Sim_Engine.py

def initialize_parcels(parcel_map, cluster_labels):
    parcel_dict = {}
    for i in range(parcel_map.shape[0]):
        for j in range(parcel_map.shape[1]):
            cluster_id = parcel_map[i, j]
            land_type = cluster_labels.get(cluster_id, "Unknown")

            parcel_dict[(i, j)] = {
                "land_type": land_type,
                "forage": None,
                "health": 1.0,
                "degraded": False,
                "cattle_grazing": {
                    "conservative": land_type == "Productive Grass",
                    "moderate": land_type in ["Productive Grass", "Pasture/Desert"],
                    "aggressive": land_type not in ["Water"]
                },
                "elk_grazing": {
                    "default": land_type in ["Riparian Sensitive Zone", "Productive Grass"]
                }
            }
    return parcel_dict

def get_land_forage_rates():
    return {
        'Productive Grass': 1.0,
        'Pasture/Desert': 0.4,
        'Riparian Sensitive Zone': 1.2,
        'Rocky Area': 0.2,
        'Water': 0.0
    }


def assign_initial_forage(parcel_dict, land_forage_rates):
    for parcel in parcel_dict.values():
        rate = land_forage_rates.get(parcel["land_type"], 0.0)
        parcel["forage"] = rate * 100  # initial AUMs

import numpy as np
import numpy as np
import matplotlib.pyplot as plt
from collections import Counter
from matplotlib.colors import ListedColormap
import matplotlib.patches as mpatches

def simulate_period(parcel_dict, grazing_strategy="moderate", cattle_stocking_rate=100000, elk_pressure=3000):
    print(f"\n🟢 Running LP-based simulation using grazing strategy: **{grazing_strategy.upper()}**")

    import numpy as np
    from scipy.optimize import linprog

    keys = list(parcel_dict.keys())
    n_rows = max(i for i, _ in keys) + 1
    n_cols = max(j for _, j in keys) + 1
    num_cells = n_rows * n_cols

    # Step 1: Regrowth
    land_growth_rates = {
        'Productive Grass': 1.0,
        'Pasture/Desert': 0.4,
        'Riparian Sensitive Zone': 1.2,
        'Rocky Area': 0.2,
        'Water': 0.0
    }
    for parcel in parcel_dict.values():
        base_growth = land_growth_rates.get(parcel["land_type"], 0.0)
        weather = np.random.normal(1.0, 0.15)
        regrowth = base_growth * weather * 1
        regrowth *= parcel["health"]
        parcel["forage"] = min(parcel["forage"] + regrowth, 100)

    # Step 2: Subtract uniform elk grazing from all parcels
    elk_grazing_per_parcel = elk_pressure / num_cells
    for parcel in parcel_dict.values():
        parcel["forage"] -= elk_grazing_per_parcel
        parcel["forage"] = max(parcel["forage"], 0.0)

    # Step 3: LP for cattle
    cost = []
    bounds = []
    eligible_keys = []
    for i in range(n_rows):
        for j in range(n_cols):
            p = parcel_dict[(i, j)]
            if not p["cattle_grazing"].get(grazing_strategy, False):
                cost.append(0)
                bounds.append((0, 0))
                continue
            if grazing_strategy in {"conservative", "moderate"} and p["land_type"] == "Riparian Sensitive Zone":
                cost.append(0)
                bounds.append((0, 0))
                continue
            cost.append((i + j) * 0.02)
            bounds.append((0, p["forage"]))
            eligible_keys.append((i, j))

    A_eq = [1.0 if b[1] > 0 else 0.0 for b in bounds]
    b_eq = [cattle_stocking_rate]

    result = linprog(c=cost, A_eq=[A_eq], b_eq=b_eq, bounds=bounds, method="highs")
    if not result.success:
        raise RuntimeError("Grazing LP failed: " + result.message)

    grazing_values = result.x

    # Step 4: Apply grazing and your specified health rule
    for idx, ((i, j), x) in enumerate(zip(parcel_dict.keys(), grazing_values)):
        parcel = parcel_dict[(i, j)]
        parcel["forage"] -= x

        # ✅ Your health rule (fully time-dynamic)
        if parcel["forage"] <= 0:
            parcel["health"] = max(parcel["health"] - 0.25, 0.0)
        elif parcel["forage"] < 20:
            parcel["health"] = max(parcel["health"] - 0.1, 0.0)
        else:
            parcel["health"] = min(parcel["health"] + 0.02, 1.0)

def simulate_periodold(parcel_dict, grazing_strategy="moderate", cattle_stocking_rate=5000, elk_pressure=3000):
    print(f"\n🟢 Running simulation using cattle grazing strategy: **{grazing_strategy.upper()}**")

    land_growth_rates = {
        'Productive Grass': 1.0,
        'Pasture/Desert': 0.4,
        'Riparian Sensitive Zone': 1.2,
        'Rocky Area': 0.2,
        'Water': 0.0
    }

    # 1. Simulate forage regrowth for 8 months
    for parcel in parcel_dict.values():
        base_growth = land_growth_rates.get(parcel["land_type"], 0.0)
        weather = np.random.normal(1.0, 0.15)
        regrowth = base_growth * weather * 8  # ← 8 months, as you said
        regrowth *= parcel["health"]  # degrade means slower regrowth
        parcel["forage"] = min(parcel["forage"] + regrowth, 100)

    # 2. Count eligible parcels
    total_grazed_parcels = sum(
        1 for parcel in parcel_dict.values() if parcel["cattle_grazing"].get(grazing_strategy, False)
    )
    if total_grazed_parcels == 0:
        print("⚠️ No parcels match the selected grazing strategy.")
        return

    cattle_grazing_per_parcel = cattle_stocking_rate / total_grazed_parcels
    elk_grazing_per_parcel = elk_pressure / len(parcel_dict)

    # 3. Simulate grazing and degradation
    for parcel in parcel_dict.values():
        if not parcel["cattle_grazing"].get(grazing_strategy, False):
            continue

        total_grazing = cattle_grazing_per_parcel + elk_grazing_per_parcel

        if total_grazing > parcel["forage"]:
            parcel["degraded"] = True
            parcel["health"] = max(parcel["health"] - 0.1, 0.0)
        else:
            parcel["health"] = min(parcel["health"] + 0.02, 1.0)

        parcel["forage"] = max(parcel["forage"] - total_grazing, 0)

def get_forage_map(parcel_dict, n_rows, n_cols):
    return np.array([[parcel_dict[(i, j)]["forage"] for j in range(n_cols)] for i in range(n_rows)])

def get_health_map(parcel_dict, n_rows, n_cols):
    """
    Returns a 2D numpy array representing the health of each parcel.
    """
    return np.array([[parcel_dict[(i, j)]["health"] for j in range(n_cols)] for i in range(n_rows)])


def plot_health_map(health_map, title="Parcel Health Levels", save_path=None):
    """
    Plots a heatmap of the parcel health values.
    """
    import matplotlib.pyplot as plt

    plt.figure(figsize=(8, 6))
    plt.imshow(health_map, cmap='RdYlGn', origin='upper', vmin=0, vmax=1)
    plt.colorbar(label="Health Index (0–1)")
    plt.title(title)
    plt.axis('off')
    plt.tight_layout()
    if save_path:
        plt.savefig(save_path)
    plt.show()



def plot_forage_map(forage_map, title="Parcel Forage Levels"):
    plt.figure(figsize=(8, 6))
    plt.imshow(forage_map, cmap='YlGn', origin='upper')
    plt.colorbar(label="Forage AUMs")
    plt.title(title)
    plt.axis('off')
    plt.tight_layout()
    plt.show()

def run_full_simulation(parcel_map, cluster_labels, n_rows, n_cols, strategy="moderate"):
    parcel_dict = initialize_parcels(parcel_map, cluster_labels)
    land_forage_rates = get_land_forage_rates()
    assign_initial_forage(parcel_dict, land_forage_rates)
    simulate_period(parcel_dict, grazing_strategy=strategy)
    return parcel_dict