buri, the monsoon season runs half a year long from May through October. Therefore, the temperatures during the day are somewhat cooler with heavy rain, although they remain warm at night, while in the winter it is warm and dry. About 70% of the area of the province is mixed plains and hill. The other 30% is very low alluvial plain including almost all of Tha Wung, the southwestern parts of Ban Mi and Mueang Lop Buri.

The growing cycle of rice paddy cultivation in Lop Buri is closely tied to the seasonal weather patterns, mainly floating or deep-water rice, which grows in water depth between 50 and 100 cm. Fortunately, the rice is developed to be taller and longer leaves than standard rice in upland and lowland rice paddy. However, rice paddy in Lop Buri exceeds 7 mm. in length, which is considered as long grains rice paddy. In Lop Buri, there are two categories of rice paddy farming: in-season and off-season. In-season rice paddy refers to regular wet season rice cultivation, which typically begins with onset of the monsoon in May and continues until through October, followed by the harvest period extending to February; this production cycle normally occurs once per year and requires approximately 120 days from transplanting to maturity (Ministry of Agriculture and Cooperatives, 2020). Also, off-season rice paddy is a rice cultivation method during the irregular period, which is very common in the Central region of Thailand with exceptional irrigation system, but less support from the light for flowering. The cultivation takes about 90 days. Expectedly, due to the advanced irrigation condition, off-season rice paddy in Lop Buri can produce 2 to 3 crops per year.

Mapping Land Suitability for Rice Paddy Cultivation

Various studies clearly demonstrate that using AHP and GIS provides valuable insights for land suitability assessments for rice cultivation has proven effective, providing critical insights for sustainable agricultural planning. The integration of these methodologies allows for a more systematic and quantified approach to land assessment, which is crucial for developing future strategies that align agricultural practices with environmental sustainability and socio-economic considerations (Karim & Aliyah, 2019; Khemka et al., 2021; Suriyamongkol et al., 2022; Thungsuk et al., 2022; Wang et al., 2019).

The spatial data used in this study were processed using ArcGIS 9.3 following a standardized multi-step workflow to produce accurate and comparable land suitability layers. First, all spatial datasets including land use, soil type, irrigation networks, precipitation, pH, slope, and temperature were collected from relevant agencies and converted into a uniform vector or raster format depending on the original data type. Each dataset was then projected into a common coordinate system (UTM Zone 47N, WGS 84) to ensure spatial alignment and avoid geometric distortion during overlay operations (ESRI, 2016).

Second, each thematic layer was pre-processed to prepare for the AHP-weighted overlay. Raster layers such as precipitation, temperature, pH, and slope were resampled to a consistent spatial resolution to ensure comparability across grid cells. Vector layers such as irrigation canals or administrative boundaries were converted into raster format where necessary using cell-based encoding, consistent with standard multi-criteria evaluation procedures (Malczewski, 1999). All layers were clipped to the provincial boundary of Lop Buri to define a uniform study area.

Third, reclassification was applied to each layer based on suitability thresholds derived from agronomic literature and national rice cultivation guidelines. This step transformed raw environmental data into standardized suitability levels compatible with the AHP weighting structure.

Fourth, the reclassified layers were normalized using the AHP-derived weights to ensure that the relative importance of each factor The Weighted Overlay tool in ArcGIS was applied to combine all seven criteria layers into a single continuous land suitability raster. This method multiplies each standardized cell value by its corresponding AHP weight and sums the results to produce a composite suitability score (Malczewski, 2006; Saaty, 1990).

Finally, the continuous composite layer was classified into four suitability categories highly suitable, suitable, marginally suitable, and non-suitable—using natural breaks and reference thresholds from the FAO land evaluation framework (FAO, 1976). The resulting map was validated by comparing the spatial patterns with observed irrigation zones, rice-growing districts, and expert knowledge obtained during field consultations. The completed suitability map represents an integrated and spatially explicit assessment of Lop Buri’s rice cultivation potential.

Therefore, Lop Buri’s assessment of land suitability for rice paddy cultivation was performed by applying Geographic Information System (GIS) and Analytic Hierarchy process (AHP) technique. Land suitability for rice paddy cultivation mapping was selected as a representative of the factors related impact which performed by using Geographic Information System (GIS) and Analytic Hierarchy process (AHP) technique.

The conceptual framework illustrated in Figure 2 was utilized for the analysis of land suitability for rice paddy cultivation in Lop Buri. Using ArcGIS 9.3, the overlay method was employed to integrate seven keys factors into land suitability areas: land-use type, irrigation, precipitation, soil type, temperature, pH, and slope into a composite land suitability map. Each layer was combined through a weighting approach, with continuous criteria standardized to weighted average. Therefore, the resulting land suitability for rice paddy cultivation in Lop Buri was categorized into four classes: highly, suitable, marginal, and non suitable.

OPEN IN VIEWER

Figure 2.

Conceptual framework of land suitability for rice paddy cultivation.

In the AHP technique, experts and specialists-including the Lop Buri Province Administration, Land Development Department, Royal Irrigation Office, Thai Meteorological Department, Lop Buri Rice Research Center, and Thai Rice Export Association (n = 15)-were asked to complete pairwise comparisons of each land suitability factor for rice paddy cultivation, rating them on a scale from 1 to 9. A rating of 1 indicates that the factor is equally important, while a rating of 9 signifies that the factor is extremely more important than the other (Saaty, 1990; Saaty, 1977; Saaty & Vargas, 1984).

The use of 1–9 scale is justified by its proven ability to capture human judgment with high discrimination power, allowing experts to express varying degree of intensity in their preferences without causing cognitive overload. The scale is nonlinear by design, enabling users to differentiate subtle and strong importance levels more effectively than linear scale (Saaty, 2008). Furthermore, empirical evidence shows that 1–9 fundamental scale produces higher reliability, greater judgment consistency, and more stable results compared with shorter or overly granular scales (Ishizaka & Labib, 2011). These characteristics make the 1–9 scale particularly suitable for complex multi-criteria evaluations, such as land suitability assessment, where expert judgment must reflect real-world conditions with sufficient nuance. Thus, it is necessary to ensure that the pairwise comparisons are reasonably consistent (P. Li et al., 2013). To assess consistency, the consistency ratio (CR) was computed to measure the discordance between the pairwise comparisons and their reliability. The consistency ratio must be less than 0.1 and is used as a tool to validate the matrix. The consistency ratio (CR) can be calculated using Equations 1 and 2.

CR = CI RI

(1)

Where:

CI refers to the Consistency Index

CI = β max − n n − 1

(2)

Where:

βmax is the sum of the priority vector multiplied by each column total.

n represents the size of the matrix.

RI refers to the Random Index.

Results

Land Suitability Map for Rice Cultivation in Lop Buri

By applying ArcGIS 9.3, the overlay method was conducted to combine the characteristics of the following seven factors into land suitability areas: land use types, annual average daily rainfall, soil types, irrigation system, pH, slope, and temperature (Figures 3–9). Each layer was combined using a weighted approach, where the weighted averages of continuous criteria were standardized to a weighted average (Table 1). Finally, land suitability for rice paddy cultivation was classified as highly suitable, suitable, marginally suitable, and non-suitable (Figure 10).

OPEN IN VIEWER

Figure 3.

Land use of Lop Buri.

OPEN IN VIEWER

Figure 4.

Irrigation of Lop Buri.

OPEN IN VIEWER

Figure 5.

Percipitation of Lop Buri.

OPEN IN VIEWER

Figure 6.

Soil type of Lop Buri.

OPEN IN VIEWER

Figure 7.

Slope of Lop Buri.

OPEN IN VIEWER

Figure 8.

pH Lop Buri.

OPEN IN VIEWER

Figure 9.

Temperature of Lop Buri.

OPEN IN VIEWER

Table 1.

AHP Pairwise Comparison.

Parameters	Land use	Irrigation	Precipitation	Soil type	Slope	Temperature	pH
Land use	1.00	1.00	2.00	5.00	3.00	8	3
Irrigation	1.00	1.00	1.00	2.00	3.00	8	2
Precipitation	0.50	1.00	1.00	1.00	2.00	6	2
Soil type	0.20	0.50	1.00	1.00	1.00	2	1
Slope	0.33	0.33	0.50	1.00	1.00	2	2
Temperature	0.12	0.12	0.17	0.50	0.50	1	1
pH	0.33	0.50	0.50	1.00	0.50	1	1

OPEN IN VIEWER

Figure 10.

Mapping of land suitability for rice paddy cultivation of Lop Buri.

To determine what is the distribution of land suitability for rice paddy cultivation in Lop Buri, the relative weights for each factor were established. The result of the AHP pairwise comparison showed that land use (0.299), irrigation (0.236), and precipitation (0.169) were the most important factors influencing land suitability for rice paddy cultivation in Lop Buri. Meanwhile, soil type (0.095) and slope (0.094) were ranked fourth and fifth, with almost similar relative weights in the AHP analysis. These finding are consistent with previous studies emphasizing the critical role of land use and water availability in determining rice cultivation potential. For instance highlighted that land use patterns and irrigation infrastructure are primary determinants of rice productivity in Southeast Asia. Similarly, found that precipitation and irrigation management are key factors shaping spatial land suitability for rice in China. The influence of soil type and slope has also been noted in other GIS-based suitability assessments, where these factors, although less influential when hydrological variables, still significantly affect crop yield potential (Rahman et al., 2019)

Moreover, pH (0.076) and temperature (0.042) were identified as the least influential factors in determining land suitability for rice cultivation in Lop Buri. Although soil pH and temperature are known to affect rice growth, their relative impact on spatial suitability assessment is often lower compare to land use, irrigation, and precipitation (Rahman et al., 2019). The spatial data layers and weight evaluation of all factors affecting rice paddy cultivation in Lop Buri are summarized in Table 2. The weight of each factor was used to generate a land suitability map for rice paddy cultivation (CR = 0.037).

OPEN IN VIEWER

Table 2.

AHP Weight Evaluation of Factors Influencing Rice Paddy Cultivation in Lop Buri, Thailand.

Factors	Rank	Weighting	Sub-factor	Rating	Source of data
Land-use	1	0.299	Crop land	8	Land-use data from Land Development Department
			Settlement	6
			Forest land	4
			Others	2
Irrigation (sq. km)	2	0.236	Actively irrigated	8	Royal Irrigation Office
			Somewhat irrigated	6
			Poorly irrigated	4
			Non irrigated	2
Precipitation (mm./y)	3	0.169	>1,200	8	Annual average daily rainfall during 2014–2023, Thai Meteorological Department
			801–1,200	6
			401–800	4
			<400	2
Soil type	4	0.095	Aquic soil moisture regime	8	Soil type data from Land Development Department
			Ustic soil moisture regime	6
			Slope complex soil	4
			Others	2
Slope (%)	5	0.094	<0	8	Soil type data from Land Development Department
			0–5	6
			5–20	4
			>20	2
pH	6	0.076	5.5–6.5	8	Soil type data from Land Development Department
			4.1–5.4 / 6.6–8	4
			<4 / >8	2
Temperature (°C)	7	0.042	27.32–28.13	8	Annual average daily temperature during 2014–2023, Thai Meteorological Department
			28.14–28.94	6
	CI = 0.4884		CR = 0.037
	IR = 1.32

The GIS AHP analysis identified that Lop Buri were mainly defined as suitable for rice paddy cultivation based on seven thematic layers used for assessing land suitability (Figures 3–9), accounting for 34.47% (2,203.853 sq. km.) of the total area, which is the highest compared to the marginal suitable 25.85% (1,657.648 sq. km.) and highly suitable area 24.82% (1,591.428 sq. km.) for rice cultivation, respectively. While the non-suitable area is at only 14.95% or 958.745 sq. km. of Lop Buri (Figure 10).

The spatial distribution of highly suitable areas for rice paddy cultivation is concentrated in the central districts of Lop Buri. Notably, Ban Mi and Tha Wung emerge as the core zones of high suitability, while nearly half of Mueang Lop Buri and Khok Samrong districts also fall within this category. A key factor explaining the strong suitability of Ban Mi is its direct access to well-established irrigation infrastructure. The district is extensively served by primary and secondary irrigation canals under the Chao Phraya River Basin irrigation network, which ensures stable year-round water supply for rice cultivation. This consistent water availability significantly enhances agricultural resilience, reduces production risk, and strengthens the district’s capacity for high-productivity rice farming. As a result, Ban Mi benefits more directly from irrigation allocation than other surrounding districts, contributing to its superior suitability rating in the model.

In addition to the spatial suitability classification, the analysis examined key environmental and infrastructural factors that influence rice land suitability in Lop Buri. These include land use patterns, irrigation coverage, precipitation, climate condition, soil characteristics, soil pH, and slope.

Determinants of Land Suitability

The spatial assessment of rice land suitability in Lop Buri incorporates multiple environment and infrastructural determinants.

Land-Use Patterns

Land-use analysis indicates that cropland dominates the provincial landscape, covering 4,259.47 sq. km or 68.67% of the total area. Forest land counts for 16.09%, while settlement occupy 8.22%. The remaining 7.02% consists of other land-use types such as water bodies and miscellaneous land cover as shown in Table 3 and Figure 3.

OPEN IN VIEWER

Table 3.

The Summary of Land-Use Classification in Lop Buri.

Land-use	Area (sq. km)	Percentage (%)
Settlement	510.0304	8.22
Crop land	4,259.4736	68.67
Forest land	996.6880	16.09
Others	433.5616	7.02
Total	6,199.7536	100.00

Settlement areas include residential zones, industrial facilities, buildings, and infrastructure.

Irrigation Coverage

Agricultural production in Lop Buri remains largely rainfed. The province contains 331 water resource facilities, including 1 large-scale, 11 medium-scale, and 297 small-scale systems, along with additional pumping machinery.

Together, these facilities provide approximately 1,066.60 million cubic meters of water storage capacity. Despite this availability, irrigation coverage extends to only 1,069.12 sq.km, representing approximately 24.6% of the total agricultural area (Figure 4).

Precipitation

Rice cultivation requires substantial water availability throughout its growth cycle, typically ranging between 1,200 and 2,500 mm of rainfall annually (Aryal, 2013; Reyes & Fermin, 2003).

Between 2014 and 2023, Lop Buri received and average annual rainfall of approximately 1,185 mm. While this level is generally sufficient for rice cultivation, rainfall variability across months may influence water availability during critical growth stages (Figure 5).

Climate Conditions

Rice is a tropical crop that performs optimally under temperatures between 25°C and 35°C (Azman, 2019). Temperature conditions in Lop Buri fall within this general range (Figure 6).

However, previous studies indicate that grain yield may decline when average daily temperature exceed 29°C, with future reductions associated with continued temperature increases.

Soil Charateristics

Soil in Lop Buri can be classified into four major groups: aquic soil moisture regime, ustic soil moisture regime, udic soil moisture regime, and slope complex soil. Clay and clay-loam textures are present in several areas, supporting water retention suitable for paddy cultivation (Figure 7).

Soil pH

Soil pH values across the province generally fall within the acceptable range for rice cultivation (Figure 8). Most rice varieties perform best under slightly acidic to neutral conditions, typically between pH 5.5 and 7.0 (Shrestha et al., 2019; Yu, 1990).

Terrain Slope

Slope analysis indicates that large portions of the province fall within ranges considered suitable for rice cultivation (Figure 9). Areas with slopes between 0% and 4% are widely recognized as optimal for paddy cultivation, while slopes exceed 20% are generally unsuitable (Ayehu et al., 2018).

Discussion

The findings of this study suggest that land suitability for rice cultivation in Lop Buri is shaped not solely by biophysical characteristics, but by the interaction between environmental conditions and irrigation infrastructure. While conventional land evaluation frameworks emphasize soil quality, slope, rainfall, and pH as the primary determinants of agricultural suitability (Ayehu et al., 2018; Shrestha et al., 2019), the spatial analysis presented here indicates that access to irrigation plays a decisive role in translating natural potential into productive capacity. This perspective aligns with broader land evaluation approaches that recognize suitability as an outcome of both environmental conditions and human interventions (FAO, 1976; Sys et al., 1993).

In this sense, the study supports an emerging understanding within agricultural and water governance literature that productivity is often mediated by infrastructural arrangements rather than land quality alone. Similar dynamics have been documented in irrigated agricultural systems where disparities in output are closely linked to uneven access to water resources (Hussain & Hanjra, 2004; Molden, 2007). In Lop Buri, districts such as Ban Mi benefit from integration within the Chao Phraya River Basin irrigation network, allowing them to sustain high levels of suitability despite rainfall variability. Conversely, several areas with favorable soil composition and topographic characteristics remain underutilized due to limited irrigation coverage.

This spatial misalignment between environmentally suitable land and irrigation accessibility represents a key finding of the study. It suggests that land suitability should not be interpreted as a fixed natural attribute, but rather as a dynamic outcome shaped by infrastructural distribution and water governance. In this respect, the results extend conventional suitability assessments by highlighting how investment patterns in irrigation systems can redefine agricultural potential independently of natural land quality.

At the same time, the analysis reveals an emerging tension between agricultural sustainability and land-use change. Highly suitable rice-growing zones in Lop Buri increasingly overlap with districts experiencing urban expansion, particularly in Ban Mi and Mueang Lop Buri. This reflects patterns widely observed in peri-urban regions undergoing rapid transformation, where fertile lowland areas attract both agricultural and residential development due to their accessibility and favorable terrain (Seto et al., 2012; Tacoli, 2003). Without coordinated land-use planning, such convergence may gradually displace productive farmland despite the presence of suitable natural conditions.

The contribution of this study lies in demonstrating how irrigation infrastructure can reshape agricultural potential by mediating the relationship between environmental suitability and actual production capacity. By mapping the spatial relationship between irrigation access and biophysical conditions, the analysis provides empirical evidence that uneven water distribution can constrain productivity even in otherwise favorable landscapes. This perspective offers an important extension to traditional land suitability approaches and contributes to ongoing discussions on climate resilience and adaptive agricultural planning.

Nevertheless, several limitations should be acknowledged. The analysis relies on spatial datasets that capture current conditions but do not fully reflect temporal variability in water allocation or climate dynamics. Farmer-level adaptive practices—such as groundwater use, crop diversification, or informal irrigation—were also beyond the scope of the study. Furthermore, the research focuses primarily on physical and infrastructural determinants without incorporating socio-economic or institutional variables that may influence land-use decisions.

Future research could build on these findings by incorporating longitudinal climate projections and examining farmer responses to irrigation constraints. Comparative analyses across provinces would also help determine whether the observed mismatch between environmental suitability and irrigation coverage represents a localized phenomenon or a broader structural pattern within Thailand’s rice production system.

Overall, the study underscores the importance of moving beyond static environmental indicators toward a more integrated understanding of agricultural suitability—one that recognizes the role of infrastructure, governance, and land-use dynamics in shaping the productive landscape.

Conclusion and Recommendations

This study contributes to advancing the understanding of agricultural land-use dynamics in Thailand by offering an integrated, spatially explicit assessment of rice paddy suitability using GIS and AHP-an approach that remains underapplied in provincial-level analyses despite its proven value in agricultural planning. The findings add empirical clarity to how environmental variables, particularly irrigation availability, land use patterns, and precipitation, interact to shape the sustainability of rice cultivation in rapidly transforming landscapes. By highlighting the relative weight of each factor, this research provides a structured decision-making framework that complements existing literature emphasizing sustainable irrigation systems and strategic land management (Thong et al., 2020).

In conclusion, this study offers a major contribution to the field by demonstrating the necessity of a multifaceted land management strategy in Lop Buri one that integrates hydrological considerations, economic constraints, and long-term sustainability goals. The analytical framework developed here can be applied to other regions facing similar tensions between agricultural production and land-use change, thereby supporting more resilient and evidence-based agricultural policy design.

As Thailand continues to position itself as a leading global rice producer, the challenge of sustaining productivity amid climate variability, land constraints, and evolving socio-economic pressures has become increasingly evident. Lop Buri Province historically important to Thailand’s rice sector captures these national tensions in a microcosm. While some areas exhibit ideal biophysical conditions for intensive rice production, others face limitations linked to soil quality, water availability, and landscape characteristics. To ensure long-term sustainability, it is crucial to align national strategies with provincial development priorities and site-specific agricultural realities. The following recommendations integrate insights from global research on sustainable intensification, climate-smart agriculture, irrigation management, and rural development (FAO, 2017; IRRI, 2021; Tilman et al., 2011).

At the national scale, Thailand must adopt a forward-looking policy framework that enhances water security, fosters agricultural innovation, and strengthens market competitiveness. Expanding strategic irrigation infrastructure and adopting basin-level water allocation systems can reduce production volatility, particularly in drought-prone regions (FAO, 2017; Shah, 2020). The integration of climate-smart agriculture (CSA) practices including drought-tolerant rice varieties, alternate wetting and drying (AWD), and resilient cropping systems aligns with global recommendations for reducing climate-related risks (IRRI, 2021).

Additionally, improved financial mechanisms such as low-interest green loans and climate-indexed crop insurance can enable farmers to adopt new technologies and withstand climatic shocks. Strengthening Thailand’s rice value chain through modernized milling, storage, and logistics systems will also enhance international competitiveness (World Bank, 2020). Together, these national strategies establish the enabling environment that provinces like Lop Buri require to implement sustainable rice production systems.

Lop Buri’s agricultural landscape is diverse, with pockets of highly fertile irrigated plains, transitions zones with moderate limitations, and upland areas increasingly affected by water scarcity. To address these differences, the province must pursue a balanced development strategy that improves infrastructure, expands technological innovation, and empowers local farmers through knowledge transfer.

Expanding irrigation distribution beyond the areas currently serviced by the Pasak Jolasid Dam can significantly increase dry-season rice production. However, more water alone is insufficient. The adoption of precision agriculture technologies such as GPS-guided leveling, drone imaging, and soil moisture sensors can help farmers use inputs more efficiently and reduce production costs (Gebbers & Adamchuk, 2010; Zhang et al., 2021). Enhancing soil fertility management through integrated nutrient strategies and systematic soil testing will further maintain long-term productivity (Tilman et al., 2011).

Provincial extension services should also be strengthened to deliver training on CSA, water-saving irrigation methods, pest management, and the judicious use of fertilizers. Investments in post-harvest systems, including mechanical dryers and improved storage facilities, will help reduce losses one of the most persistent constraints on farmer income (FAO, 2019). These provincial strategies ensure that sustainable development aligns with the unique biophysical and socioeconomic contexts within Lop Buri.

Given that Lop Buri’s land exhibits varying degrees of suitability for rice production ranging from highly suitable to non-suitable localized interventions are essential. Managing land according to its ecological capacity not only maximizes productivity but also prevents long-term degradation.