###### Abstract  
Human activity and land-use changes have affected the water quality of Kwan Phayao, Upper Ing watershed, due to the associated high sediment load and eutrophication. This study aims to identify suitable LULC allocation scenarios for minimizing sediment and nutrient export into the lake. For this purpose, the LULC status and change were first assessed, based on classified LULC data in 2009 and 2019 from Landsat images, using the SVM algorithm. Later, the land requirements of three scenarios between 2020 and 2029 were estimated, based on their characteristics, and applied to predict LULC change using the CLUE-S model. Then, actual LULC data in 2019 and predicted LULC data under three scenarios between 2020 and 2029 were used to estimate sediment and nutrient export using the SDR and NDR models. Finally, the ecosystem service change index identified a suitable LULC allocation for minimizing sediment or/and nutrient export. According to the results, LULC status and change indicated perennial trees and orchards, para rubber, and rangeland increased, while forest land and paddy fields decreased. The land requirements of the three scenarios provided reasonable results, as expected, particularly Scenario II, which adopts linear programming to calculate the land requirements for maximizing ecosystem service values. For sediment and nutrient export estimation under the predicted LULC for the three scenarios, Scenario II led to the lowest yield of sediment and nutrient exports, and provided the lowest average ESCI value among the three scenarios. Thus, the LULC allocation under Scenario II was chosen as suitable for minimizing sediment or/and nutrient export into Kwan Phayao. These results can serve as crucial information to minimize sediment and nutrient loads for land-use planners, land managers, and decision makers. lake basin [4; 5]. Furthermore, land-use and land-cover changes are significant drivers of the accelerated eutrophication of surface waters, due to soil loss and nutrient loading into water bodies. Agricultural soil losses also have an impact on sediment deposition [6]. Meanwhile, land-use changes lead to changes in ecosystem services (ESs). The impacts of various land uses on ESs occur in three ways: major ESs are generated under different land-use practices, land-use patterns have a significant impact on ESs, and differing intensities of land use may have different impacts on the generation of ESs [7]. Ecosystem services are the utilities that people obtain from ecosystems. These include provisioning, regulating, cultural, and supporting services [8; 9]. Thus, the assessment of ecosystem services and their relationship to human well-being requires an integrated approach. The modeling of land-use changes provides effective methods to estimate the impact on the environment and ecosystem services [10; 11; 12], and ecosystem services models such as InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) have been used to assess and model ecosystem services quantitatively, as well as to analyze and map ecosystem services through GIS-based spatially explicit modeling tools. Additionally, InVEST can be used to estimate the monetary value of ecosystem services [13]. For example, [PERSON] et al. [14] have applied toolsets for multiple ecosystem service evaluations--namely water yield and sediment delivery ratio models--to estimate water yield and sediment retention ecosystem services in the Klong U-Tapao watershed, Songkha Province, Thailand, for the mitigation of flooding by reducing runoff and the prevention of soil erosion by increasing sediment retention in the basin. Kwan Phayao or Phayao lake is the largest freshwater lake in the Northern region and the fourth largest in Thailand, and has been classified in the list of wetlands of international importance. This lake is an essential source of food security and species diversity conservation. About 36 species of aquatic plants are found in the lake [15], and 44 species of fish have been identified [16].